Hantavirus

Habitat fragmentation and diversity loss due to increased conversion of natural habitats to agricultural uses influence the distribution and abundance of wildlife species and thus may change the ecology of pathogen transmission. We used hantaviruses in Panama as a research model to determine whether anthropogenic environmental change is associated with changes in the dynamics of viral transmission. Specifically, we wanted to determine whether hantavirus infection was correlated with spatial attributes of the landscape at both large and small scales or whether these changes are mediated by changes in community composition. When analyzed at coarse spatial scales, hantavirus reservoirs were more commonly found in disturbed habitats and edge habitats than in forested areas. At local scales, reservoir species dominance was significantly correlated with the slope of the terrain. To evaluate the effect of small-mammal diversity loss on infection dynamics, we implemented an experiment with selective species removal at experimental sites. Seroprevalence of hantavirus was higher in the community of small mammals and increased through time in the experimental sites. The higher seroprevalence in experimental plots suggests that greater diversity likely reduces encounter rates between infected and susceptible hosts. Our studies suggest that habitat loss and fragmentation and species diversity loss are altering hantavirus infection dynamics in Panama. Our work represents a multidisciplinary approach toward disease research that includes biodiversity concerns such as environmental change and degradation, human settlement patterns, and the ecology of host and nonhost species, work that may be especially important in tropical countries.

Hantaviruses are causative agents of some severe human illnesses, including hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The viruses are maintained by rodent hosts, and humans acquire infection by inhaling virus-contaminated excreta from infected animals. To examine the epidemiology of hantavirus infections in Japan and Far East Russia, we conducted epidemiological surveys in these regions. In Japan, anti-hantavirus antibodies were found in four rodent species, Clethrionomys rufocanus, Rattus norvegicus, R. rattus, and Apodemus speciosus. Although no new HFRS cases have been officially reported over the past 20 years in Japan, one member of the Japan Ground Self-Defense Force did test positive for hantavirus antibody. Repeated surveys in Far East Russia have revealed that two distinct hantavirus types cause severe HFRS in this region. Hantavirus sequences identified from A. peninsulae, fetal HFRS cases in Vladivostok, and Amur virus are highl...

Human encroachment on wildlife habitats has contributed to the emergence of several zoonoses. Pathogenic hantaviruses are hosted by rodents and cause severe diseases in the Americas and Eurasia. We reviewed several factors that potentially drive prevalence (the proportion of infected rodents) in host populations. These include demography, behavior, host density, small mammal diversity, predation, and habitat and landscape characteristics. This review is the first to include a quantitative summary of the literature investigating hantavirus prevalence in rodents. Demographic structure and density were investigated the most and predation the least. Reported effects of demographic structure and small mammal diversity were consistent, whereby reproductive males were most likely to be infected and prevalence decreased with small mammal diversity. The influences of habitat and landscape properties are often complex and indirect. The relationship between density and prevalence merits more investigation. Most hantavirus hosts are habitat generalists and their control is challenging. Incorporating all potential factors and their interactions is essential to understanding and controlling infection in host populations.

The core topic of our 9th Hands-on Science conference is "Science Education, Environment and Society; Reconnecting Society with Nature through Hands-on Science". Environmental and sustainable development are issues of critical importance. A widened awareness of the importance of preserving Nature to our life in today's' societies must be achieve. A sound use of the natural resources and monitoring and care of the environment and the different ecosystems that surround us, requires a sound widespread science and technology literacy. Science education, from very early ages and all along life, can and should have a major positive impact in this effort. On these lines back in 2006 we organised the 3rd International Conference on "Hands-on Science. Science Education and Sustainable Development" with the aim to promote an open broad exchange of experiences on good practices, syllabus and policy matters, social factors and the learning of science, and other issues related to Science Education its development and the potential impact environment and natural resources preservation and sustainable development. Six year after its time to again renew this discussion exploring newer ways of approaching science education in our schools and at society … reconnecting Society with Nature... by stressing the significance of discovering Nature through an enlarged use of indoor and outdoor hands-on science learning activities in classroom formal context but also in different informal or non-formal environments. Students are again invited to bring their insights to our conference. The 1st Childrens' Summit on Handson Science and Environmental Education (HSCI-EE) will be a first annual children's' summit where they will present and discuss their proposals for solving environmental problems and views on our relationship with Nature.

