Entomo-ecological studies on vector potential in aes affected areas of muzaffarpur district, bihar (india) with reference to prevalence of rodent and their ectoparasites

Acute encephalitis syndrome (AES) is a major public health problem in India. Seasonal outbreaks of AES occurring regularity in Muzaffarpur district, Bihar. Present investigation was carried out to explore the possible entomological causative factors for sudden onset of the disease. A total of fifty two rodents belonging to four different species viz. Mus musculus, Bendicota benglensis, Rattus rattus, and Suncus murinus were collected. In commensal rodents overall infestation rate of ectoprasites was recorded as 77.5% and in wild rodents 33.3%. Mites were the predominant ectoparisite retrieved from rodents. The oriental rat fleas (Xenopsila cheopis) were retrieved giving an overall flea index as 0.33 and vector larval trombiculid mite chiggers (Leptotrombidium deliense) were collected from commensal rodents with chigger index 7.5. Total 533 mosquitoes belong to Culex quinquefasciatus (86.9%) followed by Armigeres subalbatus (12.9%) and An. subpictus (0.19%). Maximum number of Cx. quinquefasciatus females collected from Bhikhanpur village with per man hour density (PMHD) of 31.5. Larvae and pupae were collected from the various water sources and belongs to Cx. quinquefasciatus (77.3%) and Ar. subalbatus (22.7%). Present investigations do not support any vector borne diseases in AES affected areas but ecology and environment highly support the propagation and multiplication of rodents and their ectoparasites. Present investigation suggests further deep study to correlate entomological findings with other clinical and epidemiological studies.