[Genomic analysis of Wenzhou virus in rodents from Zhejiang province].

Objective: Arenavirus is a negative single-stranded RNA virus and an important human pathogen, mainly harbored and transmitted by rodents, causing severe diseases, including hemorrhagic fever and encephalitis. Following the discovery of a novel pathogenic arenavirus (Wenzhou virus, WENV), the prevalence of WENV in local small rodents was investigated. Methods: By using RT-PCR, WENV was screened in 48 and 156 rodents sampled from Wenzhou and Longquan, respectively. Results: Consequently, WENV was detected in 5 (10.41%) rodents sampled from Wenzhou. However, no WENV was identified in all the rodents sampled from Longquan. Genetic analysis of complete genome sequences indicated that 4 of 5 virus strains were closely related to the known Wenzhou viruses with high homology. Especially, the L and S segments of Wencheng-Rn-288 strain shared homology of 87.5% and 91.6% with other viruses, respectively. They formed a distinct lineage, suggesting that this strain might be a novel variant of WENV. Conclusions: Our results indicate that WENV has a high prevalence and high genetic diversity among rodents in Wenzhou. As the respiratory disease caused by WENV has been detected in Cambodia, it is necessary to strengthen the surveillance for WENV in China.

Novel Arenavirus Isolates from Namaqua Rock Mice, Namibia, Southern Africa.

Arenaviruses are feared as agents that cause viral hemorrhagic fevers. We report the identification, isolation, and genetic characterization of 2 novel arenaviruses from Namaqua rock mice in Namibia. These findings extend knowledge of the distribution and diversity of arenaviruses in Africa.

Hantaan virus surveillance targeting small mammals at nightmare range, a high elevation military training area, Gyeonggi Province, Republic of Korea.

Rodent-borne disease surveillance was conducted at Nightmare Range (NM-R), near the demilitarized zone in northeast Gyeonggi Province, Republic of Korea, to identify hemorrhagic fever with renal syndrome (HFRS) risks for a mountainous high-elevation (500 m) military training site. Monthly surveys were conducted from January 2008-December 2009. A total of 1,720 small mammals were captured belonging to the Orders Rodentia [Families, Sciuridae (1 species) and Muridae (7 species)] and Soricomorpha [Family, Soricidae (1species)]. Apodemus agrarius, the primary reservoir for Hantaan virus (HTNV), accounted for 89.9% (1,546) of all small mammals captured, followed by Myodes regulus (4.0%), Crocidura lasiura (3.9%), Micromys minutus (1.4%), Mus musculus (0.3%), Microtus fortis (0.2%), Apodemus peninsulae (0.2%), Tamias sibiricus (0.1%), and Rattus norvegicus (<0.1%). Three species were antibody-positive (Ab+) for hantaviruses: A. agrarius (8.2%), M. minutus (4.2%), and C. lasiura (1.5%). HTNV specific RNA was detected in 93/127 Ab+ A. agrarius, while Imjin virus specific RNA was detected in 1/1 Ab+ C. lasiura. Overall, hantavirus Ab+ rates for A. agrarius increased with weight (age) and were significantly higher among males (10.9%) than females (5.1%) (P<0.0001). High A. agrarius gravid rates during the fall (August-September) were associated with peak numbers of HFRS cases in Korea that followed high gravid rates. From 79 RT-PCR positive A. agrarius, 12 HTNV RNA samples were sequenced and compared phylogenetically based on a 320 nt sequence from the GC glycoprotein-encoding M segment. These results demonstrate that the HTNV isolates from NM-R are distinctly separated from HTNV isolated from the People's Republic of China. These studies provide for improved disease risk assessments that identify military activities, rodent HTNV rates, and other factors associated with the transmission of hantaviruses during field training exercises.

Isolation and characterization of a novel arenavirus harbored by Rodents and Shrews in Zhejiang province, China.

To determine the biodiversity of arenaviruses in China, we captured and screened rodents and shrews in Wenzhou city, Zhejiang province, a locality where hemorrhagic fever diseases are endemic in humans. Accordingly, arenaviruses were detected in 42 of 351 rodents from eight species, and in 12 of 272 Asian house shrews (Suncus murinus), by RT-PCR targeting the L segment. From these, a single arenavirus was successfully isolated in cell culture. The virion particles exhibited a typical arenavirus morphology under transmission electron microscopy. Comparison of the S and L segment sequences revealed high levels of nucleotide (>32.2% and >39.6%) and amino acid (>28.8% and >43.8%) sequence differences from known arenaviruses, suggesting that it represents a novel arenavirus, which we designated Wenzhou virus (WENV). Phylogenetic analysis revealed that all WENV strains harbored by both rodents and Asian house shrews formed a distinct lineage most closely related to Old World arenaviruses.

