Publications des scientifiques de l'IRD

Viet T. L., Choisy Marc, Bryant J. E., Trong D. V., Quang T. P., Horby P., Tran H. N., Kieu H. T. T., Vu T. N., Van K. N., Quynh M. L., Wertheim H. F. L. (2015). A dengue outbreak on a floating village at Cat Ba Island in Vietnam. Bmc Public Health, 15, p. art. 940 [8 p.]. ISSN 1471-2458.

Titre du document
A dengue outbreak on a floating village at Cat Ba Island in Vietnam
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000361523000003
Auteurs
Viet T. L., Choisy Marc, Bryant J. E., Trong D. V., Quang T. P., Horby P., Tran H. N., Kieu H. T. T., Vu T. N., Van K. N., Quynh M. L., Wertheim H. F. L.
Source
Bmc Public Health, 2015, 15, p. art. 940 [8 p.] ISSN 1471-2458
Background: A dengue outbreak in an ecotourism destination spot in Vietnam, from September to November 2013, impacted a floating village of fishermen on the coastal island of Cat Ba. The outbreak raises questions about how tourism may impact disease spread in rural areas. Methods: Epidemiological data were obtained from the Hai Phong Preventive Medical Center (PMC), including case histories and residential location from all notified dengue cases from this outbreak. All household addresses were geo-located. Knox test, a spatio-temporal analysis that enables inference dengue clustering constrained by space and time, was performed on the geocoded locations. From the plasma available from two patients, positive for Dengue serotype 3 virus (DENV3), the Envelope (E) gene was sequenced, and their genetic relationships compared to other E sequences in the region. Results: Of 192 dengue cases, the odds ratio of contracting dengue infections for people living in the floating villages compared to those living on the island was 4.9 (95 % CI: 3.6-6.7). The space-time analyses on 111 geocoded dengue residences found the risk of dengue infection to be the highest within 4 days and a radius of 20 m of a given case. Of the total of ten detected clusters with an excess risk greater than 2, the cluster with the highest number of cases was in the floating village area (24 patients for a total duration of 31 days). Phylogenetic analysis revealed a high homology of the two DENV3 strains (genotype III) from Cat Ba with DENV3 viruses circulating in Hanoi in the same year (99.1 %). Conclusions: Our study showed that dengue transmission is unlikely to be sustained on Cat Ba Island and that the 2013 epidemic likely originated through introduction of viruses from the mainland, potentially Hanoi. These findings suggest that prevention efforts should be focused on mainland rather than on the island.
Plan de classement
Santé : généralités [050] ; Entomologie médicale / Parasitologie / Virologie [052]
Description Géographique
VIET NAM
Localisation
Fonds IRD [F B010065297]
Identifiant IRD
fdi:010065297
Contact