Puumala Virus Research Articles

Poor Prognosis for Puumala Virus Infections Predicted by Lymphopenia and Dyspnea

We investigated a prospective cohort of 23 patients who had Puumala virus infection in Austria to determine predictors of infection outcomes. We reviewed routinely available clinical and laboratory parameters collected when patients initially sought care. Low absolute lymphocyte count and dyspnea were parameters associated with a severe course of infection.

Optimization of storage conditions for Puumala virus based vaccine

We report the effects of storage conditions and human serum albumin addition to the vaccine composition on the immunogenic properties of an experimental vaccine against hemorrhagic fever with renal syndrome. To obtain an experimental vaccine, the Puumala virus, propagated in Vero cells culture, was concentrated, inactivated with beta-propiolactone, and purified by chromatography on the CaptoCore 700 multimodal sorbent (GE Healthcare). The target component in the vaccine was 20.2 106 of viral RNA copies/ml. The humoral immune response to the vaccine was determined by measuring the neutralizing antibodies in the blood serum of immunized Syrian hamsters (Mesocricetus auratus). It was revealed that the Puumala virus inactivated with beta-propiolactone induces a pronounced humoral immune response, which indicates preservation of relevant immunogenic epitopes. Аccording to our study, viral RNA is more stable during storage of the inactivated vs. intact virus. It was confirmed that full virus inactivation occurred after 24 hours of storage at 37C. A significant decrease in the virus immunogenicity during the thermal inactivation was noted, which confirms the need for careful selection of storage conditions for thermolabile Hantaviruses. A direct correlation was observed between viral titer and viral RNA copy number/ml. Adding human serum albumin stabilized viral infectivity during storage: Puumala virus titer remained at the same level for 3 months of storage at 62C, whereas without albumin, the titer decreased to undetectable level. The addition of 0.1% human serum albumin to the inactivated virus stabilized its immunogenic properties during long-term storage. It was shown that vaccine preparations with human serum albumin (0.11%) show higher dose-dependent stability upon repeated freezing assessed by detecting viral RNA level and their immunogenicity. It can be assumed that human serum albumin provides better preservation of of viral genetic material during storage, as well the protein epitopes responsible for the protective immune response in the form of neutralizing antibodies induction, undergo less pronounced conformational changes in the presence of albumin. These data support the addition of human serum albumin to the vaccine formulation.

The impact of wildlife and environmental factors on hantavirus infection in the host and its translation into human risk.

Identifying factors that drive infection dynamics in reservoir host populations is essential in understanding human risk from wildlife-originated zoonoses. We studied zoonotic Puumala orthohantavirus (PUUV) in the host, the bank vole (Myodes glareolus), populations in relation to the host population, rodent and predator community and environment-related factors and whether these processes are translated into human infection incidence. We used 5-year rodent trapping and bank vole PUUV serology data collected from 30 sites located in 24 municipalities in Finland. We found that PUUV seroprevalence in the host was negatively associated with the abundance of red foxes, but this process did not translate into human disease incidence, which showed no association with PUUV seroprevalence. The abundance of weasels, the proportion of juvenile bank voles in the host populations and rodent species diversity were negatively associated with the abundance index of PUUV positive bank voles, which, in turn, showed a positive association with human disease incidence. Our results suggest certain predators, a high proportion of young bank vole individuals, and a diverse rodent community, may reduce PUUV risk for humans through their negative impacts on the abundance of infected bank voles.

The pathogenesis of zoonotic viral infections: Lessons learned by studying reservoir hosts.

Zoonotic viral infections that cause severe disease or even death in some people may be asymptomatic or mild in reservoir hosts. Comparison of the pathogenesis of these two host categories may potentially explain the difference in disease. However, infections in reservoir hosts are often neglected. Therefore, we compared the pathogenesis of rabies virus, macacine alphaherpesvirus, West Nile virus, Puumala orthohantavirus, monkeypox virus, Lassa mammarenavirus, H5N1 highly pathogenic avian influenza, Marburg virus, Nipah virus, Middle East respiratory syndrome, and simian/human immunodeficiency viruses in both humans and reservoir hosts. We showed that most aspects of the pathogeneses were remarkably similar. The remaining differences lead to the identification of tipping points in the pathogeneses that are important for explaining the disease outcome in severe human cases. Further elucidating these tipping points by studying zoonotic viral infections in their reservoir hosts may teach us how to reduce the severity of zoonotic viral diseases in humans.

