Targeted Active Case Detection Among High Risk Populations in Southern Lao Peoples Democratic Republic

Assessing the Effectiveness of Targeted Active Case Detection Among High Risk Populations in Southern Lao PDR

This study assesses the effectiveness of targeted active case detection among high-risk populations in Southern Lao Peoples Democratic Republic (PDR). The investigators hypothesize that active case detection using the next generation of HRP-2 rapid diagnostic tests (RDTs) can help bridge gaps in identification of high-risk asymptomatic individuals with low density parasitemia, allowing for targeting of this reservoir and thereby reducing transmission. The investigators hypothesize that active case detection (testing and treating positive cases) with these RDTs will lead to a reduction in P. falciparum transmission.

This study is the second phase of work in Champasak Province, Southern Lao PDR, building off a formative phase of work that characterized the demographics, occupations, migratory patterns, health-seeking behaviors, and social networks of mobile and migrant populations (MMPs) in four target districts. This phase of the study now aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of proactive targeted test-and-treat activities using high-sensitivity malaria rapid diagnostic tests (HS-RDTs) for reducing Plasmodium falciparum malaria transmission in Champasak Province among (1) village residents and (2) mobile and migrant populations (MMPs) and other high-risk populations (HRPs).

The study will specifically assess the role of HS-RDTs, a diagnostic test that offers potentially ~10-fold greater sensitivity than standard RDTs, in active case detection at both the village-level and in forest-going HRPs for decreasing prevalence and incidence of P. falciparum in target areas. The effectiveness of these interventions will be compared independently and in combination against areas with no study interventions (standard of care) over the course of implementation (planned for October 2017 - November 2018).

The two main study interventions are mass test and treat (MTAT) using HS-RDTs in village-based populations, and peer navigator (PN) led focal test and treat (FTAT) using HS-RDTs in forest based HRPs. Primary outcomes will include PCR-based P. falciparum prevalence at endline. Following a baseline cross-sectional survey in November-December 2017, the interventions will consist of 3 rounds of MTAT spaced throughout the year, with potential to reduce to 2 based upon initial prevalence estimates, and ongoing FTAT by PNs among forest and forest-fringe HRPs, with the primary evaluation to be conducted through an end-line cross-sectional survey in November 2018.

Village Based MTAT

Inclusion Criteria

• All household members 18 months of age and older.
• Study participants include those in the 14 selected health center catchment areas within the four target districts in Champasak Province, Southern Lao PDR; Moulapamook, Panthampone, Sanamsaboun, and Soukhuma.
• Members of households who have provided informed consent will be included for blood samples collection and treatment for identified malaria cases if meeting the appropriate criteria.

Exclusion Criteria

• Household members less than 18 months of age will be excluded.
• Any individuals under the age of 18 months will be excluded from RDT testing and blood collection.

Peer Naviagtor-Led FTAT

Inclusion Criteria

• All persons 15 years and older who have spent at least one night outside a formal village in the past one month.
• Individuals must be 18 years and older and willing and able to provide consent to be included in the peer navigator or study staff focus group discussions and key informant interviews
• Study participants include those in the 14 selected health center catchment areas within the four target districts in Champasak Province, Southern Lao PDR; Moulapamook, Panthampone, Sanamsaboun, and Soukhuma
• High-risk populations in forested areas, rice field regions, plantations and any informal settlements
• Individuals travelling into the HCCA who are willing and sufficiently able to communicate with PNs to assess their eligibility

Exclusion criteria

- Individuals under the age of 18 will be excluded from peer navigator or study staff focus group discussions and key informant interviews.