Recent introduction and rapid dissemination of chikungunya virus and dengue virus serotype 2 associated with human and mosquito coinfections in Gabon, Central Africa

2012

Article référencé dans le Web of Science WOS:000308008900001

Caron M., Paupy Christophe, Grard G., Becquart Pierre, Mombo I., Nso B. B. B., Kassa F. K., Nkoghe D., Leroy Eric

Clinical Infectious Diseases, 2012, 55 (6), p. E45-E53 ISSN 1058-4838

Background. Chikungunya virus (CHIKV) and Dengue virus serotype 2 (DENV-2) were recently introduced in central Africa, along with Aedes albopictus. Simultaneous outbreaks of CHIKV and DENV-2 have subsequently occurred, in Cameroon in 2006 and Gabon in 2007. Methods. To study the spread of the 2 viruses, we conducted active surveillance of acute febrile syndromes throughout Gabon between 2007 and 2010. Diagnostic methods included quantitative real-time reverse-transcription polymerase chain reaction, and molecular characterization was based on partial envelope gene sequences. Results. Between 2007 and 2010, 4287 acutely febrile patients were investigated for CHIKV and DENV-2 infections, of whom 1567 were CHIKV-positive, 376 DENV-2-positive, and 37 coinfected. We diagnosed 153 CHIKV and 11 DENV-2 cases in 2008, and 5 CHIKV and 9 DENV-2 cases in 2009. In 2010, CHIKV and DENV-2 caused a second large simultaneous outbreak. Among 2826 acutely febrile patients examined during this outbreak, 1112 were CHIKV-positive, 288 DENV-2-positive, and 28 coinfected. Mosquitoes were collected near the homes of coinfected patients, and 1 Aedes albopictus specimen was found to be positive for both CHIKV and DENV-2. Conclusions. These findings show the rapid dissemination of CHIKV and DENV-2 within a nonimmune population in a tropical African country, probably facilitated by the spread of Aedes albopictus. This has resulted in major simultaneous outbreaks with numerous coinfections in both human and mosquito.

Entomologie médicale / Parasitologie / Virologie [052]

Fonds IRD [F B010057167]

fdi:010057167