Febrile episode among a floating population of C.R.P.F. Jawans stationed at Calcutta.

A virological investigation was carried out to establish the etiologic agent of a febrile outbreak amongst a floating population of C.R.P.F. Jawans, stationed at Calcutta during May-July, 1993. The illness was associated with fever, severe headache, bodyache and arthralgia which lasted for 2-4 days in most of the cases. Fifty cases were examined clinically and blood samples (both acute and convalescent) were subjected to virological study. One mouse-pathogenic agent could be isolated in suckling mice and identified as DEN-3. Sero-investigation of 50 single sera by HI & CF method revealed evidence of presumptive dengue infection in 33, while sero-conversion could be noted in 10 out of 25 available paired sera tested. Results of MAC ELISA revealed evidence of primary dengue infection in 6 out of 12 acute phase sera examined. Thus, the study shows that the episode is strongly suggestive of primary dengue infection.