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Seoul orthohantavirus (SEOV) has been identified as one of the main causative agents of hemorrhagic fever with renal syndrome (HFRS) in China. The virus was found circulating in rodent populations in almost all provinces of the country, reflecting the wide distribution of HFRS. Here, using the direct immunofluorescence assay (DFA) and real-time quantitative reverse transcription PCR (qRT-PCR) approach, we performed screening in 1784 small mammals belonging to 14 species of three orders captured in the main areas of HFRS endemicity in Yunnan province (southwestern China) and identified 37 SEOV-positive rats (36 Rattus norvegicus and 1 Rattus tanezumi). A 3-year surveillance of HFRS epidemics and dynamics of rodent reservoir density and virus prevalence implied a potential correlation between them. The subsequent meta-transcriptomic sequencing and phylogenetic analyses revealed three SEOV variants, among which two are completely novel. The ancestral character state reconstruction (ACSR) analysis based on both novel variants and documented strains from 5 continents demonstrated that SEOV appeared to originate near the southwestern area (Yunnan-Kweichow Plateau) of China, then could spread to other regions and countries by their rodent carriers, resulting in a global distribution today. In summary, these data furthered the understanding regards genetic diversity and the potential origin for SEOV. However, the expanding endemic foci in the province suggest that the virus is spreading over a wider region and is much more diverse than previous depicted, which means that increased sampling is necessary., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kuang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Hemorrhagic fever with renal syndrome caused by hantaviruses has long been a serious public health issue in Yunnan Province. Hantaviruses exhibit a high extent of biodiversity in their natural hosts, particularly in mammalian hosts. This study was conducted to screen for hantaviruses in bats and rodents in Yunnan Province and elucidate their genetic characteristics and possible zoonotic disease risk. Hantaviruses were detected in 202 bats and 372 rodents with the positive rates 27.49% and 1.25% respectively. A novel lineage (named Lineage 10) of the Seoul virus (SEOV) from rodents and the geographic clustering of hantavirus in bats were identified using phylogenetic analyses of the full-length M- and S-segments. Our study suggest a high cross-species transmissibility of hantaviruses in bats and existence of a new lineage of SEOV in rodents differing significantly from other SEOVs. These results provide data to support the prevention and control of hantavirus-associated diseases in Yunnan Province., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Hou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Seoul virus (SEOV) is an orthohantavirus primarily carried by rats. In humans, it may cause hemorrhagic fever with renal syndrome (HFRS). Its incidence is likely underestimated and given the expansion of urban areas, a better knowledge of SEOV circulation in rat populations is called for. Beyond the need to improve human case detection, we need to deepen our comprehension of the ecological, epidemiological, and evolutionary processes involved in the transmission of SEOV., Methodology / Principal Findings: We performed a comprehensive serological and molecular characterization of SEOV in Rattus norvegicus in a popular urban park within a large city (Lyon, France) to provide essential information to design surveillance strategies regarding SEOV. We sampled rats within the urban park of 'La Tête d'Or' in Lyon city from 2020 to 2022. We combined rat population genetics, immunofluorescence assays, SEOV high-throughput sequencing (S, M, and L segments), and phylogenetic analyses. We found low structuring of wild rat populations within Lyon city. Only one sampling site within the park (building created in 2021) showed high genetic differentiation and deserves further attention. We confirmed the circulation of SEOV in rats from the park with high seroprevalence (17.2%) and high genetic similarity with the strain previously described in 2011 in Lyon city., Conclusion/significance: This study confirms the continuous circulation of SEOV in a popular urban park where the risk for SEOV transmission to humans is present. Implementing a surveillance of this virus could provide an efficient early warning system and help prepare risk-based interventions. As we reveal high gene flow between rat populations from the park and the rest of the city, we advocate for SEOV surveillance to be conducted at the scale of the entire city., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Alburkat et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: During 2017, a multistate outbreak investigation occurred after the confirmation of Seoul virus (SEOV) infections in people and pet rats. A total of 147 humans and 897 rats were tested., Methods: In addition to immunoglobulin (Ig)G and IgM serology and traditional reverse-transcription polymerase chain reaction (RT-PCR), novel quantitative RT-PCR primers/probe were developed, and whole genome sequencing was performed., Results: Seventeen people had SEOV IgM, indicating recent infection; 7 reported symptoms and 3 were hospitalized. All patients recovered. Thirty-one facilities in 11 US states had SEOV infection, and among those with ≥10 rats tested, rat IgG prevalence ranged 2%-70% and SEOV RT-PCR positivity ranged 0%-70%. Human laboratory-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (P = .03 and P = .006, respectively). Genomic sequencing identified >99.5% homology between SEOV sequences in this outbreak, and these were >99% identical to SEOV associated with previous pet rat infections in England, the Netherlands, and France. Frequent trade of rats between home-based ratteries contributed to transmission of SEOV between facilities., Conclusions: Pet rat owners, breeders, and the healthcare and public health community should be aware and take steps to prevent SEOV transmission in pet rats and to humans. Biosecurity measures and diagnostic testing can prevent further infections., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

