Why are 'brain-eating amoeba' cases increasing? Experts issue warning on warm water and nasal irrigation

More commonly known as the "brain-eating amoeba", Naegleria fowleriis an organism that can be found in warm freshwater and can cause severe infection by reaching the brain when it enters the body through the nose. Although the number of cases remains very low, experts say that infections reported in different regions in recent years should be monitored carefully.

Jordan, the 11-year-old son of Steve Smelski from the US state of Florida, passed away days after swimming in a natural hot spring during a vacation in Costa Rica in 2014. The process, which began with headaches and vomiting, progressed to hallucinations and seizures; by the time doctors confirmed the illness, the infection had caused severe damage to the brain.

The cause of Jordan's death was recorded as primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri. Diagnosis can be delayed because this condition may resemble meningitis symptoms in the initial stages. Describing his son's illness, Smelski highlighted the speed of the process, saying, "He had no problems before this. He was completely healthy."

WHY ARE CASES APPEARING IN NEW REGIONS?

The report of more than 200 Naegleria fowleri infections in India in 2025 was considered the largest outbreak recorded worldwide. While it was previously stated that the total number of cases globally was under 500, the continued emergence of new cases in India in recent months has increased the interest of researchers.

According to a review published in the Journal of Infection and Public Health, 488 cases were reported worldwide between 1962 and 2023, and approximately 97 percent of these individuals lost their lives. While cases were long associated primarily with the southern US states, Pakistan, and Australia, infections have also been recorded in Italy, Belgium, Slovakia, and the cooler northern states of the US over the last 20 years.

According to experts, climate change may be paving the way for the amoeba to appear in areas where it could not previously survive by increasing water temperatures in lakes and ponds. Dr. Anastasios Tsaousis, a molecular parasitology expert at the University of Kent, states that "as the water warms, the amoeba becomes more active," noting that the risk of contact during recreational water activities may increase.

However, experts also emphasize that the increase in cases may not be explained solely by environmental conditions. Increased testing capacity and greater awareness among healthcare workers may have contributed to making previously undetected infections more visible.

RISK FOR CHILDREN AND WARM FRESHWATER

Scientists state that children may be at higher risk due to their behavior of playing in warm water and diving. Prof. Ian Wright, a water science expert at Western Sydney University, states that while the probability of contracting the disease is very low, the risk of death is very high once the infection develops.

Nevertheless, the recent outbreak in the Indian state of Kerala has called into question some long-held assumptions about the treatability of the disease. According to research published in the journal Communications Medicine, more than half of the 200 patients with known outcomes survived. Researchers believe that early diagnosis, increased awareness among healthcare workers, and more standardized treatment protocols may have been effective in this result.

WHAT CAN BE DONE TO REDUCE THE RISK?

Naegleria fowleri usually enters the body through the nose while swimming in warm freshwater. For this reason, experts recommend closing the nose, using a nose clip, or avoiding putting the head underwater when swimming in warm lakes, streams, hot springs, or similar environments. In the words of Wright, "If in doubt, keep your head above water."

The risk is not limited to swimming. Nasal irrigation systems can also cause the amoeba to enter the body through the nose if non-sterile water is used. The US Centers for Disease Control and Prevention (CDC) recommends using sterile, distilled, or previously boiled and cooled water for nasal irrigation.

Experts emphasize that the overall risk is low and there is no need for panic. However, they note that symptoms can progress rapidly during periods of increased contact with warm freshwater, and medical help should be sought without delay for complaints such as headache, fever, nausea, vomiting, stiff neck, confusion, seizures, and hallucinations.