Transmission characteristics
With a population of 16.2 million, around 9.3 million are at risk of malaria. There were 4,047 reported malaria cases (vivax, falciparum, and mixed) in 2022.1 88% of cases were due to P. vivax (3,577/4.047). Malaria is endemic in 21 out of Cambodia’s 25 provinces, though the transmission characteristics are highly variable. Malaria incidence is highest in the Northeast and lowest in the Western provinces.1 The peak transmission season is between July and November, coinciding with the transition from the hot to the rainy season.1
Malaria predominantly affects males 15–49 years of age, many of whom are mobile workers moving between areas of low and high malaria transmission. These workers often have poor access to healthcare.1
Surveillance
Cambodia relies on the Health Management Information System (HMIS) to collect data from district and provincial hospitals throughout the country. In addition, a parallel malaria information system developed on an Access ® platform has been used to capture malaria caseload data from community level, health centres and some private providers.1 Malaria surveillance requires strengthening, particularly for case follow-up and investigation. Until recently, a large proportion of patients used the private sector in Cambodia, however, this was recently shutdown and banned by the Ministry of Health.2
2020 milestones/ malaria elimination
Between 2015 and 2017, malaria deaths increased from 235 to 335, an increase of 47%. though over the period 2010–2017, malaria deaths have decreased by 63% (901 to 335).3
Based on trends over in most recent years, Cambodia is on track for a 20–40% reduction in malaria case incidence by 2020 (falciparum and vivax). However, cases increased for both vivax and falciparum in 2017 versus 2016.3
Cambodia is included in the Mekong Malaria Elimination (MME) Initiative in the Greater Mekong subregion, supported through a Global Fund financed regional artemisinin-resistance initiative, which aims to eliminate P. falciparum by 2025 and all species of malaria by 2030.3
The National Strategic Plan for Elimination of Malaria aims to move step by step toward elimination of malaria across Cambodia with an initial focus on P. falciparum malaria elimination by 2020 before achieving elimination of all forms of malaria, including P. vivax in 2025.3
Treatment policy for P. vivax
- Artemisinin-based combination therapy – dihydroartemisinin-piperaquine or mefloquine-artesunate (depending on susceptibility to P. falciparum in the region).4
- Primaquine 0.25 mg/kg/day for 14 days following a negative G6PD test.3
- Diagnosis and treatment is free of charge in the public sector.3
G6PD testing policy
G6PD testing before treatment with primaquine is required, though according to anecdotal reports, is rarely implemented.
G6PD deficiency prevalence
The prevalence rate for G6DP deficiency in Cambodia varies between about 13% to 26% in males and 3% and 4% in females, depending on the sampled population. The severe G6PD-deficient variant, G6PD Viangchan (871G>A), predominates in Cambodia.