The brain-eating amoeba, Naegleria fowleri, which claimed 16 lives in Karachi last year, might be a strain unique to Pakistan, according to a recent study by researchers in Rawalpindi.
This is because most of the cases reported in Pakistan were in adults between the ages of 26-45 years, while those reported in the US were mostly children younger than 14 years.
“Of all the reported cases of [primary amoebic meningoencephalitis] PAM in Pakistan, all were in Muslims and only two individuals had a history of recreational water activity,” said the article, which was published in The Lancet Journal of Infectious Diseases in January.
“Therefore, it can be inferred that Naegleria fowleri exists in the domestic water supply of Karachi and that infection largely results from ablution, which is unexpected because water is normally saline in Karachi city, and amoebas are unable to survive in saline water.”
The authors say this suggests that the Naegleria fowleri strain present in Pakistan has developed resistance to saline environments or that it is different from strains reported from the rest of the world.
Till October last year, 146 cases have been reported from Pakistan. In only a decade, the number of cases in the country surpassed those reported over 50 years in the US, which recorded 142 cases between 1968 and 2019, said the paper, citing the US Centres for Disease Control and Prevention.
In Pakistan, the first case of infection by Naegleria fowleri was reported in 2008.
The paper goes on to say that prolonged summers and humid conditions due to climate change will provide an ideal environment for the amoeba to flourish.
There is a need to map the whole genome of Naegleria fowleri to figure out the resistant strain in Pakistan and help in diagnosis and early disease prevention, the authors concluded.