Andes virus (ANDV), a member of the Hantavirus genus in the family Bunyaviridae, causes an acute disease characteristic of New-World hantaviruses called hantavirus pulmonary syndrome (HPS). HPS is a highly pathogenic disease with a case-fatality rate of 40%. ANDV is the only hantavirus reported to spread directly from human-to-human. The aim of the present study was to develop a quantitative and high-throughput pseudovirion assay to study ANDV infection and neutralization in biosafety level 2 facilities (BSL-2).

Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease caused by Hantavirus, which is highly virulent for humans. High temperatures and conversion of native vegetation to agriculture , particularly sugarcane cultivation can alter abundance of rodent generalist species that serve as the principal reservoir host for HCPS, but our understanding of the compound effects of land use and climate on HCPS incidence remains limited, particularly in tropical regions. Here we rely on a Bayesian model to fill this research gap and to predict the effects of sugarcane expansion and expected changes in temperature on Hantavirus infection risk in the state of São Paulo, Brazil. The sugarcane expansion scenario was based on historical data between 2000 and 2010 combined with an agro-environment zoning guideline for the sugar and ethanol industry. Future evolution of temperature anomalies was derived using 32 general circulation models from scenarios RCP4.5 and RCP8.5 (Representative greenhouse gases Concentration Pathways adopted by IPCC). Currently, the state of São Paulo has an average Hantavirus risk of 1.3%, with 6% of the 645 municipalities of the state being classified as high risk (HCPS risk ! 5%). Our results indicate that sugarcane expansion alone will increase average HCPS risk to 1.5%, placing 20% more people at HCPS risk. Temperature anomalies alone increase HCPS risk even more (1.6% for RCP4.5 and 1.7%, for RCP8.5), and place 31% and 34% more people at risk. Combined sugarcane and temperature increases led to the same predictions as scenarios that only included temperature. Our results demonstrate that climate change effects are likely to be more severe than those from sugarcane expansion. Forecasting disease is critical for the timely and efficient planning of operational control programs that can address the expected effects of sugarcane expansion and climate change on HCPS infection risk. The predicted spatial location of HCPS infection risks obtained here can be used to prioritize management actions and develop educational campaigns.

The demand for interdisciplinary research is increasing in the new millennium to help us understand complex problems and find solutions by integrating the knowledge from different disciplines. The present review is an excellent example of this and shows how unique combination of physics, chemistry, and biological techniques can be used for the evaluation of Indian medicinal herbs used for treating diabetes mellitus. Laser-induced breakdown spectroscopy (LIBS) is a sensitive optical technique that is widely used for its simplicity and versatility. This review presents the most recent application of LIBS for detection of glycemic elements in medicinal plants. The characteristics of matrices, object analysis, use of laser system, and analytical performances with respect to Indian herbs are discussed.

