Reference number  
DRS 394 -2: 2018  
© RSB 2018  
 
 
 RWANDA 
STANDARD  DRS  
394-2 
 
First edition  
2018 -mm-dd 
 
Mosquito repellents — Performance Test 
Guidelines — 
Part 2: 
Spatial repellents  
  DRS 394 -2: 2018  
©RSB 2018 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2018  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 394 -2: 2018  
iii                ©RSB 2018 - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Term s and definitions  ................................ ................................ ................................ ..................  1 
4 Symbols and abbreviated terms  ................................ ................................ ................................ . 3 
5 Laboratory studies  ................................ ................................ ................................ .......................  4 
5.1 General  ................................ ................................ ................................ ................................ ..........  4 
5.1.1  Objective  ................................ ................................ ................................ ................................ ....... 4 
5.1.2  Mosquito rearing and physiological status  ................................ ................................ ...............  5 
5.1.3  Laboratory test procedure  ................................ ................................ ................................ ...........  6 
5.2 Spatial repellency of active ingredients (technical material)  ................................ ...................  6 
5.2.1  Movement away from a chemical stimulus  ................................ ................................ ...............  6 
5.2.2  Host attraction -inhibition  ................................ ................................ ................................ .............  8 
5.3 Spatial repellency of active ingredients against insecticide -resistant strains  ....................  10 
5.4 Protective efficacy of formulated products  ................................ ................................ .............  10 
6 Semi -field trials of formulated products  ................................ ................................ ..................  12 
6.1 General  ................................ ................................ ................................ ................................ ........  12 
6.2 Study design  ................................ ................................ ................................ ...............................  13 
6.3 Indoor effective dosage and duration of protective efficacy  ................................ .............  1413 
6.4 Outdoor effective dosage and duration of protective efficacy  ................................ ..............  15 
7 Field trials of formulated products  ................................ ................................ ...........................  15 
8 8. Ethical considerations  ................................ ................................ ................................ ...........  16 
8.1 General  ................................ ................................ ................................ ................................ ........  16 
8.2 Informed consent  ................................ ................................ ................................ .......................  17 
8.3 Huma n landing catch in semi -field and field testing  ................................ ..............................  17 
Annex  A (Informative)  Definition of knockdown and mortality for adult mosquit oes.....................  18 
Annex  B (informative)  Example of informed consent form  ................................ ...............................  19 
 DRS 394 -2: 2018  
©RSB 2018 - All rights reserved                  iv 
 Foreword  
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adopted 
by Technical committ ees are ratifie d by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 394-2 was prepared by Technical Committee RSB/TC 015, Pharmaceutical Products . 
DRS 394 consists of the following parts, under the general title Mosquito repellents — Performance test 
guidelines : 
 Part 1: Skin applied  repellents  
 Part 2: Spatial repellents  
Committee membership  
The following organizations were represented on the Technical Committee on Pharmaceutical Products 
(RSB/TC 015) in the preparation of this standard.  
Paragraph of p articipants  
National Industrial Research and Development Agency (NIRDA)  
National Pharmacy Council (NPC)  
University of Rwanda/College of Sciences and Technology (UR/CST)  
Pharmacie NOVA  
Rwanda Development Board (RDB)  
AGROPY LTD  
IKIREZI NATURAL PRODUCTS  
HORIZON/SOPYRWA  
Rwanda Social Security Board (RSSB)  DRS 394 -2: 2018  
v                ©RSB 2018 - All rights reserved  
 Pharmavie  
University of Rwanda/College of Medicine and Health Sciences (UR/CMHS)  
Rwanda Biomedical Center/ Malaria and Other Parasitic Diseases Division  (RBC/MOPDD)  
Society for Fam ily Health  (SFH) – Rwanda  
Rwanda Biomedical Center/Medical Procurement and Production Division (RBC/MPPD)  
Institut d’Enseignement Superieur (INES) – RUHENGERI  
Rwanda  Standards Board  (RSB) – Secretariat  
 DRS 394 -2: 2018  
©RSB 2018 - All rights reserved                  vi 
 Introduction  
The term ‘spatial repellency’ is used here to refer to a range of insect behaviors  induced by airborne chemicals 
that result in a reduction in human –vector contact and therefore personal protection. The behaviors  can include 
movement away from a chemical s timulus, interference with host detection (attraction /inhibition) and feeding 
response.  
While many household insecticide products have been used for personal protection, most are based on the 
insecticidal activity (knock -down and mortality) of the active ingredient.  
The document provides guidance and describes steps for laboratory testing and for semi -field and field 
evaluations of spatial repellent products (technical materials and formulated products) designed to provide 
protection in a specific space (i ndoor and/or outdoor) against mosquitoes. With some modifications, the 
guidelines can be used to determine the efficacy and personal protectiveness of candidate products against 
other flying nuisance pests. These guidelines may have to be modified when pro of of principle is established 
(i.e. the public health value of spatial repellents for vector -borne disease control) and as new methods for 
assessing the spatial repellency of such products become available.  
These guidelines are designed for using active i ngredients that have already undergone safety assessment, 
including toxicity by inhalation. Nevertheless, any adverse -effects or undesirable  characteristics observed 
during laboratory studies and field trials should be recorded and reported.  
Technical mate rial or formulated products submitted for laboratory testing and field trials should be sent with 
the material safety data sheet, the labeling  recommendations and the manufacturer’s certification that the 
product is within the company’s manufacturing speci fications. Independent physical and chemical assessment 
for compliance with the specifications may be required before efficacy testing.  
Biological tests are subject to the variations inherent to living organisms. Test insects must be reared carefully 
for standardized size and good biological fitness in order to ensure representative responses to test compounds. 
Testing should be conducted under the close supervision of personnel familiar with biological testing of 
insecticides and by sound scientific and ex perimental procedures; the principles of good laboratory practice or 
other suitable quality assurance schemes should be applied.  
All laboratory and field personnel should be given adequate training in safety and the standard operating 
procedures associated  with an assay before beginning testing, and such training should be documented. Use 
of a standard operating procedure for data processing, management and validation is advisable, and copies of 
the procedures should be made available and accessible in the relevant languages for all study staff.  
The quality of data reporting should be sufficient to allow comparisons of efficacy at multiple evaluation sites. 
The minimum data to be reported include a measure of centrality (e.g. mean), sample size and a measure  of 
variability (e.g. standard error).  
Evaluations of spatial repellents should be conducted in accordance with applicable national ethical regulations.  
 
