Experimental parameters of infection and intraspecific transmission of Hantaan virus, the etiologic agent of Korean hemorrhagic fever, in Apodemus agrarius rodents were determined. Mice inoculated by the intramuscular route experienced viremia for about 1 week beginning on day 7. After 3 weeks, immunofluorescent and neutralizing antibodies were present and no mouse ever developed signs of acute illness. Virus was recovered from lung, kidney, salivary gland, and liver, and virus excretion in urine, saliva, and feces occurred from about day 10 through day 360 (urine) post-inoculation. Antigen, but not infectious virus, was persistent in lung tissue for as long as 1 year. Horizontal contact infection occurred among cage-mates regardless of sexual pairing up to 360 days after infection and no evidence for participation of ectoparasitic arthropods in such transmission was obtained.

No abstract

In order to investigate the prevalence of tick-borne infectious agents among ticks, ticks comprising five species from two genera (Hemaphysalis spp. and Ixodes spp.) were screened using molecular techniques. Ticks (3,135) were collected from small wild-caught mammals or by dragging/flagging in the Republic of Korea (ROK) and were pooled into a total of 1,638 samples (1 to 27 ticks per pool). From the 1,638 tick samples, species-specific fragments of Anaplasma phagocytophilum (

Background-Live oral rotavirus vaccines have been less immunogenic and efficacious among children in poor developing countries compared with middle income and industrialized countries for reasons that are not yet completely understood. We assessed whether the neutralizing activity of breast milk could lower the titer of vaccine virus and explain this difference in vitro.

Until recently, the single known exception to the rodent-hantavirus association was Thottapalayam virus (TPMV), a long-unclassified virus isolated from the Asian house shrew (Suncus murinus)Hantaviruses (family Bunyaviridae, genus Hantavirus) are medically important rodent-borne pathogens, causing hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). The belief in long-standing coevolutionary relationships between hantaviruses and their reservoir rodent host species is supported by virus and rodent gene phylogenies. That is, phylogenetic analyses, based on full-length viral genomic sequences and rodent mitochondrial DNA (mtDNA) or nuclear gene sequences, indicate that antigenically distinct hantaviruses segregate into clades, which parallel the evolution of rodents in the subfamilies Murinae, Arvicolinae, Neotominae, and Sigmodontinae (23,25,26,28,39,54). Previously, this phylogenetic insight has been successfully employed to direct the discovery of new hantaviruses, such as those found in the Korean field mouse (Apodemus peninsulae) (5) and the royal vole (Myodes regulus) (47).Renewed interest in the role of nonrodent reservoirs in the evolution of hantaviruses has been spurred by recent analysis of the entire genome of Thottapalayam virus (TPMV), a hantavirus isolated from the Asian house shrew (Suncus murinus) (10, 61), which revealed a separate phylogenetic clade, suggesting early evolutionary divergence from rodent-borne hantaviruses (44, 56). Armed with oligonucleotide primers designed on the basis of conserved regions of the TPMV genome and guided by long-ignored reports of serologic and antigenic evidence of hantavirus infection in shrews (20, 33, 52), we have previously detected genetically distinct hantaviruses in the Eurasian common shrew (Sorex araneus) from Switzerland (45); the Chinese mole shrew (Anourosorex squamipes) from Vietnam (46); and the northern short-tailed shrew (Blarina brevicauda), masked shrew (Sorex cinereus), and dusky shrew (Sorex monticolus) from the United States (1, 2) by reverse transcription-PCR (RT-PCR). Novel hantavirus genomes in Therese's shrew (Crocidura theresae) from Guinea (29); the vagrant shrew (Sorex vagrans), Trowbridge's shrew (Sorex trowbridgii), and the American water shrew (Sorex palustris) from the United States (H. J. Kang and R. Yanagihara, unpublished data); and the flat-skulled shrew (Sorex roboratus) and Laxmann's shrew (Sorex caecutiens) from Russia (Kang and Yanagihara, unpublished) have also been detected.Here, we report the antigenic, genetic, and phylogenetic characterization of a newly identified hantavirus, designated Imjin virus (MJNV), isolated from Ussuri white-toothed shrews of the species Crocidura lasiura (order Soricomorpha, family Soricidae, subfamily Crocidurinae) captured near the demilitarized zone (DMZ) in the Republic of Korea. The discovery of MJNV and other soricid-borne hantaviruses from widely separated geographic regions, spanning four continents,