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Objectives: To determine the clinical and laboratory predictors of fatality among patients with Hantavirus infection. Materials and methods: A retrospective study was conducted on the patients with Hantavirus infection between April 2009 and October 2011 at the Black Sea and the Mediterranean regions in Turkey. Demographic, clinical and laboratory findings of fatal cases and non-fatal cases at the admission were compared. Results: Twenty-two patients with confirmed Hantavirus infection were evaluated. Five patients died (22.7%). The cause of death was massive bleeding. The rate of hemorrhage was significantly higher in the fatal cases than non-fatal cases (p<0.001). Massive gastrointestinal hemorrhage was seen in four of these patients, cerebral hemorrhage in two and both gastrointestinal and pulmonary hemorrhage in one. Disseminated intravascular coagulation (DIC) was present in four of the fatal cases and a remarkable cause of the bleeding (p=0.02). White blood cell count (WBC) (p=0.002), creatine phosphokinase (CPK) (p=0.011), blood-urea-nitrogen (BUN) (p=0.014), C reactive protein (CRP) (p=0.005) and D-dimer levels (p=0.001), prothrombin time (PT) (p=0.023), activated partial thromboplastin time (aPTT) (p=0.001) and international normalized ratio (INR) (p=0.021) were significantly higher, and platelet counts (p=0.038) significantly lower in the fatal cases. Optimum diagnostic cutoff points for specific laboratory parameters which may be predictive of fatality were; WBC=16,000 µL-1, PLT=30000 µL-1, PT=19.7 s, aPTT=36 s, INR=1.2, D-dimer=9.3 µg/mL, CPK=600 U/L, BUN=47 mg/dL and CRP=13.4 mg/dL. Conclusions: Physicians should be aware of the high fatality risk for patients with Hantavirus infection with hemorrhage, elevated WBC, CPK, BUN, CRP, PT, aPTT, INR and D-dimer and reduced platelet counts. J Microbiol Infect Dis 2012; 2(4): 155-159

Hantavirus pulmonary syndrome is an emerging disease of humans that is carried by wild rodents. Humans are usually exposed to the virus through geographically isolated outbreaks. The driving forces behind these outbreaks is poorly understood. Certainly, one key driver of the emergence of these viruses is the virus population dynamics within the rodent population. Two new mathematical models for hantavirus infection in rodents are formulated and studied. The new models include the dynamics of susceptible, exposed, infective, and recovered male and female rodents. The first model is a system of ordinary differential equations while the second model is a system of stochastic differential equations. These new models capture some of the realistic dynamics of the male/female rodent hantavirus interaction: higher seroprevalence in males and variability in seroprevalence levels.

During 5,230 trapping nights, 672 small mammals were trapped in the areas where most hantavirus pulmonary syndrome (HPS) cases occur in Uruguay. Yellow pygmy rice rats (Oligoryzomys flavescens) were the only rodents that showed evidence of antibodies to hantavirus, with a seroprevalence of 2.6%. The rodents were trapped in all the explored environments, and most of the seropositive rodents were found in habitats frequented by humans. Nucleotide sequences were obtained from four HPS case-patients and four yellow pygmy rice rats of the M genome segment. Sequence comparison and phylogenetic analysis showed that rodent-borne viruses and viruses from three HPS case-patients form a well-supported clade and share a 96.4% identity with the previously characterized Central Plata hantavirus. These results suggest that yellow pygmy rice rat (O. flavescens) may be the host for Central Plata, a hantavirus associated with HPS in the southern area of Uruguay.

Hantaviruses infect humans via inhalation of viral particles in infected rodents&#39; secretions such as saliva, urine and faeces or via direct contact with infected rodents. The rodent species that are known as the carriers of Dobrava (DOBV), Puumala (PUUV), Saaremaa (SAAV), Tula (TULV) and Seoul (SEOV) viruses are found in our country. The presence of specific antibodies against hantaviruses have been demonstrated in rodents collected from Black Sea and Aegean Regions of Turkey in 2004 for the first time. The first hantavirus-related hemorrhagic fever with renal syndrome (HFRS) cases were reported in Black Sea region in 2009. The determination of the hantavirus prevalence in wild life and rodent populations in the field is crucial for the information about hantavirus-related cases and to clarify the state of risk. There is no commercial product optimized for the screening of rodent serum samples in terms of HFRS agents like DOBV and PUUV that are widely seen in Eurasia as well as ...

