Epidemiology of Brugia malayi infection and its co-existence with Wuchereria bancrofti in and around Sillaberia PHC, District Midnapur, West Bengal

Of 2186 persons investigated in thirteen villages of Sillaberia PHC, 19 were found to be infected with Brugia malayi and only one person harboured microfilaria (mf) of Wuchereria bancrofti. Similarly 41 persons exhibited signs and symptoms of chronic filariasis. The mf and disease rates percent worked out to be 0.914 and 1.87 respectively. The earliest ages showing mf and disease manifestations were 3 and 11 respectively. The mean mf density ranged from 2 to 12.2 per 20 cumm of blood. The male and female ratio in terms of mf carriers and chronic cases worked out to be 1.4:1 and 1:2 respectively. The entomological collections revealed a high ten man hour density (163.20) in case of Culex quinquefasciatus and comparatively much lower in case of Mansonia (Mansonioides) annulifera (47.51) and Mansonia (Mansoni oides) uniformis (23.83) respectively. The infection and infectivity rates in case of Mansonia (Mansonioides) annulifera were 6.1 and 1.2 per cent respectively.