HFRS and hantaviruses in the Balkans/South-East Europe

Serum Concentrations of TIM-3, LAG-3, and PD-1 in Patients with Hemorrhagic Fever with Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease widespread in Europe and Asia. HFRS is caused by negative-sensed single-stranded RNA orthohantaviruses transmitted to humans through inhaling aerosolized excreta of infected rodents. Symptoms of HFRS include acute kidney injury, thrombocytopenia, hemorrhages, and hypotension. The immune response raised against viral antigens plays an important role in the pathogenesis of HFRS. Inhibitory co-receptors are essential in regulating immune responses, mitigating immunopathogenesis, and reducing tissue damage. Our research showed an increased soluble form of inhibitory co-receptors TIM-3, LAG-3, and PD-1 in HFRS patients associated with disease severity. Our study aimed to investigate the impact of HFRS on the concentrations of soluble forms of inhibitory receptors TIM-3, LAG-3, and PD-1 in the patient's serum and the potential correlation with key clinical parameters. Our study aimed to investigate the impact of HFRS on the concentrations of soluble forms of inhibitory receptors TIM-3, LAG-3, and PD-1 in the patient's serum and their possible association with relevant clinical parameters. Using multiplex immunoassay, we found elevated levels of TIM-3, LAG-3, and PD-1 proteins in the serum of HFRS patients. Furthermore, increased levels were associated with creatinine, urea, lactate dehydrogenase concentrations, and platelet count. These findings suggest that these proteins play a role in regulating the immune response and disease progression.

Phylogenetic Characterization of Orthohantavirus dobravaense (Dobrava Virus)

We report complete coding sequences of Orthohantavirus dobravaense (Dobrava virus) Igneada strains and phylogenetic characterization of all available complete coding sequences. Our analyses suggested separation of host-dependent lineages, followed by geographic clustering. Surveillance of orthohantaviruses using complete genomes would be useful for assessing public health threats from Dobrava virus.

Hantavirus in humans: a review of clinical aspects and management

Hantavirus infections are part of the broad group of viral haemorrhagic fevers. They are also recognised as a distinct model of an emergent zoonotic infection with a global distribution. Many factors influence their epidemiology and transmission, such as climate, environment, social development, ecology of rodent hosts, and human behaviour in endemic regions. Transmission to humans occurs by exposure to infected rodents in endemic areas; however, Andes hantavirus is unique in that it can be transmitted from person to person. As hantaviruses target endothelial cells, they can affect diverse organ systems; increased vascular permeability is central to pathogenesis. The main clinical syndromes associated with hantaviruses are haemorrhagic fever with renal syndrome (HFRS), which is endemic in Europe and Asia, and hantavirus cardiopulmonary syndrome (HCPS), which is endemic in the Americas. HCPS and HFRS are separate clinical entities, but they share several features and have many overlapping symptoms, signs, and pathogenic alterations. For HCPS in particular, clinical outcomes are highly associated with early clinical suspicion, access to rapid diagnostic testing or algorithms for presumptive diagnosis, and prompt transfer to a facility with critical care units. No specific effective antiviral treatment is available.

Epidemiology and Clinical Course of Haemorrhagic Fever with Renal Syndrome in New Endemic Area for Hantavirus Infection in Croatia

BACKGROUND

Hantaviruses remain an important case of emerging and re-emerging infections in human medicine. This study aimed to analyse the epidemiology, clinical presentation, and outcome of hantavirus infections in the western part of Republic of Croatia, a new geographical area for hantavirus infections.

METHODS

Retrospective analysis of medical records of patients treated for hemorrhagic fever with renal syndrome (HFRS) at the infectious diseases Clinic of the Clinical Hospital Center in Rijeka, Croatia, from 1 January 2014, to 31 December 2021.

RESULTS

During the eight-year period, 251 patients were hospitalized and treated for HFRS, with epidemic outbreaks in years 2014 and 2021. Most patients had a typical clinical course of HFRS and received supportive care. Serological analysis revealed the Puumala Virus (PUUV) as the predominant etiology of the disease. Epidemiological analysis revealed clustering of infections in the region of Gorski Kotar and spread to the area on the Mediterranean coast (Adriatic Sea), which was previously considered an area free from hantavirus infections.

CONCLUSIONS

The presented results indicate the spread of hantavirus infections in Croatia from the central low-lying parts of the country to the tourist-attractive western area adjacent to the Mediterranean coast, which was previously considered free of hantavirus infections.