Risk of lymphoid malignancies increased after Puumala virus infection in Finland, 2009-2019: A retrospective register-based cohort study

ObjectivesThe Puumala virus (PUUV) is a hantavirus that causes hemorrhagic fever with renal syndrome. Studies showing an increased risk of lymphoid malignancies after hantavirus infection, together with the observation that PUUV infects B cells, motivated us to study the risk of lymphoid malignancies after PUUV infection. MethodsWe linked data from the Finnish Cancer Registry and National Infectious Diseases Register for 2009-2019. We used a time-dependent Cox regression model to evaluate the hazard of the lymphoid malignancies grouped according to the HAEMACARE classification. ResultsWe identified 68 cases of lymphoid malignancies after PUUV infection among 16,075 PUUV-infected individuals during 61,114,826 person-years of observation. A total of 10 cases occurred within 3-<12 months and 38 within 1-<5 years after PUUV infection, and the risk of lymphoid malignancies increased with hazard ratios (HRs) of 2.0 (95% confidence interval [CI], 1.1-3.7) and 1.6 (95% CI, 1.2-2.3), respectively. The group of mature B cell neoplasms showed an increased risk 3-<12 months and 1-<5 years after PUUV infection, HR 2.2 (95% CI, 1.2-4.3) and HR 1.8 (95% CI, 1.3-2.5), respectively. ConclusionPUUV infection is associated with lymphoid malignancies in the Finnish population, supporting the earlier studies. Further research is required to understand the pathophysiological mechanisms behind this association.

Machine learning identifies straightforward early warning rules for human Puumala hantavirus outbreaks

Human Puumala virus (PUUV) infections in Germany fluctuate multi-annually, following fluctuations of the bank vole population size. We applied a transformation to the annual incidence values and established a heuristic method to develop a straightforward robust model for the binary human infection risk at the district level. The classification model was powered by a machine-learning algorithm and achieved 85% sensitivity and 71% precision, despite using only three weather parameters from the previous years as inputs, namely the soil temperature in April of two years before and in September of the previous year, and the sunshine duration in September of two years before. Moreover, we introduced the PUUV Outbreak Index that quantifies the spatial synchrony of local PUUV-outbreaks, and applied it to the seven reported outbreaks in the period 2006–2021. Finally, we used the classification model to estimate the PUUV Outbreak Index, achieving 20% maximum uncertainty.

Tropism of Puumala orthohantavirus and Endoparasite Coinfection in the Bank Vole Reservoir.

In Europe, most cases of human hantavirus disease are caused by Puumala orthohantavirus (PUUV) transmitted by bank voles (Clethrionomys glareolus, syn. Myodes glareolus), in which PUUV causes inconspicuous infection. Little is known about tropism and endoparasite coinfections in PUUV-infected reservoir and spillover-infected rodents. Here, we characterized PUUV tropism, pathological changes and endoparasite coinfections. The voles and some non-reservoir rodents were examined histologically, immunohistochemically, by in situ hybridization, indirect IgG enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction. PUUV RNA and anti-PUUV antibodies were detected simultaneously in a large proportion of the bank voles, indicating persistent infection. Although PUUV RNA was not detected in non-reservoir rodents, the detection of PUUV-reactive antibodies suggests virus contact. No specific gross and histological findings were detected in the infected bank voles. A broad organ tropism of PUUV was observed: kidney and stomach were most frequently infected. Remarkably, PUUV was detected in cells lacking the typical secretory capacity, which may contribute to the maintenance of virus persistence. PUUV-infected wild bank voles were found to be frequently coinfected with Hepatozoon spp. and Sarcocystis (Frenkelia) spp., possibly causing immune modulation that may influence susceptibility to PUUV infection or vice versa. The results are a prerequisite for a deeper understanding of virus-host interactions in natural hantavirus reservoirs.

