Reducing Malaria Transmission in Forest-going Mobile and Migrant Populations in Lao PDR and Cambodia

Study Overview
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Brief Summary
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This stepped-wedge cluster-randomized controlled trial with nested mixed methods study will assess the effectiveness, acceptability, feasibility and cost-effectiveness of a personal protection package to reduce malaria transmission among mobile and migrant populations (MMPs) and the general population in their residing villages in Lao People's Democratic Republic (PDR) and Cambodia.

Detailed Description
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Over the last decade, the burden of malaria has fallen dramatically in the Greater Mekong Subregion, with deaths falling by 95% and cases by 76% between 2012 and 2019.The declining malaria burden in GMS has largely attributed by the deployment of interventions of malaria prevention tools such as long-lasting Insecticidal Nets (LLIN), and widespread availability of rapid diagnostic tests and artemisinin combination therapies. However, residual transmission still exists among high risk populations, particularly mobile and migrant populations who enter forests for work. New interventions targetting these high risk groups are needed if countries of the Greater Mekong Subregion are to achieve malaria elimination by 2030. The study will be conducted in malaria endemic areas of Lao PDR (Attapeu, Saravanh, Savannakhet and Khammouane Provinces) and Cambodia (Preah Vihear, Stung Treng and Ratanakiri Provinces) which have large forest going MMP populations. The aim of the study is to assess the effectiveness, acceptability, feasibility and cost-effectiveness of a personal protection package to reduce malaria transmission among mobile and migrant populations (MMPs) and the general population in their residing villages in Lao People's Democratic Republic (PDR) and Cambodia. The personal protection package comprises a long-lasting insecticidal hammock net (LLIHN), insect repellent (Icaridin), and a behavioural change communication (BCC) package tailored to mobile and migrant populations. The study design is a stepped-wedge cluster-randomized controlled trial with nested mixed methods study. The stepped-wedge cluster randomized trial will estimate the effectiveness of a personal protection package provided to forest-going MMPs (the intervention) delivered by village malaria volunteers at the site (village/worksite) level on reducing Plasmodium spp. infections. Whilst the personal protection package will be provided to mobile and migrant populations in each village in a step-wise manner, primary and secondary outcomes relating to malaria testing will be collected in all consenting individuals in the village who present for malaria rapid diagnostic tests, whether they are mobile and migrant people or not. The open stepped-wedge cluster-randomised controlled trial, randomized at the volunteer level (i.e. the volunteer and the village / workplaces they service), will be implemented between July 2021 to June 2022. The personal protection package for MMPs will be implemented sequentially in a minimum of  488 villages serviced by approximately  488 VMWs ( 428 in Lao PDR and  60 in Cambodia). Villages from each country will be randomised into 11 ordered blocks, with blocks transitioned from control (no personal protection package) to intervention (distribution of personal protection package) states at monthly intervals (10 blocks of 44 villages for the first 10 steps and a block of 48 villages transitioned at the last step). This follows an initial baseline control period of one-month at the start of the study Approximately 11 RDTs per month will be undertaken in each study site (village/ worksite). Given the design we estimate that the study has power to detect a relative minimum detectable difference of 34% (OR = 0.66) in odds of RDT-detectable malaria infection due to the intervention (assuming a village intraclass correlation [ICC]= 0.42; 5% significance; 90% power and 1% RDT malaria prevalence). For the stepped-wedged cluster randomized trial, both descriptive and primary outcome trial analyses will be performed. Using Stata version 15, differences in prevalence of Plasmodium spp. infections will be estimated across intervention and control periods using generalized linear mixed modelling (e.g. logit link function and binomial distribution) with crossed random effects for village and time, and intervention state, time and seasonality estimated as independent fixed factors. Temporal and spatial trends of Plasmodium spp. infections will also be explored including analysis of the effectiveness of the intervention across the study period. We will also explore any village-specific heterogeneity in effect by specifying a random effect for the intervention. Generalised linear mixed modelling will be extended to include model terms for country (main and interaction effects), and these will used to assess the extent of country-specific heterogeneity in intervention effect. The same approach will be used to assess risk group-specific heterogeneity (MMP, forest-goer, villager) in intervention effect.

