Laser-cut paper-based device for the detection of dengue non-structural NS1 protein and specific IgM in human samples.

The incidence of flavivirus infections has increased dramatically in recent decades in tropical and sub-tropical areas worldwide, affecting hundreds of millions of people each year. Dengue viruses are typically transmitted by mosquitoes and can cause a wide range of symptoms from flu-like fever to organ impairment and death. Although conventional diagnostic tests can provide early diagnosis of acute dengue infections, access to these tests is often limited in developing countries. Consequently, there is an urgent need to develop affordable, simple, rapid, and robust diagnostic tools that can be used at 'Point of Care' settings. Early diagnosis is crucial to improve patient management and reduce the risk of complications. In the present study, a novel laser-cut device made of glass-fiber paper was designed and tested for the detection of the dengue Non Structural 1 (NS1) viral protein and specific IgM in blood and plasma. The device, called PAD, was able to detect around 25 ng/mL of NS1 protein in various sample types in 8 minutes, following a few simple steps. The PAD was also able to detect specific IgM in human plasmas in less than 10 minutes. The PAD appears to have all the potential to assist health workers in early diagnosis of dengue fever or other tropical fevers caused by flaviviruses.

Transient myocarditis associated with acute Zika virus infection.

Zika virus outbreak is spreading in America. This emerging infection is associated with neurological complication. We report the first travel-acquired Zika acute infection complicated with myocarditis imported in Mainland France. We recommand an electrocardiogram and an troponin if any cardiac symptoms are present in a patient with acute Zika infection.

Survey of laboratory-acquired infections around the world in biosafety level 3 and 4 laboratories.

Laboratory-acquired infections due to a variety of bacteria, viruses, parasites, and fungi have been described over the last century, and laboratory workers are at risk of exposure to these infectious agents. However, reporting laboratory-associated infections has been largely voluntary, and there is no way to determine the real number of people involved or to know the precise risks for workers. In this study, an international survey based on volunteering was conducted in biosafety level 3 and 4 laboratories to determine the number of laboratory-acquired infections and the possible underlying causes of these contaminations. The analysis of the survey reveals that laboratory-acquired infections have been infrequent and even rare in recent years, and human errors represent a very high percentage of the cases. Today, most risks from biological hazards can be reduced through the use of appropriate procedures and techniques, containment devices and facilities, and the training of personnel.

Travel-associated and autochthonous Zika virus infection in mainland France, 1 January to 15 July 2016.

During summer 2016, all the conditions for local mosquito-borne transmission of Zika virus (ZIKV) are met in mainland France: a competent vector, Aedes albopictus, a large number of travellers returning from ZIKV-affected areas, and an immunologically naive population. From 1 January to 15 July 2016, 625 persons with evidence of recent ZIKV infection were reported in mainland France. We describe the surveillance system in place and control measures implemented to reduce the risk of infection.

West Nile virus epizootics in the Camargue (France) in 2015 and reinforcement of surveillance and control networks.

West Nile virus (WNV) infection is a non-contagious disease mainly transmitted by the bites of infected mosquitoes from the genus Culex. The virus is maintained in a mosquito-bird-mosquito cycle, and can accidentally be transmitted to mammalian hosts. Among mammalian hosts, equines and humans are the most sensitive to WNV infection and can develop severe meningoencephalitis. As WNV infections are zoonotic and can be severe in humans and equines, West Nile fever is considered to be a public and animal health concern. After a silent period of almost ten years, WNV re-emerged in France at the periphery of the Camargue area during the summer of 2015, underlining the fact that the Camargue area creates favourable conditions for WNV emergence and amplification in France. The French Network for Epidemiological Surveillance of Equine Diseases (Réseau d'Épidémio-Surveillance en Pathologie Équine [RESPE]) facilitated the early detection of WNV cases in horses. In total, 49 horses were found to be infected; among them, 44 presented clinical signs, 41 with meningoencephalitis and three with hyperthermia only. Six horses among the 41 with nervous symptoms died from the disease or were euthanised (a case fatality rate of 14.6%). The authors describe the characteristics of the 2015 WNV epizootics, the early detection of the first WNV equine cases via the RESPE network and the coordination of WNV surveillance in France.