Hantavirus Infection in Children-A Pilot Study of Single Regional Center

BACKGROUND

Hantaviruses are infectious etiological agents of a group of rodent-borne hemorrhagic fevers, with two types of clinical manifestations in humans: hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS). According to available statistics, the disease occurs mainly in adults, but the lower incidence in the pediatric population might also be related to a lack of diagnosis possibilities or even unsatisfactory knowledge about the disease.

MATERIALS AND METHODS

The purpose of this study was to evaluate the cases of hemorrhagic fever with renal syndrome diagnosed and treated in the Department of Nephrology at St. Mary's Emergency Hospital for Children in Iasi, Romania, representative of the North-East of Romania. We also reviewed the specialized literature on the topic.

RESULTS

Between January 2017 and January 2022, eight cases of HFRS, all men, and seven from rural areas, aged 11-18 years old, were referred to our clinic because of an acute kidney injury (AKI). Seven cases were identified as Dobrava serotype while one case was determined by Haantan serotype.

CONCLUSIONS

HFRS should always be considered as a differential diagnosis when faced with a patient with AKI and thrombocytopenia. Dobrava serotype is the most common hantavirus subtype in the Balkans. For the specific prevention of human infections, mainly in high-risk groups, vaccines are needed. As far as we know, this is the first study on HFRS in Romanian children.

Multisectoral Perspectives on Global Warming and Vector-borne Diseases: a Focus on Southern Europe

Purpose of Review

The climate change (CC) or global warming (GW) modifies environment that favors vectors' abundance, growth, and reproduction, and consequently, the rate of development of pathogens within the vectors. This review highlights the threats of GW-induced vector-borne diseases (VBDs) in Southern Europe (SE) and the need for mitigation efforts to prevent potential global health catastrophe.

Recent Findings

Reports showed astronomical surges in the incidences of CC-induced VBDs in the SE. The recently (2022) reported first cases of African swine fever in Northern Italy and West Nile fever in SE are linked to the CC-modified environmental conditions that support vectors and pathogens' growth and development, and disease transmission.

Summary

VBDs endemic to the tropics are increasingly becoming a major health challenge in the SE, a temperate region, due to the favorable environmental conditions caused by CC/GW that support vectors and pathogens' biology in the previously non-endemic temperate regions.

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.

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.

Epidemiological study on the incidence of haemorrhagic fever with renal syndrome in five Western Balkan countries for a 10-year period: 2006-2015

BACKGROUND

Large-scale epidemics of haemorrhagic fever with renal syndrome (HFRS) have been reported mostly in Asia and Europe, with around 100,000 people affected each year. In the Southeast Europe, Balkan region, HFRS is endemic disease with approximately 100 cases per year. Our aim was to describe epidemiological characteristics of HFRS in five Western Balkan (WB) countries and to describe correlation between HFRS incidence and major meteorological event that hit the area in May 2014.

METHODS

National surveillance data of HFRS from Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia and Serbia obtained from 1 January 2006 to 31 December 2015 were collected and analysed.

RESULTS

In a 10-year period, a total of 1,065 HFRS patients were reported in five WB countries. Cumulative incidence rate ranged from 0.05 to 15.80 per 100.000 inhabitants (in North Macedonia and Montenegro respectively). Increasing number of HFRS cases was reported with a peak incidence in three specific years (2008, 2012, and 2014). Average incidence for the entire area was higher in males than females (5.63 and 1.90 per 100.000 inhabitants respectively). Summer was the season with the highest number of cases and an average incidence rate of 1.74/100.000 inhabitants across 10-year period. Haemorrhagic fever with renal syndrome incidence was significantly increased (7.91/100.000 inhabitants) in 2014, when a few months earlier, severe floods affected several WB countries. A strong significant negative correlation (r = -.84, p < .01) between the monthly incidence of HFRS and the number of months after May's floods was demonstrated for the total area of WB.

CONCLUSION

Our findings demonstrate that the HFRS incidence had similar distribution (general, age, sex and seasonality) across majority of the included countries. Summer was the season with the highest recorded incidence. Common epidemic years were detected in all observed countries as well as a negative correlation between the monthly incidence of HFRS and the number of months after May's cyclone.

