A Study of Transmission Dynamics of VIVAX and Falciparum Malaria in an Endemic Area in Kolkata

Abstract

The nature and the extent of transmission dynamics of vivax and falciparum malaria in Burrabazar area, which is known to be one of the most endemic areas in Kolkata, have been studied longitudinally through different seasons during 1997-2001. A significant difference in the seasonal variation of endemicity of the vivax and the falciparum malaria is evident throughout the years. This statistical finding is interesting in view of the fact that the transmission of both Plasmodium vivax and Plasmodium falciparum parasites is achieved through the same mosquito Anopheles stephensi in recent times in Kolkata. In this article, we carry out a detailed statistical analysis of monthly numbers of vivax and falciparum cases detected in a leading pathological laboratory located in Burrabazar area during the five year period. We also analyze monthly figures of gametocyte carriers among malaria patients detected in the laboratory. The objective here is to make some attempts to determine possible reasons behind the apparent difference in the seasonal variations in the occurrence of the two types of malaria cases.