 DRS 394 -2: 2018  
1                ©RSB 2018 - All rights reserved  
 Mosquito repellents  — Performance test guidelines — Part 2: Spatial 
repellents  
1 Scope  
This guideline provides recommendation for the design and execution of studies to evaluate the performance 
of mosquito repellents formulated and prepared for space application.  
This guidance applies to products in any formulation – such as coils, sprays, c andles, papers, liquid vaporizers, 
vaporizing  mats, tablets and liquid detergents – intended to be applied in space  
2 Normative references  
The following documents are referred to in the text in such a way that some or all of  their content constitutes 
require ments of this document.  For dated references, only the edition  cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
There are no normative references in this  document . 
3 Terms and definition s 
For the purposes of this standard, the follow ing terms and definitions  apply . 
3.1.  
spatial repellent   
Spatial repellent  are chemical products designed to be 'active' (requiring heat or electricity) or 'passive' 
(requiring no heat or electricity) and release volatile chemicals into the air within the treated space.  
3.2 
landing  
the act of flying or jumping mosquito on human skin without probing or biting.  
3.3 
probe  
the act of penetrating human skin by mouthparts on a mosquito without ingestion of blood.   
©RSB 2018 - All rights reserved                  2 
 3.4 
bite 
the act penetrating human skin by mouthparts on a mosquito with ingestion of blood, typically associated with 
abdominal swelling and color change.  
3.5 
crossing  
the act of passage by mosquitoes  from an area of untreated skin to an area of treated skin. A crossing may be 
quantified either or both by the distance the mosquitoes moves onto treated skin or by how long the mosquitoes 
remains treated skin.  
3.6 
unconfirmed event  
a landing, probe, bite, or crossing not followed by another similar event within 30 minutes.  
3.7 
confirming event  
one landing, probe, bite, or crossing followed by another similar event within 30 minutes. The first event is 
confirmed by the second; the second event in the confirming event.  
3.8 
human subject  
a living individual about whom an inv estigator conducting research obtains either data through intervention or 
interaction with the individual or identifiable private information.  
3.9 
questing  
the behavior of mosquitoes  actively seeking a host.  
3.10 
repellent  
a product intend ed to disrupt the host -seeking behaviour of mosquito, driving or keeping them away from treated 
human skin.  DRS 394 -2: 2018  
3                ©RSB 2018 - All rights reserved  
 3.11 
Complete Protection Time (CPT)  
The time from application of repellent until efficacy failure as it is defined in each study – for example, the time 
from application until the first efficacy failure event confirmed within 30 minutes by a second similar event.  
3.12 
dose determination  
a testing procedure used to estimate a “typical consumer dose” of a topical repellent.  
3.13 
Vector -borne diseases   
vector -borne diseases  are infections  transmitted  by the bite of infected arthropod species, such as mosquitoes, 
ticks, triatomine bugs, sandflies, and blackflies  
3.14 
dose –response relations  
measurement of the relationship between the quantity of a substanc e or exposure to radiation (the dose) 
and its overall effect (the response) on an organism . 
4 Symbols and abbreviated terms  
AI: active ingredient  
ED: effective dosage  
ED 50: effective dosage of the active ingredient  for 50% movement away from a chemical stimulus  
ED 95: effective dosage of the active ingredient  for 95% movement away from a chemical stimulus  
  
©RSB 2018 - All rights reserved                  4 
 5 Laboratory studies  
5.1 General  
5.1.1  Objective  
5.1.1.1  The primary objective of laboratory studies is to determine the inh erent properties of the AI under well -
controlled, standardized conditions and its activity against well -characterized mosquito strains.  
Such studies include measurement of movement away from a chemical stimulus, interference with host 
detection (attraction –inhibition) and feeding response. Laboratory studies also include determinations of the 
efficacy, including the duration of protection, of a formulated product in various delivery formats under well -
controlled, standard conditions.  
5.1.1.2  The specific objectives of laboratory studies are to:  
a) establish dose –response relations and determine the effective dosage (ED) of the AI for 50% and 95% (ED 50 
and ED 95) movement away from a chemical stimulus;  
b) establish dose –response relations and deter mine the ED 50and ED 95of the AI for host attraction –inhibition;  
c) determine the efficacy and duration of protection (landing and feeding inhibition) of formulated spatial 
repellent products.  
5.1.1.3  If the  spatial repellent product is intended for applica tion to a large surface area (e.g. fabric), 
determination of contact irritancy may also be required, following established guidelines.  
5.1.1.4  If there is any significant mortality in the spatial repellency assay (see below), the insecticidal activity 
(e.g. vapor  toxicity) of the product should be determined by established guidelines, to fully understand its overall 
performance.  
5.1.1.5 A flow -chart of the decision -making process for laboratory studies of a candidate spatial repellent 
product is shown in figure 1.  DRS 394 -2: 2018  
5                ©RSB 2018 - All rights reserved  
  
Figure 1  – Flow chart for making decisions on the basis of laboratory studies of candidate spatial 
repellent technical material  
5.1.1.5  Ideally, tests should be conducted with three or more local anthropophilic, fully susceptible species of 
Anopheles (preferably An. gambiae S.L.) characterized according to standard  guidelines for monitoring 
susceptibility.  
5.1.1.6  As the physiological status of mosquitoes can significantly  affect their behavioral  response, use of the 
assays described below for measuring various physiological states (e.g. parity) should be considered.  
5.1.2  Mosquito rearing and p hysiological status  
5.1.2.1  Use of standardized mosquito rearing and testing conditions for laboratory assays is essential to 
ensure the reliability and reproducibility of data. The conditions are generally a temperature of 27 ± 2 °C, a 
relative humidity of 80 ± 10%, and a photoperiod of 12 h light: 12 h dark. Temperate species may have different 
requirements, and  the assay conditions should be matched as closely as possible to the environmental 
conditions of the target locale. Adults are maintained on sugar solution (typically 10% glucose on cotton wool 
or filter paper).  
5.1.2.2  Assays should be carried out on fem ale mosquitoes that are nulliparous and of uniform age, preferably 
5–8 days post -emergence. Actively host -seeking females should be selected from general colony groups to 
ensure a maximum behavioral  response. This can be done with an aspirator or an approp riate airflow apparatus 
while holding a hand close to (but not touching) the cage and collecting those mosquitoes that actively probe. 
Spatial repellency should be observed in female mosquitoes starved for the preceding 12 h, preferably during 
times in the  diel period that correspond to the biting activity of that species. Mosquitoes must be transferred to 
holding containers or assay devices with care to avoid physically damaging them.  
 
©RSB 2018 - All rights reserved                  6 
 5.1.3  Laboratory test procedure  
5.1.3.1  All test chambers and other assay inst ruments should be properly cleaned and decontaminated after 
the completion of each test according to assay -specific instructions. Test chambers must be checked for 
contamination by performing assays under blank conditions before the start of each subsequen t test. Under 
chemical -free conditions, knock -down (see Annex A for a full definition of knock -down response) must not 
exceed 5% among mosquito populations held for 10 min.  
5.1.3.2  Inclusion of an appropriate, well -characterized AI as a reference or positive control is highly 
recommended.  
5.1.3.3  The temperature and humidity at the time of testing as well as time of each replicate should be reported 
for each laboratory test.  
5.2 Spatial repellency of active ingredients (technical material)  
5.2.1  Movement away f rom a chemical stimulus  
5.2.1.1  The objective of this test is to measure the movement away from an AI in a spatial repellency assay, 
which is a modular test system (Figure 2).  
5.2.1.2  A central clear cylinder is connected to two metal test cylinders (one c ontrol (C) and one treatment (T)) 
with gated funnels to build one test unit (C –T). The funnel bevels (interior slope) are positioned towards the 
clear cylinder to facilitate mosquito movement into the metal cylinders of the test unit. A blank is placed wit hin 
a metal spool at one end of the system and a treated substrate within another metal spool at the other end, 
creating a concentration gradient between the two ends. Pieces of opaque felt can be wrapped around the clear 
cylinder and over the rectangular ports in the end caps to simulate darkness, depending on the diel pattern of 
the target species.  
5.2.1.3  As a negative control, substrate treated only with diluent is placed at both ends of the test unit (C –C) 
simultaneously to ensure that no greater propo rtion of mosquitoes moves into a particular end of the test system 
for a given test population, time of day and assay conditions (i.e. temperature and humidity). If multiple assays 
are being run at the same time, the metal cylinders should be labeled  C1, C2…C n and T 1, T2…T n to facilitate 
data recording . 
5.2.1.4  Serial dilutions of AI are made with acetone (or another suitable diluent recommended by the 
manufacturer) and tested to identify the effective dose range. Minimum of five concentrations covering a range 
of responses should be chosen, i.e. two to three concentrations resulting in <50% spatial repellent response 
and two to three concentrations that give >50% response (excluding 0% and 100% response).  
Figure 2 - Schematic drawing of the spatial repelle ncy assay  DRS 394 -2: 2018  
7                ©RSB 2018 - All rights reserved  
  