L'infection par le virus de West Nile est une maladie non contagieuse essentiellement transmise lors de piqûres de moustiques infectés appartenant au genre Culex ; le virus se maintient dans la nature au moyen d'un cycle moustique­ oiseau­moustique ; la transmission à des hôtes mammifères a lieu de manière accidentelle. Parmi les mammifères hôtes, les plus sensibles à l'infection par le virus de West Nile sont les équidés et l'homme, chez qui l'infection peut se manifester sous forme d'une méningo-encéphalite sévère. Les infections par le virus de West Nile étant des zoonoses potentiellement graves chez l'homme et chez les équidés, la fièvre de West Nile doit être considérée comme une priorité de santé publique et animale. Resté silencieux pendant plus d'une décennie, le virus de West Nile est réapparu en France à l'été 2015 en bordure de la Camargue, confirmant que les conditions de cette région sont favorables à l'émergence et à l'amplification du virus. Le réseau français d'épidémiosurveillance en pathologie équine (RESPE) a contribué à la détection précoce du virus de West Nile chez les chevaux. Au total, 49 chevaux étaient infectés, parmi lesquels 44 présentaient des signes cliniques, correspondant à une méningo-encéphalite pour 41 d'entre eux et à une hyperthermie seule pour les trois autres. Six chevaux parmi les 41 qui présentaient des signes neurologiques ont succombé à la maladie ou ont été euthanasiés (taux de létalité de 14,6 %). Les auteurs de cet article décrivent les principales caractéristiques de l'épizootie de 2015 due au virus de West Nile ainsi que la détection précoce des premiers cas équins grâce au réseau RESPE et la coordination des activités de surveillance du virus en France.

La infección por el virus West Nile es una enfermedad no contagiosa que se transmite básicamente por la picadura de mosquitos infectados del género Culex. El virus, que se instala en un ciclo mosquito­ave­mosquito, también puede transmitirse accidentalmente a mamíferos, de entre los cuales los más sensibles a la infección son los equinos y el ser humano, que pueden contraer graves meningoencefalitis. Puesto que las infecciones por este virus son zoonóticas y pueden revestir gravedad en personas y equinos, se considera que la fiebre West Nile es una enfermedad de importancia sanitaria y zoosanitaria. En Francia, tras un periodo silente de más de diez años, el virus reapareció en verano de 2015 en la periferia de la zona de la Camarga, poniendo así de manifiesto que esta zona genera condiciones propicias al surgimiento y la amplificación del virus en el país. La red francesa de vigilancia epidemiológica de patologías equinas (Réseau d'Épidémio-Surveillance en Pathologie Équine: RESPE]) facilitó la rápida detección de caballos infectados por el virus West Nile. Se detectaron en total 49 animales infectados, entre ellos 44 con signos clínicos, de los que 41 sufrían meningoencefalitis y tres solo presentaban hipertermia. Seis de los 41 caballos que mostraban signos neurológicos murieron a causa de la enfermedad o fueron sacrificados con métodos de eutanasia (lo que supone una tasa de letalidad del 14,6%). Los autores describen las principales características de la epizootia causada por el virus West Nile en 2015, la pronta detección de los primeros casos de caballos infectados gracias a la red RESPE y la coordinación de las labores de vigilancia del virus en Francia.

Chikungunya outbreak in Montpellier, France, September to October 2014.

