Genetic detection of Dobrava/Belgrade virus in a Czech patient with Haemorrhagic fever with renal syndrome

Orthohantaviruses in Reservoir and Atypical Hosts in the Czech Republic: Spillover Infection and Indication of Virus-Specific Tissue Tropism

Orthohantaviruses (genus Orthohantavirus) are a diverse group of viruses that are closely associated with their natural hosts (rodents, shrews, and moles). Several orthohantaviruses cause severe disease in humans. Central and western Europe are areas with emerging orthohantavirus occurrences. In our study, several orthohantaviruses, including the pathogenic Kurkino virus (KURV), were detected in their natural hosts trapped at several study sites in the Czech Republic. KURV was detected mainly in its typical host, the striped field mouse (Apodemus agrarius). Nevertheless, spillover infections were also detected in wood mice (Apodemus sylvaticus) and common voles (Microtus arvalis). Similarly, Tula virus (TULV) was found primarily in common voles, and events of spillover to rodents of other host species, including Apodemus spp., were recorded. In addition, unlike most previous studies, different tissues were sampled and compared to assess their suitability for orthohantavirus screening and possible tissue tropism. Our data suggest possible virus-specific tissue tropism in rodent hosts. TULV was most commonly detected in the lung tissue, whereas KURV was more common in the liver, spleen, and brain. Moreover, Seewis and Asikkala viruses were detected in randomly found common shrews (Sorex araneus). In conclusion, we have demonstrated the presence of human-pathogenic KURV and the potentially pathogenic TULV in their typical hosts as well as their spillover to atypical host species belonging to another family. Furthermore, we suggest the possibility of virus-specific tissue tropism of orthohantaviruses in their natural hosts. IMPORTANCE Orthohantaviruses (genus Orthohantavirus, family Hantaviridae) are a diverse group of globally distributed viruses that are closely associated with their natural hosts. Some orthohantaviruses are capable of infecting humans and causing severe disease. Orthohantaviruses are considered emerging pathogens due to their ever-increasing diversity and increasing numbers of disease cases. We report the detection of four different orthohantaviruses in rodents and shrews in the Czech Republic. Most viruses were found in their typical hosts, Kurkino virus (KURV) in striped field mice (Apodemus agrarius), Tula virus (TULV) in common voles (Microtus arvalis), and Seewis virus in common shrews (Sorex araneus). Nevertheless, spillover infections of atypical host species were also recorded for KURV, TULV, and another shrew-borne orthohantavirus, Asikkala virus. In addition, indications of virus-specific patterns of tissue tropism were observed. Our results highlight the circulation of several orthohantaviruses, including KURV, which is pathogenic to humans, among rodents and shrews in the Czech Republic.

Hantavirus infections in humans in Poland-current state of knowledge and perspectives for research

BACKGROUND

In Europe, hantaviruses cause serious human disease, hemorrhagic fever with renal syndrome (HFRS). The geographic distribution of human cases of HFRS is a consequence of distribution of reservoir host species. Epidemiology of HFRS is well-studied in Western Europe, while data from Central and Eastern Europe are poor or unavailable.

METHODS

The data on hantavirus infections in humans during 2007-2017 were gathered to distinguish pattern of HFRS occurrence and characterize potential factors shaping HFRS epidemiology in Poland.

RESULTS

The south-eastern part of Poland (Podkarpackie voivodeship) was recognized as endemic area of hantavirus prevalence. Incidence rate of HFRS in Poland was positively correlated with mast years and higher abundance of rodents, urbanization index, and forest cover, while the climatic factors (average temperatures in January and July and average annual precipitation) have had no significant impact.

CONCLUSIONS

In Poland, HFRS is still not recognized entity. Further studies on hantavirus infection rate in reservoir host species (rodents, shrews, and bats) and virus transmission to humans are needed to prevent outbreaks of HFRS in the future.

