Malaria-attributable morbidity in Assam, north-eastern India.

Malaria is endemic in the Indian state of Assam and transmission of the causative parasites is perennial and persistent. The available data on malaria-related morbidity and mortality in the state for the years 1991-1999 have been reviewed. Over this period, Plasmodium falciparum was the predominant parasite, causing 58%-68% of the malaria cases; all other cases were attributed to P. vivax. All malaria-related deaths were attributed to P. falciparum infection, and the numbers of such deaths were correlated with the numbers of cases of P. falciparum malaria. The deaths occurred mostly in the rainy season (April-September) and among all age-groups of both sexes. The factors responsible for focal outbreaks of malaria across the state are discussed in relation to the existing health infrastructure.

An outbreak of Plasmodium falciparum malaria due to Anopheles minimus in central Assam, India.

Epidemiological investigations were conducted in Nellie subcentre, PHC Jhargaon, under Morigaon district (Assam). The results of fever cases revealed 68 per cent slide positivity rate (SPR) and 40 per cent slide falciparum rate (SfR). The Pf proportion was > 87 per cent and remaining cases were P. vivax infections. An. minimus was incriminated as a malaria vector during the study period. The sporozoite rate was 3.08 per cent. The indoor man mosquito contact was 35 per bait/night as against 23 in outdoors. Results of susceptibility test revealed that the vector was still susceptible to both DDT and malathion at discriminating dosages. The study revealed that inadequate surveillance and vector control measures were contributing factors for malaria outbreak. In view of this, insecticide treated nets may be introduced to provide cost-effective control of malaria.