Anopheline ecology and malaria transmission at a new irrigation project area (Bargi dam) in Jabalpur (Central India)

Anopheline ecology and malaria transmission were studied in a newly irrigat ed area of the Bargi Project, District Jabalpur, Madhya Pradesh, Central In dia. Observations were made for 2 years (1993-95) in 10 villages along the Bargi irrigation canal, which are situated between 44 km (head end of canal ) and 78 km (tail end of canal) from the dam site. Anopheles annularis was the predominant species in the head-end villages and its abundance was dire ctly related to the opening of the canal, whereas Anopheles culicifacies wa s the most abundant species in tail-end villages, where irrigation is limit ed. Anopheles culicifacies showed 2 typical peaks not related to canal irri gation. Site-related differences in species prevalence were significant in both immatures and adults. Malaria infection was due to Plasmodium vivax an d Plasmodium falciparum. The annual parasite incidence in children and adul ts was significantly higher in head-end villages (>4-fold) as compared to t hat in tail-end villages. However, seasonal trends in the prevalence of P. falciparum and P. vivax were the same in each group, with some fluctuations . In this study, preliminary results of the investigation are presented, de monstrating the trends in anopheline ecology and parasite prevalence in rel ation to the dynamics of irrigation development.