Seroepidemiological study of Toxoplasma infection in central and western regions in Nepal.

The present study was carried out to ascertain the seroprevalence rate in different geographical areas in Central and Western Regions in Nepal. A total of 1,237 serum samples collected from Nuwakot (217), Kathmandu valley (402) and Chitawan (159) districts in Central Region, and Mustang (143), Surkhet (64) and Banke (252) districts in Western Region in Nepal were included in this study. Toxoplasma antibodies were detected by micro-latex agglutination (MLA) and enzyme linked immunosorbent assay (IgM-ELISA) methods. The seropositive rate in Central and Western Regions were found to be 48% and 49%, respectively; with an overall positive rate of 48 percent. Districtwise, the seropositive rate in Nuwakot, Kathmandu valley, Chitawan, Mustang, Surkhet and Banke districts were 38, 46, 64, 51, 67 and 44%, respectively. Interestingly, the relatively newly inhabited Surkhet district in Western Region and Chitawan district in Central Region showed significantly higher seropositive rate compared with those of two other districts in the respective Regions (p < 0.05). Ethnically, Tibeto-Burmans showed higher seropositive rates in Central Region (p > 0.05). In contrast, Indo-Aryans showed higher seropositive rate in Western Region (p > 0.05). Age related increase in seropositivity was observed only in Central Region. One percent of Toxoplasma antibody positive samples also showed Toxoplasma IgM antibody positivity.