Context:
In recent times, Amoebic meningoencephalitis has emerged as a serious but under-recognised public health threat in India, particularly highlighted by the recent surge in Kerala, which reported 133 infections and 33 deaths in the first five months of 2026..
About Amoebic Meningoencephalitis:
Amoebic Meningoencephalitis (AME) is a rare but highly fatal infection of the central nervous system caused by free-living amoebae found in warm freshwater and soil. These organisms enter the human body accidentally and lead to severe inflammation and destruction of brain tissue. AME is not spread from person to person and is primarily an environmental infection.
Types of Amoebic Meningoencephalitis:
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- Primary Amoebic Meningoencephalitis (PAM)
- Primary Amoebic Meningoencephalitis (PAM) is caused by the amoeba Naegleria fowleri. It is an acute, rapidly progressing infection that typically affects healthy individuals. Infection occurs when contaminated warm freshwater enters the nasal passages during swimming, diving, or bathing. The organism travels through the olfactory nerve to the brain, causing severe and often fatal meningoencephalitis within days.
- Primary Amoebic Meningoencephalitis (PAM) is caused by the amoeba Naegleria fowleri. It is an acute, rapidly progressing infection that typically affects healthy individuals. Infection occurs when contaminated warm freshwater enters the nasal passages during swimming, diving, or bathing. The organism travels through the olfactory nerve to the brain, causing severe and often fatal meningoencephalitis within days.
- Granulomatous Amoebic Encephalitis (GAE):
- Granulomatous Amoebic Encephalitis (GAE) is caused mainly by Acanthamoeba infection and Balamuthia mandrillaris infection. Unlike PAM, GAE is a subacute to chronic infection that develops over weeks to months. It often affects immunocompromised individuals but can also occur in healthy people. The amoebae may enter through the respiratory tract or broken skin and spread via the bloodstream to the brain.
- Importantly, infection does not occur through drinking contaminated water and there is no evidence of transmission through air, vapour, or aerosol droplets.
- Granulomatous Amoebic Encephalitis (GAE) is caused mainly by Acanthamoeba infection and Balamuthia mandrillaris infection. Unlike PAM, GAE is a subacute to chronic infection that develops over weeks to months. It often affects immunocompromised individuals but can also occur in healthy people. The amoebae may enter through the respiratory tract or broken skin and spread via the bloodstream to the brain.
- Primary Amoebic Meningoencephalitis (PAM)
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Conclusion:
The rising cases of AME highlights the need for improved water safety, early diagnosis, and clinical awareness. Climate change, warm freshwater exposure, and better detection are contributing to increased reporting. Strengthening surveillance and public education is crucial to reduce fatalities associated with these infections.
