Performance of Ultrasensitive Rapid Diagnostic Tests for Detecting Asymptomatic Plasmodium falciparum.

Proposed interventions for eliminating drug-resistant Plasmodium falciparum malaria include the targeting of asymptomatic carriers through screening and treatment. We report on the diagnostic performance of the recently developed ultrasensitive rapid diagnostic test (uRDT) compared with screening with conventional RDTs (cRDT) and polymerase chain reaction (PCR) under field conditions in Cambodia in a total of 2,729 individuals. The P. falciparum positivity by quantitative PCR (qPCR) was 3.8% (26/678) in those screened during active case detection and 0.5% (10/2,051) in the cross-sectional survey. Compared with qPCR, the sensitivity of the uRDTs was 53.8% (95% CI: 33.4-73.4%) when used in active case detection and 60.0% (95% CI: 26.2-87.8%) in the cross-sectional survey. The uRDTs did not show a significant improvement in diagnostic performance over cRDTs when used for active case detection and for a malaria prevalence survey in the context of this low-transmission setting

Assessment of net lending strategy to better reach mobile and migrant populations in malaria endemic areas of Cambodia

Abstract Background In Cambodia, internal migration involves migrants moving from non-malaria endemic areas to malaria endemic areas and vice versa. The majority of them work in farms or forests with various malaria transmission levels. In Cambodia, as one of the national approaches to ensure LLIN accessibility and use among mobile and migrant populations (MMPs), a lending scheme of long lasting insecticide treated nets (LLINs) was initiated among farm workers. Through this net lending program, LLINs and long-lasting insecticide treated hammock nets (LLIHNs) will be distributed annually at workplace (e.g. longstanding farms, plantations, industrial sites, as identified by operational district and health center staff) on a ratio of one LLIN per one worker. The main objective of this study is to assess MMPs’ accessibility to LLINs through a lending scheme with plantation owners in remote malaria endemic areas of Cambodia. Methods The study used a cross-sectional survey among MMPs using two-stage cluster sampling method. The sampling frame is the list of farms in the four provinces of Banteay Meanchey, Battambang, Pailin, and Pursat in western and northwestern Cambodia bordering with Thailand where the LLIN lending scheme was implemented and where an estimated 100 000 MMPs worked annually. The assessment was carried out from January to February 2013 in these four provinces. It was estimated that 768 workers would be required. Results A total of 702 MMPs were interviewed. The ratio of male: female is 1:1. The age group of 21–60 was the largest accounting for 77.6%. About 91% of the MMPs stayed on the farm for less than 6 months. 93.2% of them owned either untreated or insecticide treated nets. LLINs and LLIHNs accounted for 89.5%; and 46.6% of them borrowed the nets from a lending scheme. Among those workers who have LLINs/LLIHNs, 99% slept under LLINs/LLIHNs the night before. However, only 87.4% knew that sleeping under LLINs/LLIHNs protects against malaria. Conclusions LLIN lending scheme provides an important delivery channel for a substantial percentage of net accessibility (46.6%) to the Cambodian national free-net distribution campaign in remote malaria endemic areas

Feasibility and acceptability of G6PD testing and radical cure for Plasmodium vivax in Cambodia: the VIGTARC study

This study aimed to design, implement and evaluate a new care pathway for P.v. malaria in Pursat province, Cambodia. Patients diagnosed with P.v infection by Village Malaria Workers (VMWs) were referred to local health centres for point-of-care G6PD testing and initiation of radical cure treatment depending on G6PD status. Primaquine was administered as 14 daily doses or 8 weekly doses of primaquine depending on G6PD status, with counselling and community follow-up including directly observed therapy by the VMW. Feasibility and acceptability were evaluated using a mixed methods approach

Correction to: Prevalence of K13 mutation and Day-3 positive parasitaemia in artemisinin-resistant malaria endemic area of Cambodia: a cross-sectional study

After publication of the article [1], it has been brought to our attention that the funding acknowledgements for this article are incomplete. The authors would like to also include the following

Radical cure for Plasmodium vivax malaria after G6PD qualitative testing in four provinces in Cambodia, results from Phase I implementation

Abstract Background Cambodia aims to eliminate all forms of malaria by 2025. In 2020, 90% of all malaria cases were Plasmodium vivax. Thus, preventing P. vivax and relapse malaria is a top priority for elimination. 14-day primaquine, a World Health Organization-recommended radical cure treatment regimen, specifically targets dormant hypnozoites in the liver to prevent relapse. Cambodia introduced P. vivax radical cure with primaquine after glucose-6-phosphate dehydrogenase (G6PD) qualitative testing in 2019. This paper presents Cambodia’s radical cure Phase I implementation results and assesses the safety, effectiveness, and feasibility of the programme prior to nationwide scale up. Methods Phase I implementation was carried out in 88 select health facilities (HFs) across four provinces. Males over 20kgs with confirmed P. vivax or mixed (P. vivax and Plasmodium falciparum) infections were enrolled. A descriptive analysis evaluated the following: successful referral to health facilities, G6PD testing results, and self-reported 14-day treatment adherence. P. vivax incidence was compared before and after radical cure rollout and a controlled interrupted time series analysis compared the estimated relapse rate between implementation and non-implementation provinces before and after radical cure. Results In the 4 provinces from November 2019 to December 2020, 3,239 P. vivax/mixed infections were reported, 1,282 patients underwent G6PD deficiency testing, and 959 patients received radical cure, achieving 29.6% radical cure coverage among all P. vivax/mixed cases and 98.8% coverage among G6PD normal patients. Among those who initiated radical cure, 747 patients (78%) completed treatment. Six patients reported side effects. In implementation provinces, an average 31.8 relapse cases per month were estimated signaling a 90% (286 cases) reduction in relapse compared to what would be expected if radical cure was not implemented. Conclusions Plasmodium vivax radical cure is a crucial tool for malaria elimination in Cambodia. The high coverage of radical cure initiation and adherence among G6PD normal patients demonstrated the high feasibility of providing radical cure at point of care in Cambodia. Incomplete referral from community to HFs and limited capacity of HF staff to conduct G6PD testing in high burden areas led to lower coverage of G6PD testing. Phase I implementation informed approaches to improve referral completion and patient adherence during the nationwide expansion of radical cure in 2021