Hantavirus is a causative agent of rodent-borne viral zoonoses, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome. Seoul virus (SEOV) is a causative agent of urban and laboratory rat-associated HFRS worldwide. Surveillance of rodents has been done mainly by serological detection of hantavirus-specific antibodies by enzyme linked immunosorbent assay (ELISA) and immunofluorescent antibody assay (IFA). An immunochromatographic (ICG) test was developed with the N-terminal 103 amino acids of nucleocapsid protein of Hantaan virus expressed by Escherichia coli as an antigen to detect IgG antibody specific to hantavirus in sera from Rattus sp. animals. Antibodydetecting sensitivity of the ICG test was the same as that of ELISA and about 100-times higher than that of IFA. Overall sensitivities and specificities of the ICG test in comparison to ELISA and IFA for sera from 192 urban rats and 123 laboratory rats were 99.3% and 100%, respectively. Diluted whole blood samples without separation could be used for the ICG test. The ICG test enabled detection of antibodies to SEOV, Hantaan, Dobrava/Belgrade, and Thailand viruses, which are causative agents of HFRS throughout Eurasia. The ICG test is a rapid, simple and safe method for diagnosis of SEOV infection in rats.

We developed serological tools for the detection of hantavirus-specific antibodies and hantavirus antigens in shrews. The work was focussed to generate Thottapalayam virus (TPMV)-specific monoclonal antibodies (mAbs) and anti-shrew immunoglobulin G (IgG) antibodies. The mAbs against TPMV nucleocapsid (N) protein were produced after immunization of BALB/c mice with recombinant TPMV N proteins expressed in Escherichia coli, baculovirus and Saccharomyces cerevisiae-mediated expression systems. In total, six TPMV N-protein-specific mAbs were generated that showed a characteristic fluorescent pattern in indirect immunofluorescence assay (IFA) using TPMV-infected Vero cells. Out of the six mAbs tested, five showed no cross-reaction to rodent-associated hantaviruses (Hantaan, Seoul, Puumala, Tula, Dobrava-Belgrade and Sin Nombre viruses) in IFA and enzyme-linked immunosorbent assay (ELISA), although one mAb reacted to Sin Nombre virus in IFA. None of the mAbs cross-reacted with an amino-terminal segment of the shrew-borne Asama virus N protein. Antishrew-IgG sera were prepared after immunization of rabbits and BALB/c-mice with protein-G-purified shrew IgG. TPMV-N-protein-specific sera were raised by immunisation of Asian house shrews (Suncus murinus) with purified yeast-expressed TPMV N protein. Using these tools, an indirect ELISA was developed to detect TPMV-N-proteinspecific antibodies in the sera of shrews. Using an established serological assay, high TPMV N protein specific antibody titres were measured in the sera of TPMV-N-protein-immunized and experimentally TPMV-infected shrews, whereas no cross-reactivity to other hantavirus N proteins was found. Therefore, the generated mAbs and the established ELISA system represent useful serological tools to detect TPMV, TPMV-related virus antigens or hantavirus-specific antibodies in hantavirus-infected shrews.

Wild rodents (n5330) were trapped around the villages of Altındere and
Cos¸andere (Maçka, Trabzon Province), Ayder, Ortan, and Yolkiyi (Çamlıhemşin, Rize Province), and Bozdağ (Ödemiş)¸, İzmir Province) in
northeastern and western Turkey during April 2004. Samples were tested for arenavirus, hantavirus, and cowpox virus (family Poxviridae, genus Orthopoxvirus, CPXV) antibodies by using immunofluorescence assays (IFAs). Antibodies against arenaviruses were found in eight of 330 (2.4%) rodents. Arenavirus-sero-positive animals were found from all study sites. Antibodies to Puumala virus (family Bunyaviridae, genus Hantavirus, PUUV) were detected in four of 65 Microtusvoles tested. Of the PUUV-IFA-positive voles, one Microtus guentheri lydius was caught from Izmir, and one Microtus roberti and two Microtus rossiaemeridionalis were captured near Trabzon. All 264
Apodemus spp. mice tested negative for anti-bodies to Saaremaa virus (family Bunyaviridae, genus Hantavirus, SAAV); the single Dryomys
nitedula tested negative for both PUUV and SAAV antibodies. Only one (0.3%) of the rodents, an Apodemus sylvaticus from Trabzon
area, tested seropositive to CPXV. This is the iirst serologic survey for rodent-borne viruses in their natural hosts in Turkey. Although these
preliminary results support presence of several virus groups with zoonotic potential, additional studies are needed to identify the specific
viruses that are present in these populations.
Key words: Arenaviruses, hantaviruses, poxviruses, rodent-borne viruses, rodents, seroprevalence.