Official Title
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A Personal Protection Package for Reducing Malaria Transmission in Forest-going Mobile and Migrant Populations in Lao PDR and Cambodia: A Stepped-wedge Trial With Nested Mixed-methods Study

Conditions
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Plasmodium Infection

Intervention / Treatment
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* Combination Product: Personal protection package


Participation Criteria
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Eligibility Criteria
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Inclusion: Mobile and migrant individuals aged 18 years and over in selected villages including: Traditional slash-and-burn and paddy field farming communities visiting their forest farms (commonly ethnic minority groups) Seasonal agricultural laborers Forest workers in the informal sector (hunters, small-scale gem/gold miners, people gathering forest products (precious timber, construction timber, rattan/bamboo) Transient or mobile camp residents associated with commercial projects (road/pipeline construction, large-scale logging, deep seaport projects, etc.) Formal and informal cross-border migrant workers For qualitative research component, local health stakeholders meeting the following criteria will be eligible: Aged 18 years and over The local health stakeholders such as health centre staff, Operational District Malaria Supervisor (ODMS), and Provincial Malaria Supervisor (PMS), and basic health staff such as malaria unit staff in health centres, midwives, health assistants, district health officers and district focal person from CMPE and CNM Health staff members from HPA and Lao malaria community service organisations Exclusion: A village will be excluded from the study if: The village has an VHV/VMW program operated by any organizations other than CMPE, CNM, HPA, malaria CSOs in Lao PDR The village has no malaria cases or API less than 1 in any of the past three years (2018 - 2020) The village has no MMPs The village has no VHV/VMW The village has a government health facility for provision of malaria services

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Stepped-wedge cluster-randomized controlled trial (one-way crossover) with nested mixed methods study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Personal protection package<br>A personal protection package that includes Long-lasting insecticidal hammock net (LLIHN), insect repellent (Icaridin), and mobile and migrant population-tailored behavioural change communication (BCC) package | Combination Product: Personal protection package<br>* A personal protection package that includes Long-lasting insecticidal hammock net (LLIHN), insect repellent (Icaridin), and MMP-tailored behavioural change communication (BCC) package<br>|
| No Intervention: Control<br>No personal protection package | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasmodium spp. infection diagnosed by RDT | Change in the number of Plasmodium spp. infections detected by RDT per week per village | Assessed weekly, longitudinally over 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptomatic malaria diagnosed by RDT | Change in the number of symptomatic Plasmodium spp. infections detected by RDT per week per village | Assessed weekly, longitudinally over 12 months | 
| Plasmodium spp. infection as determined by polymerase chain reaction (PCR) on RDT cassette samples | Change in the prevalence of Plasmodium spp. infection as determined by polymerase chain reaction (PCR) from RDT cassette samples | Assessed weekly, longitudinally over 12 months | 
| Plasmodium spp. infection as determined by polymerase chain reaction (PCR) on dried blood spot samples | Change in the prevalence of Plasmodium spp. infection as determined by polymerase chain reaction (PCR) from dried blood spot (DBS) samples | Assessed weekly, longitudinally over 12 months | 
| Plasmodium spp. infections with drug resistance mutations | Change in the prevalence of Plasmodium spp. infection with drug resistance mutations. | Assessed weekly, longitudinally over 12 months | 
| Prevalence of antibodies to Plasmodium spp. | Prevalence of antibodies to Plasmodium spp. determined by Enzyme Linked Immunosorbent assay (ELISA) from RDT and DBS samples | Assessed weekly, longitudinally over 12 months | 
| Levels of antibodies to Plasmodium spp. | Levels of antibodies to Plasmodium spp. determined by Enzyme Linked Immunosorbent assay (ELISA) from RDT and DBS samples | Assessed weekly, longitudinally over 12 months | 
| Prevalence of antibodies to vector salivary antigens | Levels of antibody biomarkers of vector exposure | Assessed weekly, longitudinally over 12 months | 
| Levels of antibodies to vector salivary antigens | Levels of antibody biomarkers of vector exposure | Assessed weekly, longitudinally over 12 months | 
| Levels of knowledge, attitude and practice regarding malaria prevention among MMPs | Focus group discussions | At approximately 12 months | 
| Proportion of survey respondents (MMPs) who accept and are willing to use/ did use the personal protection package according to the protocol | Questionnaire | At approximately 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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malaria, prevention, vector, migrant, elimination, vivax, falciparum, community-delivered, intervention