In October 2014, an outbreak of 12 autochthonous chikungunya cases, 11 confirmed and 1 probable, was detected in a district of Montpellier, a town in the south of France colonised by the vector Aedes albopictus since 2010. A case returning from Cameroon living in the affected district was identified as the primary case. The epidemiological investigations and the repeated vector control treatments performed in the area and around places frequented by cases helped to contain the outbreak. In 2014, the chikungunya and dengue surveillance system in mainland France was challenged by numerous imported cases due to the chikungunya epidemic ongoing in the Caribbean Islands. This first significant outbreak of chikungunya in Europe since the 2007 Italian epidemic, however, was due to an East Central South African (ECSA) strain, imported by a traveller returning from West Africa. Important lessons were learned from this episode, which reminds us that the threat of a chikungunya epidemic in southern Europe is real.

Zika virus infection complicated by Guillain-Barre syndrome--case report, French Polynesia, December 2013.

Zika fever, considered as an emerging disease of arboviral origin, because of its expanding geographic area, is known as a benign infection usually presenting as an influenza-like illness with cutaneous rash. So far, Zika virus infection has never led to hospitalisation. We describe the first case of Guillain-Barré syndrome (GBS) occurring immediately after a Zika virus infection, during the current Zika and type 1 and 3 dengue fever co-epidemics in French Polynesia.

Large number of imported chikungunya cases in mainland France, 2014: a challenge for surveillance and response.

During the summer of 2014, all the pre-requisites for autochthonous transmission of chikungunya virus are present in southern France: a competent vector, Aedes albopictus, and a large number of travellers returning from the French Caribbean islands where an outbreak is occurring. We describe the system implemented for the surveillance of chikungunya and dengue in mainland France. From 2 May to 4 July 2014, there were 126 laboratory-confirmed imported chikungunya cases in mainland France.

Autochthonous case of dengue in France, October 2013.

In October 2013, autochthonous dengue fever was diagnosed in a laboratory technician in Bouches-du-Rhone, southern France, a department colonised by Aedes albopictus since 2010. After ruling out occupational contamination, we identified the likely chain of local vector-borne transmission from which the autochthonous case arose. Though limited, this second occurrence of autochthonous dengue transmission in France highlights that efforts should be continued to rapidly detect dengue virus introduction and prevent its further dissemination in France.

The Wood equation allows consistent fitting of individual antibody-response profiles of Zika virus or SARS-CoV-2 infected patients.

Antibody kinetic curves obtained during a viral infection are often fitted using aggregated patient data, hiding the heterogeneity of individual humoral immune responses. Individual antibody responses can be modeled using the Wood equation and grouped according to their profile. Such modeling takes into account several important kinetic parameters, such as the day when antibody detection becomes positive [daypos], the day of the maximal response [daymax], the maximum antibody level [levelmax], and the day when antibody detection becomes negative [dayneg]. Potential associations between these profiles and studied factors can then be tested.

Re-emergence of dengue in Reunion, France, January to April 2012.

Since January 2012, 20 autochthonous cases of dengue virus (DENV) infection have been identified in Réunion. The first cases were detected on the western coast, but the two co-circulating viruses (DENV-1 and DENV-3) seemed to have spread later to different cities of the island. There is a non-negligible risk of increase in viral transmission over the following weeks, so health professionals and public health authorities in Réunion are preparing to face a potential epidemic.

[An update on Lassa virus]. / Le virus lassa, état des lieux.

Lassa virus, the etiologic agent of Lassa hemorrhagic fever, infects 100,000 to 300,000 people every year in West Africa with an overall mortality rate ranging from 1 to 2%. It was discovered in 1969 and remains a significant public health risk in endemic areas. Because airborne transmission is possible and mortality can be high under certain conditions, Lassa virus has been classified as a category A bioterrorism agent. Early diagnosis is difficult due to insidious non-specific onset and to the great genetic divergence of the virus that makes RT-PCR assays unreliable. The lack of proper diagnostic tools promotes nosocomial infection and diminishes the efficacy of treatment. Recently, numerous advances have been made in the development of both diagnostic and vaccination techniques. The purpose of this review is to present an update on that research as well as the current epidemiology of Lassa virus.

