Re-emergence of malaria in Karen State, Myanmar: has the battle of Burma been lost?

Abstract

Background: Historically malaria has been a major cause of morbidity and mortality in the Greater Mekong Sub-region. In recent years, significant progress towards malaria elimination has been made. Myanmar harbours most of the region’s malaria burden, however after initial progress during peace time, the civil war and the COVID-19 pandemic have coincided with a resurgence of malaria. This observational study examines the resurgence of malaria in Eastern Myanmar and its contributory factors. Methods and results: Malariometric and genomic data from a long-established network of malaria clinics and village health workers in eastern Karen State serving an estimated population of 350,000 were reviewed and analysed in the context of the COVID-19 pandemic and the military coup that followed. Data from 2020 and 2024 show that the number of cases of P. falciparum malaria increased 12-fold and those of P. vivax malaria increased threefold. This resurgence was greatest in the northern parts of Karen State and coincided with reduced access to timely diagnosis and treatment. This was associated with increased malaria transmission of P. falciparum (RR = 1.72, 95% CI 1.68–1.76) and P. vivax (RR = 1.82, 95% CI 1.80–1.84). Reported malaria-related deaths remained low during the study period though underreporting cannot be excluded. Conclusion: Our study provides evidence that the disruption of services (early diagnosis and treatment) caused by the COVID-19 pandemic followed by insecurity, explains the resurgence of malaria in Karen State in Myanmar. Population movements and the clonal expansion of a specific parasite lineage were likely contributing factors. However, the decline recorded in 2024 in the number of cases and the near absence of malaria mortality showed that despite the difficulties, the malaria control system has been successful in containing the crisis. The battle for malaria control in Burma has not been lost, but the future remains uncertain.