The spatial repellency assay components are: 1, end cap; 2, metallic net; 3, treated chamber; 4, linking section (with butter fly 
valve ; 5, untreated chamber.  
5.2.1.5  Aliquots of 1.5 ml of the repellent AI and of the diluent are applied evenly t o 11 x 25 cm (275 cm2) 
pieces of Whatman No. 1 paper with a pipette. All filter papers, both control (diluents only) and treatment (AI 
and diluent), are allowed to sit for 30 min (for acetone) or less (depending on the diluent) before the first test 
replic ate is initiated, to ensure that the diluent has completely evaporated, leaving only the chemical of interest 
on the filter paper. Other substrates that can be used in the spatial repellency assay include polyester and 
cotton, depending on the textile or p roduct format into which the AI is expected to be incorporated.  
5.2.1.6  The spatial repellency assay is typically performed under static airflow under a chemical hood. Groups 
of 20 female mosquitoes are introduced from holding tubes into the clear cylinder (with an aspirator) and are 
allowed to acclimatize to the test environm ent for 30 s. The number of mosquitoes that are physically damaged 
and are incapable of flying or walking is recorded to correct for the total mosquito sample size available to 
respond to the AI in that replicate. The butterfly valves are simultaneously op ened for 10 min to allow chemical 
vapors  to flow through the test unit and also to allow free movement of the mosquitoes throughout the unit, as 
indicated by the grey arrows in Figure 2. The gates are closed after 10 min, and the number of mosquitoes in 
each cylinder is recorded. The number of knock -down mosquitoes (see Annex 1) in each cylinder is also 
recorded. All mosquitoes are kept overnight to check for 24 -h mortality. If the mortality is significantly higher 
than among controls, insecticidal activity  must be evaluated by established WHO efficacy guidelines(Figure 1).  
5.2.1.7  Between replicates, the metal cylinders are disconnected from the clear cylinder and the end cap is 
removed from the control metal cylinder for 3 min to allow passive ventilation of the AI from the clear and control 
metal cylinders before the next replicate. During the ventilation period, all treated substrates remain in place 
within the metal cylinders under the chemical hood. Successive replicates are carried out without delay.  
5.2.1.8  The cylinders are washed at the end of each evaluation. The metal spools are washed with acetone 
solution. The clear cylinders, end caps, gated funnels and metal cylinders are washed with non -fragrant 
laboratory detergent solution. Component section s are allowed to dry overnight before reuse for testing other 
AIs and/or dosages.  
5.2.1.9  Nine replicates are performed for each AI dosage. At the conclusion of testing, the proportion of 
mosquitoes repelled by the treatment is determined. Spatial repellen cy is expressed as the proportion of 
mosquitoes prevented from entering the treatment space in relation to all mosquitoes moving within the system 
and is calculated from a “spatial activity index ”: 
 
©RSB 2018 - All rights reserved                  8 
 SAI =𝑁𝑐−𝑁𝑡
𝑁𝑐+𝑁𝑡𝑥𝑁𝑚
𝑁 
Where,  
  SAI is the spatia l activity index,  
  Nc is the number of mosquitoes in the control metal chamber,  
  Nt is the number of mosquitoes in the treatment metal chamber,  
  Nm is the total number of mosquitoes in the two metal chamber, and  
  N is the total number of mosquitoes in the test unit.  
5.2.1.10  The spatial activity index varies from –1 to 1: ;zero indicates no response; –1 indicates that all 
mosquitoes moved into the treatment chamber, resulting in an attractant response; and 1 indicates that all the 
mosquitoes moved into the control chamber (away from the treatment source), resulting in a spat ial repellent 
response. If no movement is recorded within the system (i.e. Nt = 0, Nc = 0), the test is valid but the spatial 
activity index is 0 . 
5.2.1.11  The spatial activity index is calculated for each replicate, and the mean index for each AI dosage i s 
analysed by probit -plane regression analysis, from which the ED 50 and ED 95 and corresponding 95% confidence 
limits can be estimated. The number of replicates, the total number of mosquitoes and the mean spatial activity 
index (± standard error) for each AI dosage and negative control should be reported.  
5.2.2  Host attraction -inhibition  
5.2.2.1  The objective of this test is to measure the ability of an AI to inhibit mosquito attraction to a host. This 
is achieved by use of a Y -tube olfactometer to measure attrac tion to host odours in the absence and presence 
of the AI. A dual port design, such as a Y -tube, is recommended, and a variety of suitable olfactometers can be 
used.  
5.2.2.2  A scheme of a Y -tube olfactometer is presented in Figure 3.  
5.2.2.3  A central base  leg made of acrylic plastic constitutes the main body of the olfactometer. Two branches 
meet the base leg at a decision point. Each branch has a trapping port with a mesh screen over the end, and 
each trapping port has a rotating circular door that also h as a mesh screen. The mesh on the control and 
treatment trapping ports allows odours from the air input to pass through these areas and also prevents direct 
contact between the mosquitoes and the odour sources. During a test, odours in the air migrate down  the 
branches, through the base leg and then to the holding port, from which test mosquitoes are released at the 
start of the test.  
5.2.2.4  The time of day and assay conditions (i.e. temperature and humidity) should be recorded, and an 
attempt should be made to maintain these conditions in all subsequent tests in a single evaluation.  
5.2.2.5  A preliminary test with diluent only at one port of the test unit should be performed, with a sufficient 
number of replications to ensure no response to the solvent ( indicated by an attraction response ≤ 10%).  DRS 394 -2: 2018  
9                ©RSB 2018 - All rights reserved  
 Figure 3 – Schematic drawing of a Y -tube olfactometer used to measure attraction –inhibition from the 
ability of a chemical to inhibit attraction to a port containing odours from a host  
  
5.2.2.6  Two negative con trol assays are performed: one with no diluents (blank control) before AI testing to 
ensure no contamination (indicated by ≤ 10% attraction to either port) and a second in which host odour is 
released from both ports (positive control) to ensure no contami nation by attraction –inhibitor from a previous 
test (indicated by equal responses to both ports and > 50% response overall).  
5.2.2.7  Serial dilutions of AI are made with methanol (or another suitable diluent based on AI chemistry and 
the manufacturer’s re commendation) and tested to identify the effective dose range. Dosages that give 
responses between 10% and 95% are used for this analysis, preferably with two or three dosages that induce 
an attraction response of > 50% and the remaining two or three dosag es that induce an attraction of < 50%.  
5.2.2.8  A pipette is used to deliver 400 μl of the repellent AI solution or diluent to a 9 -mm vial cap. All vial caps, 
both control (diluents only) and treatment (AI and diluent), are placed in position in the end cap s and attached 
to the trapping ports before a test. The placement of spatial repellent and control treatments should be fully 
randomized in replicates . 
5.2.2.9  The olfactometer is operated with airflow in a chemical hood. Hoods are equipped with vacuum and  
air lines that can be used to provide this airflow. The vacuum line in a hood can be connected to the base leg 
trap by an end cap fitted with a gas nozzle. An anemometer is used to adjust the vacuum so that the airflow 
through the control and treatment po rts is 0.20 ± 0.05 m/s. The air velocity through the base leg should be 0.40 
± 0.10 m/s.  
5.2.2.10  Lots of 10 female mosquitoes are introduced from holding tubes into the holding port (with aspirators) 
and are allowed to acclimatize to the test environment with clean air for 15 min with no treatment. The numbers 
of mosquitoes that are physically damaged  and are incapable of flying or walking are discounted; only those 
mosquitoes that are able to respond are observed and recorded for each replicate. After the acclimatization 
period, the treatment and control are positioned in corresponding ports, and the doors are opened for the 
exposure period, usually 30 s. The exposure period is species specific and is determined by the measurement 
in the negative control assay of the initial attraction response (i.e. 50% total movement). The total numbers of 
 
