Seroprevalence of Chikungunya at the End of the First Chikungunya Outbreak in the French Antilles Within a Sample of Patients Treated for a HIV Infection

Seroprevalence of Chikungunya at the End of the First Chikungunya Outbreak in the French Antilles Within a Sample of Patients Treated for a HIV Infection

Late 2013, the first indigenous cases of chikungunya have been observed in the French Antilles. At the end of May 2014, almost all of the islands of the Caribbean were affected by the outbreak.

During the large epidemic which affected the Island of La Réunion in 2005/2006, the attack rate was 38%. The most active period was three months.

In this context, knowledge of the attack rate and the epidemic in the Caribbean is an important issue for outbreak management and modeling work.

As the chikungunya virus had never circulated in the Caribbean, determining the seroconversion rate can be achieved by realizing a seroprevalence survey among the general population at the end of the outbreak. Another simple method is to estimate the rate in a cohort of patients followed regularly and whose habitat is distributed throughout the territory studied.

The follow up of patients infected by the human immunodeficiency virus (HIV) in the French West Indies is almost exclusively performed in hospitals in department of Infectious and Tropical Diseases.The high prevalence of HIV and homogeneous distribution of infected patients on all of our territories, allow to hypothesize that the risk of transmission of arboviruses by exposure to mosquito bites is comparable to the general population. This patient cohort is well suited to study the emergence of Chikungunya in the French West Indie .

Primary objective :

To estimate the cumulative incidence at the end of the first Chikungunya outbreak in the French West Indies by estimating the prevalence of specific antibodies of chikungunya virus in a sample (randomly constituted) from patients infected by HIV and representative of the general population of Martinique and Guadeloupe

Secondary objective :

To estimate the frequency of asymptomatic infections by the chikungunya virus in the studied population To estimate the frequency of chronic forms of chikungunya in the studied population

Inclusion Criteria:

• Adult (> 18 years old)
• Followed for HIV infection at the 2 investigators centers (1 located at Martinique and 1 at Guadeloupe)
• resident in Martinique /Guadeloupe ( French West Indies)
• informed consent signed by the patient

Exclusion Criteria:

• patient who lived more than 6 month in an risk area for chikungunya virus infection
• patient with or documented chronic rheumatism
• patient who has received a blood transfusion during year 2013 or patient who is supposed to receive a blood transfusion during the study
• patient who has planned to live outside French West Indies during the follow up period