Clinical trial NCT05125133: Evaluation of Insecticide-treated Eave Nets and Window Screens for Malaria Control in Tanzania.
Official title: A Household Randomized Control Trial of Insecticide-treated Eave Nets and Window Screens for Malaria Control in Chalinze District, Tanzania.
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Malaria,Falciparum
Keywords: Insecticide-treated nets, Eaves, windows, Malaria, Tanzania.
Lead sponsor: Ifakara Health Institute
Sponsor class: OTHER
Collaborators: name: London School of Hygiene and Tropical Medicine
name: Swiss Tropical & Public Health Institute
First posted: 2021-11-18
Enrollment: 1800
Sex: ALL
Minimum age (years): 6
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Households allocated into Two arms to receive ITENs+ITWS installed or none with a 1:1 ratio at sub-village level.
Primary purpose: PREVENTION

Brief summary: This is a household randomized trial of a new tool for house modification, Insecticide-Treated Eave nets (ITENs) in combination with insecticide-treated window screens (ITWS), coated with a dual active ingredient (dual AI): Deltamethrin at 3g AI/kg, which corresponds to 144 mg/m² and PBO synergist at 10g/kg which corresponds to 480 mg/m², as used in the so-called dual-AI LLIN or "resistance breaking" nets for resistance malaria vector control.

Four hundred and fifty (450) households with intact walls, opened eaves, and those without screens or nets on the windows in Chalinze district, Tanzania will be eligible and only recruited upon written informed consent. The households will be randomly allocated into two arms: one with ITENs and ITWS installed and the other without.

The primary outcome will be malaria parasite detection in household residents aged over 6 months old using a quantitative Polymerase Chain Reaction (qPCR) at approximately 12 months post-installation, coinciding with the long rainy season.

Detailed description: In Tanzania, long-lasting insecticidal nets (LLINs) contributed to the high reduction of malaria in the last decade. However, malaria reduction in Tanzania is threatened due to increasing insecticidal resistance of malaria vectors, low access to LLIN, LLINs not lasting up to three years, and net usage compliance. Therefore, it is evident that an additional cost-effective vector control tool is required that may confer protection against resistant malaria vectors, protect every member of the household, requires little or less compliance to use after distribution, and lasts longer.

The proposed additional vector control tool for trial is the Insecticide-Treated Eave nets (ITENs) in combination with Insecticide Treated Window screens (ITWS) for house modification. The tool is coated with a dual active ingredient (dual AI): Deltamethrin at 3g AI/kg, which corresponds to 144 mg/m², and PBO synergist at 10g/kg which corresponds to 480 mg/m², which are coated at the same concentration in insecticide-treated nets that are already in use in the population to control pyrethroid-resistant mosquitoes. These can protect everyone in the house by blocking mosquito entry and killing mosquitos that contact them to protect everyone in the community.

In this trial, 450 households will be randomly allocated into two arms. One arm with ITENs \& ITWS installed and the other without to serve as the control arm. The 450 households are recruited and assigned codes during baseline data collection. The assigned codes are randomized to either of the two arms by simple randomization in STATA and stratified by sub-village.

Approximately 6 months and 12 months post-installation, coinciding with the rainy seasons, clinical officers will screen for malaria parasites in household residents of over 6 months old (it is estimated that 4.4 persons reside in each household, thus approx. 1,800 persons will be screened for malaria per survey) in both arms and confirmation of malaria parasite will be done using qPCR analysis as the primary assessment of the primary outcome. As a point of care, SD Bioline Malaria Ag Pf/Pan rapid diagnostic test (RDT) as per Tanzanian guidelines will also be conducted on all household residents. Any participant (s) with an axillary temperature of 37.5 degrees (fever) and that test positive using mRDT will be considered as a clinical malaria case. All malaria-positive participants will be treated using free Artemether Lumefantrine (ALu). This drug is approved by the national guideline for the treatment of uncomplicated malaria.