Molecular Epidemiology of Hantaviruses in the Czech Republic

During 2008–2018, we collected samples from rodents and patients throughout the Czech Republic and characterized hantavirus isolates. We detected Dobrava-Belgrade and Puumala orthohantaviruses in patients and Dobrava-Belgrade, Tula, and Seewis orthohantaviruses in rodents. Increased knowledge of eco-epidemiology of hantaviruses will improve awareness among physicians and better outcomes of patients.

Detection of Dobrava hantavirus RNA in Apodemus mice in Bulgaria

Several Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) in Europe: Dobrava-Belgrade virus (DOBV), Puumala, Saaremaa, Sochi, and Seoul virus. Although HFRS is endemic in Bulgaria, genome sequences of hantaviruses have never been detected in wild rodents. To identify rodent reservoirs, a total of 691 rodents from three endemic regions were trapped in 2011-2012 and screened by TaqMan RT-PCR for detection of hantaviral genomic RNA. Partial small (S) and/or large (L)-segment sequences were recovered from six Apodemus mice: five of the species A. flavicollis and one A. agrarius. Phylogenetic analysis revealed that all recovered sequences belonged to DOBV. On the phylogenetic trees, the novel Bulgarian hantavirus sequences clustered together with sequences of established previously DOBV variants recovered from Bulgarian HFRS patients and also with variants found in wild rodents trapped in Slovenia, Greece, and Slovakia. One of the novel Bulgarian DOBV S-sequences from A. agrarius was related closely to DOBV sequences recovered from A. flavicollis, suggesting a spillover of DOBV from its natural host to A. agrarius mice. The results of this study confirmed the circulation of DOBV in wild rodents in Bulgaria. The complexity of the epidemiological situation in the Balkans requires further studies of hantaviruses in rodent hosts and human HFRS cases.

Epidemiology of Hantavirus infections in humans: a comprehensive, global overview

Hantaviruses comprise an emerging global threat for public health, affecting about 30,000 humans annually. Infection may lead to Hantavirus pulmonary syndrome (HPS) in the Americas and hemorrhagic fever with renal syndrome (HFRS) in the Europe and Asia. Humans are spillover hosts, acquiring infection primarily through the inhalation of aerosolized excreta from infected rodents and insectivores. Risk factors for infection include involvement in outdoor activities, such as rural- and forest-related activities, peridomestic rodent presence, exposure to potentially infected dust and outdoor military training; prolonged, intimate contact with infected individuals promotes transmission of Andes virus, the only Hantavirus known to be transmitted from human-to-human. The total number of Hantavirus case reports is generally on the rise, as is the number of affected countries. Knowledge of the geographical distribution, regional incidence and associated risk factors of the disease are crucial for clinicians to suspect and diagnose infected individuals early on. Climatic, ecological and environmental changes are related to fluctuations in rodent populations, and subsequently to human epidemics. Thus, prevention may be enhanced by host-reservoir control and human exposure prophylaxis interventions, which likely have led to a dramatic reduction of human cases in China over the past decades; vaccination may also play a role in the future.

Complex evolution and epidemiology of Dobrava-Belgrade hantavirus: definition of genotypes and their characteristics

Dobrava-Belgrade virus (DOBV) is a human pathogen that has evolved in, and is hosted by, mice of several species of the genus Apodemus. We propose a subdivision of the species Dobrava-Belgrade virus into four related genotypes - Dobrava, Kurkino, Saaremaa, and Sochi - that show characteristic differences in their phylogeny, specific host reservoirs, geographical distribution, and pathogenicity for humans.

Hantavirus infection during a stay in a mountain hut in Northern Slovakia

Hantaviruses in Europe cause human hemorrhagic fever with renal syndrome (HFRS) with various degree of severity. The most severe form is caused by the Dobrava/Belgrade virus (DOBV), associated with the rodent Apodemus flavicollis. During the last decade cases of infection caused by DOBV have been reported in Central Europe. The present study is a report on two Czech patients with severe HFRS who were infected during their stay in a mountain hut in Northern Slovakia. The two patients, combined with a third case observed in the same year in a nearby village in the Czech Republic, suggest that this region in Central Europe has to be considered as endemic for HFRS.