©RSB 2018 - All rights reserved                  10 
 mosquitoes  in the treatment trapping port, the control trapping port and outside these trapping ports are 
recorded.  
5.2.2.11  Between replicates, the end caps and trapping ports are disconnected from the branches of the Y -
tube, and the end cap and holding port are disconnected from the base leg. Clean holding and trapping ports 
are then placed on the unit, with the end caps reinstalled, and the unit is passively cleaned (with airflow) for a 
minimum of 3 min under the chemical hood to allow odours from the AI and/or host to clear from the olfactometer 
before the next replicate.  
5.2.2.12  During the ventilation period, all traps remain in place. Successive replicates are done by repeating 
the process of loading a new trap with 10 mosquitoes onto the base leg and allowin g the mosquitoes to 
acclimatize.  
5.2.2.13  The Y -tube body and individual trapping ports are washed at the end of each chemical evaluation. As 
the unit is made of acrylic, all parts should be washed with non -fragrant laboratory detergent solution. 
Component  sections are allowed to dry overnight before reuse for testing other AI and/or dosages.  
5.2.2.14  A minimum of six replicates is performed for each AI dosage. At the end of testing, the proportion of 
mosquitoes attracted to the treatment is determined. The  percentage attracted to the treatment port is calculated 
by dividing the number of mosquitoes trapped in the treatment port by the total number of mosquitoes in the 
test (minus damaged mosquitoes). Spatial repellency is indicated by a lower percentage att raction of 
mosquitoes to host odours plus AI than to host odours with diluent only (i.e. no AI). The mean percentage 
attraction is calculated from the responses of the six replicates to each treatment.  
5.2.2.15  The percentage attraction for each AI dosage is determined by probit -plane regression analysis, from 
which the ED 50 and ED 95 and corresponding 95% confidence limits can be estimated. The number of replicates, 
the total number of mosquitoes and the mean percentage attraction (± standard error) for eac h AI dosage and 
negative control should be reported.  
5.3 Spatial repellency of active ingredients against insecticide -resistant strains  
The objective of this study is to determine any difference in spatial repellency between susceptible and 
insecticide -resista nt strains to provide information for disease protection and control strategies. The difference 
is determined by comparing the dose –response curves generated in the spatial repellency assay and the 
olfactometer assay, as outlined above (sections 5.2.1 and 5.2.2) against mosquito populations that are known to 
be resistant.  
5.4 Protective efficacy of formulated products  
5.4.1 The objective of this study is to determine the optimum dosage(s) to be applied (Note 1) and the duration 
of protective efficacy in a specifi ed treated space under well -controlled and standardized conditions. Protective 
efficacy (personal protection) is measured by the difference in the inhibition of landing or feeding between 
treated groups and controls over time. The reduction in vector entry  into or resting inside test spaces can be 
compared (Note 2) when appropriate.  
Note 1  The necessity for testing various dosages of a formulated product depends on whether a final product or a 
product that is formulated but still under development is being evaluated.  DRS 394 -2: 2018  
11                ©RSB 2018 - All rights reserved  
 Note 2  A decision to include measures of reduced entry and resting in addition to or in place of landing or feeding 
inhibition for estimating protection time should be based on product claims. If a claim states that the product prevents inse cts 
from entering a space, entry evaluation is necessary.  
5.4.2 Products should be evaluated and placed in the free -flight room according to the label instructions. The 
efficacy of a product is assessed from a minimum of four replicates with 50 mosquitoes for both treatment and 
control. Comparison with a standard product or suitable positive control is necessary. The duration of protective 
efficacy over time can be measured by making collections at various times after product activation from 
laboratory findings  and/or label claims. For example, if the product performance in laboratory testing indicated 
18-week efficacy, tests should be performed at systematic sampling times (e.g. weekly) throughout the 18 -week 
expected efficacy period. Products should be stored according to the label claims between evaluations under 
environmental conditions similar to those during evaluation. Longer -lasting products can be stressed or aged 
experimentally in environmental chambers before testing.  
5.4.3 Free-flight rooms constructe d within testing facilities should be mosquito -proof and well ventilated, with 
an extraction fan for safety to clear vapour remaining from spatial repellent formulations between tests. Rooms 
should measure 30 m 3,(Note 3) with smooth, light coloured surface s such as tiles (walls, ceilings and floors) 
that make it easy to see mosquitoes and easy to clean with detergent or solvent. Before evaluation of repellents, 
the chambers should be cleaned with suitable detergent or solvent and ventilated to clear residua l traces of 
cleaning product. Rooms should be maintained at 27 ± 2 °C and 80% ± 10% relative humidity during the test 
period and evaluations conducted at appropriate times in the diel period for the target mosquito species. 
Instrumentation should be mounte d in the room to ensure consistent comparison of measurements over time.  
Note 3  This minimum volume space was set on the basis of the WHO Guidelines for efficacy testing of household 
insecticides products,  Geneva, 2009.  
5.4.4 A domestic extractor fan or pa ssive ventilator is switched on (air exchange of about 110 m3/h), and a 
single person remains in the room for the duration of the tests, either to conduct a human landing catch for 
measuring landing inhibition or to measure feeding inhibition. The placemen t of the product in the free -flight 
room should be in accordance with the label instructions. The duration of the evaluation and sampling periods 
depends on the product label specifications. Biological efficacy should be assessed at several times, until it  has 
fallen to < 50%.  
5.4.5 Mosquitoes should be allowed to acclimatize for 1 h under conditions similar to those of the test space 
before they are released into the test area. Mosquitoes are released into the room containing a human volunteer 
or an adjace nt room if vector entry into a space is the objective of the evaluation. If human landing catch is 
being measured, mosquitoes are collected for 1 h continuously. If feeding inhibition is being measured, the 
volunteer remains in the room for the period of i nterest, and blood -fed mosquitoes are collected by aspiration 
from the interior space at the end of the test.  
   % 𝑙𝑎𝑛𝑑𝑖𝑛𝑔  𝑖𝑛ℎ𝑖𝑏𝑖𝑡𝑖𝑜𝑛 =100  𝑥(𝐶𝑙 −𝑇𝑙)
𝐶𝑙 
Where,  
  Cl is the number of mosquitoes landing in the control space, and  
  Tl is the  number of mosquitoes landing in the treatment space.  
   % 𝑓𝑒𝑒𝑑𝑖𝑛𝑔  𝑖𝑛ℎ𝑖𝑏𝑖𝑡𝑖𝑜𝑛 =100  𝑥(𝐶𝑓 −𝑇𝑓)
𝐶𝑓  
©RSB 2018 - All rights reserved                  12 
 Where,  
  Cf is the number of blood fed mosquitoes in the control space, and  
  Tf is the number of blood fed mosquitoes in the treatment space.  
5.4.6 An appropriate statistical analysis (e.g. probit -plane regression or linear mixed -effects regression with an 
appropriate error structure and link function) at a significance level of p = 0.05 should be used. Data should 
include the duration of  the test, the duration of protective efficacy, the number of replicates of the control and 
treatment and the mean percentage landing inhibition or feeding inhibition  with the 95% confidence interval. 
The size of the room(s) used in the evaluation should b e reported in m 3. If more than one interconnected room 
is used, the distance between the source of the spatial repellent and the human should be stated.  
Note 4  Usually, the effective dose that provided 99.9% protection in a  defined time in laboratory testi ng is used to 
establish the  dosages for semi -field trials.  
6 Semi -field trials of formulated products  
6.1 General  
6.1.1 The objective of semi -field trials is to extend the results of laboratory efficacy studies and to test 
formulated products against free -flying populations of one or more target species under simulated indoor or 
outdoor conditions.  
The specific objectives of these trials are to determine the optimum application dosage(s) (Note 5) and duration 
of protective efficacy in a specific treated indoor space or outdoor area. Efficacy (personal protection) is 
measured by comparing landing inhibition or feeding inhibi tion in treatment and controls over time. Alternatively, 
a reduction in vector entry into or resting in the test space may be compared. (Note 6).  
Note 5  The necessity for testing various dosages of a formulated product depends on whether a final product or  a 
product that is formulated but still under development is being evaluated.  
Note 6  A decision to include measures of reduced entry and resting in addition to or in place of landing or feeding 
inhibition for estimating protection time should be based on p roduct claims. If a claim states that the product prevents insects 
from entering a space, entry evaluation is necessary.  
6.1.2 Semi -field trials are conducted in screened enclosures (with or without experimental huts) using the 
release of well characterize d mosquitoes, ideally in the natural ecosystem of a target disease vector. The 
advantages of using screened enclosures for semi -field evaluation ensures that the mosquitoes are pathogen -
free, that a known number of mosquitoes of fixed physiological status (e.g. parity) is used and there is a known 
distance between the point at which the mosquito populations originate and the source of the chemical stimulus, 
allowing estimation of the protective area (especially important in outdoor evaluation).  
6.1.3 Approp riate arthropod containment guidelines should be followed. The use of netting around the 
enclosure allows tests to be conducted in local conditions at ambient temperature, light, humidity and air 
movement. The enclosure should be sufficiently large to refl ect the area over which the product is intended for 
use. DRS 394 -2: 2018  
13                ©RSB 2018 - All rights reserved  
 6.1.4 The dimensions of screened enclosures should be reported in m3, with a minimum size of 10 x 10 x 2 m2 
per compartment and, ideally, three identical compartments to evaluate  simultaneously: the spatial repellent, a 
negative control and a  positive control. It is important to evaluate each treatment  independently of the others 
and to avoid interaction between  treatments, especially as spatial repellents may exert an effectover several 
metres. Testi ng a spatial repellent and a control in  the same space can result in a push –pull effect,  resulting in  
over estimation of the repellent’s efficacy.  
6.1.5 To facilitate sampling, it is preferable to conduct evaluations in enclosures with cement floors surrounded 
by a water -filled moat to prevent entry of ants, so that resting or blood -fed mosquitoes are not scavenged by 
them. Evaluations should be conducted at appropriate times in the diel period for the target mosquito species. 
Temperature, humidity an d airflow  should be recorded throughout the test. Instrumentation should be mounted 
in each compartment in the same location to allow consistent comparisons of measurements.  
6.2 Study design  
6.2.1 A minimum of three semi -field trials in three geographical sett ing is recommended. Human landing 
catches are performed during the natural diel pattern of the target species. For target species that have a short 
period of main biting activity, tests with spatial repellent material should be conducted such that the expe cted 
end-points occur within the biting period.  
6.2.2 The duration of protective efficacy (inhibition of landing and feeding) can be measured by collecting 
mosquitoes at various times after product activation as shown in laboratory findings and/or label cl aims. For 
example, if a product is claimed from laboratory testing to be effective for 18 weeks, field trials should be 
performed at systematic sampling times (e.g. weekly) throughout the 18 -week expected efficacy period.  
6.2.3 Products should be stored be tween evaluations according to the label claims under environmental 
conditions similar to those during evaluation. Longer -lasting products can be stressed or aged experimentally 
in environmental chambers to facilitate logistics.  
6.2.4 The dosage(s) for eva luation of spatial repellent products should be based on laboratory studies (see 
section 4.2.1).  
6.2.5 The number of replicates per product being evaluated should be based on sample size estimates, which 
are required to ensure that a statistical evaluation  has sufficient power and depend on the expected efficacy of 
the repellent. It is highly desirable that all field operatives be ‘blinded’ regarding the allocation of treatments to 
avoid bias during the evaluation. If that is not possible owing to the chara cteristics of the product (e.g. odour), 
the data should be coded by an independent person before analysis.  
6.2.6 For each evaluation, a randomized Latin square design is used. The number of volunteers is equal to the 
number of products to be tested plus bo th positive (standard product if available) and negative (no product) 
control(s). Negative controls are used to monitor mosquito landing or feeding response, depending on the 
outcome of interest. If overall landing or biting in the controls is < 50% or < 2 5%, respectively, the data should 
be discarded and another replicate performed.  
6.2.7 Collections are performed by volunteers skilled in the use of aspirators, so that they catch all mosquitoes 
landing on an exposed limb (for landing inhibition) or all tho se that are blood -engorged and resting (for biting 
inhibition). Records should be made throughout each trial of wind speed and direction, temperature, relative 
humidity and precipitation for consideration and analysis if appropriate.   
©RSB 2018 - All rights reserved                  14 
 6.3 Indoor effective dosag e and duration of protective efficacy  