Europe. It is hosted by at least two rodent species, Apodemus flavicollis and A. agrarius. According to their natural hosts they form the distinct genetic lineages DOBV-Af and DOBV-Aa, respectively. We have now established a DOBV isolate named Slovakia (SK/Aa) from an A. agrarius animal captured in Slovakia. The complete S and M and partial L segment nucleotide sequences of the new isolate were determined. Phylogenetic analyses showed that the SK/Aa isolate clustered together with the other DOBV-Aa sequences amplified from A. agrarius before and can be taken as the representative of this genetic lineage. SK/Aa, in comparison with a DOBV-Af isolate, was used for serotyping neutralizing antibodies of HFRS patients in Central Europe. Most patients' sera exhibited a higher endpoint titer when probed with our new isolate, suggesting that DOBV-Aa strains are responsible for most of the DOBV-caused HFRS cases in this region.

In order to evaluate the circulation of hantaviruses present in southeast Asia, a large scale survey of small mammal species was carried out at seven main sites in the region (Cambodia, Lao People's Democratic Republic, and Thailand). Small scale opportunistic trapping was also performed at an eighth site (Cambodia).

Since the recognition of hantavirus as the agent responsible for haemorrhagic fever in Eurasia in the 1970s and, 20 years later, the descovery of hantavirus pulmonary syndrome in the Americas, the genus Hantavirus has been continually described throughout the World in a variety of wild animals. The diversity of wild animals infected with hantaviruses has only recently come into focus as a result of expanded wildlife studies. The known reservoirs are more than 80, belonging to 51 species of rodents, 7 bats (order Chiroptera) and 20 shrews and moles (order Soricomorpha). More than 80genetically related viruses have been classified within Hantavirus genus; 25 recognized as human pathogens responsible for a large spectrum of diseases in the Old and New World. In Brazil, where the diversity of mammals and especially rodents is considered one of the largest in the world, 9 hantavirus genotypes have been identified in 12 rodent species belonging to the genus Akodon, Calomys, Holochilus, Oligoryzomys, Oxymycterus, Necromys and Rattus. Considering the increasing number of animals that have been implicated as reservoirs of different hantaviruses, the understanding of this diversity is important for evaluating the risk of distinct hantavirus species as human pathogens. OPEN ACCESS Viruses 2014, 6 1930

In the summer of 1993, patients, mostly young and previously healthy adults, were admitted to hospitals in New Mexico, Arizona, and Colorado with fever and acute respiratory distress syndrome (ARDS); a number subsequently died from pulmonary edema and respiratory failure. Serology and detection of genetic sequences by polymerase chain reaction (PCR) rovided evidence condition is now called Hantavirus Pulmonary Syndrome).' By PCR, the same sequences were identified in tissues taken at autopsy from several of the patients and in tissue samples from local rodents. The major reservoir was Peromyscw maniculatus, the deer mouse, which was also the rodent most commonly trapped near houses in the area. A high proportion (20-30%) of captured Peromyscus maniculatus proved positive by serolo

Here we describe an acute Dobrava-Belgrade virus (DOBV) infection that presented as severe hemorrhagic fever with renal syndrome (HFRS) in an active-duty U.S. soldier. The infection was acquired in northern Kosovo in spring 2013. Amplification of DOBV genome segments directly from the patient's serum sample was successfully performed. Phylogenetic analysis demonstrated that the strain belong to DOBV genotype Dobrava and is closely related to strains circulating in Southeast Europe and Slovakia. Thus, our case confirms that DOBV genotype Dobrava is able to cause a severe form of HFRS, especially when compared to the other less pathogenic DOBV genotypes.

