The first Chikungunya case from Sonipat district near the national capital city of Delhi, India.

Copyright © 2010 Kumari et al. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Chikungunya, a mosquito-borne disease, is caused by chikungunya virus (CHIKV), an alphavirus belonging to the Togaviridae family. After a gap of about 32 years, the infection re-emerged in India in 2005 [1,2]. In 2005-2006, the years of emergence, several areas in southern India were affected by a chikungunya outbreak [3]. However, in 2006, chikungunya cases were reported for the first time from northern India, where 52 cases were detected from the Delhi region [http://www.nvbdcp.gov.in]. These cases probably originated from elsewhere as local transmission of CHIKV had not yet been established in Delhi. It is noteworthy that the area has high potential for CHIKV transmission as the two known vectors, Aedes aegypti and Aedes albopictus, are prevalent in Delhi [4]. From the surrounding areas of Delhi (i.e., Sonipat, Gurgaon, Faridabad and Noida), people in large numbers come to Delhi for work every day and therefore constitute an important epidemiological sector for the disease. Such a large-scale population movement between cities masks the importance of the source and the origin of infections such as chikungunya and dengue, which is vital in planning control strategies. Sonipat is an urban township of Haryana state about 70 km from Delhi. The population of Sonipat district is about 1.7 million, which is important from the point of view of the occurrence of dengue fever cases. During a dengue vector survey conducted in Sonipat district on 24 September 2008, the survey team encountered a patient with symptoms related to Chikungunya: joint pains, fever, severe pain in fingers and muscles, and mild headache [ was a 25-year-old female from Saragthal, an agricultural village, about 32 km away from Sonipat city. Investigation revealed negative results for malaria infection, so a blood sample of the patient was taken on 24 September 2008, which was tested for IgM antibodies against dengue and chikungunya virus using IgM Capture ELISA method (National Institute of Virology, Pune, India). The sample was found to be positive for IgM antibodies against chikungunya virus. This was the first case of chikungunya reported from a northern state. An interview with the patient revealed that she had never traveled outside her village for the past one month. Only one member of her family travelled …