ENTOMOLOGICAL AND RODENT SURVEILLANCE IN PLAGUE-SUSPECTED AREAS DURING SEPTEMBER 1994 AND THEREAFTER

Studies carried out in the states of Maharashtra, Gujarat, Uttar Prade sh and Union Territory of Delhi after the bubonic plague outbreak duri ng 1994 revealed the presence of seven species of rodents, viz. Rattus rattus, R. norvegicus, Mus. musculus, Tatera indica, Suncus murinus, Bandicoota bengalensis and B. indica. The flea species encountered wer e Xenopsylla cheopis and X. astia. The X. cheopis and X. astia index r ecorded in different areas of Beed district of Maharashtra; Surat, Vad odra and Baruch districts in Gujarat and Varanasi district in Uttar Pr adesh and their implications have been discussed. Insecticide suspecti bility tests carried out against DDT, dieldrin, malathion and deltamet hrin with X. cheopis collected from Maharashtra, Delhi and Varanasi re vealed that this vector species is resistant to DDT and dieldrin but s usceptible to malathion and deltamethrin. The prevalence and distribut ion of rodents species, high cheopis index and prevalence of Tatera in dica just at the door steps of houses in village Mamla of Reed distric t provides highly congenital conditions for the intermingling of wild and domestic rodents and transfer of flea population from wild to dome stic rodents and vice-versa. These conditions were found to be highly supportive for bubonic plague transmission in the district. The presen ce of Yersinia pestis antibodies in Rattus rattus collected from Beed, Surat and Varanasi areas are also indicative of bubonic plague in Bee d and Varanasi and pneumonic plague in Surat during 1994.