Susceptibility of muridae cell lines to ecotropic murine leukemia virus and the cationic amino acid transporter 1 viral receptor sequences: implications for evolution of the viral receptor.

Ecotropic murine leukemia viruses (Eco-MLVs) infect mouse and rat, but not other mammalian cells, and gain access for infection through binding the cationic amino acid transporter 1 (CAT1). Glycosylation of the rat and hamster CAT1s inhibits Eco-MLV infection, and treatment of rat and hamster cells with a glycosylation inhibitor, tunicamycin, enhances Eco-MLV infection. Although the mouse CAT1 is also glycosylated, it does not inhibit Eco-MLV infection. Comparison of amino acid sequences between the rat and mouse CAT1s shows amino acid insertions in the rat protein near the Eco-MLV-binding motif. In addition to the insertion present in the rat CAT1, the hamster CAT1 has additional amino acid insertions. In contrast, tunicamycin treatment of mink and human cells does not elevate the infection, because their CAT1s do not have the Eco-MLV-binding motif. To define the evolutionary pathway of the Eco-MLV receptor, we analyzed CAT1 sequences and susceptibility to Eco-MLV infection of other several murinae animals, including the southern vole (Microtus rossiaemeridionalis), large Japanese field mouse (Apodemus speciosus), and Eurasian harvest mouse (Micromys minutus). Eco-MLV infection was enhanced by tunicamycin in these cells, and their CAT1 sequences have the insertions like the hamster CAT1. Phylogenetic analysis of mammalian CAT1s suggested that the ancestral CAT1 does not have the Eco-MLV-binding motif, like the human CAT1, and the mouse CAT1 is thought to be generated by the amino acid deletions in the third extracellular loop of CAT1.

[Bolivian hemorrhagic fever].

Analysis of data of the available literature on epidemiology of Bolivian hemorrhagic fever, manifestations of human disease, biological properties of the causative agent and development carried out abroad of means and methods of diagnostics, prophylaxis and therapy of this infection that presents a potential threat for the population and economy of the Russian Federation in case of introduction of the causative agent is presented.

A small-scale survey of hantavirus in mammals from eastern Poland.

Samples of 30 dead small mammals each were collected on area 'A' located in eastern Poland which is exposed to flooding by the Vistula river, and on the area 'B', also located in eastern Poland but not exposed to flooding. Kidneys and livers of the mammals were examined by the PCR and nested PCR methods for the presence of hantavirus RNA. Out of 7 species of small mammals examined, the presence of hantaviruses was detected in 4 of them. Hantavirus prevalence was low in Apodemus agrarius (2.6%), the most numerous mammal species, whereas in the remaining 3 positive species (Microtus agrestis, Myodes glareolus, Sorex araneus) this was 12.5-100%. The presence of hantaviruses was detected only in the animals found on area 'A' exposed to flooding, and their prevalence was statistically greater compared to area 'B' not exposed to flooding (16.7% vs. 0%, p=0.0345). The overall positivity of the examined small mammals population from the areas 'A' and 'B' was 8.3%. The sequence analysis of the samples positive for hantavirus proved that the amplified products showed 77-86% homology with the L segment sequence of hantavirus Fusong-Mf-731 isolated from Microtus fortis in China. The presented study is the first to demonstrate the occurrence of hantavirus infection in small mammals from eastern Poland, and the first to demonstrate the significant relationship between flooding and the prevalence of hantaviruses in small mammals.

Tick-borne encephalitis virus - a review of an emerging zoonosis.

During the last 30 years, there has been a continued increase in human cases of tick-borne encephalitis (TBE) in Europe, a disease caused by tick-borne encephalitis virus (TBEV). TBEV is endemic in an area ranging from northern China and Japan, through far-eastern Russia to Europe, and is maintained in cycles involving Ixodid ticks (Ixodes ricinus and Ixodes persulcatus) and wild vertebrate hosts. The virus causes a potentially fatal neurological infection, with thousands of cases reported annually throughout Europe. TBE has a significant mortality rate depending upon the strain of virus or may cause long-term neurological/neuropsychiatric sequelae in people affected. In this review, we comprehensively reviewed TBEV, its epidemiology and pathogenesis, the clinical manifestations of TBE, along with vaccination and prevention. We also discuss the factors which may have influenced an apparent increase in the number of reported human cases each year, despite the availability of effective vaccines.

Complete genomic characterization of a murine papillomavirus isolated from papillomatous lesions of a European harvest mouse (Micromys minutus).