Seoul virus (SEOV), which causes hemorrhagic fever with renal syndrome (HFRS) in humans, has spread all over the world, especially in mainland China. Understanding basic mechanisms of SEOV evolution is essential to better combat and prevent viral diseases. Here, we examined SEOV prevalence and evolution in the residential area of four districts in Guangzhou city, China. The carriage of SEOV was observed in 33.33% of the sampled rodents, with 35.96% of the sampled Rattus norvegicus and 13.33% of R. tanezumi . Based on the comprehensive analyses of large (L), medium (M), and small (S) segments, our study first demonstrated that the genetic characterization of urban SEOV was shaped by high nucleotide substitution rates, purifying selection, and recombination. Additionally, we detected mutational saturation in the S segment of SEOV, which may lead to the biases of genetic divergence and substitution rates in our study. Importantly, we have filled the gap of SEOV evolution in the urban area. The genetic variation of SEOV may highlight the risk of HFRS, which merits further investigation.

Seoul virus (SEOV) is the etiologic agent of hemorrhagic fever with renal syndrome. It is carried by brown rats (Rattus norvegicus), a commensal rodent that closely cohabitates with humans in urban environments. SEOV has a worldwide distribution, and in Europe, it has been found in rats in UK, France, Sweden, and Belgium, and human cases of SEOV infection have been reported in Germany, UK, France, and Belgium. In the search of hantaviruses in brown rats from the Netherlands, we found both serological and genetic evidence for the presence of SEOV in the local wild rat population. To further decipher the relationship with other SEOV variants globally, the complete genome of SEOV in the Netherlands was recovered. SEOV sequences obtained from three positive rats (captured at close trapping locations at the same time) were found highly similar. Phylogenetic analyses demonstrated that two lineages of SEOV circulate in Europe. Strains from the Netherlands and UK, together with the Baxter strain from US, constitute one of these two, while the second includes strains from Europe and Asia. Our results support a hypothesis of diverse routes of SEOV spread into Europe. These findings, combined with other indications on the expansion of the spatial European range of SEOV, suggest an increased risk of this virus for the public health, highlighting the need for increased surveillance., (© 2019 Wiley Periodicals, Inc.)

Hantavirus is the causative agent of hemorrhagic fever with renal syndrome (HFRS). Heilongjiang Province is experiencing an epidemic of HFRS, the main causative agent is a variant of hantavirus called Seoul virus (SEOV). In this study, the entire genome of one SEOV, the DN2 strain, was sequenced and analyzed. The alignment analysis of the sequences indicated that the DN2 strain shares the highest homology with the SEOV-LYO852 strain. The nucleotide identity is 97.6% for the S segment, 97.7% for the M segment, and 98.0% for the L segment. The corresponding amino acid sequence homologies are 99.1%, 98.9% and 99.8%. The phylogenetic analysis of the segments suggests that the DN2 strain has a high genetic relationship with SEOV strains and no genetic recombination occurs.

Seoul hantavirus-associated hemorrhagic fever with renal syndrome cases are rare outside Asia and have not yet been found in Germany. We report clinical and molecular evidence for a Seoul virus infection in a patient in Germany. The infection was most likely acquired during a stay in Sulawesi, Indonesia.