Emerging and Neglected Viruses of Zoonotic Importance in Croatia

Several arboviruses have emerged in Croatia in recent years. Tick-borne encephalitis is endemic in continental counties; however, new natural micro-foci have been detected. Two autochthonous dengue cases were reported in 2010. West Nile virus emerged in 2012, followed by emergence of Usutu virus in 2013. Although high seroprevalence rates of Toscana virus have been detected among residents of Croatian littoral, the virus remains neglected, with only a few clinical cases of neuroinvasive infections reported. Lymphocytic choriomeningitis virus is a neglected neuroinvasive rodent-borne virus. So far, there are no reports on human clinical cases; however, the seroprevalence studies indicate the virus presence in the Croatian mainland. Puumala and Dobrava hantaviruses are widely distributing rodent-borne viruses with sporadic and epidemic occurrence. Hepatitis E virus is an emerging food-borne virus in Croatia. After the emergence in 2012, cases were regularly recorded. Seropositivity varies greatly by region and population group. Rotaviruses represent a significant healthcare burden since rotavirus vaccination is not included in the Croatian national immunization program. Additionally, rotaviruses are widely distributed in the Croatian ecosystem. A novel coronavirus, SARS-CoV-2, emerged in February 2020 and spread rapidly throughout the country. This review focuses on emerging and neglected viruses of zoonotic importance detected in Croatia.

Kidney Diseases Associated With Parvovirus B19, Hanta, Ebola, and Dengue Virus Infection: A Brief Review

Viral infection-associated kidney diseases are an emerging public health issue in both developing and developed countries. Many new viruses have emerged with new paradigms of kidney injury, either directly through their cytopathic effect or indirectly through immune-mediated glomerulopathy, tubulointerstitial disease, and acute kidney injury as part of multiorgan failure. Herein, we will discuss Parvovirus, which causes glomerulopathy, and Hanta, Ebola, and Dengue viruses, which cause viral hemorrhagic fever and acute kidney injury. Clinical manifestations also depend on extrarenal organ systems involved. Diagnosis of these viral infections is mainly based on a high index of suspicion, serologic testing, and isolation of viral DNA/RNA. Management is largely conservative, as specific antiviral agents are unavailable.

Molecular identification of Puumala orthohantavirus in Bulgaria

In Bulgaria, only Dobrava orthohantavirus has been detected in patients and in rodents. In order to elucidate possible Puumala orthohantavirus (PUUV) circulation, 131 bank voles (Myodes glareolus) were captured. PUUV RNA was detected in 14 (10.7%). Partial L segment sequences were recovered from six M. glareolus. Phylogenetic analysis showed that all PUUV sequences from this study clustered together among the Alpe-Adrian lineage. It is the first genetic evidence of the virus circulation in a Balkan country outside north-western Balkans. The findings in this study extended the known edge of virus distribution towards Southeastern Europe.

RECENT CHANGES IN INFECTIOUS DISEASES IN EUROPEAN WILDLIFE

Many infectious diseases originating from, or carried by, wildlife affect wildlife conservation and biodiversity, livestock health, or human health. We provide an update on changes in the epidemiology of 25 selected infectious, wildlife-related diseases in Europe (from 2010-16) that had an impact, or may have a future impact, on the health of wildlife, livestock, and humans. These pathogens were selected based on their: 1) identification in recent Europe-wide projects as important surveillance targets, 2) inclusion in European Union legislation as pathogens requiring obligatory surveillance, 3) presence in recent literature on wildlife-related diseases in Europe since 2010, 4) inclusion in key pathogen lists released by the Office International des Epizooties, 5) identification in conference presentations and informal discussions on a group email list by a European network of wildlife disease scientists from the European Wildlife Disease Association, or 6) identification as pathogens with changes in their epidemiology during 2010-16. The wildlife pathogens or diseases included in this review are: avian influenza virus, seal influenza virus, lagoviruses, rabies virus, bat lyssaviruses, filoviruses, canine distemper virus, morbilliviruses in aquatic mammals, bluetongue virus, West Nile virus, hantaviruses, Schmallenberg virus, Crimean-Congo hemorrhagic fever virus, African swine fever virus, amphibian ranavirus, hepatitis E virus, bovine tuberculosis ( Mycobacterium bovis), tularemia ( Francisella tularensis), brucellosis ( Brucella spp.), salmonellosis ( Salmonella spp.), Coxiella burnetii, chytridiomycosis, Echinococcus multilocularis, Leishmania infantum, and chronic wasting disease. Further work is needed to identify all of the key drivers of disease change and emergence, as they appear to be influencing the incidence and spread of these pathogens in Europe. We present a summary of these recent changes during 2010-16 to discuss possible commonalities and drivers of disease change and to identify directions for future work on wildlife-related diseases in Europe. Many of the pathogens are entering Europe from other continents while others are expanding their ranges inside and beyond Europe. Surveillance for these wildlife-related diseases at a continental scale is therefore important for planet-wide assessment, awareness of, and preparedness for the risks they may pose to wildlife, domestic animal, and human health.