Hemorrhagic Fever with Renal Syndrome in Asia: History, Pathogenesis, Diagnosis, Treatment, and Prevention.

Hemorrhagic Fever with Renal Syndrome (HFRS) is the most frequently diagnosed zoonosis in Asia. This zoonotic infection is the result of exposure to the virus-contaminated aerosols. Orthohantavirus infection may cause Hemorrhagic Fever with Renal Syndrome (HRFS), a disease that is characterized by acute kidney injury and increased vascular permeability. Several species of orthohantaviruses were identified as causing infection, where Hantaan, Puumala, and Seoul viruses are most common. Orthohantaviruses are endemic to several Asian countries, such as China, South Korea, and Japan. Along with those countries, HFRS tops the list of zoonotic infections in the Far Eastern Federal District of Russia. Recently, orthohantavirus circulation was demonstrated in small mammals in Thailand and India, where orthohantavirus was not believed to be endemic. In this review, we summarized the current data on orthohantaviruses in Asia. We gave the synopsis of the history and diversity of orthohantaviruses in Asia. We also described the clinical presentation and current understanding of the pathogenesis of orthohantavirus infection. Additionally, conventional and novel approaches for preventing and treating orthohantavirus infection are discussed.

Characterization of a Panel of Cross-Reactive Hantavirus Nucleocapsid Protein-Specific Monoclonal Antibodies.

Hantaviruses are emerging pathogens with a worldwide distribution that can cause life-threatening diseases in humans. Monoclonal antibodies (MAbs) against hantavirus nucleocapsid (N) proteins are important tools in virus diagnostics, epidemiological studies and basic research studies on virus replication and pathogenesis. Here, we extend the collection of previously generated MAbs raised against a segment of Puumala orthohantavirus (PUUV) N protein harbored on virus-like particles (VLPs) and MAbs against N proteins of Sin Nombre orthohantavirus/Andes orthohantavirus by generating nine novel MAbs against N proteins of Dobrava-Belgrade orthohantavirus (DOBV), Tula orthohantavirus (TULV), Thottapalayam thottimvirus (TPMV) and PUUV. In order to have a wide collection of well-described hantavirus-specific MAbs, the cross-reactivity of novel and previously generated MAbs was determined against N proteins of 15 rodent- and shrew-borne hantaviruses by different immunological methods. We found that all MAbs, excluding TPMV-specific MAbs, demonstrated different cross-reactivity patterns with N proteins of hantaviruses and recognized native viral antigens in infected mammalian cells. This well-characterized collection of cross-reactive hantavirus-specific MAbs has a potential application in various fields of hantavirus research, diagnostics and therapy.

Seroprevalence of Hantavirus in Forestry Workers, Northern France, 2019-2020.

We aimed to estimate the seroprevalence of Puumala orthohantavirus (PUUV) among forestry workers in northern France, and to explore sociodemographic risk factors. We conducted a random cross-sectional seroprevalence survey among 1777 forestry workers in 2019-2020. The presence of immunoglobulin G against PUUV antigens in serum was assessed using enzyme-linked immunosorbent assay and confirmed using immunofluorescence assay. Poisson regression models were used to explore factors associated with seropositivity. Weighted seroprevalence was 5% (3-6) in northeastern France, 4% (2-6) in north central France, and 1% in two regions located in the center of the country (Auvergne and Limousin). There were no seropositive workers detected in northwestern France. Seropositivity was associated with age, sex, and cumulative seniority in the forestry sector. Seroprevalence was highest in known endemic areas of the northeast and lowest in the northwest. Nevertheless, we found serological evidence of PUUV infection in two regions located in the center of the country, suggesting circulation of the virus in these regions, previously thought to be non-endemic.

Puumala Orthohantavirus Reassortant Genome Variants Likely Emerging in the Watershed Forests.

