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Epidemiology of chikungunya based on laboratory surveillance data—India, 2016–2018

BACKGROUND
We analysed the laboratory surveillance data generated by the network of virology laboratories from January 2016 to July 2018 to describe the epidemiology of chikungunya in India.


METHODS
Suspected patients reporting to virology laboratories are investigated for the presence of immunoglobulin M (IgM) antibodies against chikungunya virus (CHIKV) as evidence of recent infection. We analysed the data to describe the distribution of seropositive individuals by time, place and demographic characteristics.


RESULTS
Of the 49 380 sera tested from suspected patients, 20.5% were seropositive. CHIKV IgM positivity was seen throughout the year, with a peak between September and December. The laboratories diagnosed 28 outbreaks of chikungunya during the study period.


CONCLUSIONS
Laboratory surveillance data indicate continued transmission of CHIKV in many regions of India.