Isabelle Leparc-Goffart

Chikungunya virus, southeastern France.

In September 2010, autochthonous transmission of chikungunya virus was recorded in southeastern France, where the Aedes albopictus mosquito vector is present. Sequence analysis of the viral genomes of imported and autochthonous isolates indicated new features for the potential emergence and spread of the virus in Europe.

Chikungunya outbreak in the Caribbean region, December 2013 to March 2014, and the significance for Europe

On 6 December 2013, two laboratory-confirmed cases of chikungunya without a travel history were reported on the French part of the Caribbean island of Saint Martin, indicating the start of the first documented outbreak of chikungunya in the Americas. Since this report, the virus spread to several Caribbean islands and French Guiana, and between 6 December 2013 and 27 March 2014 more than 17,000 suspected and confirmed cases have been reported. Further spread and establishment of the disease in the Americas is likely, given the high number of people travelling between the affected and non-affected areas and the widespread occurrence of efficient vectors. Also, the likelihood of the introduction of the virus into Europe from the Americas and subsequent transmission should be considered especially in the context of the next mosquito season in Europe. Clinicians should be aware that, besides dengue, chikungunya should be carefully considered among travellers currently returning from the Caribbean region.

Emergence of chikungunya fever on the French side of Saint Martin island, October to December 2013.

On 18 November 2013, five residents of Saint Martin presented with severe joint pain after an acute episode of dengue-like fever. Epidemiological, laboratory and entomological investigations provided evidence of the first autochthonous transmission of chikungunya virus in the Americas. The event indicates a risk of epidemics in America and Europe through substantial passenger traffic to and from continental France. We describe detection and confirmation of the first six cases and results of the first weeks of surveillance.

Zika Virus Strains Potentially Display Different Infectious Profiles in Human Neural Cells.

The recent Zika virus (ZIKV) epidemic has highlighted the poor knowledge on its physiopathology. Recent studies showed that ZIKV of the Asian lineage, responsible for this international outbreak, causes neuropathology in vitro and in vivo. However, two African lineages exist and the virus is currently found circulating in Africa. The original African strain was also suggested to be neurovirulent but its laboratory usage has been criticized due to its multiple passages. In this study, we compared the French Polynesian (Asian) ZIKV strain to an African strain isolated in Central African Republic and show a difference in infectivity and cellular response between both strains in human neural stem cells and astrocytes. Consistently, this African strain led to a higher infection rate and viral production, as well as stronger cell death and anti-viral response. Our results highlight the need to better characterize the physiopathology and predict neurological impairment associated with African ZIKV.

Increase in cases of Guillain-Barré syndrome during a Chikungunya outbreak, French Polynesia, 2014 to 2015.

During the recent chikungunya fever outbreak in French Polynesia in October 2014 to March 2015, we observed an abnormally high number of patients with neurological deficit. Clinical presentation and complementary exams were suggestive of Guillain-Barré syndrome (GBS) for nine patients. All nine had a recent dengue-like syndrome and tested positive for chikungunya virus (CHIKV) in serology or RT-PCR. GBS incidence was increased four- to nine-fold during this period, suggesting a link to CHIKV infection.

Analysis of blood from Zika virus-infected fetuses: a prospective case series

BACKGROUNDnZika virus has spread through the Americas and the Caribbean since early 2015 and was rapidly declared a Public Health Emergency of International Concern by WHO because of the potential association with fetal anomalies. We analysed fetal and maternal fluids and tissues in fetuses with confirmed Zika virus infection prospectively monitored in Martinique, a French Caribbean island.nnnMETHODSnSince the beginning of the Zika virus outbreak in Martinique, all pregnant women undergo monthly fetal ultrasound examination surveillance. In this study, we prospectively studied all patients with fetal anomalies and a positive amniotic fluid for Zika virus by RT-PCR. Maternal and fetal blood, urine, amniotic fluid, placenta, and fetal tissues were tested for Zika virus by RT-PCR. Fetal blood was analysed to identify haematological and biological anomalies.nnnFINDINGSnBetween Jan 1, 2016, and Nov 10, 2016, we recruited eight cases of Zika virus infection. All but two cases were symptomatic during the first trimester. Fetal anomalies were only detected after 20 weeks gestation. After an initial positive result, amniocentesis became negative in two cases and fetal blood was transiently Zika virus-positive in six cases. Fetal blood analyses showed a cholestatic pattern, anaemia, and infectious response.nnnINTERPRETATIONnNormalisation of amniotic fluid and fetal blood for Zika virus, as well as maternal blood and urine, shows the limitations of the performance of these investigations, due to the possibility of false negative results. Abnormal fetal blood needs to be investigated further to establish prognostic factors of severe Zika virus infections.nnnFUNDINGnNone.