Emerging Rodent-Borne Viral Zoonoses in Trento, Italy

Rodent-borne hanta- and arenaviruses are an emerging public health threat in Europe; however, their circulation in human populations is usually underestimated since most infections are asymptomatic. Compared to other European countries, Italy is considered 'low risk' for these viruses, yet in the Province of Trento, two pathogenic hantaviruses (Puumala and Dobrava-Belgrade virus) and one arenavirus (Lymphocytic Choriomeningitis Virus) are known to circulate in rodent reservoirs. In this paper, we performed a follow-up serological screening in humans to detect variation in the prevalence of these three viruses compared to previous analyses carried out in 2002. We also used a statistical model to link seropositivity to risk factors such as occupational exposure, cutting firewood, hunting, collecting mushrooms, having a garden and owning a woodshed, a dog or a companion rodent. We demonstrate a significant increase in the seroprevalence of all three target viruses between 2002 and 2015, but no risk factors that we considered were significantly correlated with this increase. We conclude that the general exposure of residents in the Alps to these viruses has probably increased during the last decade. These results provide an early warning to public health authorities, and we suggest more detailed diagnostic and clinical investigations on suspected cases.

Two cases of imported hemorrhagic fever with renal syndrome and systematic review of literature

Many factors are involved in the epidemiology of hemorrhagic fever with renal syndrome (HFRS). Imported cases, as well as those by emigrants, have been reported in literature worldwide. Our goal is to document two cases of HFRS, imported by two immigrants from two countries, and to make a review of the imported HFRS literature data. We performed a systematic literature review (PRISMA guidelines) of imported cases of HFRS and herein describe our two clinical cases. We found 20 published papers, with 16 of them in English and 4 in other languages. Twenty-three patients with travel- or immigration-associated HFRS, including our two cases, were identified. We included only papers that were in English. The average age of the patients was 35.9 ± 15.13 years, and the ratio of male to female was 8:1. Imported disease from Europe to Europe occurred in seven cases, America to Europe occurred in four cases, Europe to America occurred in two cases, America to America occurred in two cases, Asia to Asia in one case, Asia to Europe in one case, and Europe to Asia in one case. The results of the two cited cases are based on the clinical-laboratory, anamnestic, and serologic data for both the patients who tested positive for HFRS. Our systematic analysis shows that international travelers are important sources of infectious diseases. HFRS related to travel and immigration is a rare event. Principal risk factors for travelers and immigrants are camping outside recommended areas or under unsuitable conditions. In recent years, various publications have shown that international travelers and immigrants have expanded the spectrum of imported infectious diseases. The literature data show that the actual reported numbers of imported case of HFRS are limited.

Platelet Distribution Width at First Day of Hospital Admission in Patients with Hemorrhagic Fever with Renal Syndrome Caused by Hantaan Virus May Predict Disease Severity and Critical Patients' Survival

Thrombocytopenia is one of the main characteristics of hemorrhagic fever with renal syndrome (HFRS). This study aimed to evaluate the associations of platelet distribution width (PDW) with the disease severity and critical patients' survival of HFRS. The demographics, clinical data, and white blood cell and platelet parameters including PDW in 260 patients hospitalized for HFRS were analyzed. The results showed that PDW on the first day (PDW1) was positively associated with the disease severity (p = 0.005). Multiple regression analysis showed that in addition to age (odds ratio [OR], 1.091; 95% confidence interval [CI], 1.015-1.172) and occurrence of sepsis (OR, 22.283; 95% CI, 2.985-166.325), PDW1 (OR, 0.782; 95% CI, 0.617-0.992) was a risk factor of the mortality, having an area under the receiver operating characteristic curve of 0.709 (95% CI, 0.572-0.846, p = 0.013) for predicting mortality, with a sensitivity of 70% and a specificity of 67% at a cutoff of 16.5 fL, in patients with critical HFRS. These results suggest the potential of PDW at the first day of hospitalization as a valuable parameter for evaluating the severity of HFRS and a moderate parameter for predicting the prognosis of critical HFRS patients. A prospective study in large patient population is needed to validate these findings.