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Hantaviruses which are the members of Bunyaviridae, differ from other members of this family since they are transmitted to humans by rodents. More than 200.000 cases of hantavirus infections are reported annually worldwide. Hantaviruses can lead to two different types of infection in humans, namely, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). HFRS is the most common type of hantavirus infection in Europe and Asia and the most common virus types are Dobrava, Puumala, Hantaan and Seoul. A total of 25 hantavirus suspected cases have been reported from the Western Black Sea region of Turkey and 12 of these were confirmed serologically as &quot;Puumala&quot; subtype. Serological tests such as indirect immunofluorescence assay (IFA), are used for diagnosis and typing of the hantaviruses, however, since cross-reactions are common between the subtypes, the results of these tests should be confirmed by other methods. In this report two cases with han...

Hantavirus activity in 39 National Parks in the eastern and central United States was surveyed by testing 1,815 small mammals of 38 species for antibody reactive to Sin Nombre virus. Antibody-positive rodents were found throughout the area sampled, and in most biotic communities. Antibody was detected in 7% of 647 deer mice (Peromyscus maniculatus), 2% of 590 white-footed mice (P. leucopus), 17% of 12 rice rats (Oryzomys palustris), 3% of 31 cotton rats (Sigmodon hispidus), and 33% of 18 western harvest mice (Reithrodontomys megalotis). Antibody was also found in three of six species of voles, and in one of 33 chipmunks (Tamias minimus). Prevalence among Peromyscus was highest in the northeast. Although few cases of hantavirus pulmonary syndrome have been identified from the eastern and central regions, widespread infection in reservoir populations indicates that potential exists for human infection throughout much of the United States.

Hantaviruses, well-known human pathogens, have only recently been identified on the African continent. Tigray virus (TIGV) was found in Ethiopia in 2012 in a Murinae species, Stenocephalemys albipes, but the genetic data obtained at that time were too limited to correctly assess its phylogenetic position within the hantavirus tree. We used high throughput sequencing to determine the complete genome of TIGV, which showed a typical han-tavirus organisation. The large (L), medium (M), and small (S) genome segments were found to be 6532, 3594 and 1908 nucleotides long, respectively, and the 5′ and 3′ termini for all three segments were predicted to form the panhandle-like structure typical for bunyaviruses. Nucleotide-based phylogenetic analyses revealed that all three coding segments cluster in the phylogroup III sensu Guo et al. (2013). However, while TIGV S segment is basal to the Murinae-associated hantaviruses, the M and L segments are basal to the Soricomorpha-associated hantaviruses. TIGV is the first Murinae-borne hantavirus showing this inconsistent segmental clustering in the hantavirus phylogenetic tree. We finally propose non-exclusive scenarios that could explain the original phylogenetic position of TIGV.

Dobrava-Belgrade hantavirus infection mimicked acute appendicitis in a patient suffering from hemorrhagic fever with renal syndrome in Hungary. The 27-year-old man was admitted to the local hospital with severe abdominal pain localized mainly at the right lower quadrant of the abdomen and with fever, nausea, vomiting and bloody diarrhea. Based on these findings supported by computerized tomography acute perforated appendicitis was suspected and an explorative laparatomy was performed, which did not confirm the diagnosis. Next day he developed acute oliguric renal failure raising the possibility of hantavirus infection. Specific serum IgG and IgM antibodies against hantavirus were identified, and by molecular methods the presence of Dobrava-Belgrade virus was proven. This report describes a rare clinical manifestation of hemorrhagic fever with renal syndrome (HFRS), and shows that HFRS might be difficult to diagnose especially when symptoms mimick those of an acute abdominal inflammation.

