1Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad-500007.
2C 11/7, River Bank Colony, Lucknow-226001.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
An outbreak of mysterious brain fever in Uttar Pradesh, and adjoining districts of Bihar and Nepal sickened more than 5347 people and taken life of more than 1180, with a case fatality rate (CFR) of ~22.1%, during 29 July to 24 October 2005. Our IgM-ELISA/RT-PCR/immunofluorescence investigations (n=38) revealed 55.3% samples positive for Japanese encephalitis virus (JEV), and 10.5% for other flavivirus infection (such as Dengue and West Nile) while 34.2% were inconclusive (tentatively attributed to Chandipura, Chikungunya, etc.). The association of JEV as one of the causative agent implicates JEV as an emerging pathogen of substantial public-health importance. The disease affected predominantly the low socio-economic, rural children between 5–15 years, in far-flung paddy fields, with male to female ratio of 1.4:1. Infection was marked by high-grade fever, headache, tremors, convulsions, depressed consciousness and spastic paralysis followed by death. Our pathological investigations revealed pleocytosis in cerebrospinal fluid with 7–72% neutrophils, and peripheral leucocytosis with anemia. The disease coincided with rainfall and population density of the mosquito (vector) Culex tritaeniorrhynchus. This epidemic started about a month earlier as compared to previous epidemics of 1978 and 1980. In intensity and magnitude, it surpassed all the previously reported epidemics, as there were more clusters of cases, lasting a longer period of time, and affecting a greater age range. Those vaccinated had also got infected. It seems virus is becoming more virulent. Considering the seriousness of the disease and lack of specific antiviral therapy, it is imperative to proceed with a sense of urgency in this matter.