The papillomaviruses form a large group of species-specific pathogens that cause epithelial proliferations in a wide spectrum of animal hosts. Previous reports demonstrated a relatively high frequency of a variety of skin lesions in captive European harvest mice. The Micromys minutus papillomavirus (MmPV) was isolated from one of these lesions found on a captive European harvest mouse in a regional zoo in Chicago. In this study we present the entire genomic sequence of MmPV. The MmPV genome is organized into the seven classical papillomaviral open reading frames. Phylogenetic analysis places MmPV together with a papillomavirus (PV) isolated from a Syrian golden Hamster (HaOPV) in the genus Pipapillomavirus. The similar clustering pattern of the MmPV-HaOPV pair and their rodent hosts support the hypothesis of papillomaviral and host co-phylogenetic descent. The availability of the complete genomic sequence of a mouse PV should allow researchers to use MmPV as a model for PV carcinogenesis.

[The epizootological and virological characteristics of a natural hantavirus infection focus in the subtropic zone of the Krasnodarsk Territory].

A natural focus of hantavirus infection was detected and examined during the studies conducted in 2000-2002 around the Sochi (the western spurs of the Great Caucasus Ridge, which descended to the Black Sea (the Krasnodar Territory of Russia). At least 4 rodent species, such as Microtus majori, A. (S.) ponticus, A. agrarius, A. (S.) ciscaucasicus, were shown to participate in the circulation of hantaviruses. A comparative analysis of the nucleotide sequences of genomic S- and M-segments of hantaviruses has provided evidence that 13 viral RNA isolates from the A. (S.) ciscaucasicus belong to the Dobrava/Belgrade virus clade; however the RNA isolate from the Microtus majori belong to the Tula virus clade.

Identification of genetic evidence for dobrava virus spillover in rodents by nested reverse transcription (RT)-PCR and TaqMan RT-PCR.

A survey of 158 rodents caught in the Czech Republic identified Dobrava virus sequences closely related to that of the Dobrava virus type strain in Apodemus sylvaticus and Mus musculus rodents. The identity of A. sylvaticus was unequivocally confirmed by random amplified polymorphic DNA analysis. The data seem to indicate hantavirus spillover from Apodemus flavicollis to other rodents.

Epizootiological and epidemiological study of hantavirus infection in Japan.

Epizootiological surveys on hantavirus infections in rodents were carried out in various areas of Japan, including the four major islands of Hokkaido, Honshu, Shikoku, and Kyushu from 2000 to 2003. A total of 1,221 rodents and insectivores were captured. Seropositive animals were found in Apodemus (A.) speciosus (5/482, 1.0%), Rattus (R.) norvegicus (4/364, 1.1%), R. rattus (3/45, 6.7%), and Clethrionomys (C.) rufocanus (7/197, 3.6%). The partial S segment was amplified from one seropositive R. rattus captured at Hakodate. The nucleotide sequence showed 96% identity with the Seoul virus (SEOV) prototype strain SR-11. In addition, we conducted an epidemiological survey on human hantavirus infection in a high-risk population, the personnel of the Japan Ground Self-defense Force on Hokkaido. One out of 207 human blood samples was positive for anti-hantavirus antibody by IFA, ELISA, and WB analysis. The result of the serotype specific ELISA indicates that this individual acquired SEOV infection. This study indicates that A. speciosus, R. norvegicus, R. rattus, and C. rufocanus carry hantaviruses as the reservoir animals in Japan. Infected R. rattus and R. norvegicus in port areas could be the sources of human SEOV infection and a threat to travelers and individuals working in seaports.

Saaremaa hantavirus in Denmark.

Most human hantavirus infections in Denmark have been registered on the Fyn island with Puumala hantavirus hosted by Clethrionomys glareolus as the causative agent. To search for other known European hantaviruses in Denmark, we analyzed 101 Apodemus spp. mice trapped on the Lolland island. Genome sequences of Saaremaa hantavirus (SAAV) were recovered from one of the A. agrarius, thus suggesting SAAV presence in Denmark. We also analyzed serum samples from a patient from Lolland with a history of hantavirus-like infection, probably caused by SAAV. Thus, in addition to Puumala virus, SAAV can impose a threat for the human health in Denmark.

Increased incidence of squamous cell carcinomas in Mastomys natalensis papillomavirus E6 transgenic mice during two-stage skin carcinogenesis.

