Malaria outbreak in a tribal area of Gujarat state, India.

ABSTRACT

Malaria incidence in Gujarat state had been on a general decline since 1989. However in some tribal villages in forested areas of Valsad district, southern Gujarat, there was an outbreak of malaria in September 1995. Five children died in Ashlona village. During investigation conducted in October 1995 in affected villages, the malaria parasite rate was 26% (217/833) with >91% infections due to P. falciparum. A high proportion of P. falciparum infections had ring stages suggesting active transmission. Against a minimum norm of 10% annual blood examination rate, there was a major breakdown of active surveillance for malaria. In the absence of health agencies in or near affected villages, the malaria parasite load continued to build up leading to an outbreak towards the end of monsoon season. Indoor residual spraying with deltamethrin caused significant reduction in densities of malaria vector An. culicifacies. Measures to prevent malaria outbreaks in inaccessible areas have been discussed.