Detection and genetic characterization of Seoul Virus from commensal brown rats in France

Abstract

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.

Seoul Virus Infection in Humans, France, 2014–2016

“…Open green circles indicate SEOV serologically confirmed human infections with SEOV reported by Ragnaud et al ( 10 ), Le Guenno ( 11 ), and Bour et al ( 6 ); solid blue circles indicate virologically confirmed human infections with SEOV reported in this study (patients 1, 2, and 3); solid yellow square indicates virologically confirmed human infection with SEOV reported by Macé al. ( 5 ); solid red diamonds indicate virologically confirmed SEOV infections in brown rats reported in this study; and open blue diamonds indicate virologically confirmed SEOV infections in brown rats reported by Heyman et al ( 12 ) and Dupinay et al ( 13 ). …”

High prevalence of Seoul hantavirus in a breeding colony of pet rats

“…S1) with no apparent relationships to each other. A similar lack of connectivity can be observed for the cyt b sequences obtained for a selection of 17 wild rats trapped in and around Lyon, France [21]. This suggests that whilst the cyt b gene is useful for confirming the host species, it may not be the optimum host marker for determining finite intra-species relationships or population connectivity nor to identify the geographic origin of an imported or introduced rat.…”

“…The detection of the SEOV Humber strain in 2/4 (50%) trapped rats on the farm of the HFRS patient in Yorkshire [4] compares to earlier UK wild rat seroprevalence estimates of 21·6% (Northern Ireland n = 51) [16] and 4% (England n = 100) [15]. No SEOV RNA was detected in the lungs of 133 wild rats trapped in the port city of Liverpool, UK [3], whereas SEOV RNA was detected in the lungs of 18/128 (14%) wild rats trapped in and around the port city of Lyon, France [21]. In the Netherlands, 3/16 (19%) rats were recently shown to have SEOV-specific neutralising antibodies in a region where earlier attempts to confirm SEOV seropositivity by FRNT in 161 brown rats had failed [23].…”

Prevalence ofLeptospiraspp. and Seoul hantavirus in brown rats (Rattus norvegicus) in four regions in the Netherlands, 2011-2015

“…Furthermore, a serosurvey among farmers exposed to wild rats showed a seroprevalence of 8% in the UK [20]. Since 2000, the presence of SEOV in wild brown rats was demonstrated in Belgium, France and the UK [18,21–23]. In the Netherlands, SEOV infection was detected in wild brown rats captured in the area around Doetinchem in 2013 [24].…”