Malaria risk factors amongst forest going populations in Mondulkiri Province and Kampong Speu Province, Cambodia: a large cross-sectional survey.

Background: Cambodia strives to eliminate all species of human malaria by 2025, requiring that foci among forest-exposed populations in remote settings be addressed. This study explores malaria risk factors amongst forest-exposed groups in Mondulkiri and Kampong Speu Provinces, Cambodia as part of a multi-stage study on novel bite prevention tools (Project BITE).

Methods: A serial cross-sectional survey explored the demographics, housing structure openness, mosquito bite prevention habits, and gaps in protection amongst three target groups: forest goers who work in the forest, forest dwellers who live in the forest, and forest rangers who patrol forested regions.

Applying the COM-B behavior model to inform the delivery of spatial repellents and insecticide-treated clothing among forest exposed populations in Mondulkiri Province, Cambodia.

Background: Southeast Asia is making tremendous progress towards their 2030 malaria elimination goal but needs new interventions to stop forest malaria. This study trials two new vector control tools, a volatile pyrethroid spatial repellent (VSPR) and insecticide-treated clothing (ITC), amongst forest-exposed populations in Mondulkiri Province Cambodia to inform their potential use for eliminating forest malaria.

Methods: 21 forest-exposed individuals were given a questionnaire on their perceptions of malaria and preventive practices used, after which they trialed two products sequentially.

Malaria Control by Mass Drug Administration With Artemisinin Plus Piperaquine on Grande Comore Island, Union of Comoros.

Background: Mass drug administration (MDA) is a powerful tool for malaria control, but the medicines to use, dosing, number of rounds, and potential selection of drug resistance remain open questions.

Methods: Two monthly rounds of artemisinin-piperaquine (AP), each comprising 2 daily doses, were administered across the 7 districts of Grande Comore Island. In 3 districts, low-dose primaquine (PMQ) was also given on the first day of each monthly round.

Artemisinin-piperaquine versus artemether-lumefantrine for treatment of uncomplicated Plasmodium falciparum malaria in Grande Comore island: an open-label, non-randomised controlled trial.

Background: Malaria significantly rebounded in 2018 in the Comoros; this created an urgent need to conduct clinical trials to investigate the effectiveness of artemisinin and its derivatives.

Methods: An open-label, non-randomised controlled trial of artemisinin-piperaquine (AP) and artemether-lumefantrine (AL) was conducted in Grande Comore island from June 2019 to January 2020. A total of 238 uncomplicated falciparum malaria cases were enrolled and divided 1:1 into two treatments.

Smartphones for community health in rural Cambodia: A feasibility study.

Village Malaria Workers (VMWs) are lay people trained to provide a valuable role in frontline testing and treatment of malaria in rural villages in Cambodia. Emergence of artemisinin-resistant malaria highlights the essential role of such VMWs in surveillance and early treatment of malaria. Smartphone technology offers huge potential to support VMWs in isolated and resource-poor settings.

Microscopic Plasmodium falciparum Gametocytemia and Infectivity to Mosquitoes in Cambodia.

Although gametocytes are essential for malaria transmission, in Africa many falciparum-infected persons without smear-detectable gametocytes still infect mosquitoes. To see whether the same is true in Southeast Asia, we determined the infectiousness of 119 falciparum-infected Cambodian adults to Anopheles dirus mosquitoes by membrane feeding. Just 5.

Assessing the impact of next-generation rapid diagnostic tests on Plasmodium falciparum malaria elimination strategies.

Mass-screen-and-treat and targeted mass-drug-administration strategies are being considered as a means to interrupt transmission of Plasmodium falciparum malaria. However, the effectiveness of such strategies will depend on the extent to which current and future diagnostics are able to detect those individuals who are infectious to mosquitoes. We estimate the relationship between parasite density and onward infectivity using sensitive quantitative parasite diagnostics and mosquito feeding assays from Burkina Faso.

Defining the in vivo phenotype of artemisinin-resistant falciparum malaria: a modelling approach.

Background: Artemisinin-resistant falciparum malaria has emerged in Southeast Asia, posing a major threat to malaria control. It is characterised by delayed asexual-stage parasite clearance, which is the reference comparator for the molecular marker 'Kelch 13' and in vitro sensitivity tests. However, current cut-off values denoting slow clearance based on the proportion of individuals remaining parasitaemic on the third day of treatment ('day-3'), or on peripheral blood parasite half-life, are not well supported.

Differing patterns of selection and geospatial genetic diversity within two leading Plasmodium vivax candidate vaccine antigens.

Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1) and Plasmodium vivax circumsporozoite protein (pvcsp). Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44) and the complete gene of pvcsp (n = 47) from Cambodian isolates.

Zoonotic trematode metacercariae in fish from Phnom Penh and Pursat, Cambodia.

A survey was performed to investigate the infection status of freshwater fish with zoonotic trematode metacercariae in Phnom Penh and Pursat Province, Cambodia. All collected fish with ice were transferred to our laboratory and examined using the artificial digestion method. In fish from Phnom Penh, 2 kinds of metacercariae (Opisthorchis viverrini and Haplorchis yokogawai) were detected.

Pyronaridine-artesunate versus chloroquine in patients with acute Plasmodium vivax malaria: a randomized, double-blind, non-inferiority trial.

Background: New antimalarials are needed for P. vivax and P. falciparum malaria.

Efficacy of Bacillus thuringiensis israelensis, VectoBac WG and DT, formulations against dengue mosquito vectors in cement potable water jars in Cambodia.

This study reports the evaluation of Bacillus thuringiensis israelensis (Bti), a biological larvicide, in cement jars holding river, well and rain water. Two Bti formulations, VectoBac WG and VectoBac DT, were evaluated in a village in Phnom Penh. Thirty-one households with cement jars supporting the colonization of Ae.

Intestinal parasites in school-aged children in villages bordering Tonle Sap Lake, Cambodia.

The objective of this study was to study Schistosoma mekongi and other intestinal parasitic infections, and intestinal symptoms and related complaints among school-age children and adolescents living around Tonle Sap Lake. Villages were selected where there were potential signs of schistosomiasis (hepatomegaly), and where subjects complained of intestinal symptoms. Stool samples were collected from 1,616 children and were examined by Kato-Katz, SAF concentration, and Baermann technique; short clinical examinations were also performed.

Glucose-6-phosphate dehydrogenase (G6PD) mutations in Cambodia: G6PD Viangchan (871G>A) is the most common variant in the Cambodian population.

We conducted a survey of malaria diagnoses and glucose-6-phosphate dehydrogenase (G6PD) testing in remote areas of Cambodia. Blood specimens from 670 people were collected by the finger-prick method. Of these people, 24.

Financial costs of deworming children in all primary schools in Cambodia.

In 2002, Cambodia's Ministry of Health launched a deworming programme to deliver an anthelmintic drug (mebendazole 500 mg) and health education to 75% of its school children twice a year. Cambodia's school population is approximately 2.8 million.