Se Hun Gu

Seewis virus, a genetically distinct hantavirus in the Eurasian common shrew (Sorex araneus)

More than 20 years ago, hantaviral antigens were reported in tissues of the Eurasian common shrew (Sorex araneus), Eurasian water shrew (Neomys fodiens) and common mole (Talpa europea), suggesting that insectivores, or soricomorphs, might serve as reservoirs of unique hantaviruses. Using RT-PCR, sequences of a genetically distinct hantavirus, designated Seewis virus (SWSV), were amplified from lung tissue of a Eurasian common shrew, captured in October 2006 in Graubünden, Switzerland. Pair-wise analysis of the full-length S and partial M and L segments of SWSV indicated approximately 55%–72% similarity with hantaviruses harbored by Murinae, Arvicolinae, Neotominae and Sigmodontinae rodents. Phylogenetically, SWSV grouped with other recently identified shrew-borne hantaviruses. Intensified efforts are underway to clarify the genetic diversity of SWSV throughout the geographic range of the Eurasian common shrew, as well as to determine its relevance to human health.

Hantaviruses: rediscovery and new beginnings.

Virus and host gene phylogenies, indicating that antigenically distinct hantaviruses (family Bunyaviridae, genus Hantavirus) segregate into clades, which parallel the molecular evolution of rodents belonging to the Murinae, Arvicolinae, Neotominae and Sigmodontinae subfamilies, suggested co-divergence of hantaviruses and their rodent reservoirs. Lately, this concept has been vigorously contested in favor of preferential host switching and local host-specific adaptation. To gain insights into the host range, spatial and temporal distribution, genetic diversity and evolutionary origins of hantaviruses, we employed reverse transcription-polymerase chain reaction to analyze frozen, RNAlater(®)-preserved and ethanol-fixed tissues from 1546 shrews (9 genera and 47 species), 281 moles (8 genera and 10 species) and 520 bats (26 genera and 53 species), collected in Europe, Asia, Africa and North America during 1980-2012. Thus far, we have identified 24 novel hantaviruses in shrews, moles and bats. That these newfound hantaviruses are geographically widespread and genetically more diverse than those harbored by rodents suggests that the evolutionary history of hantaviruses is far more complex than previously conjectured. Phylogenetic analyses indicate four distinct clades, with the most divergent comprising hantaviruses harbored by the European mole and insectivorous bats, with evidence for both co-divergence and host switching. Future studies will provide new knowledge about the transmission dynamics and pathogenic potential of these newly discovered, still-orphan, non-rodent-borne hantaviruses.

Divergent ancestral lineages of newfound hantaviruses harbored by phylogenetically related crocidurine shrew species in Korea

Spurred by the recent isolation of a novel hantavirus, named Imjin virus (MJNV), from the Ussuri white-toothed shrew (Crocidura lasiura), targeted trapping was conducted for the phylogenetically related Asian lesser white-toothed shrew (Crocidura shantungensis). Pair-wise alignment and comparison of the S, M and L segments of a newfound hantavirus, designated Jeju virus (JJUV), indicated remarkably low nucleotide and amino acid sequence similarity with MJNV. Phylogenetic analyses, using maximum likelihood and Bayesian methods, showed divergent ancestral lineages for JJUV and MJNV, despite the close phylogenetic relationship of their reservoir soricid hosts. Also, no evidence of host switching was apparent in tanglegrams, generated by TreeMap 2.0β.

Reconstructing the evolutionary origins and phylogeography of hantaviruses

Rodents have long been recognized as the principal reservoirs of hantaviruses. However, with the discovery of genetically distinct and phylogenetically divergent lineages of hantaviruses in multiple species of shrews, moles, and insectivorous bats from widely separated geographic regions, a far more complex landscape of hantavirus host distribution, evolution, and phylogeography is emerging. Detailed phylogenetic analyses, based on partial and full-length genomes of previously described rodent-borne hantaviruses and newly detected non-rodent-borne hantaviruses, indicate an Asian origin and support the emerging concept that ancestral non-rodent mammals may have served as the hosts of primordial hantaviruses.

Full genome analysis of a novel adenovirus from the South Polar skua (Catharacta maccormicki) in Antarctica

Abstract Adenoviruses have been identified in humans and a wide range of vertebrate animals, but not previously from the polar region. Here, we report the entire 26,340-bp genome of a novel adenovirus, detected by PCR, in tissues of six of nine South Polar skuas (Catharacta maccormicki), collected in Lake King Sejong, King George Island, Antarctica, from 2007 to 2009. The DNA polymerase, penton base, hexon and fiber genes of the South Polar skua adenovirus (SPSAdV) exhibited 68.3%, 75.4%, 74.9% and 48.0% nucleotide sequence similarity with their counterparts in turkey hemorrhagic enteritis virus. Phylogenetic analysis based on the entire genome revealed that SPSAdV belonged to the genus Siadenovirus, family Adenoviridae. This is the first evidence of a novel adenovirus, SPSAdV, from a large polar seabird (family Stercorariidae) in Antarctica.

