Vanessa Ardillon

Malaria on the Guiana Shield: a review of the situation in French Guiana.

In a climate of growing concern that Plasmodium falciparum may be developing a drug resistance to artemisinin derivatives in the Guiana Shield, this review details our current knowledge of malaria and control strategy in one part of the Shield, French Guiana. Local epidemiology, test-treat-track strategy, the state of parasite drug resistance and vector control measures are summarised. Current issues in terms of mobile populations and legislative limitations are also discussed.

Pregnancy Outcomes after ZIKV Infection in French Territories in the Americas

BACKGROUND The risk of congenital neurologic defects related to Zika virus (ZIKV) infection has ranged from 6 to 42% in various reports. The aim of this study was to estimate this risk among pregnant women with symptomatic ZIKV infection in French territories in the Americas. METHODS From March 2016 through November 2016, we enrolled in this prospective cohort study pregnant women with symptomatic ZIKV infection that was confirmed by polymerase‐chain‐reaction (PCR) assay. The analysis included all data collected up to April 27, 2017, the date of the last delivery in the cohort. RESULTS Among the 555 fetuses and infants in the 546 pregnancies included in the analysis, 28 (5.0%) were not carried to term or were stillborn, and 527 were born alive. Neurologic and ocular defects possibly associated with ZIKV infection were seen in 39 fetuses and infants (7.0%; 95% confidence interval, 5.0 to 9.5); of these, 10 were not carried to term because of termination of pregnancy for medical reasons, 1 was stillborn, and 28 were live‐born. Microcephaly (defined as head circumference more than 2 SD below the mean for sex and gestational age) was detected in 32 fetuses and infants (5.8%), of whom 9 (1.6%) had severe microcephaly (more than 3 SD below the mean). Neurologic and ocular defects were more common when ZIKV infection occurred during the first trimester (24 of 189 fetuses and infants [12.7%]) than when it occurred during the second trimester (9 of 252 [3.6%]) or third trimester (6 of 114 [5.3%]) (P=0.001). CONCLUSIONS Among pregnant women with symptomatic, PCR‐confirmed ZIKV infection, birth defects possibly associated with ZIKV infection were present in 7% of fetuses and infants. Defects occurred more frequently in fetuses and infants whose mothers had been infected early in pregnancy. Longer‐term follow‐up of infants is required to assess any manifestations not detected at birth. (Funded by the French Ministry of Health and others; ClinicalTrials.gov number, NCT02916732.)

Zika emergence in the French Territories of America and description of first confirmed cases of Zika virus infection on Martinique, November 2015 to February 2016

Following of the emergence of Zika virus in Brazil in 2015, an epidemiological surveillance system was quickly implemented in the French overseas Territories of America (FTA) according to previous experience with dengue and chikungunya and has detected first cases of Zika. General practitioners and medical microbiologists were invited to report all clinically suspected cases of Zika, laboratory investigations were systematically conducted (RT-PCR). On 18 December, the first autochthonous case of Zika virus infection was confirmed by RT-PCR on French Guiana and Martinique, indicating introduction of Zika virus in FTA. The viral circulation of Zika virus was then also confirmed on Guadeloupe and Saint-Martin. We report here early findings on 203 confirmed cases of Zika virus infection identified by RT-PCR or seroneutralisation on Martinique Island between 24 November 2015 and 20 January 2016. All cases were investigated. Common clinical signs were observed (maculopapular rash, arthralgia, fever, myalgia and conjunctival hyperaemia) among these patients, but the rash, the foundation of our case definition, may be absent in a significant proportion of patients (16%). These results are important for the implementation of a suspected case definition, the main tool for epidemiological surveillance, in territories that may be affected by ZIKV emergence, including Europe.

Investigation of a Sudden Malaria Outbreak in the Isolated Amazonian Village of Saül, French Guiana, January–April 2009

Malaria is endemic in French Guiana. Plasmodium falciparum and Plasmodium vivax are the predominant species responsible and Anopheles darlingi is described as the major vector. In mid-August 2008, an increase in malaria incidence was observed in Saül. A retrospective cohort survey was performed. In vitro susceptibility profiles to antimalarials were determined on P. falciparum isolates. Collections of mosquitoes were organized. The malaria attack rate reached 70.6/100. The risk of malaria increased for people between 40 and 49 years of age, living in a house not subjected to a recent indoor residual insecticide spraying or staying overnight in the surrounding forest. All isolates were susceptible. Anopheles darlingi females and larvae were collected in the village suggesting a local transmission. Our results strongly support a role of illegal mining activities in the emergence of new foci of malaria. Therefore, public health authorities should define policies to fight malaria at a transborder level.

First human rabies case in French Guiana, 2008: epidemiological investigation and control.

Background Until 2008, human rabies had never been reported in French Guiana. On 28 May 2008, the French National Reference Center for Rabies (Institut Pasteur, Paris) confirmed the rabies diagnosis, based on hemi-nested polymerase chain reaction on skin biopsy and saliva specimens from a Guianan, who had never travelled overseas and died in Cayenne after presenting clinically typical meningoencephalitis. Methodology/Principal Findings Molecular typing of the virus identified a Lyssavirus (Rabies virus species), closely related to those circulating in hematophagous bats (mainly Desmodus rotundus) in Latin America. A multidisciplinary Crisis Unit was activated. Its objectives were to implement an epidemiological investigation and a veterinary survey, to provide control measures and establish a communications program. The origin of the contamination was not formally established, but was probably linked to a bat bite based on the virus type isolated. After confirming exposure of 90 persons, they were vaccinated against rabies: 42 from the cases entourage and 48 healthcare workers. To handle that emergence and the local populations increased demand to be vaccinated, a specific communications program was established using several media: television, newspaper, radio. Conclusion/Significance This episode, occurring in the context of a Department far from continental France, strongly affected the local population, healthcare workers and authorities, and the management team faced intense pressure. This observation confirms that the risk of contracting rabies in French Guiana is real, with consequences for population educational program, control measures, medical diagnosis and post-exposure prophylaxis.

