Real-Time Assessment of Health-Care Requirements During the Zika Virus Epidemic in Martinique.

The spread of Zika virus in the Americas has been associated with a surge in Guillain-Barré syndrome (GBS) cases. Given the severity of GBS, territories affected by Zika virus need to plan health-care resources to manage GBS patients. To inform such planning in Martinique, we analyzed Zika virus surveillance and GBS data from Martinique in real time with a modeling framework that captured dynamics of the Zika virus epidemic, the risk of GBS in Zika virus-infected persons, and the clinical management of GBS cases. We compared our estimates with those from the 2013-2014 Zika virus epidemic in French Polynesia. We were able to predict just a few weeks into the epidemic that, due to lower transmission potential and lower probability of developing GBS following infection in Martinique, the total number of GBS cases in Martinique would be substantially lower than suggested by simple extrapolations from French Polynesia. We correctly predicted that 8 intensive-care beds and 7 ventilators would be sufficient to treat GBS cases. This study showcased the contribution of modeling to inform local health-care planning during an outbreak. Timely studies that estimate the proportion of infected persons that seek care are needed to improve the predictive power of such approaches

Recent Emergence of Dengue Virus Serotype 4 in French Polynesia Results from Multiple Introductions from Other South Pacific Islands

BACKGROUND: Infection by dengue virus (DENV) is a major public health concern in hundreds of tropical and subtropical countries. French Polynesia (FP) regularly experiences epidemics that initiate, or are consecutive to, DENV circulation in other South Pacific Island Countries (SPICs). In January 2009, after a decade of serotype 1 (DENV-1) circulation, the first cases of DENV-4 infection were reported in FP. Two months later a new epidemic emerged, occurring about 20 years after the previous circulation of DENV-4 in FP. In this study, we investigated the epidemiological and molecular characteristics of the introduction, spread and genetic microevolution of DENV-4 in FP. METHODOLOGY/PRINCIPAL FINDINGS: Epidemiological data suggested that recent transmission of DENV-4 in FP started in the Leeward Islands and this serotype quickly displaced DENV-1 throughout FP. Phylogenetic analyses of the nucleotide sequences of the envelope (E) gene of 64 DENV-4 strains collected in FP in the 1980s and in 2009-2010, and some additional strains from other SPICs showed that DENV-4 strains from the SPICs were distributed into genotypes IIa and IIb. Recent FP strains were distributed into two clusters, each comprising viruses from other but distinct SPICs, suggesting that emergence of DENV-4 in FP in 2009 resulted from multiple introductions. Otherwise, we observed that almost all strains collected in the SPICs in the 1980s exhibit an amino acid (aa) substitution V287I within domain I of the E protein, and all recent South Pacific strains exhibit a T365I substitution within domain III. CONCLUSIONS/SIGNIFICANCE: This study confirmed the cyclic re-emergence and displacement of DENV serotypes in FP. Otherwise, our results showed that specific aa substitutions on the E protein were present on all DENV-4 strains circulating in SPICs. These substitutions probably acquired and subsequently conserved could reflect a founder effect to be associated with epidemiological, geographical, eco-biological and social specificities in SPICs

Comités d'Experts des Maladies Infectieuses & Émergentes aux Antilles françaises

National audienc

Incidence and clinical characteristics of ciguatera fish poisoning in Guadeloupe (French West Indies) between 2013 and 2016: a retrospective cases-series

International audienc

Revising rates of asymptomatic Zika virus infection based on sentinel surveillance data from French Overseas Territories

French Polynesia and the French Territories of the Americas (FTAs) have experienced outbreaks of Zika virus (ZIKV) infection. These territories used similar sentinel syndromic surveillance to follow the epidemics. However, the surveillance system only takes into account consulting patients diagnosed with ZIKV disease, while non-consulting cases, as well as asymptomatic cases, are not taken into account. In the French territories under study, the ratio of consulting to non-consulting patients was found to likely be as low as 1/3 to 1/4, and rough estimates of the ZIKV asymptomatic infections indicated a lower rate than previously reported (i.e., not more than half). Keywords: Zika virus, Sentinel surveillance, Asymptomatic infections, Pacific islands, Caribbean region, Vector-borne infection

Salmonella enterica serotype enteritidis in French Polynesia, South Pacific, 2008-2013.

International audienceOutbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008-2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible

Evolutionary relationships of DENV-4 E gene sequences.

<p>ML original tree derived from 110 DENV-4 E gene sequences. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) is shown for values over 80. The number of strains with identical E gene sequence is indicated in parenthesis (these additional strains could have been collected in a different district or island and at a different date than the strain that appears in the tree).</p

Significant nucleotide substitutions on the E gene (1485 bp) within the DENV-4 clade IIa Oceania group.

<p>- Identical to Solomon.</p

Relevant amino acid substitutions on the E protein based on the consensus sequence of 142 DENV-4 strains.

<p>*non conservative aa substitution; strains of interest are in bold characters.</p