Boginia virus, a newfound hantavirus harbored by the Eurasian water shrew (Neomys fodiens) in Poland

BackgroundGuided by decades-old reports of hantaviral antigens in the Eurasian common shrew (Sorex araneus) and the Eurasian water shrew (Neomys fodiens) in European Russia, we employed RT-PCR to analyze lung tissues of soricine shrews, captured in Boginia, Huta Dłutowska and Kurowice in central Poland during September 2010, 2011 and 2012.FindingsIn addition to Seewis virus (SWSV), which had been previously found in Eurasian common shrews elsewhere in Europe, a genetically distinct hantavirus, designated Boginia virus (BOGV), was detected in Eurasian water shrews captured in each of the three villages. Phylogenetic analysis, using maximum likelihood and Bayesian methods, showed that BOGV formed a separate lineage distantly related to SWSV.ConclusionsAlthough the pathogenic potential of BOGV and other recently identified shrew-borne hantaviruses is still unknown, clinicians should be vigilant for unusual febrile diseases and clinical syndromes occurring among individuals reporting exposures to shrews.

Serosurveillance of Scrub Typhus in Small Mammals Collected from Military Training Sites near the DMZ, Northern Gyeonggi-do, Korea, and Analysis of the Relative Abundance of Chiggers from Mammals Examined

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. palpale (15.7%), Neotrombicula tamiyai (14.3%), L. orientale (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticulum (0.8%), while the remaining 3 species, L. subintermedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpale (21.4), were observed during the spring season.

Hemorrhagic fever with renal syndrome in 4 US soldiers, South Korea, 2005.

Four US soldiers acquired hemorrhagic fever with renal syndrome while training near the Demilitarized Zone, South Korea, in 2005. Hantaan virus sequences were amplified by reverse transcription–PCR from patient serum samples and from lung tissues of striped field mice (Apodemus agrarius) captured at training sites. Epidemiologic investigations specified the ecology of possible sites of patient infection.

Complete genome sequence and molecular phylogeny of a newfound hantavirus harbored by the Doucet's musk shrew (Crocidura douceti) in Guinea.

Elucidation of the molecular phylogeny of shrew-borne hantaviruses in sub-Saharan Africa has been hampered by the lack of full-length viral genomes. In this report, we present the complete genome analysis of a newfound hantavirus, designated Bowé virus, detected in ethanol-fixed intercostal muscle of a Doucets musk shrew (Crocidura douceti), captured in southwestern Guinea in February 2012. Full-length amino acid sequence comparison of the S-, M- and L-segment gene products revealed that Bowé virus differed by 24.1-53.4%, 17.0-59.9% and 14.6-39.7%, respectively, from all other representative rodent-, shrew- and mole-borne hantaviruses. Phylogenetic analysis, using maximum-likelihood and Bayesian methods, under the GTR+I+Γ model of evolution, showed that Bowé virus shared a common ancestry with Tanganya virus, a hantavirus detected in the Thereses shrew (Crocidura theresae) in Guinea. Whole genome analysis of many more hantaviruses from sub-Saharan Africa are needed to better clarify how the radiation of African shrews might have contributed to the phylogeography of hantaviruses.

Hantaan virus surveillance targeting small mammals at Dagmar North Training Area, Gyeonggi Province, Republic of Korea, 2001-2005

ABSTRACT: In response to a hemorrhagic fever with renal syndrome case in November 2000, a seasonal rodent-borne disease surveillance program was initiated at Dagmar North Training Area (DNTA), Gyeonggi Province, Republic of Korea. From April 2001-December 2005, 1,848 small mammals were captured. Apodemus agrarius accounted for 92.5%, followed by Mus musculus (3.6%), Crocidura lasiura (2.1%), and Microtus fortis (1.1%). Three species of rodents were found to be antibody-positive (Ab+) for Hantaan virus (HTNV): A. agrarius (22.3%), M. musculus (9.1%), and M. fortis (5.0%). Ab+ rates for A. agrarius increased with increasing weight (age), except for those weighing <10 g. The peak HTNV transmission period in Korea coincided with the peak reproductive potential of A. agrarius during the fall (August/September) surveys. HTNV strains from DNTA were distinct from HTNV strains from the Peoples Republic of China. From these studies, more accurate risk assessments can be developed to better protect personnel from rodent-borne diseases.