6.3.1 Indoor trials can be performed in experimental huts within a screened enclosure. Ideally, several huts 
should be available to allow comparison of several treatments simultaneously. In order to estimate efficacy i n 
local houses, the experimental huts at the test site should be similar in design (e.g. number, orientation and size 
of windows and doors), volume (a minimum of 30 m3, unless local homes are much smaller) and materials and 
be constructed in the fashion of  indigenous homes at the site with locally acquired materials when possible. 
Although hut designs may vary by test site, depending on local culture, it is critical that the design used at a 
specific evaluation site is standardized to allow direct compariso n of AIs or formulated products.  
6.3.2 An appropriate description of the design, size, furnishings, wall and ceiling characteristics and layout 
should be reported. Huts should be checked for contamination by an appropriate control test before evaluation 
of each new product. The attractiveness of the experimental huts to the target species should be tested before 
the trial using landing rates under control conditions.  
6.3.3 The study design for indoor evaluation of point -source treatments (e.g. coils and ema nators) differs from 
that for nonpoint source treatments (e.g. treated textiles or wall surfaces). Point -source treatments can be 
rotated between huts, whereas rotation of non -point source treatments may be limited by format. For point -
source trials, rotat ion between huts should be in accordance with a Latin square design, in which every treatment 
is tested in every hut an equal number of times.  
6.3.4 Rotation schedules should be based on the expected protection time from laboratory findings or product 
claims, with 1 or 2 days between rotations to clean and ventilate the hut and to remove contamination from 
previous treatments. When non -point source products cannot be rotated, it is essential to demonstrate before 
the evaluation that the attractiveness of ex perimental huts has little or no variation. (This also shows the 
importance of optimum positioning during selection or construction.)  
6.3.5 Human volunteers are positioned at the centre of each hut throughout a single test to either conduct a 
human landing  catch for measuring landing inhibition or to rest or sleep for measurement of feeding inhibition. 
Product placement in the hut should be in accordance with the label instructions. The duration of the evaluation 
and sampling periods will depend on the prod uct label specifications.  
6.3.6 Each replicate consists of releasing 100 mosquitoes inside the hut, for both the treatment and negative 
control. A positive control can be used when appropriate. The mosquitoes collected are placed in separate 
holding cups f or each sampling period. If insecticidal activity is indicated in laboratory studies, knock -down must 
also be monitored inside huts. All mosquitoes are held 24 h at optimum temperature and humidity conditions for 
observation of mortality. Data should be re ported for knockdown, mortality, blood -fed status and location of 
collection (to estimate movement into or out of the test structure).  
6.3.7 Marking each release population with a different coloured fluorescent powder can facilitate recapture; 
however, the  effect of marking on mosquito behavior  and mortality should be evaluated before use in testing. 
Mechanical aspiration can be used to recapture all mosquitoes that were not collected during testing and remain 
inside the screened enclosure.  
6.3.8 At the end  of a trial, the number of mosquitoes collected during each observation period (i.e. at hour 1, 
hour 2 and hour 3) in the treatment and control groups can be averaged for each replicate (i.e. full treatment 
rotation). Landing inhibition or feeding inhibiti on is reported as a percentage with a 95% confidence interval (see 
section 2.3). An appropriate statistical analysis (e.g. probit -plane regression or linear mixed -effects regression 
with an appropriate error structure and link function) at a significance l evel of p = 0.05 should be used for 
comparison.  DRS 394 -2: 2018  
15                ©RSB 2018 - All rights reserved  
 6.3.9 The data reported should include  the duration of the test, the age of the product (duration of protective 
efficacy), the number of replicates of the control and treatment, mean percentage landing inhibi tion or mean 
percentage feeding inhibition with 95% confidence interval.  
6.4 Outdoor effective dosage and duration of protective efficacy  
6.4.1 In a semi -field system, volunteers are positioned singly at a collection station at a specified distance from 
the sp atial repellent product, according to the label recommendations, or act as a control for the duration of the 
test to either conduct human landing catch for measurement of landing inhibition or to rest or sleep for 
measurement of feeding inhibition. The dur ation of the evaluation and sampling periods depends on the product 
label specifications.  
6.4.2 Two semi -field compartments are used simultaneously to monitor landing inhibition at a set distance from 
a spatial repellent or control.  
6.4.5 Each replicate consists of releasing 100 mosquitoes, for both the treatment and the negative control. 
Mosquitoes are released from netted boxes at a set distance from the volunteer by a pulley system. Plastic 
sheeting is used to separate semi -field compartments to ensure  the independence of samples. Control and 
treatment can be rotated by day to prevent interference among collection stations. Temperature, humidity, wind 
speed and direction should be recorded for the duration of each replicate. For each defined distance, e valuations 
should be repeated.  
6.4.6 At the end of a trial, the number of mosquitoes collected within each observation period (e.g. at hour 1, 
hour 2 and hour 3), for treatment and control, can be averaged for each replicate (i.e. full treatment rotation).  
The data reported should include the duration of the test, the age of the product (duration of protective efficacy), 
the number of replicates of the control and treatment, the mean percentage landing inhibition or mean 
percentage feeding inhibition ( Equat ion 3 ) with 95% confidence interval (see section 2.3). The size of the semi -
field system used during the evaluation should be reported in m3.Efficacy at each distance between the source 
of the spatial  repellent and the volunteer should be stated. An approp riate statistical analysis (e.g. probit -plane 
regression or linear mixed  effects  regression with an appropriate error structure and link  function) at a 
significance level of p = 0.05 should be used for  comparison.  
7 Field trials of formulated products  
7.1 The objectives of field trials are to measure the personal protection offered by a spatial repellent product 
in operational settings and against free -flying natural indoor and/or outdoor populations of a target species. 
These are measured by comparing landin g inhibition with treatment and with control.  (Note 7) 
Note 7 Because of ethical considerations, alternative collection methods and measures might be required to assess 
personal protection in locations with known active circulation of arboviruses (i.e. dengue), such as monitoring indoor resting 
density, use of outdoor traps or monitoring mosquito entry with window traps.  
7.2 The specific objectives of such tests are to:  
a) confirm the effective dosage under operational conditions;  
b) observe and record the ease of application, handling and perceived adverse -effects during product 
application and use; and  
c) observe and record community acceptance.   
©RSB 2018 - All rights reserved                  16 
 7.3 Operational trials may have to be conducted in different  ecological settings (e.g. urban or rural and indoor 
or outdoor),  depending on the target species. The area and location of trial  sites should be representative of the 
target species’ habitat and  the expected conditions of human exposure. Trials should be  sufficiently replicated 
to allow robust statistical ana lysis with  relevant sample size estimations based on predicted product  efficacy. 
The outcomes are locale -specific, and the results may  not be applicable to other settings. The environmental  
conditions of temperature, humidity and wind speed should be  repor ted during both indoor and outdoor 
evaluations.  Information on the insecticide resistance profile of the target  species is desirable.  
7.4 For indoor evaluations, several houses should be used, when feasible. Houses should be well described, 
especially with  regard to the conditions relevant to product efficacy, including estimates of indoor volume and 
air ventilation (e.g. sealed or gapped walls, number of windows, doors or eave area). Houses are randomized 
to receive either active (formulated spatial  repell ent) or blank (placebo; inert ingredients alone) treatment during 
the trial. Collectors should be ‘blinded’ to treatment allocation.  
7.5  In outdoor evaluations, spatial repellent product or blank should be allocated randomly to comparable 
outdoor spaces with human exposure.  
7.6 A minimum of three replicates is required on different occasions at the optimal dose required for a 90% 
reduction in landing inhibition or a statistically significant difference between treatment and control at the dosage 
recommend ed on the label. The initial dosage for operational trials should be based on the dosage(s) 
recommended on the label or that which inhibited feeding by at least 90% in semi -field trials. The number and 
placement of spatial repellent products should be base d on label claims.  
7.7 Human landing catch methods should be used to measure protective efficacy. The method, statistics and 
minimum data reporting for evaluation of landing inhibition are outlined in sections 5.3 and 5.4 for indoor and 
outdoor trials, res pectively.  
7.8 It is advisable that the health status of volunteers be examined before, during and after product use. Brief 
records of exposure should be kept for each volunteer, including the spatial repellent product used, the dosage, 
total exposure in h ours and any perceived adverse -effects. A list of mild, moderate and severe signs and 
symptoms of poisoning can be kept for reference. Problems encountered in use and application should be 
reported. The material safety data sheet issued by the manufacturer  should be consulted if necessary.  
7.9 Perceived adverse -effects (and other adverse events) due to use of the spatial repellent product indoors 
or outdoors and the general acceptability of treatment by local inhabitants in the trial  area should also be 
observed and recorded.  
8 8. Ethical considerations  
8.1 General  
8.1.1 Participants’ well -being must be assured and their autonomy respected. The inclusion and exclusion 
criteria for participation in a test, informed consent for risk of pathogen infection, pathogen detection and 
monitoring as well as chemoprophylaxis and treatment should follow national guidelines, and the study protocol 
should be approved by the relevant research ethics committee in the country or institution in which the study is 
taking place.  
8.1.2 Like all studies in which infectious agents are involved, efficacy testing often entails an occupational risk 
of acquiring infection in both laboratory and field settings. Measures for reducing such risks have been DRS 394 -2: 2018  
17                ©RSB 2018 - All rights reserved  
 developed and widely implemented and in clude insect containment and manipulation, worker training and using 
known uninfected target species, when possible.  
8.1.3 When human participants are hired or recruited, they must be informed about any responsibilities that 
may expose them to vectors, suc h as colony maintenance or conducting human landing catches in natural or 
field conditions. Participants are then expected to follow standard protocols, as outlined by the project leader or 
national guidelines; they will therefore be protected under occupa tional health standards to control exposure to 
biohazards.  
8.2 Informed consent  
Volunteers should be given the full details of the project, including the purpose of the study, the procedures, 
product to be evaluated, the risks and benefits, reporting adverse e ffects and the voluntary right to refuse or 
withdraw from the study. Informed consent is usually documented on a signed and dated consent form. An 
example of an informed consent document is provided in Annex B. 
8.3 Human landing catch in semi -field and field t esting  
8.3.1 Evaluations of landing and feeding inhibition should be based on the pathogen -specific risks of volunteers. 
By using laboratory -reared mosquito populations in semi -field trials, however, it may be acceptable to allow 
mosquitoes to feed with mi nimal or no greater risk of disease for the volunteers.  
8.3.2 In all instances, ethical clearance from relevant ethics committees and informed consent from 
participating individuals is mandatory. In malaria -endemic countries, all participants must be scre ened for 
malaria before participation, and only parasite free individuals should be allowed to participate.  
8.3.3 For field trials with human landing catch in areas endemic for vector -borne disease, it is recommended, 
when feasible, to use healthy male rec ruits aged between 18 and 45 years. Males from outside the trial area 
(with potential exposure to unmatched vectors) and pregnant women should be excluded.  
8.3.4 Volunteers should be given protective clothing (i.e. a screen mesh jacket to protect the upper body, head 
and face, and closed -toe shoes to prevent bites to the feet). In malaria endemic countries, it is recommended 
that participants in field trials be giv en appropriate prophylaxis, when possible under supervision to ensure 
correct compliance.  
8.3.5 When applicable, participants should be screened for parasitaemia by WHO standard microscopy or a 
parasite -appropriate rapid diagnostic test; malaria treatment  should be provided subsequently for infected 
volunteers, according to national ethical guidelines.  
8.3.6 Alternative methods for assessing personal protection may be required in field trials conducted in locales 
with known active circulation of arboviruse s (i.e. dengue), such as monitoring indoor resting density, use of 
outdoor traps or monitoring mosquito entry with window traps.  
  
