Kerala is facing a concerning outbreak of amoebic meningoencephalitis, a rare but severe brain infection. State Health Minister Veena George has reported that a total of 104 cases have been recorded, with 23 fatalities. The most affected districts appear to be Kollam and Thiruvananthapuram, with rising cases also noted in Kozhikode and Malappuram.
Amoebic meningoencephalitis is caused by free-living amoebae, including Naegleria fowleri, Acanthamoeba, Sappinia, Balamuthia, and Vermamoeba. Naegleria fowleri, often referred to as the "brain-eating amoeba," is a primary cause of the disease. The infection occurs when amoebae enter the brain, typically through the nasal passages while swimming or diving in contaminated water. It does not spread from person to person.
Health Minister Veena George has addressed the situation, attributing the increased reporting of cases to the state's proactive approach to investigating all encephalitis cases since 2023. This has led to the development of local testing facilities, including PCR tests, in microbiology labs across the region. Technical guidelines were issued in 2024, emphasizing early detection, treatment, and preventive measures such as water source chlorination.
In response to the outbreak, the Health Department has formulated an action plan based on the One Health principle, aiming to raise awareness and involve local bodies and other departments in cleaning and maintaining water bodies throughout the state. Public awareness campaigns are underway, urging caution against swimming in freshwater sources. People are advised to avoid swimming or bathing in untreated or stagnant freshwater sources like ponds and lakes. The state government has asked people to seek immediate medical attention if they experience symptoms similar to a PAM infection after exposure to stagnant water.
Health officials suspect that rising pollution levels in Kerala's water bodies and increasing ambient temperatures could contribute to higher amoebic concentrations, leading to a greater incidence of amoebic meningoencephalitis. Samples of water from household wells, storage tanks, piped water, public wells, ponds, and swimming pools used by affected individuals have tested positive for the presence of amoebae. The species identified include Balamuthia mandrillaris, Vermamoeba vermiformis, Paravahikampfika Francinae, and Acanthamoeba.
While the global mortality rate for PAM is around 97%, Kerala has managed to reduce it to about 25% due to early detection and treatment efforts. Until early 2023, only an average of 3.7 cases were reported worldwide every year. In 2024, 36 cases were found in Kerala. The health minister also clarified that the cases are not clustered around a single water source, which has complicated epidemiological investigations.
