BackgroundHantaviruses are single-stranded RNA viruses, which are transmitted to humans primarily via inhalation of aerosolised virus in contaminated rodent urine and faeces. Whilst infected reservoir hosts are asymptomatic, human infections can lead to two clinical manifestations, haemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), with varying degrees of clinical severity. The incidence of rodent and human cases of Seoul virus (SEOV) in Europe has been considered to be low, and speculated to be driven by the sporadic introduction of infected brown rats (Rattus norvegicus) via ports.MethodsBetween October 2010 and March 2012, 128 brown rats were caught at sites across the Lyon region in France.ResultsSEOV RNA was detected in the lungs of 14% (95% CI 8.01 – 20.11) of brown rats tested using a nested pan-hantavirus RT-PCR (polymerase gene). Phylogenetic analysis supports the inclusion of the Lyon SEOV within Lineage 7 with SEOV strains originating from SE Asia and the previously reported French & Belgian SEOV strains. Sequence data obtained from the recent human SEOV case (Replonges) was most similar to that obtained from one brown rat trapped in a public park in Lyon city centre. We obtained significantly improved recovery of virus genome sequence directly from SEOV infected lung material using a simple viral enrichment approach and NGS technology.ConclusionsThe detection of SEOV in two wild caught brown rats in the UK and the multiple detection of SEOV infected brown rats in the Lyon region of France, suggests that SEOV is circulating in European brown rats. Under-reporting and difficulties in identifying the hantaviruses associated with HFRS may mask the public health impact of SEOV in Europe.

SUMMARYLeptospira interrogans, hantaviruses (particularly Seoul virus), hepatitis E virus (HEV), and Toxoplasma gondii are rat-associated zoonoses that are responsible for human morbidity and mortality worldwide. This study aimed to describe the infection patterns of these four pathogens in wild rats (Rattus norvegicus) across socioeconomic levels in neighbourhoods in Lyon, France. The infection or exposure status was determined using polymerase chain reaction or serology for 178 wild rats captured in 23 locations; additionally, confirmatory culture or mouse inoculation was performed. Multivariate logistic regression analyses were used to investigate whether morphological and socioeconomic data could predict the infection status of the rats. This study revealed that the rat colony's age structure may influence the prevalence of L. interrogans, hantavirus, and HEV. In addition, areas with high human population densities and low incomes may be associated with a greater number of infected rats and an increased risk of disease transmission.

A retrospective study was conducted to identify and describe the distribution pattern of Leptospira serogroups in domestic animals in France. The population consisted of cattle herds and dogs with clinically suspected leptospirosis that were tested at the “Laboratoire des Leptospires” between 2008 and 2011. The laboratory database was queried for records of cattle and dogs in which seroreactivity in Leptospira microagglutination tests was consistent with a recent or current infection, excluding vaccine serogroups in dogs. A total of 394 cattle herds and 232 dogs were diagnosed with clinical leptospirosis, and the results suggested infection by the Leptospira serogroup Australis in 43% and 63%, respectively; by the Leptospira serogroup Grippotyphosa in 17% and 9%, respectively; and by the Leptospira serogroup Sejroe in 33% and 6%, respectively. This inventory of infecting Leptospira serogroups revealed that current vaccines in France are not fully capable of preventing the clinical form of the disease.

Human leptospirosis is a zoonotic and potentially fatal disease that has increasingly been reported in both developing and developed countries, including France. However, our understanding of the basic aspects of the epidemiology of this disease, including the source of Leptospira serogroup Australis infections in humans and domestic animals, remains incomplete. We investigated the genetic diversity of Leptospira in 28 species of wildlife other than rats using variable number tandem repeat (VNTR) and multispacer sequence typing (MST). The DNA of pathogenic Leptospira was detected in the kidney tissues of 201 individuals out of 3,738 tested individuals. A wide diversity, including 50 VNTR profiles and 8 MST profiles, was observed. Hedgehogs and mustelid species had the highest risk of being infected (logistic regression, OR = 66.8, CI95% = 30.9–144 and OR = 16.7, CI95% = 8.7–31.8, respectively). Almost all genetic profiles obtained from the hedgehogs were related to Leptospira interrogans Australis, suggesting the latter as a host-adapted bacterium, whereas mustelid species were infected by various genotypes, suggesting their interaction with Leptospira was different. By providing an inventory of the circulating strains of Leptospira and by pointing to hedgehogs as a potential reservoir of L. interrogans Australis, our study advances current knowledge on Leptospira animal carriers, and this information could serve to enhance epidemiological investigations in the future.

Leptospirosis is a worldwide zoonosis which is responsible for the typical form of Weil's disease. The epidemiological surveillance of the Leptospira species agent is important for host prevalence control. Although the genotyping methods have progressed, the identification of some serovars remains ambiguous. We investigated the multispacer sequence typing (MST) method for genotyping strains belonging to the species Leptospira interrogans, which is the main agent of leptospirosis worldwide. A total of 33 DNA samples isolated from the reference strains of L. interrogans serogroups Icterohaemorrhagiae, Australis, Canicola, and Grippotyphosa, which are the most prevalent serogroups in France, were analyzed by both the variable-number tandem-repeat (VNTR) and MST methods. An MST database has been constructed from the DNA of these reference strains to define the MST profiles. The MST profiles corroborated with the VNTR results. Moreover, the MST analysis allowed the identification at the serovar level or potentially to the isolate level for strains belonging to L. interrogans serovar Icterohaemorrhagiae, which then results in a higher resolution than VNTR (Hunter-Gaston index of 0.94 versus 0.68). Regarding L. interrogans serogroups Australis, Canicola, and Grippotyphosa, the MST and VNTR methods similarly identified the genotype. The MST method enabled the acquisition of simple and robust results that were based on the nucleotide sequences. The MST identified clinical isolates in correlation with the reference serovar profiles, thus permitting an epidemiological surveillance of circulating L. interrogans strains, especially for the Icterohaemorrhagiae serogroup, which includes the most prevalent strains of public health interest.

