Quartan malaria--an investigation on the incidence of Plasmodium malariae in Bisra PHC, District Sundargarh, Orissa.

A longitudinal study on the incidence of P. malariae was taken up from September 1988 to December 1989 in Bisra block, District Sundargarh, Orissa covering 38,615 population, which is mainly tribal. The area is a known hard-core malarious region in the Garhjat hill range in eastern India. In this study, out of 22,217 blood smears examined through weekly active surveillance, 7362 (33.1%) were found malaria parasite positive. Out of the total positive cases, 82 (1.1%) were P. malariae. These occurred mostly (91.4%) in persons below 40 years of age and children below 9 years accounted for 36.6% of total quartan malaria cases. In this age group the disease was found to be associated with splenomegaly (average enlarged spleen 2.07; spleen rate 45.9%) and 9 out of 13 mixed infections of P. malariae with P. falciparum and/or P. vivax were detected from this age group. This is the first report of quartan malaria from this area.