Pak study may help Kerala docs treat 3-month-old amoebic encephalitis patient

Kerala epidemiologists probing the amoebic encephalitis infection in a three-month-old infant in Kozhikode have reasons to consider other sources of infection than water bodies. It is the youngest case of PAM (primary amoebic meningoencephalitis) recorded in the state so far. In 2024, a three-year-old child from Palakkad was diagnosed with the disease. The Health Department has recorded 45 cases between 2016 and 2024 and Naegleria fowleri was the dominant causative agent. In three cases, the diagnosis was traced to Vermamoeba Vermicularis and Acanthamoeba, other genera of the free-living amoebae.

Kerala now has 18 active cases across various districts, including Thiruvananthapuram, Kollam, Kozhikode, Wayanad and Malappuram. The source of infection in several cases was exposure to contaminated water, mostly in ponds, swimming pools and water bodies with the presence of amoebae. N fowleri enters the body through the nose during swimming or bathing in water bodies, and it moves up the nose to the brain, where it results in infection. Given the infant's negligible exposure to natural water sources, the health team sought a source of infection through the well or other means.

The samples of well water returned positive for one genus of amoeba. However, the examination of the baby's cerebrospinal fluid (CSF) led to the detection of another type. Considering the nature of cases in other countries, especially Pakistan, the team also probed chances of nasal rinsing. It has been learnt that the child's nasal rinsing was done with holy water. 

Preliminary examination of this water sample has revealed the presence of trophozoite, a temporary flagellar stage of amoeba known as an amebo-flagellate. Due to inadequate samples, further tests could not be conducted to identify the exact genus. The infant was taken to a private hospital with fever and seizure on August 3 and was then shifted to Kozhikode Medical College Hospital, where the baby has been put on a ventilator.

A research paper jointly published by Pakistan-based medical colleges and medical universities and the University of Cambridge shows that in the cases of amoebic infection reported in Karachi in the past 14 years, only two cases were linked to recreational water activities and the vast majority of cases were not directly related to water bodies. The infection has been linked to nasal rinsing and other nasal moistening methods, such as sinus cleaning, which may also contribute to infection, the study report notes.

"Without a PCR or sequencing, there is no way to get conclusive proof of the amoeba that caused infection in the infant. We know that the well water and the holy water to which the child was exposed have the presence of amoeba. The treatment is same irrespective of exact type of the microorganism. What is important is that there needs to be a sense of awareness against nasal rinsing with water that may be contaminated," senior officials with the health department who are investigating PAM cases said. Infectious disease specialists in Kerala have taken note of this practice and have inserted a word of caution in the guidelines published by the department. Nasal rinsing should only be carried out with water that is sterile, distilled, or filtered, the note says.

The infant has been immunosuppressed and prone to disease. "The holy water may get contaminated after being stored for a period of time, this necessitates extreme caution while using the water," a doctor associated with the investigation said. The Directorate of Health Services is mulling a sensitisation campaign in the wake of possible infection via other sources apart from water bodies.

As per the available medical literature, PAM was diagnosed in babies in Haryana, Allahabad and Karnataka. In Haryana, an eight-month-old girl child was infected in 2018. The patient had no history of exposure to contaminated water such as ponds, lakes, etc., and was too young to swim; thus, the exact source of infection could not be pointed out. 

An eight-month-old baby boy was diagnosed with N fowleri infection in Allahabad in 2007. The source was also not identified in the case of a five-month-old infant in Karnataka in 2011.

A newborn with brain-eating amoeba infection was reported in Turkey in 2020, which is believed to be the youngest case of PAM in the world. The child was admitted with destructive clinical features of PAM after having been bathed with water from an unchlorinated well on a summer day, according to a research paper published by the Department of Paediatrics, Mersin University School of Medicine, Mersin.