Hookworm infection: Prevalence among the tribal populations of Meghalaya (Northeast India) and development of the infective stage larvae under varied environmental conditions

The prevalence of hookworm infection was ascertained among the tribal populations, the Khasis, the Jaintias and the Garos of Nongkya, Sutnga and Williamnagar, respectively at three different periods of the year, i.e., pre-monsoon (March-June), monsoon (July-October) and post-monsoon (November-February) that relate to different climatic conditions prevailing through the year. All the positive samples were cultured for larvae, which in all the cases were identified as belonging to Necator americanus. Females showed a higher prevalence infection in most of the cases. Though no age-related trend in prevalence was evident, the intensity of infection was found to be more in the higher age groups i.e., 15-19 years and 20 years and above. The infected individuals in all the three study sites were treated with mebendazole in the post-monsoon time. Three weeks post treatment, the infection rate among them lowered down but showed an increasing trend again after 5-7 months and beyond. Among the environmental objects, soil was found to be the important transmitting medium. The optimal periods of development and hatching of eggs and development of L-3 larvae coincided with warmer temperatures and higher humidity, which also favoured a longer period of survival of L3 larvae in the soil.