Ce que vous devez savoir sur les amoebas " mangeuses de cerveau "

Authorities in Mexico’s Yucatán state have closed six artificial lakes after detecting the presence of Naegleria fowleri, a rare but often deadly amoeba known as the “brain-eating” amoeba. The closures were announced following the death of a 34-year-old man who worked as a waterski instructor at one of the affected lakes. He died in September from an infection caused by the amoeba, which led to a severe brain inflammation. All six impacted lakes are used for recreational activities such as waterskiing, kayaking, and stand-up paddling. The health ministry of Yucatán confirmed that tests conducted on nine lakes in the city of Mérida found the amoeba in six of them. The infected lakes are located in luxury residential areas and shopping centers. This marks the first recorded death linked to Naegleria fowleri in the state, according to local officials. While the closure applies specifically to these artificial lakes, authorities have not imposed restrictions on natural water bodies such as cenotes, natural freshwater pools formed in limestone sinkholes, which are popular attractions in the region. The amoeba thrives in warm freshwater environments, typically in temperatures ranging from 30°C to 46°C. According to the U.S. Centers for Disease Control and Prevention (CDC), infections with Naegleria fowleri are extremely rare, yet almost always fatal. Out of approximately ten annual cases in the United States, 97 percent result in death. The infection occurs when contaminated water enters the body through the nose, allowing the amoeba to travel along the olfactory nerve into the brain, causing a hemorrhagic necrotizing meningitis that destroys brain tissue. Alberto Alcocer, Yucatán’s health secretary, emphasized that finding the amoeba in the environment does not indicate an epidemic or that visitors to the area are sick. He urged anyone potentially exposed to seek medical attention promptly. The infection can occur during swimming, diving, or nasal irrigation with contaminated water, but not through drinking contaminated water or airborne transmission. The closure of the lakes follows increased concerns over the spread of Naegleria fowleri, particularly due to climate change. Rising global temperatures could expand the amoeba’s habitat, increasing the risk of infection in regions previously unaffected. The CDC has noted that cases are no longer limited to southern states in the U.S., with reports emerging from northern states as well. Health officials in Yucatán have pledged to monitor the water quality of cenotes more strictly, given their popularity among tourists. The state is a major destination for international travelers, including Germans and Swiss, drawn by its beaches, Mayan ruins, and cenotes. However, the current measures focus solely on the artificial lakes, leaving natural water bodies untouched. Treatment for primary amoebic meningoencephalitis (PAM), the condition caused by Naegleria fowleri, involves a combination of antibiotics and antifungal drugs. Medications such as rifampin, amphotericin B, and miltefosin, originally developed for breast cancer treatment, have shown promise in treating survivors. Despite these treatments, the rarity of the disease makes research and effective therapies challenging. Authorities continue to investigate the circumstances surrounding the initial case, including the maintenance and water quality control practices at the first contaminated lake. As of now, no further deaths have been reported, and the situation remains under close watch.