Haemorrhagic fever with renal syndrome in Montenegro, 2004-14

From 2004 to 2014, 106 cases of Human haemorrhagic fever with renal syndrome were notified in Montenegro, with a peak in 2014. Most of the cases occurred in summer, in the North-east and Central Montenegro, a hilly/mountainous area, that provides suitable habitats for the main rodent carriers. Cases were mainly males (71) and exposures were often working outdoor or spending time visiting mountains and lakes. Incidence correlated with average annual temperature increase and average annual rainfalls decrease, but not with land cover. Environment and climate effects on HFRS in Montenegro need further investigation to get insight into future trends.

Sequential assessment of clinical and laboratory parameters in patients with hemorrhagic fever with renal syndrome

Background

Information on the sequential appearance, duration, and magnitude of clinical and laboratory parameters in hemorrhagic fever with renal syndrome (HFRS) is limited.

Methods

Analysis of clinical and laboratory parameters obtained serially in 81 patients with HFRS, of whom 15 were infected with Dobrava virus and 66 with Puumala virus.

Results

The initial signs/symptoms, appearing on median day 1 of illness, were fever, headache, and myalgia. These were present in 86%, 65%, and 40% of patients and had a median duration of 4, 4, and 5.5 days, respectively. The signs/symptoms were followed by myopia (appearance on day 5), insomnia (day 6), oliguria/anuria (day 6), polyuria (day 9), and sinus bradycardia (day 9.5). These were present in 35%, 30%, 28%, 91%, and 35% of patients; their median duration was 2, 2, 2, 7, and 1 day, respectively. Laboratory abnormalities, including thrombocytopenia, elevated alanine aminotransferase, CRP, procalcitonin, creatinine, diminished glomerular filtration rate, and leukocytosis, were ascertained on admission to hospital or on the following day (day 5 or 6 of illness) and were established in 95%, 87%, 99%, 91%, 94%, 87%, and 55% of patients, and had a median duration of 4, 3, 7, 3, 9, 8, and 2 days, respectively. Comparison of patients infected with Dobrava and Puumala viruses found several differences in the frequency, magnitude, and duration of abnormalities, indicating that Dobrava virus causes the more severe HFRS.

Conclusions

In the majority of patients, the classic clinical distinction into febrile, hypotonic, oliguric, polyuric, and convalescent phases of illness is unclear.

Relationship between circulating vascular endothelial growth factor and its soluble receptor in patients with hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome (HFRS) is characterized by endothelial dysfunction with capillary leakage without obvious cytopathology in the capillary endothelium. The aim of the study was to analyze the kinetics of vascular endothelial growth factor (VEGF) and its soluble receptor (sVEGFR-2) in HFRS patients infected with Dobrava (DOBV) or Puumala virus (PUUV). VEGF and sVEGFR-2 levels were measured in daily plasma and urine samples of 73 patients with HFRS (58 with PUUV, 15 with DOBV) and evaluated in relation to clinical and laboratory variables. In comparison with the healthy controls, initial samples (obtained in the first week of illness) from patients with HFRS had higher plasma and urine VEGF levels, whereas sVEGFR-2 levels were lower in plasma but higher in urine. VEGF levels did not differ in relation to hantavirus species, viral load, or the severity of HFRS. The comparison of VEGF dynamics in plasma and urine showed the pronounced secretion of VEGF in urine. Significant correlations were found between daily VEGF/sVEGFR-2 levels and platelet counts, as well as with diuresis: the correlations were positive for plasma VEGF/sVEGFR-2 levels and negative for urine levels. In addition, patients with hemorrhagic manifestations had very high plasma and urine VEGF, together with high urine sVEGFR-2. Measuring the local secretion of sVEGFR-2 in urine might be a useful biomarker for identifying HFRS patients who will progress to severe disease.

An outbreak of haemorrhagic fever with renal syndrome linked with mountain recreational activities in Zagreb, Croatia, 2017