Orthohantaviruses are a group of rodentborne viruses with a worldwide distribution. The orthohantavirus Seoul virus (SEOV) can cause hemorrhagic fever with renal syndrome in humans and is distributed worldwide, like its reservoir host, the rat. Cases of SEOV in wild and pet rats have been described in several countries, and human cases have been reported in the United Kingdom, France, Canada, and the United States. In the Netherlands, SEOV has previously been found in wild brown rats. We describe an autochthonous human case of SEOV infection in the Netherlands. This patient had nonspecific clinical symptoms of an orthohantavirus infection (gastrointestinal symptoms and distinct elevation of liver enzymes). Subsequent source investigation revealed 2 potential sources, the patient's feeder rats and a feeder rat farm. At both sources, a high prevalence of SEOV was found in the rats. The virus closely resembled the Cherwell and Turckheim SEOV strains that were previously found in Europe.

Background: Hantavirus is a tripartite negative-sense RNA virus. It can infect humans through contaminated rodent excreta and causes two types of fatal human diseases: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). China exhibits the highest HFRS occurrence rate in the world, and the Heilongjiang area is one of the most severely infected regions., Results: To obtain additional insights into the genetic characteristics of hantaviruses in the port cities of the Heilongjiang area in China, a molecular epidemiological investigation of hantaviruses isolated from rodents was performed in 2014. A total of 649 rodents (11 murine species and 1 shrew species) were caught in 12 port cities in Heilongjiang. Among these rodents, the most common species was A. agrarius, and the second-most common was R. norvegicus. A viral gene PCR assay revealed the presence of two specific genotypes of hantavirus, referred to as Hantaan virus (HTNV) and Seoul virus (SEOV), and the positive SEOV infection rate was higher than that for HTNV. A genetic analysis based on partial M segment sequences indicated that all of the isolates belonging to SEOV could be assigned to two genetic lineages, whereas the isolate belonging to HTNV could be assigned to only one genetic lineage., Conclusions: These results suggested that HTNV and SEOV are circulating in A. agrarius and R. norvegicus in the port cities in the area of Heilongjiang, but SEOV may be the dominant common hantavirus.

Seoul virus, an Old World hantavirus, is maintained in brown rats and causes a mild form of hemorrhagic fever with renal syndrome (HFRS) in humans. We captured rodents in New Orleans, Louisiana and tested them for the presence of Old World hantaviruses by reverse transcription polymerase chain reaction (RT-PCR) with sequencing, cell culture, and electron microscopy; 6 (3.4%) of 178 rodents captured--all brown rats--were positive for a Seoul virus variant previously coined Tchoupitoulas virus, which was noted in rodents in New Orleans in the 1980s. The finding of Tchoupitoulas virus in New Orleans over 25 years since its first discovery suggests stable endemicity in the city. Although the degree to which this virus causes human infection and disease remains unknown, repeated demonstration of Seoul virus in rodent populations, recent cases of laboratory-confirmed HFRS in some US cities, and a possible link with hypertensive renal disease warrant additional investigation in both rodents and humans.

To examine the prevalence of human pathogens carried by rats in urban areas in Hanoi and Hai Phong, Vietnam, we live-trapped 100 rats in January 2011 and screened them for a panel of bacteria and viruses. Antibodies against Leptospira interrogans (22·0%), Seoul virus (14·0%) and rat hepatitis E virus (23·0%) were detected in rats, but antibodies against Yersinia pestis were not detected. Antibodies against L. interrogans and Seoul virus were found only in adult rats. In contrast, antibodies to rat hepatitis E virus were also found in juvenile and sub-adult rats, indicating that the transmission mode of rat hepatitis E virus is different from that of L. interrogans and Seoul virus. Moreover, phylogenetic analyses of the S and M segments of Seoul viruses found in Rattus norvegicus showed that Seoul viruses from Hai Phong and Hanoi formed different clades. Human exposure to these pathogens has become a significant public health concern.

