Pakistan’s major city Karachi was struck by an outbreak of Naegleria fowleri, also known as ‘brain-eating amoeba.’ The deadly freshwater microbe kills 98 percent of those infected. The source of the infection has yet to be identified.
The amoeba is transmitted from contaminated water through the nasal cavity and travels to the brain, causing inflammation. Symptoms are initially mild, including headache, stiff neck, fever and stomach pain, but after five to seven days death is likely, as no treatment for the disease has been developed.
The ongoing outbreak has claimed 10 lives, including two children. The three most recent deaths occurred last week.
Some of the cases may not have been reported since many of the city’s 18 million residents are not familiar with the disease, Dr Musa Khan, head of the WHO's Disease Early Warning System in Pakistan said on Tuesday.
The infection is usually contracted through swimming in contaminated water, but health authorities said that many of the victims of the outbreak were not swimmers.
“The three people who died in September had not been to a swimming pool. It is a serious cause for concern that people are contracting the infection by using tap water,” Health Minister Dr Sagheer Ahmed said at a press conference on Monday.
Pakistani authorities launched a public awareness campaign to inform people about precautionary measures, and to avoid sparking panic.
The city’s water supplier, the Karachi Water and Sewerage Board, announced that it increased chlorine levels at its treatment facility. The company is also taking water samples in different parts of the city in hopes of locating the source of the infection.
Naegleria fowleri can only be detected by a microscopic study of the cerebrospinal fluid, which makes it impossible to test water for contamination.
Another possible source of the outbreak is the water in mosques for Muslim ablution rituals. Most mosques use underground aquifers.
The infection first surfaced in Karachi in 2006, but was not heard of again until now.