tetano
Editor, Senior Moderator
[h=2]The proportion of asymptomatic infections and spectrum of disease among pregnant women infected by Zika virus: systematic monitoring in French Guiana, 2016
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Zika virus (ZIKV) is a flavivirus that can be transmitted to humans by the bite of an infected Aedes aegypti mosquito, by sexual contact [1-3] or from mother to fetus [4]. Since the identification of ZIKV in Brazil in May 2015, the virus has spread rapidly throughout the Americas [5-10]. As at February 2017, 48 countries and territories of the region have reported active transmission of the virus [11]. Following this emergence, a number of studies showed that ZIKV infection in pregnant women was associated with congenital abnormalities such as microcephaly [4,7,12-18]. However, important discrepancies remain between the existing estimates of this risk, which was found to be substantially higher in pregnant women with symptomatic ZIKV infection [13] than in those with any ZIKV infection (i.e. symptomatic or asymptomatic infection) [17]. This suggests that the presence of symptoms might be a risk factor for complications [19,20]. In this context, risk assessment needs to rely on the proportion of asymptomatic infections among pregnant women infected by ZIKV. However, such description is currently lacking because published cohorts have so far focused on women with symptomatic ZIKV infections.
In French Guiana, a French overseas territory with 250,000 inhabitants located in the north-east of the southern American continent, the emergence of ZIKV has been considered to be of particular concern because the territory has the highest fertility rate in the Americas (3.5 children per woman), with an infant mortality rate (1.2%) that is three times higher than in metropolitan France (0.4%) [21]. On 22 January 2016, local health authorities launched an official epidemic alert following the rapid spread of ZIKV in the most inhabited part of the territory [22]. At the beginning of February, a territory-wide active monitoring system of all consenting pregnant women was implemented to report laboratory evidence of ZIKV infection during the outbreak. Here, we analyse data collected during the first 4 months of the outbreak to characterise the clinical manifestations of ZIKV infection in pregnant women, estimate the proportion of asymptomatic infections and study factors such as age and location that may affect the clinical presentation of ZIKV infection.
full article
http://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2017.22.44.17-00102
- Claude Flamand[SUP]1[/SUP], Camille Fritzell[SUP]1[/SUP], S?verine Matheus[SUP]2[/SUP], Maryvonne Dueymes[SUP]3[/SUP], Gabriel Carles[SUP]4[/SUP], Anne Favre[SUP]5[/SUP], Antoine Enfissi[SUP]2[/SUP], Antoine Adde[SUP]1[/SUP], Magalie Demar[SUP]3[/SUP], Mirdad Kazanji[SUP]1[/SUP], Simon Cauchemez[SUP]6,7,8,9[/SUP], Dominique Rousset[SUP]2,9[/SUP]
Zika virus (ZIKV) is a flavivirus that can be transmitted to humans by the bite of an infected Aedes aegypti mosquito, by sexual contact [1-3] or from mother to fetus [4]. Since the identification of ZIKV in Brazil in May 2015, the virus has spread rapidly throughout the Americas [5-10]. As at February 2017, 48 countries and territories of the region have reported active transmission of the virus [11]. Following this emergence, a number of studies showed that ZIKV infection in pregnant women was associated with congenital abnormalities such as microcephaly [4,7,12-18]. However, important discrepancies remain between the existing estimates of this risk, which was found to be substantially higher in pregnant women with symptomatic ZIKV infection [13] than in those with any ZIKV infection (i.e. symptomatic or asymptomatic infection) [17]. This suggests that the presence of symptoms might be a risk factor for complications [19,20]. In this context, risk assessment needs to rely on the proportion of asymptomatic infections among pregnant women infected by ZIKV. However, such description is currently lacking because published cohorts have so far focused on women with symptomatic ZIKV infections.
In French Guiana, a French overseas territory with 250,000 inhabitants located in the north-east of the southern American continent, the emergence of ZIKV has been considered to be of particular concern because the territory has the highest fertility rate in the Americas (3.5 children per woman), with an infant mortality rate (1.2%) that is three times higher than in metropolitan France (0.4%) [21]. On 22 January 2016, local health authorities launched an official epidemic alert following the rapid spread of ZIKV in the most inhabited part of the territory [22]. At the beginning of February, a territory-wide active monitoring system of all consenting pregnant women was implemented to report laboratory evidence of ZIKV infection during the outbreak. Here, we analyse data collected during the first 4 months of the outbreak to characterise the clinical manifestations of ZIKV infection in pregnant women, estimate the proportion of asymptomatic infections and study factors such as age and location that may affect the clinical presentation of ZIKV infection.
full article
http://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2017.22.44.17-00102