©RSB 2018 - All rights reserved                  18 
 Annex  A 
(Informative)  
 
Definition of knockdown and mortality for adult mosquitoes  
Forthe purpose of insecticide bioassays, the defini tion of knock -down and mortality involves not only the state 
of the insect but also the time at which the observation is made.  
A mosquito is classified as dead or knocked down if it is immobile or unable to stand or take off (Table A1). The 
distinction bet ween knocked down and dead is defined only by the time of observation. The assessment of 
knock -down is made within 60 min post -exposure. Mortality is determined at least 24 h post -exposure. The 
holding container may be tapped a few times before a final det ermination is made.  
In the case of slow -acting insecticides, the recovery period may be extended beyond 24 h. Control mortality 
should be measured over the same recovery period. Mortality after 24 h should be recorded and, in some cases, 
repeated observati ons may be appropriate.  
Table A1 – Classification of adult mosquitoes as alive, knocked down or dead in bioassays  
Alive  Knocked down after 60 minutes or dead after 24 hours of exposure  
Moribund  Dead  
Can both stand on 
and fly in a 
coordinated manner   Any mosquito that cannot stand (e.g. has 
1 or 2 legs)  
 Any mosquito that cannot fly in a 
coordinated manner  
 A mosquito that lies on its back, moving 
legs and wings but unable to take off  
 A mosquito that can stand and take off 
briefly but falls down immediately  No sign of life; immobile; cannot 
stand  
 