; the cause of this disease is unknown. In this study, the genetic identification and characterization of a novel virus related to human hepatitis E virus (HEV) isolated from bile samples of chickens with HS syndrome is reported. Based upon the similar genomic organization and significant sequence identity of this virus with HEV, the virus has been tentatively named avian HEV in order to distinguish it from human and swine HEV. Electron microscopy revealed that avian HEV is a nonenveloped virus particle of 30-35 nm in diameter. The sequence of the 3h half of the viral genome (" 4 kb) was determined. Sequence analyses revealed that this genomic region contains the complete 3h non-coding region, the complete genes from open reading frames (ORFs) 2 and 3, the complete RNA-dependent RNA polymerase (RdRp) gene and a partial helicase gene from ORF 1. The helicase gene is the most conserved gene between avian HEV and other HEV strains, displaying 58-61 % aa and 57-60 % nt sequence identities. The RdRp gene of avian HEV shares 47-50 % aa and 52-53 % nt sequence identities and the putative capsid gene (ORF 2) of avian HEV shares 48-49 % aa and 48-51 % nt sequence identities with the corresponding regions of other known HEV strains. Phylogenetic analysis indicates that avian HEV is genetically related to, but distinct from, other known HEV strains. This discovery has important implications for HEV animal models, nomenclature and natural history. 0001-7760 # 2001 SGM CEEJ Downloaded from www.microbiologyresearch.org by (1999). Serological evidence for swine hepatitis E virus infection in Australian pig herds. Veterinary Microbiology 68, 95-105.

Puumala hantavirus (PUUV) is a zoonotic virus that causes nephropathia epidemica (NE) in humans, a mild form of haemorrhagic fever with renal syndrome. An average of 10 000 cases are reported annually in Europe, many of which occur in Fennoscandia. The incidence of NE is connected to the distribution and population density of the the bank vole (Myodes glareolus), the main host of the virus. In Fennoscandia, high incidences of NE occur at 3-4 year intervals due to the characteristic population cycles of this woodland rodent.
This study aimed to improve our understanding of PUUV microevolution by examining genetic features of the virus in several bank vole populations of Finland and Latvia.
Genetic variation in PUUV circulating in a bank vole population at Konnevesi in Central Finland was examined and monitored over five-years throughout a complete bank vole cycle, including two peak-phases in 2005 and 2008 and two population declines in 2006 and 2009 (i.e., viral bottlenecks). Altogether, 1369 bank voles were captured and 26.3% were detected PUUV-infected. Partial sequences of the three viral genome segments (Small, Medium and Large) were inspected from 365 PUUV genomes. Genetic diversity was 6.2% for the S segment, 4.8% for the M segment, and a surprisingly high 10.1% for the L segment. Each genome segment had accumulated mutations as a separate gene pool. The majority of nucleotide substitutions were synonymous and most of the deduced amino acid substitutions were conservative, suggesting a strong stabilizing selection operating at the protein level. Genetic markers found along the genome segments allowed for the recognition of two PUUV genogroups co-circulating in the host population. Even though one of the genogroups presented a higher genetic diversity, no signs of competition were observed between them. Nearly 80% the variants exhibited a transient existence, and frequently occurring variants were integrated by the most abundant segment genotypes suggesting a viral mutational robustness. A substantial portion (19.1%) of genomes appeared to be reassortants, with S and M typically being exchanged. Reassortant variants did not outcompete parental variants and were commonly transient. Reassortment was seasonal, occurring more frequently in autumn when infection risk increases. An imperceptible intra-genogroup reassortment could contribute to the steady state of the viral population, counteracting the effects of Muller’s ratchet.
Co-circulation and interaction of two distinct PUUV lineages (Finnish and North-Scandinavian) was monitored in a bank vole population at Pallasjärvi in Northern Finland. To date, seven genetic lineages have been detected, and they exhibit geographic structure within the host distribution. Here, we present new evidence of two lineages circulating in the same bank vole phylogroup (Ural clade). Genetic diversity within each PUUV lineage was modest (up to 1.7%) and most substitutions were synonymous. However, genetic differences between the two lineages were as high as 18.9%. Phylogenetic analysis revealed that these distinct lineages naturally reassort with a frequency to that genogroups circulating at Konnevesi, i.e., 32%. In contrast to Konnevesi, only M segment was exchanged between PUUV lineages at Pallasjärvi.
Two distinct PUUV lineages were also found to co-circulate in Latvia. One (Russian) has been previously described and the other awaits formal description. The novel Latvian lineage is considerably divergent from other PUUV lineages and several amino acid markers made it easily distinguishable. Phylogenetic analysis suggested an independent evolutionary history for the segments of the Latvian lineage. Similar to Pallasjärvi, both Russian and Latvian lineages were found in a single bank vole phylogroup (Carpathian clade), confirming earlier observations that PUUV lineages are not limited to a single host phylogroup.

