The deaths of three people from Naegleria fowleri, known as the “brain-eating amoeba,” this year in Karachi has once again raised concerns over the presence of the deadly microorganism. The incident should prompt health officials to reiterate safety precautions and issue warnings to the public. The latest victim was a 25-year-old young man, a resident of Cattle Colony, who succumbed to the disease while undergoing treatment at the Jinnah Postgraduate Medical Centre (JPMC). He was the third victim of the deadly infection this year in the city. The victim had no history of swimming and presumably contracted the deadly infection through water lacking adequate levels of chlorine. Last year, at least 10 people died of Naegleria fowleri, a rare but highly dangerous microorganism that that causes the brain infection called Primary Amoebic Meningoencephalitis (PAM). The fatality rate is 98 percent. Since 2012, over 100 cases been reported in Karachi. Of them, only one patient survived for three months while another miraculously recovered in 2023. Understanding Naegleria fowleri and the measures to prevent infection is crucial for those who frequent natural water bodies. Naegleria fowleri is a free-living amoeba typically found in warm freshwater bodies such as lakes, rivers, hot springs, and poorly maintained swimming pools. It thrives in temperatures ranging from 250C to 460C, making it suitable for climatic conditions in Karachi. Infection cannot occur from drinking contaminated water and is not transmitted from person to person. Infection occurs when contaminated water enters the nose, allowing the amoeba to travel to the brain via the olfactory nerve. Once in the brain, Naegleria fowleri destroys brain tissue, leading to symptoms such as severe headache, fever, nausea, vomiting, stiff neck, and seizures. The infection progresses rapidly, often resulting in death within five days of symptom onset. It is important to note that infection cannot occur from drinking contaminated water and is not transmitted from person to person. While infections are rare and the fatality rate is high, there are safety measures which can be taken to reduce the risk. It is advisable to avoid freshwater activities in warm weather: Refrain from swimming, diving, or engaging in water sports in warm freshwater bodies, including swimming pools, especially during the hot summer months when water temperatures are high. Ensure that swimming pools are properly maintained and disinfected. Regularly check and maintain the appropriate levels of chlorine and other disinfectants. Take precautions to use sterile water while performing ablution. When swimming or diving in freshwater lakes and rivers, use nose clips to prevent water from entering the nasal passages. Try to keep your head above water to minimize the chance of water entering the nose. If you or someone you know has recently been exposed to warm freshwater and begins to exhibit symptoms such as severe headache, fever, nausea, or stiff neck, seek medical attention immediately. Early diagnosis and treatment are critical, though the prognosis remains poor even with medical intervention. Awareness and adherence to safety measures can help prevent the rare but deadly infection. As temperatures rise and people seek relief in natural water bodies, understanding the risks and taking appropriate precautions are essential steps in safeguarding public health. The writer is a freelance columnist.