Hemorrhagic fever with renal syndrome (HFRS) has been a significant public problem since the first cases were reported in 1961 in Wuhan city (capital of Hubei province of China). Epidemiological surveys were carried out to better understand the dynamics of hantavirus infection in humans and animals in Wuhan. During 1961-2011, a total of 21,820 HFRS cases were registered in Wuhan. The two large epidemics had occurred during 1970-1991. They reached peaks in 1973 and 1983, respectively. There have been <10 cases since 2005. The disease occurred in the whole region including the downtown areas, but mainly in two districts. Although in 1980s and 1990s HFRS cases mainly recorded in August and winter, since 2000 the disease has mainly occurred in spring and summer. In this study, hantaviruses were identified in Apodemus mice, Rattus rats, and Mus mice by indirect immunofluorescent-assay and RT-PCR. Serological and genetic analyses showed that Hantaan virus (HTNV) and Seoul virus (SEOV) co-circulated in rodents. Phylogenetic analysis of hantaviral genome sequences revealed a novel genetic lineage of HTNV circulating in rodents in Wuhan. Another lineage of HTNV was closely related to the lineages from the provinces located in the origin and delta of Yangtze River. Remarkably, SEOV variants identified in Wuhan were more closely related to the variants found outside China. Results of the present study showed that HFRS cases in Wuhan are caused by HTNV and SEOV. Phylogenetic analysis of the hantavirus sequences revealed that a novel genetic lineage of HTNV is present in rodents in Wuhan., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Hantaviruses (genus Hantavirus, family Bunyaviridae) cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia and hantavirus (cardio)pulmonary syndrome (HCPS) in the Americas. So far, in Europe, four pathogenic hantaviruses have been found, often in co-circulation: Puumala virus (PUUV), Dobrava virus (DOBV), Saaremaa virus (SAAV), and Seoul virus (SEOV). Of those, only PUUV was found in Belgium. Recently, in our search for hantaviruses in the Flanders region of Belgium we collected genetic and serological evidence for the presence of SEOV virus in local brown rats. In this article, the results of (phylo)genetic analysis of wild-type SEOV strain from the Flanders are presented. The analysis based on the complete S segment sequence and also partial M- and L-segment sequences revealed that the Belgian SEOV strain was related most closely to strains from France, Indonesia, Japan, Singapore, Cambodia (those associated with the species Rattus norvegicus) and Vietnam. Such a clustering was in perfect agreement with the results of direct sequence comparison and suggested the same evolutionary history for all three genome segments of the Belgian SEOV strain (i.e., no reassortment of genome segments). So far, SEOV has been found in two European countries, France and Belgium, and there is every reason to believe that the area of the virus distribution in Europe is not restricted to those countries., (Copyright © 2012 Wiley Periodicals, Inc.)

Hantaan virus (HTNV) and Seoul virus (SEOV) are two major zoonotic pathogens of hemorrhagic fever with renal syndrome (HFRS) in Asia. Hubei province, which is located in the central-south China, had been one of the most severe epidemic areas of HFRS. To investigate phylogenetic relationships, genetic diversity and geographic distribution of HTNV and SEOV in their reservoir hosts, a total of 687 rodents were trapped in this area between 2000 and 2009. Sequences of partial S- and M-segments of hantaviruses and mitochondrial D-loop gene from 30 positive samples were determined. Our data indicated that SEOV and HTNV were co-circulating in Hubei. Phylogenetic analysis based on partial S- and M-segment sequences revealed two and three previously undefined lineages of SEOV, and a novel genetic lineage of HTNV, respectively. Four inter-lineage reassortment SEOVs carried by Rattus norvegicus and Apodemus agrarius were observed. It suggests that SEOV may cause spillover infections to A. agrarius naturally. The abundance of the phylogenetic lineages of SEOV suggested that central-south China was a radiation center for SEOVs., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)

Despite the worldwide distribution, most of the known Seoul viruses (SEOV) are closely related to each other. In this study, the M and the S segment sequences of SEOV were recovered from 130 lung tissue samples (mostly of Norway rats) and from six patient serum samples by reverse transcription-PCR. Genetic analysis revealed that all sequences belong to SEOV and represent 136 novel strains. Phylogenetic analysis of all available M and S segment sequences of SEOV, including 136 novel Chinese strains, revealed four distinct groups. All non-Chinese SEOV strains and most of the Chinese variants fell into the phylogroup A, while the Chinese strains originating from mountainous areas clustered into three other distinct groups (B, C, and D). We estimated that phylogroup A viruses may have arisen only within the last several centuries. All non-Chinese variants appeared to be directly originated from China. Thus, phylogroup A viruses distributed worldwide may share a recent ancestor, whereas SEOV seems to be as diversified genetically as other hantaviruses. In addition, all available mitochondrial DNA (mtDNA) sequences of Norway rats, including our 44 newly recovered mtDNA sequences, were divided into two phylogenetic groups. The first group, which is associated with the group A SEOV variants, included most of rats from China and also all non-Chinese rats, while the second group consisted of a few rats originating only from mountain areas in China. We hypothesize that an ancestor of phylogroup A SEOV variants was first exported from China to Europe and then spread through the New World following the migration of Norway rats.

