Evaluating the Drinking Water Distribution System of Lahore for Free-Living Amoebas, Particularly Naegleria spp

Free-living amoebas are ubiquitous in distribution systems and recreational waters. Numerous studies have described the problem posed by their presence in the drinking water distribution systems of Lahore; however, very few studies have been done on Naegleria spp., particularly Naegleria fowleri that causes primary amoebic meningoencephalitis. In this study, we aimed to screen for the free-living amoebas in 100 water samples from nine zones in Lahore. These samples included water from mosques (n = 45), homes (n = 45), swimming pools (n = 10), and the Lahore canal. Cysts (3-4 μm) and rounded trophozoites (4-5 μm) along with elongated trophozoites (8-10 μm) were observed to be present in 37 (82.2%) water samples from mosques. In water from homes, we detected rounded trophozoites (5 μm) and elongated trophozoites (10 μm) from the Lahore canal. There was also a positive association with temperature (odds ratio 20.329, 95% CL) and a trend of negative association with pH (odds ratio 2.001, 95% CL). PCR amplification confirmed the presence of Naegleria spp. in three zones: Lahore canal and swimming pools. Our study indicates the presence of Naegleria spp. in drinking water distribution systems of Lahore; therefore, we recommend a routine screening for N. fowleri in order to reduce the risk of acquiring the fatal primary amoebic meningoencephalitis infection.