Puumala Virus Infection in Family, Switzerland

Presence and Persistence of Andes Virus RNA in Human Semen

When infecting humans, Andes orthohantavirus (ANDV) may cause a severe disease called hantavirus cardiopulmonary syndrome (HCPS). Following non-specific symptoms, the infection may progress to a syndrome of hemorrhagic fever combined with hyper-acute cardiopulmonary failure. The case fatality rate ranges between 25-40%, depending on the outbreak. In this study, we present the follow-up of a male patient who recovered from HCPS six years ago. We demonstrate that the ANDV genome persists within the reproductive tract for at least 71 months. Genome sequence analysis early and late after infection reveals a low number of mutations (two single nucleotide variants and one deletion), suggesting limited replication activity. We can exclude the integration of the viral genome into the host genome, since the treatment of the specimen with RNAse led to a loss of signal. We demonstrate a long-lasting, strong neutralizing antibody response using pseudovirions expressing the ANDV glycoprotein. Taken together, our results show that ANDV has the potential for sexual transmission.

In-cell Western assay to quantify infection with pathogenic orthohantavirus Puumala virus in replication kinetics and antiviral drug testing

Hemorrhagic fever with renal syndrome (HFRS) represents a serious zoonotic disease caused by orthohantaviruses in Eurasia. A specific antiviral therapy is not available. HFRS is characterized by acute kidney injury (AKI) with often massive proteinuria. Infection of kidney cells may contribute to the clinical picture. However, orthohantaviral replication in kidney cells is not well characterized. Therefore, we aimed to perform a reliable high-throughput assay that allows the quantification of infection rates and testing of antiviral compounds in different cell types. We quantified relative infection rates of Eurasian pathogenic Puumala virus (PUUV) by staining of nucleocapsid protein (N protein) in an in-cell Western (ICW) assay. Vero E6 cells, derived from the African green monkey and commonly used in viral cell culture studies, and the human podocyte cell line CIHP (conditionally immortalized human podocytes) were used to test the ICW assay for replication kinetics and antiviral drug testing. Quantification of infection by ICW revealed reliable results for both cell types, as shown by their correlation with immunofluorescence quantification results by counting infected cells. Evaluation of antiviral efficacy of ribavirin by ICW assay revealed differences in the toxicity (TC) and inhibitory concentrations (IC) between Vero E6 cells and podocytes. IC5O of ribavirin in podocytes is about 12-fold lower than in Vero E6 cells. In summary, ICW assay together with relevant human target cells represents an important tool for the study of hantaviral replication and drug testing.

Genetic features of the Puumala virus (Hantaviridae: Orthohantavirus) identified in the Moscow region

INTRODUCTION

Puumala virus (family Hantaviridae, genus Orthohantavirus) is distributed in most regions of the European part of Russia. However, information about its genetic variants circulating on the territory of the Central Federal District is extremely scarce.

MATERIALS AND METHODS

Rodents' tissue samples were tested after reverse transcription by PCR for the presence of hantaviral RNA. The amplified fragments of the L segment were sequenced by the Sanger method. For two samples, sequences of all three segments were obtained using the NGS method. Phylogenetic trees were built in the MEGA-X software.

RESULTS

Puumala virus was found in six samples. Based on the phylogenetic analysis of sequences of three segments, the obtained genetic variants belong to the sublineage previously designated as W-RUS.

CONCLUSION

A genetic variant of the Puumala virus, belonging to the subline W-RUS, circulates on the territory of the Volokolamsk district of Moscow region.

Molecular Detection of Orthohantavirus puumalaense in Plasma and Urine Samples from Hospitalized Patients Presenting with a Serologically Confirmed Acute Hantavirus Infection in France

Molecular detection of Orthohantavirus puumalaense (PUUV) RNA during the course of the disease has been studied in blood of patients in Sweden and Slovenia. The use of urine has been poorly investigated. The aims of this work were to study PUUV RNA detection in plasma from a cohort of patients in France where a different PUUV lineage circulates and to assess the use of urine instead of plasma. Matched plasma and urine samples were collected daily from hospitalized patients presenting with fever, pain, and thrombocytopenia within the last 8 days and testing positive for IgM and IgG against PUUV in serum collected at inclusion and/or approximately 1 month after release. RNA was extracted from samples, and PUUV RNA was detected using real-time reverse transcription-PCR for plasma and urine samples. Sixty-seven patients presented a serologically confirmed acute hantavirus infection. At inclusion, PUUV RNA was detected in plasma from 55 of 62 patients (88.7%) sampled within the first week after disease onset, whereas it was detected in 15 of 60 (25.0%) of matched urine samples. It was then detected from 33 (71.7%) and 2 (4.4%) of 46 patients discharged from the hospital during the second week after disease onset, in plasma and urine, respectively. When PUUV RNA was detected in urine it was also detected in plasma, and not vice versa. Detection of PUUV RNA in plasma from hospitalized patients in France is similar to that observed in Sweden and Slovenia. Urine is not an appropriate sample for this detection.