Mining local climate data to assess spatiotemporal dengue fever epidemic patterns in French Guiana

OBJECTIVE To identify local meteorological drivers of dengue fever in French Guiana, we applied an original data mining method to the available epidemiological and climatic data. Through this work, we also assessed the contribution of the data mining method to the understanding of factors associated with the dissemination of infectious diseases and their spatiotemporal spread. METHODS We applied contextual sequential pattern extraction techniques to epidemiological and meteorological data to identify the most significant climatic factors for dengue fever, and we investigated the relevance of the extracted patterns for the early warning of dengue outbreaks in French Guiana. RESULTS The maximum temperature, minimum relative humidity, global brilliance, and cumulative rainfall were identified as determinants of dengue outbreaks, and the precise intervals of their values and variations were quantified according to the epidemiologic context. The strongest significant correlations were observed between dengue incidence and meteorological drivers after a 4-6-week lag. DISCUSSION We demonstrated the use of contextual sequential patterns to better understand the determinants of the spatiotemporal spread of dengue fever in French Guiana. Future work should integrate additional variables and explore the notion of neighborhood for extracting sequential patterns. CONCLUSIONS Dengue fever remains a major public health issue in French Guiana. The development of new methods to identify such specific characteristics becomes crucial in order to better understand and control spatiotemporal transmission.

Detection of Chikungunya Virus Circulation Using Sugar-Baited Traps during a Major Outbreak in French Guiana.

1 Unité d’Entomologie Médicale, Institut Pasteur de la Guyane, Cayenne, French Guiana, 2 Cellule de l’Institut de Veille Sanitaire en Région Antilles-Guyane, Cayenne, French Guiana, 3 Groupe Interactions Virus-Insectes, Institut Pasteur, Paris, France, 4 Equipe Résidente de Recherche d’Infectiologie Tropicale, Division Expertise, Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France, 5 Unité de Recherche Associée 3012, Centre National de la Recherche Scientifique, Paris, France, 6 Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, France, 7 Direction Interarmées du Service de Santé en Guyane, Cayenne, French Guiana

First description of a dengue fever outbreak in the interior of French Guiana, February 2006.

BACKGROUND A dengue fever outbreak occurred in the interior of French Guiana from November 2005 onwards. An investigation, with epidemiological, entomological and public health inputs, was initiated. Its objectives were to confirm the outbreak, to describe the emergence of dengue fever in the High Maroni area and to initiate a specific public health response. METHODS The investigation was conducted in Maripasoula in February 2006, the biggest community in that part of the country. Definition criteria were used for suspected, probable and confirmed cases of dengue fever. An entomological evaluation for larvae and adult mosquitoes was carried out. Some personal and collective vector control measures were set up by the vector control team. RESULTS This survey identified 127 suspected dengue fever cases, whereas the epidemiological surveillance system detected only six probable and confirmed cases from the same place and for the same period. The proportion of dengue fever was higher in those people who had not travelled (23.5%) than within the population that had travelled (15.3%) in the three previous months (P = 0.01). Larvae of Stegomyia aegypti were found throughout the town, and adults were captured in 90.9% of the houses. CONCLUSION This is the first time that a dengue fever outbreak has been described beyond the coastal region of this French overseas Department.

The predictive value of a maculopapular rash in children hospitalized for dengue fever in Cayenne, French Guiana

In order to determine the predictive value of a rash during dengue fever, a cohort study was conducted in children hospitalized for dengue during an epidemic in French Guiana. A rash was predictive of uncomplicated dengue: the HR of developing a severe form of disease was 0.43 (95% CI 0.21-0.88; p-value=0.021) for patients with rash.

Epidemiological assessment of the severity of dengue epidemics in French Guiana

Background Dengue fever is the most important arboviral infection that affects humans, particularly in tropical and subtropical regions. Here, we provide the first comprehensive overview of the severity of dengue epidemics in French Guiana. Methodology/Principal findings We monitored hospitalized cases between 2008 and 2013. Detailed clinical features and biological parameters were collected on a daily basis from all cases. Among the 1,356 cases, 216 (16%) were classified according to the WHO 2009 classification as dengue without warning signs (WS), 926 (68%) were classified as dengue with WS and 214 (16%) were classified as severe dengue. The severity rates were similar between the three major epidemics that occurred during the study period, whereas the hospitalization rate was highest in 2013. Fluid accumulation, aspartate aminotransferase (ASAT) counts>193 IU/L and platelet counts<75,000 cells/mm3 were associated with dengue severity. Conclusions/Significance Our findings provide a recent epidemiological description of the severity of dengue epidemics in French Guiana. These results highlight the potential impacts and consequences of implementing the WHO 2009 classification on hospital activity. Future studies should include virological and immunological investigations of well-documented serum samples.