Oral receptivity of Aedes aegypti from Cape Verde for yellow fever, dengue, and chikungunya viruses.

At the end of 2009, 21,313 cases of dengue-3 virus (DENV-3) were reported in the islands of Cape Verde, an archipelago located in the Atlantic Ocean 570 km from the coast of western Africa. It was the first dengue outbreak ever reported in Cape Verde. Mosquitoes collected in July 2010 in the city of Praia, on the island of Santiago, were identified morphologically as Aedes aegypti formosus. Using experimental oral infections, we found that this vector showed a moderate ability to transmit the epidemic dengue-3 virus, but was highly susceptible to chikungunya and yellow fever viruses.

Epidemiology of Chikungunya Virus Outbreaks in Guadeloupe and Martinique, 2014: An Observational Study in Volunteer Blood Donors

Background During Dec-2013, a chikungunya virus (CHIKV) outbreak was first detected in the French-West Indies. Subsequently, the virus dispersed to other Caribbean islands, continental America and many islands in the Pacific Ocean. Previous estimates of the attack rate were based on declaration of clinically suspected cases. Methods/Principal findings Individual testing for CHIKV RNA of all (n = 16,386) blood donations between Feb-24th 2014 and Jan-31st 2015 identified 0·36% and 0·42% of positives in Guadeloupe and Martinique, respectively. The incidence curves faithfully correlated with those of suspected clinical cases in the general population of Guadeloupe (abrupt epidemic peak), but not in Martinique (flatter epidemic growth). No significant relationship was identified between CHIKV RNA detection and age-classes or blood groups. Prospective (Feb-2014 to Jan-2015; n = 9,506) and retrospective (Aug-2013 to Feb-2014; n = 6,559) seroepidemiological surveys in blood donors identified a final seroprevalence of 48·1% in Guadeloupe and 41·9% in Martinique. Retrospective survey also suggested the absence or limited silent CHIKV circulation before the outbreak. Parameters associated with increased seroprevalence were: Gender (M>F), KEL-1, [RH+1/KEL-1], [A/RH+1] and [A/RH+1/KEL-1] blood groups in Martiniquan donors. A simulation model based on observed incidence and actual seroprevalence values predicted 2·5 and 2·3 days of asymptomatic viraemia in Martiniquan and Guadeloupian blood donors respectively. Conclusions/Significance This study, implemented promptly with relatively limited logistical requirements during CHIKV emergence in the Caribbean, provided unique information regarding retrospective and prospective epidemiology, infection risk factors and natural history of the disease. In the stressful context of emerging infectious disease outbreaks, blood donor-based studies can serve as robust and cost-effective first-line tools for public health surveys.

Globalization of Chikungunya: 10 years to invade the world.

R. N. Charrel, I. Leparc-Goffart, P. Gallian and X. de Lamballerie 1) Aix Marseille Universit e, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 ‘Emergence des Pathologies Virales’, IHU M editerran ee Infection, APHM Public Hospitals of Marseille, Marseille, 2) National Reference Laboratory for Arboviruses, Institut de Recherche Biom edicale des Arm ees, Marseille and 3) Etablissement Franc ais du Sang Alpes-M editerran ee, Marseille, France E-mail: remi.charrel@univ-amu.fr Article published online: 28 May 2014

Preliminary report of an autochthonous chikungunya outbreak in France, July to September 2017

In August 2017, an autochthonous chikungunya case was reported in south-east France. By mid-September, eight additional autochthonous cases were found in the index case’s neighbourhood, where the chikungunya virus vector Aedes albopictus was observed. Genomic characterisation identified an East-Central South African (ECSA) lineage strain, probably from the Central African region and carrying an adaptive mutation facilitating transmission by Ae. albopictus. The event confirms we need early case detection and response to contain chikungunya in Europe.