Papillomaviruses cause certain forms of human cancers, most notably carcinomas of the uterine cervix. In contrast to the well-established involvement of papillomavirus infection in the etiology of cervical carcinomas and in carcinomas of a rare hereditary condition, epidermodysplasia verruciformis, a causative role for cutaneous human papillomavirus types in the development of nonmelanoma skin cancer has not been proven. In order to better understand the functions of individual genes of cutaneous papillomavirus types, we generated transgenic mice carrying oncogene E6 of the Mastomys natalensis papillomavirus (MnPV), which causes keratoacanthomas of the skin in its natural host. In the present study, we demonstrate that under conditions of experimental two-stage skin carcinogenesis, fast-paced squamous cell carcinomas develop in nearly 100% of MnPV E6 transgenic mice in comparison to 10% in their nontransgenic littermates (log rank test; P < 0.0001). Therefore, we conclude that the MnPV E6 transgene favors the malignant progression of chemically induced tumors. Whereas an activating H-ras mutation is a consistent feature in benign and malignant tumors in wild-type mice, the majority of papillomas and keratoacanthomas and all squamous cell carcinomas obtained in MnPV E6 transgenic mice contain nonmutated ras alleles. These results indicate that the development of squamous cell carcinomas in MnPV E6 transgenic mice does not depend on an activated H-ras oncogene.

Isolates of cytomegalovirus (CMV) from the black rat Rattus rattus form a distinct group of rat CMV.

Two different betaherpesviruses, the English and Maastricht species of rat cytomegalovirus (CMV), have previously been isolated from Rattus norvegicus. CMVs were isolated from both the brown rat, R. norvegicus, and the black rat, R. rattus, within Australia. The viruses isolated from R. norvegicus appeared to be genetically related to the English species of rat CMV by PCR, RFLP, and sequencing, but the viruses isolated from R. rattus were distinct from both prototype virus species, although more closely genetically related to the Maastricht virus. This is the first genetic characterization of cytomegaloviruses from R. rattus, and the first isolation of CMVs from Australian rats.

First molecular identification of human Dobrava virus infection in central Europe.

Viral RNA was amplified by reverse transcription-PCR from a patient suffering from hemorrhagic fever with renal syndrome (HFRS) in Germany. The virus strain could be assigned to the Dobrava hantavirus (DOBV). This is the first molecular identification of human infection by DOBV in central Europe and the first proof that a virus strain related to the DOBV-Aa lineage, carried by Apodemus agrarius rodents, is able to cause HFRS.

The detection of monkeypox in humans in the Western Hemisphere.

BACKGROUND: During May and June 2003, an outbreak of febrile illness with vesiculopustular eruptions occurred among persons in the midwestern United States who had had contact with ill pet prairie dogs obtained through a common distributor. Zoonotic transmission of a bacterial or viral pathogen was suspected. METHODS: We reviewed medical records, conducted interviews and examinations, and collected blood and tissue samples for analysis from 11 patients and one prairie dog. Histopathological and electron-microscopical examinations, microbiologic cultures, and molecular assays were performed to identify the etiologic agent. RESULTS: The initial Wisconsin cases evaluated in this outbreak occurred in five males and six females ranging in age from 3 to 43 years. All patients reported having direct contact with ill prairie dogs before experiencing a febrile illness with skin eruptions. We found immunohistochemical or ultrastructural evidence of poxvirus infection in skin-lesion tissue from four patients. Monkeypox virus was recovered in cell cultures of seven samples from patients and from the prairie dog. The virus was identified by detection of monkeypox-specific DNA sequences in tissues or isolates from six patients and the prairie dog. Epidemiologic investigation suggested that the prairie dogs had been exposed to at least one species of rodent recently imported into the United States from West Africa. CONCLUSIONS: Our investigation documents the isolation and identification of monkeypox virus from humans in the Western Hemisphere. Infection of humans was associated with direct contact with ill prairie dogs that were being kept or sold as pets.

Epizootiology of arenaviral infections in the white-throated woodrat (Muridae: Sigmodontinae) and other woodrats in Arizona.

The purpose of this study was to extend and refine our knowledge of the geographical distribution and natural host relationships of the arenaviruses associated with woodrats indigenous to Arizona. Antibody to a Tacaribe serocomplex virus was found in 112 of 1,250 white-throated woodrats, five of 208 Mexican woodrats, one of 114 Stephen's woodrats, and none of 862 other rodents captured at 51 sites in 10 counties in Arizona. Of the 112 antibody-positive white-throated woodrats, 109 (97.3%) were captured within extensive, dense patches of prickly pear cactus and cane cholla in three counties in mid-central Arizona. Analysis of the serological and zoographical data suggested that white-throated woodrats usually become infected early in life and that the distribution of antibody-positive white-throated woodrats in Arizona is not linked to a specific biome.