Background: Hemorrhagic fever with renal syndrome (HFRS) is highly endemic in mainland China, and has extended from rural areas to cities recently. Beijing metropolis is a novel affected region, where the HFRS incidence seems to be diverse from place to place., Methodology/principal Findings: The spatial scan analysis based on geographical information system (GIS) identified three geo-spatial "hotspots" of HFRS in Beijing when the passive surveillance data from 2004 to 2006 were used. The Relative Risk (RR) of the three "hotspots" was 5.45, 3.57 and 3.30, respectively. The Phylogenetic analysis based on entire coding region sequence of S segment and partial L segment sequence of Seoul virus (SEOV) revealed that the SEOV strains circulating in Beijing could be classified into at least three lineages regardless of their host origins. Two potential recombination events that happened in lineage #1 were detected and supported by comparative phylogenetic analysis. The SEOV strains in different lineages and strains with distinct special amino acid substitutions for N protein were partially associated with different spatial clustered areas of HFRS., Conclusion/significance: Hotspots of HFRS were found in Beijing, a novel endemic region, where intervention should be enhanced. Our data suggested that the genetic variation and recombination of SEOV strains was related to the high risk areas of HFRS, which merited further investigation.

Objective: Genetic analysis was performed to infer the relationship between hantaviruses carried by Rattus norvegicus from Henan and Neimenggu provinces and the other known hantavirus and the vaccine strain., Methods: Total RNA was extracted from lung tissues with Trizol reagent. The complete M and S segment sequences of strains NM133 and Q12 were amplified by RT-PCR. The purified DNA fragments were directly subjected to sequencing, and then to sequence analysis and phylogenetic analysis., Results: The complete S segment sequences of strains NM133 and Q12 were found to be 1770 nt and 1772 nt in length respectively, with one open reading frame encoding 429 amino acids. The complete M segment sequences of both two strains are 3654 nucleotide in length encoding a protein of 1133 amino acids. The two strains shared a high degree of homology with most of known Seoul virus (SEOV) but quite different from Hantaan virus and other hantaviruses. Furthermore, the nucleoprotein and glycoprotein of the two strains had the congruent structure with the vaccine strain Z37. On the S- and M-phylogenetic trees, both strains (NM133 and Q12) were grouped into the first cluster of SEOV, and were more closely related to the strains, such as: Hb8610, R22, HB55, L99, and K24-e7., Conclusion: Both strains (NM133 and Q12) belonged to SEOV, and sharing a high degree of homology and similar secondary structure with strains including the vaccine strains Z37, our data suggested that the present vaccine used in China could effectively prevent HFRS caused by SEOV.

Surveys were carried out in 2003-2006 to better understand the epidemiology of hantaviruses in the Inner Mongolia Autonomous Region of China (Inner Mongolia). Hemorrhagic fever with renal syndrome (HFRS) was first reported in this region in 1955 and has been an important public health problem here since then. During 1955-2006, 8,309 persons with HFRS were reported in Inner Mongolia (average incidence rate 0.89/100,000), and 261 (3.14%) died. Before the 1990s, all HFRS cases occurred in northeastern Inner Mongolia. Subsequently, HFRS cases were registered in central (1995) and western (1999) Inner Mongolia. In this study, hantaviral antigens were identified in striped field mice (Apodemus agrarius) from northeastern Inner Mongolia and in Norway rats (Rattus norvegicus) from middle and western Inner Mongolia. Phylogenetic analysis of hantaviral genome sequences suggests that HFRS has been caused mainly by Hantaan virus in northeastern Inner Mongolia and by Seoul virus in central and western Inner Mongolia.

