Résumé
Background
In 2014, a first outbreak of chikungunya hit the Caribbean area where chikungunya virus (CHIKV) had never circulated before.
Methodology/Principal findings
We conducted a cross-sectional study to measure the seroprevalence of CHIKV immediately after the end of the 2014 outbreak in HIV-infected people followed up in two clinical cohorts at the University hospitals of Guadeloupe and Martinique. Study patients were identified during the first months of 2015 and randomly selected to match the age and sex distribution of the general population in the two islands. They were invited to complete a survey that explored the symptoms consistent with chikungunya they could have developed during 2014 and to have a blood sample drawn for CHIKV serology.
The study population consisted of 377 patients (198 in Martinique and 179 in Guadeloupe, 178 men and 199 women), 182 of whom reported they had developed symptoms consistent with chikungunya. CHIKV serology was positive in 230 patients, which accounted for an overall seroprevalence rate of 61% [95%CI 56-66], with only 153 patients who reported symptoms consistent with chikungunya. Most frequent symptoms included arthralgia (94.1%), fever (73.2%), myalgia (53.6%), headache (45.8%), and skin rash (26.1%).
Conclusions/Significance
This study showed that the seroprevalence of CHIKV infection was 61% after the 2014 outbreak, with one third of asymptomatic infections.
Author summary
After the termination of the first documented outbreak of chikungunya in the Caribbean in 2014, the seroprevalence rate of CHIKV infection in French West Indies was estimated at 61% [95% CI 56.0-65.8] in a population-matched cohort of HIV-infected patients. This high seroprevalence may explain the abrupt and persistent cessation CHIKV circulation in these territories. One third of participants had not developed clinical symptoms of chikungunya.