Malaria in Cambodia: A Retrospective Analysis of a Changing Epidemiology 2006–2019

Abstract

Background: In Cambodia, malaria persists with changing epidemiology and resistance to antimalarials. This study aimed to describe how malaria has evolved spatially from 2006 to 2019 in Cambodia. Methods: We undertook a secondary analysis of existing malaria data from all government healthcare facilities in Cambodia. The epidemiology of malaria was described by sex, age, seasonality, and species. Spatial clusters at the district level were identified with a Poisson model. Results: Overall, incidence decreased from 7.4 cases/1000 population in 2006 to 1.9 in 2019. The decrease has been drastic for females, from 6.7 to 0.6/1000. Adults aged 15–49 years had the highest malaria incidence among all age groups. The proportion of Plasmodium (P.) falciparum + Mixed among confirmed cases declined from 87.9% (n = 67,489) in 2006 to 16.6% (n = 5290) in 2019. Clusters of P. falciparum + Mixed and P. vivax + Mixed were detected in forested provinces along all national borders. Conclusions: There has been a noted decrease in P. falciparum cases in 2019, suggesting that an intensification plan should be maintained. A decline in P. vivax cases was also noted, although less pronounced. Interventions aimed at preventing new infections of P. vivax and relapses should be prioritized. All detected malaria cases should be captured by the national surveillance system to avoid misleading trends.

Barriers to integrating diagnostic services for febrile illness to support surveillance and patient management in Asia‐Pacific

“…About 70% of malaria control funding in Cambodia was from the Global Fund. When funding was halted between 2015 and 2016 due to accountability concerns, core malaria activities were disrupted (Chhim et al., 2021).…”

“…Both countries aim to integrate dedicated malaria services into the wider healthcare landscape to make them sustainable and keep the momentum towards malaria elimination (Lao Ministry of Health, 2016; National Center for Parasitology, Entomology and Malaria Control, 2011; WHO, 2015c). However, this strategy has not been successful, partly due to the nature of funding and malaria prevalence among mobile populations (Chhim et al., 2021; Kounnavong et al., 2017).…”

The use of respondent‑driven sampling to assess febrile illness treatment-seeking behaviours among forest-goers in Cambodia and Vietnam

“…The initial bias created by the non-probability-based selection is addressed using mathematical modelling that allows for inferences to be made about the sampled population [ 18 – 21 ]. Data collection was conducted during high malaria season [ 22 , 23 ], between 20 and 24 October in Cambodia and between 15 and 26 September in Vietnam.…”

Case Report: Cambodian National Malaria Surveillance Program Detection of Plasmodium knowlesi

“… 9 National surveillance of malaria in Cambodia is conducted by the National Center for Parasitology, Entomology, and Malaria Control, a central entity that collates data submitted by regional government-run healthcare facilities on monthly malaria cases. 10 Cases are diagnosed by rapid diagnostic tests or blood microscopy, with a subset undergoing polymerase chain reaction (PCR) testing to confirm species classification ( P. falciparum, P. vivax, P. ovale, and P. malariae). In the absence of routine national surveillance for P. knowlesi species, the true prevalence of disease in Cambodia remains unknown.…”