Objective: To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS)., Methods: Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with ClustalX 1.83 software., Results: 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31% ) of them were Rattus norvegicus and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type (15 samples were from Rattus norvegicus, 4 samples Rattus flavipectus, 2 samples Rattus nitidus). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1% -99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3., Conclusion: It was confirmed that the Seoul type virus, as HFRS's pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.

An outbreak of hemorrhagic fever with renal syndrome (HFRS) occurred among students in Shenyang Pharmaceutical University in 2006. We conducted a study to characterize etiologic agents of the outbreaks and clarify the origin of hantaviruses causing infections in humans and laboratory animals. Immunoglobulin (Ig) M or IgG antibodies against Seoul virus (SEOV) were detected in the serum samples of all 8 patients. IgG antibodies against hantavirus were also identified in laboratory rats, which were used by these students for their scientific research. Phylogenetic analysis showed that partial small segment sequences recovered from humans, laboratory rats, and local wild rats belonged to SEOV. Hantavirus sequences recovered from humans and laboratory rats clustered within 1 of 3 lineages of SEOV circulating among local wild rats in Shenyang. These results suggest that the HFRS outbreak in Shenyang was caused by SEOV that was circulating among local wild rats and had also infected the laboratory rats.

Seoul hantavirus (SEOV), carried by Rattus rattus (black rat) and R. norvegicus (Norway, brown rat), was reported to circulate as well as cause HFRS cases in Asia. As Rattus sp. are present worldwide, SEOV has the potential to cause human disease worldwide. In Europe however, only SEOV prevalence in rats from France was reported and no confirmed cases of SEOV infection were published. We here report genetic and serological evidence for the presence of SEOV virus in brown rat populations in Belgium. We also serologically screened an at-risk group that was in contact with R. norvegicus on a daily basis and found no evidence for SEOV infection.

The hemorrhagic fever with renal syndrome (HFRS) incidence rate still holds in high level in some areas of the world, but a reliable and simple typing method that can be used in clinical diagnosis and epidemiologic surveys is not available. In this study, 48 serum samples were collected from patients with HFRS in Linyi area, China, that is seriously affected by this disease. The collected samples were analyzed by nested RT-PCR combined with single-strand conformation polymorphism (SSCP) for genotyping of hantaviruses (HV). Out of 48 serum samples, 41 samples were positive by the nested RT-PCR. According to the SSCP patterns, Seoul virus (SEOV) was found in 33 samples and Hantaan virus (HTNV) in 8 samples. The comparison of sequence identities of nested RT-PCR products of tested samples with reference isolates SEOV and HTNV supported the typing results. Thus, genotyping of HV by nested RT-PCR/SSCP is suitable in early diagnosis of HV infection and in epidemiologic surveys.

Hemorrhagic fever with renal syndrome (HFRS) is a significant public health problem with an increasing incidence in Beijing, China (report of disease surveillance from the Center for Disease Control and Prevention of Beijing, China). Hantaviruses were detected using RT-PCR method in blood samples of HFRS patients and lung tissues of rodents captured in Beijing. Phylogenetic analyses of 724bp partial S segment of the hantavirus gene showed that the detected Seoul virus (SEOV) fell into three different lineages, two of which circulated in Beijing. A nucleotide sequence identity of 99.7% for one of the cases of HFRS--the human- and Rattus norvegicus-originated SEOV sequences--had only two silent substitutions, suggesting genetic analysis is an essential tool for "case-investigation."

Hemorrhagic fever with renal syndrome (HFRS) is a fulminant infectious disease characterized by fever, hemorrhage, renal impairment, and thrombocytopenia. Hantaviruses associated with this belong to different serotypes: Hantaan (HTN), Seoul (SEO), Dobrava/Belgrade (DOB), and Puumala (PUU). The first two, HTN and SEO, are endemic in China. To investigate the epidemiology of HFRS and virus transmission in China, we constructed prokaryotic plasmids encoding truncated recombinant HTN and SEO nucleocapsid proteins (NPs), which lacked 154 amino acid (aa), 99 aa, or 49 aa in the N-terminal region, respectively. After expression, the truncated rNPs were tested as serotyping antigens, particularly for use in the enzyme-linked immunosorbent assay (ELISA). In addition, 68 acute and 52 convalescent sera were collected from HFRS patients from Harbin, Lantian, and Kaifeng regions in China in 2004, which had hantavirus specific antibodies by IFA. A neutralization test was used to differentiate these, which showed that 73 were due to HTN infection, 33 to SEO infection, and 14 undetermined. By ELISA, the truncated rNPs, that lacked 99 (rNP100) or 49 (rNP50) N-terminal amino acids of the NPs of HTN and SEO, were able to differentiate HTNV and SEOV-specific immune sera, but the rNP155 could not. Particularly, the ELISAs based on the rNP50s had a result comparable to PRNT. Thus, the rNP50 is recommended as efficient serotyping antigen for hantavirus infection diagnosis by ELISA., ((c) 2006 Wiley-Liss, Inc.)

