Epidemiological observations on malaria in some parts of Darrang District, Assam

A study on malaria conducted in tribal villages of Darrang district, Assam during April 1994 to March 1995 revealed that the malaria incidence due to Plasmodium falciparum was considerably high. Slide positivity rate (SPR) ranged between 2.3 to 45.67 per cent with transmission from May to October. P. falciparum was the dominant species (91.7 per cent) followed by P. vivax (7.25 per cent) and mixed infection (Pv + Pf = 1.05 per cent). Malaria cases were recorded throughout the year in all the age groups including infants, however, age groups between 0-1 and 21-30 years were more affected. Among 17 anophelines collected, Anopheles vagus, An. jamesii, An. crawfordi and An. minimus were the most abundant species. Known vectors of malaria like An. annularis, An. culicifacies, An. minimus, An. philippinensis and An. varuna were detected. Perennial transmission of malaria was attributed to low socio-economic conditions, poor surveillance and inadequate intervention measures.