Hemorrhagic fever with renal syndrome (HFRS) remains a prevalent zoonosis in the Republic of Tatarstan (RT), Russian Federation. Puumala orthohantavirus (PUUV), carried by bank voles (Myodes glareolus), is the principal zoonotic pathogen of HFRS in the RT. In this study, we sought to demonstrate the similarity of the PUUV genetic sequences detected in HFRS case patients and bank vole samples previously collected in some areas of the RT. Furthermore, we intended to identify the reassortant PUUV genomes and locate a potential site for their emergence. During 2019 outbreaks, the PUUV genome sequences of the S and M segments from 42 HFRS cases were analysed and compared with the corresponding sequences from bank voles previously trapped in the RT. Most of the PUUV strains from HFRS patients turned out to be closely related to those isolated from bank voles captured near the site of the human infection. We also found possible reassortant PUUV genomes in five patients while they were absent in bank voles. The location of the corresponding HFRS infection sites suggests that reassortant PUUV genomes could emerge in the bank voles that inhabit the forests on the watershed between the Kazanka River and Myosha River. These findings could facilitate the search for the naturally occurring reassortants of PUUV in bank vole populations.

Idiosyncratic effects of coinfection on the association between systemic pathogens and the gut microbiota of a wild rodent, the bank vole Myodes glareolus.

The effects of systemic pathogens on gut microbiota of wild animals are poorly understood. Furthermore, coinfections are the norm in nature, yet most studies of pathogen-microbiota interactions focus on effects of single pathogen infections on gut microbiota. We examined the effects of four systemic pathogens (bacteria Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato, apicomplexan protozoa Babesia microti and Puumala orthohantavirus) and coinfections among them on the (bacterial) gut microbiota of wild bank voles Myodes glareolus. We hypothesized that: (1) the effects of coinfection on gut microbiota generally differ from those of a single pathogen infection, (2) systemic pathogens have individual (i.e. distinct) associations with gut microbiota, which are modified by coinfection and (3) the effects of coinfection (compared with those of single infection) are idiosyncratic (i.e. pathogen-specific). The gut microbiota of coinfected bank voles differed from that of single pathogen infected individuals, although, as predicted, the effects of coinfections were unique for each pathogen. After accounting for coinfections, only Puumala orthohantavirus was associated with higher α-diversity; however, all pathogens affected gut microbiota ß-diversity in a pathogen-specific way, affecting both rare and abundant gut bacteria. Our results showed that the effects of systemic pathogens on host's gut microbiota vary depending on the pathogen species, resulting in idiosyncratic signatures of coinfection. Furthermore, our results emphasize that neglecting the impact of coinfections can mask patterns of pathogen-microbiota associations.

Evidence of orthohantavirus and leptospira infections in small mammals in an endemic area of Gampaha district in Sri Lanka

BackgroundOrthohantaviruses and leptospira are emerging zoonotic pathogens of high public health significance. The epidemiology of orthohantavirus infections and leptospirosis is similar and presents related clinical pictures in humans. However, a paucity of data on actual reservoir hosts for orthohantaviruses and leptospira exists. Therefore, this study aimed at determining the occurrence of orthohantaviruses and leptospira in small mammals captured in an endemic region of Sri Lanka.MethodsRodents and shrews were morphologically and/or genetically identified using morphological keys and DNA barcoding techniques targeting the cytochrome oxidase b subunit gene (Cytb). Lung tissues and sera were subsequently analyzed for the presence of orthohantavirus RNA using qRT-PCR. Sera of rats were tested for IgG antibodies against orthohantaviruses and leptospira.ResultsForty-three (43) small mammals representing: Rattus (R.) rattus (black rat) or R. tanezumi (Asian rat), Suncus murinus (Asian house shrew), R. norvegicus (brown rat) and Mus musculus (house mouse) were investigated. No orthohantavirus RNA was detected from the lung tissue or serum samples of these animals. Elevated levels of IgG antibodies against Puumala orthohantavirus (PUUV) and/or Seoul orthohantavirus (SEOV) antigens were detected in sera of 28 (72%) out of the 39 rats analysed. Interestingly, 36 (92%) of the 39 rats also showed presence of anti leptospira-IgG antibodies in their serum, representing dual infection or dual exposure in 26/39 (66.7%) of examined rats.ConclusionsThis project targets important public health questions concerning the occupational risk of orthohantavirus infections and/or leptospirosis in an endemic region of Sri Lanka. Most rats (72%) in our study displayed antibodies reacting to orthohantavirus NP antigens, related to PUUV and/or SEOV. No correlation between the orthohantavirus and leptospira IgG antibody levels were noticed. Finally, a combination of both morphological and DNA barcoding approaches revealed that several species of rats may play a role in the maintenance and transmission of orthohantavirus and leptospira in Sri Lanka.