Objective: To investigate the sub-genotypes and distribution ot Seoul virus in Henan., Methods: Rodents were collected in the major epidemic areas and rats lungs were studied by indirect immunofluorescence assay. Partial M and S segments were amplified with nested reverse transcription-polymerase chain reaction using Hantavirus genotype-specific primers, sequenced, analyzed and compared with other known sequences., Results: The Hantavirus carried by Rattus norvegicus, Rattus flavipectus and Mus musculus were all belonged to Seoul virus in the main epidemic areas of Henan. We constructed two phylogenetic tree based on the partial M and S segment sequences while phylogenetic analysis distinguished three genetic subtypes (S1, S2 and S3). S1 and S3 were found main subtypes in Henan., Conclusion: The results indicated that the genetic subtypes of Hantavirus were complicated and widely distributed in Henan.

DNA microarrays combine high-precision technology with advanced molecular biology to achieve high-throughput screening of DNA fragments. In this study, we investigated the potential of the cDNA microarray technique to identify and discriminate PCR derived amplicons from genetically highly similar viruses. The wide range of sequence variation among hantaviruses makes them suitable as a model for this purpose. The hantaviruses, carried by rodents, cause several hundred thousand cases of severe human disease every year in many parts of the world. A hantavirus-specific microarray, including DNA fragments from 12 viral isolates of six different hantaviruses, was designed. The S and M genome segments were represented by 500-nucleotide overlapping and 250-nucleotide non-overlapping fragments. A considerable ability to distinguish between different hantaviruses was demonstrated using a novel analysis method. Even different isolates of a single virus, were identified correctly despite 90% sequence similarity. The distinction ability was accompanied by a tolerance for smaller sequence differences, which makes the microarray suitable for testing samples containing unknown viruses. Viral genetic material found in samples from the lungs of bank voles caught in the wild was identified precisely, which demonstrated further the potential for this technology., (Copyright 2004 Wiley-Liss, Inc.)

A study was conducted in agricultural and urban areas in Cambodia to assess the presence of hantaviruses in rodent populations. In 1998, rodents were trapped in two villages and in Phnom Penh city around market places and a rubbish dump. IgG antibodies to Hantaan virus were detected in 54 (8.2%) rodents among 660 tested: 6.4% (13/203) among roof rats (Rattus rattus), 20.9% (39/187) among Norway rats (R. norvegicus), 16.7% (2/12) among unidentified Rattus species and none in 183 Polynesian rats (R. exulans) or in 75 bandicoot rats (Bandicota sp.). The presence of the viral genome was detected by a reverse transcription-PCR amplifying part of the sequence coding for the nucleoprotein in the S segment, in 87% of the seropositive rodents. Thirty-one representative cDNAs were sequenced. Phylogenetic studies of the sequences indicated a close relationship with Seoul virus. However, the Cambodian Seoul virus sequences clustered within two different phylogenetic lineages, one associated with R. rattus and the other with R. norvegicus.

Data on the circulation of a new genetic variant of Seol virus, which was designated as "Vladivostok" (the name of the place where it was isolated)--VDV, were obtained, by using the antigenic and genetic analysis of hantavirus strains isolated from patients with hemorrhagic fever with renal syndrome (HFRS) and from brown rats, and described in the present paper. A complete identity of nucleotide sequences of the M-segment fragment of isolates obtained from HFRS patients and of those obtained from rats was demonstrated, which confirms the key role of brown rat as a source of infection.