Pakistan: Officials issue Naegleria fowleri advisory
Pakistan has one of the highest prevalence of Naegleria fowleri infections around the world.
In fact, the first case of Primary amebic meningoencephalitis (PAM) in Pakistan was recorded in Karachi in October 2008. Within a decade of this, the number of cases in Pakistan had overtaken those reported in the USA in a span of 50 years.
From 2008 to 2023, 154 cases were reported in Pakistan.
This has prompted the National Institute of Health (NIH) to issue an advisory concerning this dangerous parasite.
According to advisory, high temperatures associated with poor chlorinated water during early summer pose a risk of Naegleria fowleri infection. “To mitigate the risks associated with the hot season ahead, it is imperative to undertake immediate and long-term preventive measures in mega cities particularly Karachi. Vigilant surveillance is also imperative to pick the suspected cases for early disease confirmation and ensuring aggressive measures to interrupt further transmission,” it stated.
The objective of the advisory is to alert the public health authorities, water and sanitation agencies and other relevant stakeholders to undertake necessary steps for prevention and control of PAM across the country especially in areas where cases are being reported every year.
Naegleria fowleri known more frequently as the “brain-eating ameba,” is a free-living ameba species belonging to the Naegleria genus and it is the only pathogenic species of the genus. It is the causative agent of Primary amebic meningoencephalitis (PAM), an infection that is rare but has a mortality rate of 95–99%.
It is a thermophilic microorganism that flourishes at elevated temperatures of up to 46°C (115°F) and may endure even greater temperatures for brief periods of time. As such, it is found in warm freshwater bodies and soil. Apart from that, it may also be present in swimming pools, splash pads, surf parks, or other recreational venues that are inadequately maintained and insufficiently chlorinated. Its thermophilic nature also explains why it is more likely to cause infection in the summer season.
The ameba can enter the nasal cavity when swimming or diving in contaminated water bodies or as is more commonly seen in Pakistan, irrigating the nose with contaminated water as part of ritual ablution. From here, it makes its way into the brain and starts devouring the brain tissue thus deriving the name “brain-eating ameba”.
PAM is characterized by symptoms that resemble those of bacterial or viral meningitis, such as fever, stiff neck, headache, vomiting, anorexia, and seizures. Fatigue, headaches, nausea, and vomiting are a few of the early signs of the illness. Later, more serious symptoms including confusion, neck stiffness, photophobia, seizures, and cranial nerve abnormalities start to appear. The amount of time between initial contact with the pathogenic N. fowleri strain and the onset of clinical symptoms can range from 2 to 3 days to as long as 7–15 days, depending on the strain's virulence and the size of the inoculums.