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

• Main Authors: Srean Chhim, Patrice Piola, Tambri Housen, Vincent Herbreteau, Bunkea Tol
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: malaria; surveillance; spatial analysis; cluster; epidemiology; GIS
• Online Access: https://www.mdpi.com/1660-4601/18/4/1960
• ISSN: 1661-7827; 1660-4601

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 <i>Plasmodium (P.) falciparum</i> + <i>Mixed</i> among confirmed cases declined from 87.9% (<i>n</i> = 67,489) in 2006 to 16.6% (<i>n</i> = 5290) in 2019. Clusters of <i>P. falciparum</i> + <i>Mixed</i> and <i>P. vivax + Mixed</i> were detected in forested provinces along all national borders. Conclusions: There has been a noted decrease in <i>P. falciparum</i> cases in 2019, suggesting that an intensification plan should be maintained. A decline in <i>P. vivax</i> cases was also noted, although less pronounced. Interventions aimed at preventing new infections of <i>P. vivax</i> and relapses should be prioritized. All detected malaria cases should be captured by the national surveillance system to avoid misleading trends.