Immune response evaluation in the guinea pigs after immunization with the experimental Puumala virus vaccine

In the Russian Federation, the vaccine against hemorrhagic fever with renal syndrome is at the stage of preclinical and clinical trials. The aim of the study was to analyze an effect of vaccine schedule on neutralizing antibodies (nAB) dynamics in guinea pig models applied with experimental Puumala virus based hantavirus vaccine (HV). Quantitative evaluation of neutralizing antibodies was presented as antibody titer geometric mean expressed in binary logarithms (log2) by the 50% reduction of focus-forming units (FRNT50) in Vero cell in the focus reduction neutralization test. The HV dual inoculation to guinea pigs was carried out in 14 day intervals, booster injection was applied on day 182 after the onset, in the thigh muscle tissue by using 0.3 ml undiluted (HV-u/d) and in the 1/10 dilution (HV-1/10). nAB titer on day 14 after the first HV-u/d and HV-1/10 injection was measured to be at titer of 5.50.3 and 4.80.3, respectively. After the second injection, the nAB peak was as high as 90.2 on day 42 after the first HV-u/f injection, and 6.50.2 on day 14 after the HV-1/10 injection. nAB decreased down to 6.20.3 and 50.3, respectively, on day 364 after the first injection. The booster HV-u/d and HV-1/10 injection induced increase in nAB up to 9.50.3 and 6.50.3, respectively. After the booster injection, it induced significantly higher nAB observed on day 238 after the first HV-u/d injection and delayed up to the 294 day for the HV-1/10. The results of the study indicated the early formation of the immune response, long-term nAB persistence and significantly enhanced immune response after the booster injection on day 182, which indicated a potential for the booster injection a year later. The immunological efficacy and protective activity of the vaccine schedule may be finally assessed according to the results of clinical trials.

Diverse susceptibilities and responses of human and rodent cells to orthohantavirus infection reveal different levels of cellular restriction.

Orthohantaviruses are rodent-borne emerging viruses that may cause severe diseases in humans but no apparent pathology in their small mammal reservoirs. However, the mechanisms leading to tolerance or pathogenicity in humans and persistence in rodent reservoirs are poorly understood, as is the manner in which they spread within and between organisms. Here, we used a range of cellular and molecular approaches to investigate the interactions of three different orthohantaviruses–Puumala virus (PUUV), responsible for a mild to moderate form of hemorrhagic fever with renal syndrome in humans, Tula virus (TULV) with low pathogenicity, and non-pathogenic Prospect Hill virus (PHV)–with human and rodent host cell lines. Besides the fact that cell susceptibility to virus infection was shown to depend on the cell type and virus strain, the three orthohantaviruses were able to infect Vero E6 and HuH7 human cells, but only the former secreted infectious particles. In cells derived from PUUV reservoir, the bank vole (Myodes glareolus), PUUV achieved a complete viral cycle, while TULV did not enter the cells and PHV infected them but did not produce infectious particles, reflecting differences in host specificity. A search for mature virions by electron microscopy (EM) revealed that TULV assembly occurred in part at the plasma membrane, whereas PHV particles were trapped in autophagic vacuoles in cells of the heterologous rodent host. We described differential interactions of orthohantaviruses with cellular factors, as supported by the cellular distribution of viral nucleocapsid protein with cell compartments, and proteomics identification of cellular partners. Our results also showed that interferon (IFN) dependent gene expression was regulated in a cell and virus species dependent manner. Overall, our study highlighted the complexity of the host-virus relationship and demonstrated that orthohantaviruses are restricted at different levels of the viral cycle. In addition, the study opens new avenues to further investigate how these viruses differ in their interactions with cells to evade innate immunity and how it depends on tissue type and host species.