In 2017 Zagreb faced the largest outbreak of haemorrhagic fever with renal syndrome (HFRS) to date. We investigated to describe the extent of the outbreak and identify risk factors for infection. We compared laboratory-confirmed cases of Hantavirus infection in Zagreb residents with the onset of illness after 1 January 2017, with individually matched controls from the same household or neighbourhood. We calculated adjusted matched odds ratios (amOR) using conditional logistic regression. During 2017, 104 cases were reported: 11-81 years old (median 37) and 71% (73) male. Compared with 104 controls, cases were more likely to report visiting Mount Medvednica (amOR 60, 95% CI 6-597), visiting a forest (amOR 46, 95% CI 4.7-450) and observing rodents (amOR 20, 95% CI 2.6-159). Seventy per cent of cases (73/104) had visited Mount Medvednica prior to infection. Among participants who had visited Mount Medvednica, cases were more likely to have drunk water from a spring (amOR 22, 95% CI 1.9-265), observed rodents (amOR 17, 95% CI 2-144), picked flowers (amOR 15, 95% CI 1.2-182) or cycled (amOR 14, 95% CI 1.6-135). Our study indicated that recreational activity around Mount Medvednica was associated with HFRS. We recommend enhanced surveillance of the recreational areas during an outbreak.

Country-wide seroprevalence studies on Crimean-Congo hemorrhagic fever and hantavirus infections in general population of Bulgaria

Crimean-Congo hemorrhagic fever (CCHF) and hantavirus infections are the two viral hemorrhagic fevers spread in Europe. To test actual circulation of CCHF virus (CCHFV) and hantaviruses in Bulgaria, we conducted country-wide seroepidemiological studies. Serum samples were collected prospectively from 1500 residents of all 28 districts in Bulgaria. CCHFV seroprevalence of 3.7% was revealed. Anamnesis for tick bites, contact with livestock, age over 40 years and residency in Haskovo district were found as risk factors. The highest CCHFV seroprevalence was observed in the known endemic districts in southeastern Bulgaria: Haskovo (28%) and Yambol (12%). Reactive samples were found in residents of 20 of the 28 districts in Bulgaria. In comparison with the previous studies, the data presented indicate that CCHFV increased substantially its circulation in the endemic regions and was introduced in many new areas. Hantavirus seroprevalence was based on results of the immunoblot and estimated as 3.1%. Surprisingly, contrary to all available data, Puumala virus seroprevalence rate was 2.3% versus 0.8% of Dobrava-Belgrade virus. Evidence for hantavirus IgG seropositivity was found in residents of 23 of the 28 districts in the country. The first hantavirus seroprevalence study in Bulgaria showed that Puumala virus is probably more wide-spread in the country than Dobrava-Belgrade virus.

Serum Cytokine Profiles Differentiating Hemorrhagic Fever with Renal Syndrome and Hantavirus Pulmonary Syndrome

Hantavirus infection is an acute zoonosis that clinically manifests in two primary forms, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). HFRS is endemic in Europe and Russia, where the mild form of the disease is prevalent in the Tatarstan region. HPS is endemic in Argentina, as well as other countries of North and South American. HFRS and HPS are usually acquired via the upper respiratory tract by inhalation of virus-contaminated aerosol. Although the pathogenesis of HFRS and HPS remains largely unknown, postmortem tissue studies have identified endothelial cells as the primary target of infection. Importantly, cell damage due to virus replication, or subsequent tissue repair, has not been documented. Since no single factor has been identified that explains the complexity of HFRS or HPS pathogenesis, it has been suggested that a cytokine storm may play a crucial role in the manifestation of both diseases. In order to identify potential serological markers that distinguish HFRS and HPS, serum samples collected during early and late phases of the disease were analyzed for 48 analytes using multiplex magnetic bead-based assays. Overall, serum cytokine profiles associated with HPS revealed a more pro-inflammatory milieu as compared to HFRS. Furthermore, HPS was strictly characterized by the upregulation of cytokine levels, in contrast to HFRS where cases were distinguished by a dichotomy in serum cytokine levels. The severe form of hantavirus zoonosis, HPS, was characterized by the upregulation of a higher number of cytokines than HFRS (40 vs 21). In general, our analysis indicates that, although HPS and HFRS share many characteristic features, there are distinct cytokine profiles for these diseases. These profiles suggest a strong activation of an innate immune and inflammatory responses are associated with HPS, relative to HFRS, as well as a robust activation of Th1-type immune responses. Finally, the results of our analysis suggest that serum cytokines profiles of HPS and HFRS cases are consistent with the presence of extracellular matrix degradation, increased mononuclear leukocyte proliferation, and transendothelial migration.

Hemorrhagic fever with renal syndrome in Albania. Focus on predictors of acute kidney injury in HFRS

BACKGROUND

Hemorrhagic fever with renal syndrome (HFRS) is a rodent borne zoonosis, caused by the members of the family Bunyaviridae, genus Hantavirus. The main clinical features of the infection by this virus family are fever, thrombocytopenia and acute kidney injury.