Occupational Hantavirus Infections in Agricultural and Forestry Workers: A Systematic Review and Metanalysis

Hantaviruses are zoonotic pathogens that can cause serious human disorders, including hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. As the main risk factor for human infections is the interaction with rodents, occupational groups such as farmers and forestry workers are reportedly at high risk, but no summary evidence has been collected to date. Therefore, we searched two different databases (PubMed and EMBASE), focusing on studies reporting the prevalence of hantaviruses in farmers and forestry workers. Data were extracted using a standardized assessment form, and results of such analyses were systematically reported, summarized and compared. We identified a total of 42 articles, including a total of 28 estimates on farmers, and 22 on forestry workers, with a total workforce of 15,043 cases (821 positive cases, 5.5%). A pooled seroprevalence of 3.7% (95% confidence interval [95% CI] 2.2–6.2) was identified in farmers, compared to 3.8% (95% CI 2.6–5.7) in forestry workers. Compared to the reference population, an increased occurrence was reported for both occupational groups (odds ratio [OR] 1.875, 95% CI 1.438–2.445 and OR 2.892, 95% CI 2.079–4.023 for farmers and forestry workers, respectively). In summary, our analyses stress the actual occurrence of hantaviruses in selected occupational groups. Improved understanding of appropriate preventive measures, as well as further studies on hantavirus infection rates in reservoir host species (rodents, shrews, and bats) and virus transmission to humans, is needed to prevent future outbreaks.

The Distribution of Puumala orthohantavirus Genome Variants Correlates with the Regional Landscapes in the Trans-Kama Area of the Republic of Tatarstan

In the European part of Russia, the highest number of hemorrhagic fever with renal syndrome (HFRS) cases are registered in the Volga Federal District (VFD), which includes the Republic of Tatarstan (RT). Puumala orthohantavirus (PUUV) is the main causative agent of HFRS identified in the RT. The goal of the current study is to analyze the genetic variations of the PUUV strains and possible presence of chimeric and reassortant variants among the PUUV strains circulating in bank vole populations in the Trans-Kama area of the RT. Complete S segment CDS as well as partial M and L segment coding nucleotide sequences were obtained from 40 PUUV-positive bank voles and used for the analysis. We found that all PUUV strains belonged to RUS genetic lineage and clustered in two subclades corresponding to the Western and Eastern Trans-Kama geographic areas. PUUV strains from Western Trans-Kama were related to the previously identified strain from Teteevo in the Pre-Kama area. It can be suggested that the PUUV strains were introduced to the Teteevo area as a result of the bank voles’ migration from Western Trans-Kama. It also appears that physical obstacles, including rivers, could be overcome by migrating rodents under favorable circumstances. Based on results of the comparative and phylogenetic analyses, we propose that bank vole distribution in the Trans-Kama area occurred upstream along the river valleys, and that watersheds could act as barriers for migrations. As a result, the diverged PUUV strains could be formed in closely located populations. In times of extensive bank vole population growth, happening every 3–4 years, some regions of watersheds may become open for contact between individual rodents from neighboring populations, leading to an exchange of the genetic material between divergent PUUV strains.

Antiviral Efficacy of Ribavirin and Favipiravir against Hantaan Virus

Ecological changes, population movements and increasing urbanization promote the expansion of hantaviruses, placing humans at high risk of virus transmission and consequent diseases. The currently limited therapeutic options make the development of antiviral strategies an urgent need. Ribavirin is the only antiviral used currently to treat hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus (HTNV), even though severe side effects are associated with this drug. We therefore investigated the antiviral activity of favipiravir, a new antiviral agent against RNA viruses. Both ribavirin and favipiravir demonstrated similar potent antiviral activity on HTNV infection. When combined, the efficacy of ribavirin is enhanced through the addition of low dose favipiravir, highlighting the possibility to provide better treatment than is currently available.