In 1993 Sin Nombre virus was recognized as the cause of hantavirus pulmonary syndrome (HPS) and the deer mouse (Peromyscus maniculatus) was identified as the reservoir host. Surveillance by the Centers for Disease Control and Prevention and state health departments includes investigation to determine the likely site(s) and activities that led to infection, an environmental assessment of the home and workplace, and possibly rodent trappings at these sites. As of December 31, 1998, there were 200 confirmed cases from 30 states (43% case-fatality ratio). The national HPS case registry was examined to determine the incubation period of HPS. Review of 11 case-patients with well-defined and isolated exposure to rodents suggests that the incubation period of HPS is 9 to 33 days, with a median of 14-17 days. Case investigations allow a better understanding of the incubation time of HPS and may define high-risk behaviors that can be targeted for intervention.

Thirteen hantavirus genotypes, associated with at least 12 sigmodontine reservoir rodents, have been recognized in the four countries that represent the Southern Cone of South America. Host-virus relationships are not as well defined as in North America; several Southern Cone hantaviruses appear to share a common host and some viruses do not occur throughout the range of their host. Although hantavirus-host relationships in the Southern Cone are less strictly concordant with the single-host-single-virus pattern reported elsewhere, recent studies suggest that much of the ambiguity may result from an incomplete understanding of host and hantavirus systematics. Although some Southern Cone host species are habitat generalists, some sympatric species are habitat specialists, helping to explain how some strict host-virus pairings may be maintained. In some cases, host population densities were higher in peridomestic habitats and prevalence of hantavirus infection was higher in host populations in peridomestic habitats. Seasonal and multiyear patterns in climate and human disturbance affect host population densities, prevalence of infection, and disease risk to humans. Unusually high hantavirus antibody prevalence in indigenous human populations may be associated with frequent and close contact with host rodents. Ongoing studies are improving our understanding of hantavirus-host ecology and providing tools that may predict human risk.

Hantaviruses are important contributors to disease burden in the New World, yet many aspects of their distribution and dynamics remain uncharacterized. To examine the patterns and processes that influence the diversity and geographic distribution of hantaviruses in South America, we performed genetic and phylogeographic analyses of all available South American hantavirus sequences. We sequenced multiple novel and previously described viruses (Anajatuba, Laguna Negra-like, two genotypes of Castelo dos Sonhos, and two genotypes of Rio Mamore) from Brazilian Oligoryzomys rodents and hantavirus pulmonary syndrome cases and identified a previously uncharacterized species of Oligoryzomys associated with a new genotype of Rio Mamore virus. Our analysis indicates that the majority of South American hantaviruses fall into three phylogenetic clades, corresponding to Andes and Andes-like viruses, Laguna Negra and Laguna Negra-like viruses, and Rio Mamore and Rio Mamore-like viruses. In addition, the dynamics and distribution of these viruses appear to be shaped by both the geographic proximity and phylogenetic relatedness of their rodent hosts. The current system of nomenclature used in the hantavirus community is a significant impediment to understanding the ecology and evolutionary history of hantaviruses; here, we suggest strict adherence to a modified taxonomic system, with species and strain designations resembling the numerical system of the enterovirus genus.

Korean hemorrhagic fever virus (KHFV) has been adapted to the Wistar and Fisher strains of rats. Infection was detected by the appearance of specific antigen in the lung tissue of the infected rats at 14 to 64 days after inoculation and by the appearance of circulating antibodies in the serum which reacted specifically with KHFV antigen in the lungs of infected Apodemus agrarius subsp. coreae 3 weeks after inoculation. Distribution of antigen in rat tissues as determined by immunofluorescent staining was the same as that in Apodemus mice except that antigen was present in the spleens of rats. Adaptation of KHFV to the laboratory rat provides an animal model that is free of wild rodent viruses and is readily available for use in studies on the characterization of KHFV.