Self-priming of reverse transcriptase impairs strand-specific detection of dengue virus RNA.

Dengue virus infection is the most frequent arthropod-borne infection affecting humans in the world. Our understanding of the pathophysiological events leading to mild or severe outcomes of the disease remains limited by the fact that viral target cells in the human body are poorly characterized. One of the most sensitive strategies for detecting cells supporting active replication of this positive-strand RNA virus is the search for the replicative intermediate, an antigenome of negative polarity, by RT-PCR. However, a phenomenon described as 'false priming' of the reverse transcriptase (RT) prevents strand-specific detection. The results of the current study showed that this event corresponds to cDNA synthesis that is independent of any primer addition. This property was general to all RNAs tested and was not associated with small free nucleic acids, such as tRNAs and microRNAs. Rather, it corresponded to initiation of cDNA synthesis from the 3' end of the RNA template, and a model is proposed in which the template RNA snaps back upon itself and creates a transient RNA primer suitable for the RT. Such a property would explain why many assays proposed for detection of a replicative intermediate are not specific, and may help in the development of a molecular biology protocol that could allow replication studies of RNA viruses of human interest, such as dengue virus, hepatitis C virus and enteroviruses.

Dengue type 3 virus infections in European travellers returning from the Comoros and Zanzibar, February-April 2010.

In late February-early April 2010, five cases of dengue fever were diagnosed in returning travellers in Europe in EurotravNet sites in Sweden and France in patients with travel history to the Comoros and/or Zanzibar, Tanzania. Four cases were non-complicated dengue fever and one case dengue hemorrhagic fever. Three patients were viraemic at the time of diagnosis and infected with Dengue type 3 virus.

First two autochthonous dengue virus infections in metropolitan France, September 2010.

In September 2010, two cases of autochthonous dengue fever were diagnosed in metropolitan France for the first time. The cases occurring in Nice, southeast France, where Aedes albopictus is established, are evidence of dengue virus circulation in this area. This local transmission of dengue calls for further enhanced surveillance, active case finding and vector control measures to reduce the spread of the virus and the risk of an epidemic.

[Rift Valley fever virus: evolution in progress]. / Le virus de la Fièvre de la Vallée du Rift: évolution en cours.

Several viruses now circulating in tropical zones around the globe are potential threats for ever-increasing human populations even in temperate zones that have long remained unaffected. The mechanisms underlying transport and transmission, which can be enhanced by human activity, can be even stronger in zones where factors needed to support development of these viruses, i.e., hosts, reservoirs and vectors, are already present. This possibility has been illustrated by dengue virus, and now by the rapid spread of the Chikungunya virus on Reunion Island in 2005 and then in Italy in 2007. The spreading of Chikungunya virus despite its mild reputation had a major unexpected impact. It showed that the evolution of the virus, whether a cause or consequence of observed events, could be determinant. The risk of extension of more pathogenic viruses due to similar mechanisms must be considered as a possibility. In this regard the Rift Valley fever virus, that already involves a large area and has a major reservoir, is one of the viruses that deserves close surveillance.

Five cases of acute Zika virus infection in French women of reproductive age returning from Central and South America.

INTRODUCTION: The favorable season for Aedes albopictus circulation has started in Europe and may lead to autochthonous transmission of Zika virus. Health care providers should be familiar with evocative clinical presentations and able to give updated information to women of reproductive age infected by Zika virus. OBSERVATIONS: We report five laboratory-confirmed Zika virus infections imported to metropolitan France from Central and South America between January and April, 2016. The five young women were not connected and not pregnant; common presentation combined a rash with persistent arthralgia. Zika virus was identified by RT-PCR from serum or urines, between two and eight days after the onset of the symptoms. CONCLUSION: As the duration of potential materno-foetal infectivity is still unknown, we were unable to answer with certitude to the patients' questions about the time interval to respect before attempting a pregnancy: one of them became pregnant one month after the diagnosis.