Comprehensive computational analysis reveals YXXΦ[I/L/M/F/V] motif and YXXΦ-like tetrapeptides across HFRS causing Hantaviruses and their association with viral pathogenesis and host immune regulation.

Hemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic disease transmitted through aerosolized excrement of rodents. The etiology of HFRS is complex due to the involvement of viral factors and host immune and genetic factors. The viral species that dominantly cause HFRS are Puumala virus (PUUV), Seoul virus (SEOV), Dobrava-Belgrade virus (DOBV), and Hantaan virus (HTNV). Despite continuous prevention and control measures, HFRS remains a significant public health problem worldwide. The nucleocapsid protein of PUUV, SEOV, DOBV, and HTNV is a multifunctional viral protein involved in various stages of the viral replication cycle. However, the exact role of nucleoproteins in viral pathogenesis is yet to be discovered. Targeting a universal host protein exploited by most viruses would be a game-changing strategy that offers broad-spectrum solutions and rapid epidemic control. The objective of this study is to understand the replication and pathogenesis of PUUV, SEOV, DOBV, and HTNV by targeting tyrosine-based motif (YXXΦ[I/L/M/F/V]) and YXXΦ-like tetrapeptides. In the light of the current study, in silico analysis uncovered many different YXXΦ[I/L/M/F/V] motifs and YXXΦ-like tetrapeptides within nucleoproteins of PUUV, SEOV, DOBV, and HTNV. Following that, the 3D structures of nucleoproteins were predicted using AlphaFold2 to map the location of YXXΦ[I/L/M/F/V] motif and YXXΦ-like tetrapeptides in a 3D environment. Further, in silico analysis and characterization of Post Translational Modifications (PTMs) revealed multiple PTMs sites within YXXΦ[I/L/M/F/V] motif and YXXΦ-like tetrapeptides, which contribute to virulence and host immune regulation. Our study proposed that the predicted YXXΦ[I/L/M/F/V] motif and YXXΦ-like tetrapeptides may confer specific functions such as virulence, host immune regulation, and pathogenesis to nucleoproteins of PUUV, SEOV, DOBV, and HTNV. However, in vivo and in vitro studies on YXXΦ[I/L/M/F/V] motif and YXXΦ-like tetrapeptides will assign new biological roles to these antiviral targets.

Hantavirus Hemorrhagic Fever with Renal Syndrome - Suspected Cases in Sri Lanka: Clinical Picture and Epidemiology from 2013–2021

Hantavirus hemorrhagic fever with renal syndrome (HFRS) is an emerging zoonotic disease in Europe and Asia, which is clinically indistinguishable from leptospirosis. A total of 1,032 patients with clinical suspicion of HFRS-like illness were included in the analysis from March 2013 to March 2021. Of these, 168 were positive for hantavirus immunoglobulin M (IgM) antibodies. Thirty-one of 35 patients had a 4-fold increase in IgG antibody titer with paired serum, confirming acute hantavirus infections. The detected antibodies showed a diverse pattern, strongly cross-reacting with the Seoul, Hantaan, and Puumala virus antigens. All the IgM-positive patients had no serological evidence of acute dengue or leptospirosis and had classical features of HFRS, including fever, thrombocytopenia, and renal involvement. More than 90% of patients had a history of rodent exposure 2-3 weeks prior to the onset of the fever. The highest number of positive cases was diagnosed in the Western and North Central Provinces of Sri Lanka during the paddy harvesting seasons. A significant number of patients develop severe complications with high mortality rates. Therefore, hantavirus infection should be considered as a differential diagnosis for leptospirosis-like illnesses in Sri Lanka.

A fatal case of haemorrhagic fever with renal syndrome in Kursk Region, Russia, caused by a novel Puumala virus clade.

