Targeting High Risk Populations With Enhanced Reactive Focal Mass Drug Administration in Thailand (COMBAT)

Expérimental: reactive focal mass drug administration (rfMDA)

Reactive FMDA (rfMDA) led by VMVs in response to cases in study area sub-district, in both villages and forest workers; quantitative G6PD testing for all individuals and 14-day PQ for G6PD non-deficient.

Autre: Case Management and Follow-up

Individuals will be told of their test result and a positive test result on either RDT will prompt treatment as per the national treatment guidelines.

• Individuals with P. falciparum infection will be treated with an age-appropriate course of dihydroartemisinin/piperaquine (DHAP) or artesunate-pyronaridine (Pyramax) and PQ.
• At all study sites in Thailand, patients with a P. vivax infection identified by the standard combination RDT will be tested by the VMV and Health Promotion Hospital (HPH) staff member using the quantitative G6PD RDT. G6PD normal individuals will be treated with Chloroquine (CQ) and a 14-day course of primaquine (PQ). G6PD deficient individuals will receive CQ alone and referred to the nearest health facility for further primaquine management decisions.

Autre: Reactive focal mass drug administration (rfMDA)

Reactive focal mass administration (rfMDA) will be implemented around the index case household and to forest co-workers/co-travelers in Thailand. The VMV will conduct the investigation visit within 7 days after the notification of the index case. All members of the index case's household as well as all members of the nearest five households around the index case's household, including temporary visitors will be invited to participate in the study and to be treated for malaria without a malaria test. After obtaining participants' or parents/guardians' consent, the VMV will proceed with the participant questionnaire, and all consenting household members will be tested for G6PD using the G6PD quantitative test prior to administration of antimalarials.

For rfMDA, all eligible participants will be offered artesunate-mefloquine (AS-MQ). Per national policy, a 14-day course of primaquine will be administered to G6PD non-deficient study participants.

Comparateur actif: Control

Standard of care including case management through health facilities and malaria posts/VMVs; village-based RACD conducted by district staff in some areas.

Autre: Case Management and Follow-up

Individuals will be told of their test result and a positive test result on either RDT will prompt treatment as per the national treatment guidelines.

• Individuals with P. falciparum infection will be treated with an age-appropriate course of dihydroartemisinin/piperaquine (DHAP) or artesunate-pyronaridine (Pyramax) and PQ.
• At all study sites in Thailand, patients with a P. vivax infection identified by the standard combination RDT will be tested by the VMV and Health Promotion Hospital (HPH) staff member using the quantitative G6PD RDT. G6PD normal individuals will be treated with Chloroquine (CQ) and a 14-day course of primaquine (PQ). G6PD deficient individuals will receive CQ alone and referred to the nearest health facility for further primaquine management decisions.

Confirmed P. falciparum and P. vivax malaria parasite incidence

Defined as the number of outpatient (OPD) malaria confirmed and suspected cases per person per year for each sub-district, as ascertained from the health facility registers, utilizing administrative catchment population size estimates for the exposure denominator.

PCR-based P. falciparum and P. vivax parasite prevalence in sampled sub-districts

Defined as the proportion of individuals ≥18 months old with P. falciparum or P. vivax infection (detected by PCR) out of all individuals ≥18 months tested within the end line survey.

Population coverage of rfMDA interventions

This indicator will be measured in two ways. Operational program coverage will be defined as the proportion of individuals ≥18 months old and households visited and offered the rfMDA interventions within the target areas per time period. Effective program coverage is defined as the proportion of individuals (≥18 months old) that agreed to participate in the rfMDA intervention among all individuals ≥18 months old eligible to participate in the intervention in the target population per time period.

Feasibility of conducting rfMDA at the community level

Feasibility will be determined based upon a combination of population coverage data, responses of provincial, district, and health staff, VMWs, and community members to interviews and focus groups at baseline and end line, village malaria workers (VMWs) competency checklists at baseline, midline, and end line, and cost data.

Acceptability of rfMDA approach

Acceptability will be determined based upon refusal rates during interventions and responses of community members and VMWs to end line questionnaire, interviews, and focus groups.

Adverse event rate

Safety measures will include the adverse event rate amongst treated individuals and hemoglobin measurement pre and post treatment for individuals receiving PQ.

Operational feasibility of glucose-6-phosphate dehydrogenase (G6PD) testing and referral

Operational feasibility of G6PD testing and referral will be determined by responses of health staff and VMWs to interviews and focus groups at baseline and end line and competency checklists at baseline, midline, and end line, the proportion of P. vivax cases with a valid G6PD result, and proportion of referred cases presenting at a health facility for G6PD testing.

Assessment of P. vivax treatment adherence

Treatment adherence will be determined by the proportion of P. vivax cases with physical evidence of adherence through pill count and the P. vivax relapse rate across study arms.