Other secondary objectives are:

* To evaluate malaria prevalence in households with ITENs \& ITWS and those without at approximately 6 months post-installation, coinciding with the short rainy season.
* To determine the prevalence of clinical malaria defined by an axillary temperature of 37.5 degrees and above (fever) and mRDT malaria positive cases at approximately 6 months and 12 months post-installation, coinciding with the rainy seasons.
* To investigate the effect of ITENs and ITWS on the density of malaria vectors and nuisance (Culex quinquefasciatus) mosquitoes in the community at approximately 6 months and 12 months post-installation, coinciding with the rainy seasons using Centres for Disease Control (CDC) light traps.
* To assess the number of fabric in meters and time of installing the intervention (feasibility of scaling-up ITENs and ITWS use) in local houses in the field during installation.
* To assess the adverse effects of ITENs and ITWS in the community.
* To determine the attrition and fabric integrity of ITENs and ITWS in the field post 6 months and 12 months of installation.
* To determine the mortality induced by (bioefficacy) ITENs and ITWS on laboratory-reared mosquitoes post 12 months of installation.
* To determine the insecticide retainment of ITENs and ITWS post 12 months of installation.
* To assess the acceptability of ITENs and ITWS to the local community post 6 months and 12 months of installation.

Eligibility criteria: Inclusion Criteria:

* Residents of study households' members.

Exclusion Criteria:

* None residence.
* Pregnant women.

Primary outcomes:
measure: Prevalence of Plasmodium falciparum parasite.
timeFrame: Approximately 12 months post-installation, coinciding with the long rainy season.
Secondary outcomes:
measure: Prevalence of Plasmodium falciparum parasite.
timeFrame: Approximately 6 months post-installation, coinciding with the short rainy season.
measure: Clinical malaria.
timeFrame: Approximately 6 months and 12 months post-installation, coinciding with the rainy seasons.
measure: The density of malaria vectors and nuisance mosquitoes density.
timeFrame: Approximately 6 months and 12 months post-installation, coinciding with the rainy seasons.
measure: ITENs & ITWS fabric cost
timeFrame: Baseline (During installation of ITENs & ITWS)
measure: ITENS & ITWS time duration
timeFrame: Baseline (During installation of ITENs & ITWS)
measure: Adverse effects
timeFrame: Approximately one month post installation.
measure: Attrition
timeFrame: Appriximately 6 months and 12 months post installation.
measure: Fabric integrity
timeFrame: Appriximately 6 months and 12 months post installation.
measure: The induced mosquito mortality of ITENs and ITWs on the population of laboratory-reared mosquitoes.
timeFrame: Approximately 12 months post installation.
measure: Insecticide retainment
timeFrame: Appriximately 12 months post installation.
measure: Use of ITENs and ITWS
timeFrame: Approximately 6 months and 12 months post installation.
Other outcomes:
Locations:
city: Bagamoyo
country: Tanzania
facility: Vector Control Product Testing Unit Facility
Study officials:
affiliation: London School of Hygiene and Tropical Medicine
name: John Bradley, PhD
role: STUDY_DIRECTOR
References:
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citation: Mboera LE, Mweya CN, Rumisha SF, Tungu PK, Stanley G, Makange MR, Misinzo G, De Nardo P, Vairo F, Oriyo NM. The Risk of Dengue Virus Transmission in Dar es Salaam, Tanzania during an Epidemic Period of 2014. PLoS Negl Trop Dis. 2016 Jan 26;10(1):e0004313. doi: 10.1371/journal.pntd.0004313. eCollection 2016 Jan.
citation: Mboma ZM, Overgaard HJ, Moore S, Bradley J, Moore J, Massue DJ, Kramer K, Lines J, Lorenz LM. Mosquito net coverage in years between mass distributions: a case study of Tanzania, 2013. Malar J. 2018 Mar 1;17(1):100. doi: 10.1186/s12936-018-2247-z.
citation: Gleave K, Lissenden N, Richardson M, Choi L, Ranson H. Piperonyl butoxide (PBO) combined with pyrethroids in insecticide-treated nets to prevent malaria in Africa. Cochrane Database Syst Rev. 2018 Nov 29;11(11):CD012776. doi: 10.1002/14651858.CD012776.pub2.