Haemorrhagic fever with renal syndrome (HFRS) is the most widespread natural-focal human disease in the Russian Federation. In this study, we report virological assessment of a fatal case of HFRS-PUUV (Puumala virus) in the Kursk Region. The infection caused severe multiorgan failure and the maximum viral load was detected in the tissue of the spleen. Viral sequences were obtained from the patient's autopsy material and lung tissues of bank voles captured in the region. These sequences formed a new clade in the PUUV phylogenetic tree, an outgroup to all known Russian (RUS) lineage sequences. On the other hand viruses collected in the Kursk Region grouped with the RUS lineage and are separated from all other PUUV linages. We propose to nominate this novel group as W-RUS as the identified viruses were collected near the western Russian boundary. The recombination signals between their ancestors and RUS lineage representatives from the Volga region were revealed. The strain Samara_94/CG/2005 suggestively emerged as the result of reassortment between the ancestors of W-RUS and DTK-Ufa-97.

Urine excreted antibodies significance in the hemorrhagic fever with renal syndrome specific diagnosis

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is an acute viral zoonosis. Being widespread in Eurasia, it holds a leading place in Russia among natural focal human diseases. The vast majority of HFRS cases in Russia, about 98%, are associated with Puumala virus. The disease is characterized by a wide range of clinical manifestations. Early specific diagnostics appears to be of a great importance for starting timely pathogenic therapy. The aim of the study was to clarify the diagnostic value of detecting hantavirus antibodies in the HFRS suspected patient urine. Materials and methods. Blood sera and urine samples from 68 patients at the Infectious Diseases Hospital in the city of Ufa, obtained with a 2-day interval, as well as urine and blood serum samples from 15 convalescents 1, 2, 3 and 6 months after disease onset were examined for hantavirus antibodies. 53 blood sera and urine samples from patients residing in Moscow, Moscow and Samara regions collected at different time points during the disease course were investigated in parallel. Antibodies were detected by the indirect immunofluorescence method. Results. On day 3, 4, 5 and 6 of disease, while specific antibodies were detected in the blood serum, antibodies in the urine were found in 85.7%, 89.4%, 93.1% and 100% of patients, respectively. The peak quantity of antibodies was excreted in the urine from days 5 to 11, which corresponds to the oliguric stage of the disease. In the convalescent period, antibodies were still detected in urine 1, 2 and 3 months afterwards in 86.7%, 46% and 20% of cases, respectively, but not detected 6 months later, which probably reflects the process of long-term restoration of the kidneys function. A moderate positive correlation between specific antibodies in serum and urine was observed only in the oliguric period of the disease. Conclusions. Detection of hantavirus antibodies simultaneously in blood serum and urine of febrile patients instead of paired blood sera allows to conduct HFRS diagnostics within the very first days of hospitalization and prevent severe complications due to timely pathogenic therapy.

Serum Markers Associated with Disease Severity in a Bosnian Hemorrhagic Fever with Renal Syndrome Cohort.

Puumala orthohantavirus (PUUV) is endemic in Europe and can cause hemorrhagic fever with renal syndrome (nephropathia epidemica). Disease features include fever, thrombocytopenia, and acute kidney injury (AKI). This retrospective cohort study of forty PUUV patients aims to characterize associations of serum immunological, hemostatic or kidney injury markers to disease severity. While interleukin-18 (IL-18) was significantly increased in severely thrombocytopenic patients (<100 × 109 platelets/L) compared to patients with higher platelet counts, RANTES was significantly decreased in these patients. These data suggest that patients with significant thrombocytopenia might have experienced pronounced Th1 immune responses. When kidney dysfunction was used as the primary disease outcome, recently identified AKI biomarkers (Cystatin C, insulin-like growth factor-binding protein 7, Nephrin, and trefoil factor 3) were significantly upregulated in patients with severe PUUV infection, defined as the estimated glomerular filtration rate (eGFR) below 30 m/min/1.73 m2. The increased expression of these markers specifically indicates pathology in glomeruli and proximal tubuli. Furthermore, E-selectin was significantly higher while interferon gamma-induced protein 10 (IP-10) was significantly lower in PUUV patients with more severe kidney dysfunction compared to patients with higher eGFR-values. Increased E-selectin illustrates the central role of endothelial cell activation, whereas decreased IP-10 could indicate a less important role of this cytokine in the pathogenesis of kidney dysfunction.