Hantaan (HTN) virus, the etiologic agent of clinically severe hemorrhagic fever with renal syndrome (HFRS), was first isolated in 1976 from lung tissue of a striped-field mouse (Apodemus agrarius) captured in Songnae-ri, Gyeonggi Province, Republic of Korea. Found primarily in mountainous areas, the Korean field mouse (A. peninsulae) is the second-most dominant field rodent species found throughout Korea. A new hantavirus, designated Soochong (SOO), was isolated in Vero E6 cells from four A. peninsulae captured in August 1997 at Mt. Gyebang in Hongcheon-gun, Mt. Gachil, Inje-gun, Gangwon Province, and in September 1998 at Mt. Deogyu, Muju-gun, Jeollabuk Province. The entire S, M, and L genomic segments of SOO virus, amplified by RT-PCR from lung tissues of seropositive A. peninsulae and from virus-infected Vero E6 cells, diverged from HTN virus (strain 76-118) by 15.6%, 22.8%, and 21.7% at the nucleotide level and 3.5%, 9.5%, and 4.6% at the amino acid level, respectively. Phylogenetic analyses of the nucleotide and deduced amino acid sequences, using the maximum parsimony and neighbor-joining methods, indicated that SOO virus was distinct from A. agrarius-borne HTN virus. SOO virus shared a common ancestry with Amur virus from Far East Russia, as well as with H5 and B78 hantaviruses, previously isolated from HFRS patients in China. Cross-focus-reduction neutralizating antibody tests showed that SOO virus, which is the first hantavirus isolated in cell culture from A. peninsulae, could be classified as a new hantavirus serotype.

This virus is antigenically and phylogenetically distinct from rodent-borne hantaviruses.

Studies were conducted to define the natural host range of the Korean henorrhagic fever (KHF) agent in South Korea, and to identify colonized rodents susceptibl64o this infection. Eight species of field rodents were captured in areas of Korea endemic for yKHF and their tissues were examined by immunofluorescence for the presence of KHF antigen. One hundred and fourteen of 817 Apodemus agrarius coreae captured between 1974 and 1978 had one or more positive organs. No positive organ was found in 239 rodents of the other seven species examined. Two hundred and thirty-eight specimens of Apodemus agrarius Ck jejuensis captured on Jeju Island, an area thought to be free of disease, were also negative. Attempted laboratory infection of nine species of rodents captured in the field but maintained in the laboratory was successful only in the two subspecies of Apodemus. The 46 specimens of A. a. jejuensis tested in this manner were all uniformly susceptible to infection as determined by immunofluorescence. Serial sacrifice of experimentally infected A. a. jejuensis revealed viremia of short duration terminating on day 10 postinfection. In contrast, other tissues of this animal, including lung, kidney, liver and parotid gland were positive on day 10 and remained so through the 100-day observation period. When 12 species of colonized laboratory rodents were inoculated with KHF agent five were found to develop KHF antibody by indirect immunofluorescence and two, Calomys callosus and Apodemus agrarius ningpoensis, developed detectable KHF antigen in their tissues. The first successful isolation and propagation demic areas of disease on the Korean peninsula, LA.) of the etiologic agent of Korean hemorrhagic fever was demonstrated utilizing the indirect fluores-... i (KHF) was described in a previous communicacent antibody (IFA) technique and human KHF 1 tion. The presence of KHF agent-specific antigen convalescent sera. Numerous isolations of the in frozen sections of various tissues of Apodemus agent have been made from rodents of this agrarius coreae, a vesper mouse indigenous to en-species, and successive passage of the agent in a boow-on_ subspecies, Apodemus agrarius jejuensis captured in areas free of natural disease, has been report