Amoebic meningoencephalitis in Kerala: Insights for strengthening global health preparedness
Sijo Asokan, Avinash Choudekar, V Makeshkumar, Rudresh SM, Rand Kamil Abbas, Zahraa Sadoon Hadi, Smitha Vijayan, Mostafa Mohammed Atiyah, Divya Rajeswary, Tijo Cherian
Abstract
Free-living amoebic meningoencephalitis (FLAM) is a rare but often fatal central nervous system infection caused by Naegleria fowleri , Acanthamoeba spp., and Balamuthia mandrillaris , with mortality exceeding 90% globally. This review integrates current understanding of their biology, epidemiology, clinical features, diagnostics, and treatment strategies, with a focus on the recent Kerala outbreaks (2024–2025) that involved nearly 80 cases and high mortality. Rising water temperatures, inadequate chlorination, and high-risk behaviors such as swimming in untreated freshwater and nasal irrigation with non-sterile water contribute to pathogen proliferation. Molecular diagnostics, including PCR and metagenomic sequencing, have improved detection but remain limited in endemic regions. Current therapy relies on empirical multidrug regimens typically amphotericin B, azoles, rifampin, azithromycin, and miltefosine with survival achieved only through rapid intervention. The Kerala experience underscores that early recognition, strengthened diagnostics, and prompt combination therapy can improve outcomes, serving as a model for resource-limited settings. Persistent challenges include underreporting, lack of standardized surveillance, limited rapid diagnostics, and absence of specific anti-amoebic agents. Enhanced awareness, environmental monitoring, and global research collaboration are urgently needed to mitigate the burden of these devastating infections. • Kerala reported the largest-ever outbreak of amoebic meningoencephalitis (2024–2025). • Rapid PCR-based diagnosis improved early case detection and treatment initiation. • Aggressive multidrug therapy, including miltefosine, reduced case-fatality to ~75%. • Climate change and poor water chlorination expanded amoebic reservoirs in Kerala. • Kerala’s response provides a One Health model for global outbreak preparedness.