  DRS 394 -2: 2018  
19                ©RSB 2018 - All rights reserved  
 Annex  B 
(informative)  
 
Example of informed consent form  
Informed consent form for participants in human landing catches for:  
Insert project title ………………………………………………………………………………………..  
Name of principal investigator …………………………………………………………………………  
Name of organization ……………………………………………………………………………………  
Name of sponsor ………………………………………………………………………………………….  
Name of proposal and version …………………………………………………………………………..  
This informed consent form has two parts:  
 Information sheet ( to share information about the research with you)  
 Certificate of consent (for signature it you agree to take part)  
You will be given a copy of the full informed consent form.  
Date and signature …………………………………………  
Part I: Information sheet  
Introduction  
Briefly  state who you are, and explain that you are inviting them to participate in the research you are doing. 
Inform them that they may talk to anyone they like about the research and that they can take time to reflect on 
whether they want to participate. Assur e the person that if he or she does not understand some of the words or 
concepts, you will take time to explain them as you go along and that they can ask questions now or later.  
(Example: I am …………………., working for the …………………….. <name of the research institute>. We are 
doing research on …………………….. disease, which is very common in this country. I am going to give you 
information and invite you to be part of this research. You do not have to decide today whether you will 
participate in the research. Befo re you decide, you can talk to anyone you like about the research. There may 
be some words that you do not understand. Please ask me to stop as we go through the information, and I will 
taketime to explain. If you have questions later, you can ask [name of  responsible staff]).  
 
Purpose of the research   
©RSB 2018 - All rights reserved                  20 
 Explain in lay terms why you are doing the research. The language used should clarify rather than confuse. Use 
local, simplified terms for a disease, e.g. local name instead of malaria, mosquito instead of ano pheles, 
“mosquitoes help in spreading the disease” rather than “mosquitoes are the vectors”. Avoid using terms like 
‘pathogenesis’, ‘indicators’, ‘determinants’ and ‘equitable’. There are guides on the Internet to help you find 
substitutes for words that a re overly scientific or are professional jargon.  
(Example …………………disease is transmitted through the bites of ………………mosquitoes. Knowledge of 
mosquito behaviour and how new methods to keep mosquitoes away from humans will help improve mosquito 
control in the  area. In this study, we are testing a new repellent that will keep mosquitoes from biting humans. 
Studies in laboratories have shown this repellent is …………effective, and we want to check this result with 
mosquitoes in this area to make sure it is useful f or people to use here.)  
Type of research intervention and procedures  
Briefly state the type of intervention that will be undertaken.  
 As a participant you will be asked to collect mosquitoes  landing on you before they bite you between ….. 
: ….. and ….. :…… h. This involves collecting mosquitoes that  land on your legs with a tube and a torch.  
 You will be asked to not smoke cigarettes or drink alcohol for the days or weeks that you are participating.  
 We will provide you with ……………………………………………………  medicine to stop you getting 
malaria if a mosquito with malaria does manage to bite you. You will have to take this every week and 
sign a form to show that you have taken the medicine; it will be paid for by the study.  
 You will have to take a malaria test every week t hat you are working on the study and sign a form to 
show that you have taken the test; it will be paid for by the study. If you are sick we will not be allowed 
to continue in the study.  
 You can leave the study at any time without explanation. It is your ch oice to take part.  
 
