An outbreak investigation of suspected Chikungunya fever in Nalgonda District, Telangana state

Background: An outbreak of fever with joint pains occurred at Proddutur village, Nalgonda District, Telangana state, India. Methods: We investigated the out-break; attempted to identify the agent, source, mode of disease transmission, study clinico-epidemiological factors and recommend control measures during the period 11th-15th, February 2014. A rapid fever survey was conducted by using pre-tested, pre-designed epidemiological case sheets. Seventeen serum samples were collected for laboratory analysis. Entomological survey was conducted to identify and study the vectors. Results: The outbreak was observed to be a seasonal disease which started on 12th January, 2014 and continued till 18th February, 2014. Out of the total population of 1365 in the village, 259 cases were identified to have chikungunya fever as per case definition. Overall attack rate was 19%. Maximum cases occurred (24.1%) in the age group of 21-30 years and the least (1.9%) in the age group of less than one year and greater than 70 years (2.8%). Proportion of cases of Chikungunya was higher in females (51.9%) compared with males (48.2%). Fever (100%) and Joint pains (92.6%) were the most common clinical manifestations; 61% had severe disability and needed family help to do daily normal activities. Out of seventeen serum samples sent for laboratory confirmation, 5, 2 and 2 were positive for Chikungunya, dengue and both Chikungunya and dengue together respectively. No mortality was reported. Conclusions: The occurrence of this outbreak stresses the need for carrying out continuous surveillance for vector borne diseases so that appropriate remedial measures are initiated.