Patient lands in West Bengal hospital with ‘brain-eating’ amoeba

KOLKATA: A 40-year-old man is battling ‘brain-eating’ amoeba at the state-run Institute of Postgraduate Medical Education & Research (IPGMER). The mortality rate of those afflicted with this rare infection, which is medically called primary amoebic meningoencephalitis (PAM), is as high as 90%. The patient from Howrah is in a critical condition.

Caused by Naegleria fowleri, a free living amoeba found in contaminated water, the organism enters the human body through the nasal passage and destroys the central nervous system within a short span of time. It is called a ‘brain- eating’ amoeba as it uses the brain as its source of food. Only a handful of PAM cases have been reported in India, mostly from the southern states.

The patient from Bagnan was brought to IPGMER last Saturday with acute encephalitis syndrome that included sudden onset of unconsciousness, disorientation, convulsion and fever. An analysis of the patient’s cerebrospinal fluid confirmed the presence of the amoeba.

“This type of amoeba enters a person through the nose via contaminated water. The amoeba then travels to the brain, causing massive damage to it and the entire central nervous system. While the immunocompromised are more vulnerable, this patient is immunocompetent with no known comorbidity. According to his family members, he has no history of bathing in a pond or going to a swimming pool. We are still unable to figure out how he contracted the infection,” said professor of internal medicine Alakes Kumar Kole, who is treating the patient.

Experts said that Naegleria fowleri is a single-celled living organism that lives in fresh and warm water bodies like ponds, lakes, rivers and even swimming pools that are not sufficiently chlorinated.

The disease was first reported in Australia in 1965. Sources said in Kolkata, the first reported case was in 2015, when a 15-year-old boy died 15 days after the diagnosis. Even as the disease has remained elusive and rare for years, the state-run medical college has come across about nine such cases in one year.

“We got two cases of PAM in the past six months. While we lost one, another is still under treatment. None of the patients has a history of frequenting water bodies. That makes us wonder why there is a surge in the number of this rare condition post the pandemic. Has Covid-19 changed the immunity pattern?” said Atanu Biswas, head of the department at Bangur Institute of Neurosciences at IPGMER.

Doctors who have dealt with the PAM cases are analysing all the cases to find an answer to the clustering of cases. Sources said the School of Tropical Medicine also got two PAM cases in mid-2023.

“In cases of meningoencephalitis, we have to look for this organism so that PAM cases are not missed out. Early detection is important in the face of high mortality,” added Kole. The incubation period takes about two to 15 days after exposure to the amoeba for symptoms to appear.