OBJECTIVE

The aim of our study was to identify, for the first time, characteristic features of HFRS in the Albanian population.

STUDY DESIGN

The study comprised 33 consecutive patients admitted with suspected HFRS from April 2011-April 2016 at one center. Clinical diagnosis was confirmed by ELISA and real-time PCR. Statistical analysis was performed to identify prognostic markers and indicators of disease severity.

RESULTS

The virus strain causing HFRS was Dobrava type in all 33 cases. The disease outbreaks occurred during the period June-July. Mean hospital stay was 15.7±6.9days. 29 (88%) of the patients were male. The mean age was 39.7±14.1. 16 (48.5%) patients were from Northeast Albania. 8 (24.2%) patients required dialysis. The strongest correlation was the inverse relationship of nadir platelet count with urea and creatinine, p<0.0001, p<0.0079 respectively. Creatinine and hyponatremia were inversely correlated p=0.0007, whereas hyponatremia and nadir platelet count had the highest sensitivity and specificity for development of severe AKI, 92.6%, 100%; 88.9%, 83.3% respectively. Mortality rate was 9.09%.

CONCLUSION

HFRS is a severe viral disease in Albania caused by Dobrava strain. It is associated with high mortality, 9.09% in our cohort. In our study, thrombocytopenia, urinary volume, hyponatremia were indicators of more severe disease.

Clinical aspects of hantavirus infections in Bulgaria

BACKGROUND

Hantaviruses cause two distinct human diseases: hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe and hantavirus pulmonary syndrome (HPS) in America. In Europe, mainly Puumala, Dobrava and Seoul viruses cause HFRS. A total of 23 cases of HFRS were detected in Bulgaria over a 2‑year period 2013-2014. The aim of the study was to present epidemiology, clinical manifestations and laboratory findings of these patients.

METHODS

Patients with HFRS were diagnosed using PCR, ELISA and immunoblotting tests.

RESULTS

Dobrava-Belgrade virus (DOBV) was revealed as etiological agent in 16 (69.6%) patients and Puumala virus (PUUV) in 7 (30.4%) patients. All 23 patients were men aged 22-66 years of which 6 (26.1%) patients originated from regions in northern and western Bulgaria previously thought to be non-endemic. Patients with HFRS, despite the infecting hantavirus, manifested acute renal failure, asthenia and less pronounced hemorrhagic syndrome. Patients with DOBV infection were much more likely to present with arthromyalgia, severe headache, severe to moderately severe asthenoadynamia, abdominal pain, vomiting, hypotension, nervous system disorders as well as kidney enlargement, leucopenia and higher levels of blood creatinine, requiring hemodialysis procedures more often and for a longer period of time than patients with PUUV infection.

CONCLUSIONS

The present report describes for the first time comparative analysis of epidemiological features, clinical manifestations and laboratory findings of DOBV and PUUV infections in Bulgaria.

Hantavirus infection: a global zoonotic challenge

Hantaviruses are comprised of tri-segmented negative sense single-stranded RNA, and are members of the Bunyaviridae family. Hantaviruses are distributed worldwide and are important zoonotic pathogens that can have severe adverse effects in humans. They are naturally maintained in specific reservoir hosts without inducing symptomatic infection. In humans, however, hantaviruses often cause two acute febrile diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). In this paper, we review the epidemiology and epizootiology of hantavirus infections worldwide.

Human Herpesvirus 6 Infection Presenting as an Acute Febrile Illness Associated with Thrombocytopenia and Leukopenia

We present an infant with acute fever, thrombocytopenia, and leukopenia, coming from an endemic region for tick-borne encephalitis, human granulocytic anaplasmosis, and hantavirus infection. The primary human herpesvirus 6 infection was diagnosed by seroconversion of specific IgM and IgG and by identification of viral DNA in the acute patient's serum. The patient did not show skin rash suggestive of exanthema subitum during the course of illness.

Fever as an important resource for infectious diseases research

Fever or pyrexia is a process where normal body temperature is raised over homeostasis conditions. Although many effects of fever over the immune system have been known for a long time, it has not been until recent studies when these effects have been evaluated in several infection processes. Results have been promising, as they have reported new ways of regulation, especially in RNA molecules. In light of these new studies, it seems important to start to evaluate the effects of pyrexia in current research efforts in host-pathogen interactions. Viruses and bacteria are responsible for different types of infectious diseases, and while it is of paramount importance to understand the mechanisms of infection, potential effects of fever on this process may have been overlooked. This is especially relevant because during the course of many infectious diseases the organism develops fever. Due to the lack of specific treatments for many of those afflictions, experimental evaluation in fever-like conditions can potentially bring new insights into the infection process and can ultimately help to develop treatments. The aim of this review is to present evidence that the temperature increase during fever affects the way the infection takes place, for both the pathogen and the host.