BackgroundUrban leptospirosis has increasingly been reported in both developing and developed countries. The control of the disease is limited because our understanding of basic aspects of the epidemiology, including the transmission routes of leptospires among rat populations, remains incomplete. Through the ability to distinguish among Leptospira strains in rats, multispacer sequence typing (MST) could provide a modern understanding of Leptospira epidemiology; however, to our knowledge, the distribution of Leptospira strains among urban rat colonies has not been investigated using MST.Aims and MethodologyThe objective of this study was to identify the Leptospira strains present in rats (Rattus norvegicus) in Lyon (France) using MST and to characterize their spatial distribution. Kidneys and urine were collected from rats trapped live in seven locations in the city and in one suburban location. Each location was considered to represent a rat colony. Bacterial cultures and quantitative polymerase chain reaction (qPCR) assays were performed, and the L. interrogans DNA identified was then genotyped using MST. The distributions of Leptospira strains were spatially described.Key ResultsAmong 84 wild rats, MST profiles were obtained in 35 of 37 rats that had a positive result for L. interrogans by bacterial culture and/or qPCR analyses. All of the MST profiles were related to reference strains previously isolated from human patients that belong to the serogroup Icterohaemorrhagiae and the serovars [strain(s)] Copenhageni [Wijinberg or M20] (n = 26), Icterohaemorrhagiae [CHU Réunion] (n = 7), Icterohaemorrhagiae [R1] (n = 1) and Copenhageni [Shibaura 9] (n = 1). Each colony was infected with leptospires having the same MST profile.Major ConclusionsThis study demonstrated that MST could be used for the purpose of field studies, either on culture isolates or on DNA extracted from kidneys and urine, to distinguish among L. interrogans isolates in rats. MST could thus be used to monitor their distributions in urban rats from the same city, thereby providing new knowledge that could be applied to explore the circulation of L. interrogans infection in rat colonies. Because the strains are related to those previously found in humans, this application of MST could aid in the source tracking of human leptospirosis, and the findings would be relevant for public health purposes according to the One Health principle.

In September 2016, a cluster of seven kayakers with clinical symptoms of leptospirosis with onset since July 2016 was reported to French health authorities. Human and animal investigations were undertaken to describe the outbreak, identify the likely place and source of infection and implement necessary control measures. We identified 103 patients with clinical symptoms of leptospirosis between 1 June and 31 October 2016 who lived in the Ille-et-Vilaine district in Brittany. Of these, 14 (including the original seven) reported contacts with the river Vilaine during the incubation period and were defined as outbreak cases: eight were confirmed by serology tests or PCR and six were probable without a laboratory confirmation for leptospirosis. All 14 cases were kayakers. Three distinct contamination sites were identified on a 30 km stretch of the river Vilaine. Nine cases reported having skin wounds while kayaking. None were vaccinated against leptospirosis. The outbreak was attributed to Leptospira kirschneri serogroup Grippotyphosa. Animal investigations did not allow identifying the possible reservoir. Leptospirosis outbreaks associated with freshwater sports are rare in temperate climates. The prevention of such outbreaks requires control of potential animal reservoirs in zones such as the Vilaine valley and that kayakers adopt the recommended individual prevention measures.

BackgroundHepatitis E virus has been detected in a wide range of animals. While Genotypes 1-2 of this virus infect only humans, 3-4 can spread from animals to humans and cause sporadic cases of human disease. Pig, and possibly also rats, may act as a reservoir for virus. From a public health perspective it is important to clarify the role of rats for infection of humans. Rats often live close to humans and are therefore of special interest to public health. Rats live of waste and inside the sewage system and may become infected. Reports of hepatitis E virus in rats have been published but not from France. The possibility that rats in an urban area in France were Hepatitis E virus infected, with which type and relationship to other strains was investigated. This study provides information important to public health and better understanding the occurrence of hepatitis E virus in the environment.Eighty one rats (Rattus Norvegicus) were captured, euthanized, sampled (liver and faeces) and analyzed by real-time RT-PCR’s, one specific for Hepatitis E virus in rats and one specific for genotype 1-4 that that is known to infect humans. Positive samples were analyzed by a nested broad spectrum RT-PCR, sequenced and compared with sequences in Genbank.FindingsTwelve liver and 11 faeces samples out of 81 liver and 81 faeces samples from 81 captured rats were positive in the PCR specific for Hepatitis E virus in rats and none in the PCR specific for genotype 1-4. Comparison by nucleotide BLAST showed a maximum of 87% similarity to Hepatitis E virus previously detected in rats and significantly less to genotype 1-4.ConclusionsThis is the first study demonstrating that rats in France carries hepatitis E virus and provide information regarding its relation to other virus strains previously detected in rats and other host animals world-wide. Genotype 1-4 was not detected.