 Example of question to improve understanding : Do you know why we are asking you to take part in 
this study? Do you know what the study is about?  
Voluntary participation  
Indicate clearly that the person can choose to participate or not. This can be repeated and expanded upon later 
in the form as well, but it is important to state clearly at the beginning of the form that participation is voluntary 
so that the other information can be heard in this context.  
(Example: Your participation in this research is entirely voluntary. It is your choice whether to participate or not. 
You may change your mind later and stop participating even if you agreed earlier.)  
 Examples of question to improve understanding: If you decide not to take part in this r esearch 
study, do you know what your options are? Do you know that you do not have to take part in this 
research study, if you do not wish to? Do you have any questions?  
Risks  
Explain and describe any possible or anticipated risks. Describe the level of ca re that will be available in the 
event that harm does occur, who will provide it, and who will pay for it. A risk can be thought of as being the DRS 394 -2: 2018  
21                ©RSB 2018 - All rights reserved  
 possibility that harm may occur. Provide enough information about the risks to allow the participant to make an  
informed decision.  
(Example: The risk of this study is you may be made uncomfortable by mosquito bites, and you have a small 
risk of getting ……………… disease, even though you are taking …………. medicine to prevent it. You will be 
given protective clothing to make sure mosquitoes can bite only on your legs, where you can catch them before 
they have time to bite. If you do become ill at any time during the study or during 1 month after the study, you 
will receive the correct treatment from…………………………… hospital. A ll costs will be paid by the study. There 
is also a risk that you might have some side effects from taking medicines to stop getting ……………… disease. 
If you feel unwell, you will see a doctor at …………………………… hospital who will give you the correct care 
and ch ange the medicines you are taking.)  
 Examples of question to improve understanding: Do you understand that, while the research study is 
under way, you will receive free health care from …………………………… hospital? Do you understand 
that you may have some unwanted  side-effects from the medicine to stop getting ……………… 
disease? Do you have any other questions?  
Benefits  
Mention only those activities that will be actual benefits and not those to which the prospective participants are 
entitled regardless of participatio n. Benefits can be categorized as those to the individual, those to the 
community in which the individual resides and those to society as a whole as a result of finding an answer to 
the research question.  
(Example: If you participate in this research, you will have the following benefits: you will be paid 
........................................  for your work each night for up to .............................. nights and will have a taxi home 
or accommodation at night after you have finished work.)  
 Examples  of question to improve understanding: Can you tell me if you have understood correctly 
the benefits that you will have if you take part in the study?  Do you know if the study will pay for your 
travel costs  and time lost, and do you know how much you will be reimbursed? Do you have any other 
questions?  
Right to refuse or withdraw  
This is reconfirmation that participation is voluntary and includes the right to withdraw.  
(Example: You do not have to take part in this research if you do not wish to do so. You may also stop 
participating in the research at any time you choose. It is your choice and all of your rights will still be respected.)  
Who to contact  
Provide the name and contact information of someone who is involved, informed and accessible (a local pers on 
who can actually be contacted). State that the proposal has been approved and how.  
(Example: If you have any questions you may ask them now or later, even after the study has started. If you 
wish to ask questions later, you may contact any of the follow ing: [name, address/telephone number/e -mail]).   
©RSB 2018 - All rights reserved                  22 
 This proposal has been reviewed and approved by [name of the local ethical review board], which is a 
committee that makes sure that research participants are protected from harm. If you wish to find more 
about  the ethical review board, contact [name, address, and telephone  number.]).  
 Example of question to improve understanding: Do you know that you do not have to take part in this 
study if you do not wish to? Do you know that you can say ‘No’ if you wish to? D o you know that you 
can ask me questions later, if you wish to? Do you know that I have given the contact details of the 
person who can give you more information about the study?  
You can ask me any questions about any part of the research study, if you wish to. Do you have any questions?  
Part II: Certificate of consent  
This section should be written in the first person and contain a statement similar to the one in bold below. If the 
participant is illiterate but gives oral consent, a witness must sign. A  researcher or the person going over the 
informed consent forms must sign each form. The certificate of consent should avoid  phrases starting with 
“I understand….”. Understanding is  better tested by targeted questions during the reading of  the 
information sheet (Some examples of questions are  given above) or by questions asked at the end of 
the reading of the information sheet, if the potential participant  is reading the information sheet him - or 
herself.  
(Example I, ………………………………………………., have clearly been i nformed of the aims of the project 
entitled “ …………………… ” and I agree to participate in the study. During my participation in these studies, I 
have been told that mosquitoes can bite me and they may be carrying parasites. I am fully aware that I may 
revoke my  consent and leave the study at any stage.  
Participant name: ………………………………………………………………………………………………..  
Participant signature: ……………………………………………………………………………………………  
Dates: …………………………………………………………………………………………………………….  
 
Witness name: …………………………………………………………………………………… …………..  
Witness signature: ……………………………………………………………………………………………  
Dates: …………………………………………………………………………………………………………….  
If illiterate  
A literate witness must sign (if possible, this person should be selected by the participant and should have no 
connection to the research team). Participants who are illiterate should oppose  their thumb print as well.  
(Example: I have witnessed the accura te reading of the consent form to the potential participant, and the 
individual has had the opportunity to ask questions. I confirm that the individual has given consent freely.)  DRS 394 -2: 2018  
23                ©RSB 2018 - All rights reserved  
 Print name  of witness: ……………………………………………………………and thumb print of participant  
Signature of witness: ……………………………………………………………………………………………  
Dates: …………………………………………………………………………………………………………….  
 
Statement by the researcher or other person taking consent:  
I have accurately read out the information sheet to the potential participant and to the best of my ability made 
sure that the participant understands that the following will be done:  
1. Human landing catch will be conducted between..... :..... and..... :......  
2. The participant has been requested to refrain from smoking and consuming alcohol f or the study duration.  
3. The participant will be given free malaria prophylaxis,  screening and treatment for the duration of the 
study.  
4. The participant will be reimbursed ……………………………..  for the working time taken up by the study.  
I confirm that the participan t was given an opportunity to ask questions about the study, and all the questions 
asked by the participant were answered correctly and to the best of my ability. I confirm that the individual has 
not been coerced into giving consent, and the consent has b een given freely and voluntarily.  
A copy of this informed consent form has been given to the participant.  
Print name of researcher or other person taking the consent: ………………………………………………………..  
Signature of researcher or other person taking the consent: …………… ……………………………………………  
Date: ………………………………………………   
©RSB 2018 - All rights reserved                  24 
 Bibliography  
[1] World Health Organization (WHO) , Guidelines for efficacy testing of spatial repellents , 2013  
[2]  Ferguson HM et al. Establishment of a large semi -field system for experimental study of African malaria 
vector ecology and control in Tanzania. Malaria Journal , 2008, 7(1):158.  
 
[3] American Society of Tropical Medicine and Hygiene. Arthropod containment levels. Vector -borne and 
Zoonotic Diseases , 2003, 3:75 –90. 
[4] American Kitau J et al. The effect of Mosquito Magnet Liberty Plus trap on the human mosquito biting rate 
under semi -field conditions. Journal of the American Mosquito Control Association , 2010, 26(3):287 –294.DRS 394 -2: 2018  
ICS 65.100.10  
 
 
©RSB 2018  - All right s reserved