[Seoul hantavirus infection-associated hemorrhagic fever with renal syndrome in France: A case report]

INTRODUCTION

Rodents are hantavirus hosts. In Europe, hantaviruses are responsible for human infections resulting in hemorrhagic fever with renal syndrome. Thousands of Puumala virus infections are reported annually in Europe, whereas human Seoul virus infections are rarely detected.

CASE REPORT

We report the case of a 38-year-old patient who presented initially with flu-like symptoms and transitory blurred vision. He developed thrombocytopenia, acute renal failure, and elevated aminotransferases levels during the disease course, but the outcome was favorable with a full recovery. Afterwards, the hantavirus serology results were indicative of Seoul virus infection.

CONCLUSION

This report serves to remind physicians to consider diagnosing hantavirus infection when observing the association of fever, acute renal failure and thrombocytopenia. Transitory blurred vision is a specific element to indicate this diagnosis.

Genetic detection of hantaviruses in rodents, Albania

In order to have a first insight into the epidemiology of hantaviruses in Albania, 263 small mammals (248 rodents, 15 insectivores) were captured in 352 locations in 29 districts and tested for hantavirus infection. Dobrava-Belgrade virus (DOBV) was detected in 10 of 148 (6.7%) Apodemus flavicollis rodents. DOBV-positive A. flavicollis were detected in six districts (Diber, Korce, Kolonje, Librazhd, Pogradec, and Vlore). The obtained nucleotide sequences were highly similar to each other and to DOBV sequences from northwestern Greece. Understanding the epidemiology of hantaviruses and identifying the endemic foci enables the public health strategies to minimize the risk of human infection. J. Med. Virol. 88:1309-1313, 2016. © 2016 Wiley Periodicals, Inc.

Two clinical cases of renal syndrome caused by Dobrava/Saaremaa hantaviruses imported to the Netherlands from Poland and Belarus, 2012-2014

We report the rare event of two imported cases in the Netherlands presenting with renal syndrome caused by Dobrava (DOBV)/Saaremaa (SAAV) hantaviruses. DOBV/SAAV hantaviruses are not circulating in the Netherlands and their clinical manifestation is typically more severe than that of the endemic Puumala virus (PUUV). This report aims to increase awareness among healthcare professionals and diagnostic laboratories to consider different hantaviruses as a cause of renal failure.

Renal Function Outcome Prognosis in Septic and Non-septic Acute Kidney Injury Patients

AIM

The objective of this study was to evaluate prognostic impact of clinical factors on outcome of renal function in septic and non-septic acute kidney injury (AKI) patients.

METHODS

The prospective, observational, clinical study was performed at Nephrology Clinic and Clinic for Infectious Diseases, University Clinical Centre Sarajevo. One hundred patients with diagnosis of AKI were enrolled in the study, and divided into two groups: septic and non-septic AKI patients. Clinical parameters included causes and type of AKI, pre-existing comorbidities and different treatment modalities. Patients were followed up until discharge or death. Renal function outcome was defined by creatinine clearance values at discharge.

RESULTS

Septic AKI patients had significantly longer hospital stay (p=0.03), significantly worse renal function outcome (p<0.001), and higher burden of comorbidities (70.6% vs. 60.6%), compared to non-septic patients. Septic AKI patients were almost three times less likely to receive renal replacement therapy (8.8% vs. 24.4%) and they had significant delay in initiation of dialysis (p=0.03). By multivariate analysis, sepsis (95% CI 0.128-0.967, p=0.043) and hypertension (95% CI 0.114-0.788, p=0.015) were independent predictors of adverse renal function outcome in AKI patients. Postrenal type of AKI was independent predictor of renal function recovery in non-septic AKI patients (95% CI 1.174-92.264, p=0.035), while Failure, as third class of AKI, was independent predictor of non-recovered renal function only in septic AKI patients (95% CI 0.026 to 0.868, p=0.034).

CONCLUSION

Septic AKI patients are clinically distinct compared to non-septic AKI patients with different prognostic factors and poorer renal function outcome.