Role of An. culicifacies and An. stephensi in malaria transmission in urban Delhi.

Studies on adult densities, vector incrimination and breeding habitats of An. culicifacies and An. stephensi were carried out during June 1984 to May 1986 in three different ecological areas of urban Delhi. Both An. culicifacies and An. stephensi prevailed throughout the year in peri-urban areas with higher densities during the post-monsoon months. In south and northwest areas, low densities of these vector species were recorded. An. culicifacies was found naturally infected with sporozoites in peri-urban and south areas, whereas An. stephensi showed gland infection in south areas only. Out of 827 blood smears collected, 302 were positive for malaria parasites. Of the positives, P. vivax formed 48.3% and P. falciparum 51.7%. Peri-urban areas showed a higher number of malaria cases than south and northwest areas.