Our Hantaan Virus Became a New Family, Hantaviridae in the Classification of Order Bunyavirales. It will Remain as a History of Virology

In February 2019, the order Bunyavirales, previously family Bunyaviridae, was amended by new order of 10 families including Hantaviridae family, and now accepted by the International Committee on Taxonomy of Viruses (ICTV). Hantaviridae is now a family of the order Bunyavirales, and the prototype virus species is Hantaan orthohantavirus. The family Hantaviridae is divided into four subfamilies including Mammantavirinae, Repantavirinae, Actantavirinae and Agantavirinae. The subfamily Mammantavirinae is divided into four genera including Orthohantavirus, Loanvirus, Mobatvirus and Thottimvirus. The four Hantavirus species have been found in Korea including three Orthohantaviruses (Hantaan orthohantavirus, Seoul orthohantavirus and Jeju orthohantavirus) and one Thottimvirus (Imjin thottimvirus).

Hemorrhagic Fever with Renal Syndrome

In Korea, hemorrhagic fever with renal syndrome (HFRS) was first reported in a United Nations (UN) soldier stationed in the central front, also known as the “Iron Triangle”. In 1976, professor Ho Wang Lee discovered an antigen in the lung and kidney tissues of Apodemus agrarius. In 1980, this novel virus was named Hantaan virus after the Hantaan river. The Old World Hantaviruses, which are usually found in East Asia and Europe, are generally transmitted to humans via the respiratory pathway during dry seasons, usually in late spring and fall. Currently, 300 – 600 cases per year are reported in Korea with a mortality rate of 1 – 2%. The typical clinical course of HFRS is classified into five phases: febrile, hypotensive, oliguric, diuretic, and convalescent. And treatment for HFRS is mostly conservative. A vaccine for the Hantaan virus was developed in 1988 and marketed in 1990. Because HFRS outbreaks mostly occur in regions near the truce line in Korea, vaccination is virtually the only protection against the virus among military personnel working in such regions and local residents. Therefore, proving the effectiveness of the HFRS vaccine and devising efficient vaccination plans have been considered a major task for Korea's health authorities.

Balance Assessment in Subacute Stroke Patients Using the Balance Control Trainer (BalPro)

OBJECTIVE: To demonstrate the efficacy of the balance control trainer (BCT), developed for training patients with balance problems, as a balance assessment tool in subacute stroke patients. METHODS: A prospective cross-sectional study was carried out on 38 subacute stroke patients in their first episode of a stroke, and having the ability to maintain a standing position without aid for at least 5 minutes. Patients were assessed using the BCT (BalPro) 43.7±35.7 days after stroke. The balance was assessed using the Berg Balance Scale (BBS), the Timed Up and Go Test (TUG), a 10-meter walking test (10mWT), a 6-minute walking test (6MWT), and the Korean version of the Modified Barthel Index. The correlation and validity between the BCT and various balance assessments were analyzed. RESULTS: Statistically significant linear correlations were observed between the BCT score and the BBS (r=0.698, p<0.001). A moderate to excellent correlation was seen between the BCT score and 11 of the 14 BBS items. The BCT scores and other secondary outcome parameters (6MWT r=0.392, p=0.048; TUG r=–0.471, p=0.006; 10mWT r=–0.437, p=0.012) had a moderate correlation. CONCLUSION: Balance control training using the BCT (BalPro) showed significant statistical correlation with the BBS, and could therefore be a useful additional balance assessment tool in subacute stroke patients.

Clinical Usefulness of Sonoelastography in Infants With Congenital Muscular Torticollis

OBJECTIVE: To evaluate the clinical usefulness of sonoelastography in infants with congenital muscular torticollis (CMT). METHODS: The medical records of 215 infants clinically diagnosed with CMT were retrospectively reviewed. Fifty-three infants met the inclusion criteria as follows: 1) infants diagnosed as CMT with a palpable neck mass before 3 months of age, 2) infants who were evaluated initially by both B-mode ultrasonography and sonoelastography, and 3) infants who had received physical therapy after being diagnosed with CMT. We checked the thickness of the sternocleidomastoid (SCM) muscles in B-mode ultrasonography, strain ratio of the SCM muscles in sonoelastography, and treatment duration. We evaluated the correlation between the treatment duration and the following factors: SCM muscle thickness, ratio of SCM muscle thickness on the affected to unaffected side (A/U ratio), and strain ratio. RESULTS: Both the thickness of the affected SCM muscle and the A/U ratio did not show significant correlation with the treatment duration (p=0.66, p=0.90). The strain ratio of the affected SCM muscle was significantly greater than that of the unaffected SCM muscle (p<0.001), and the strain ratio showed significant correlation with the treatment duration (p=0.001). CONCLUSION: Sonoelastography may be a useful adjunctive tool to B-mode ultrasonography for evaluating infants with CMT, especially when predicting their rehabilitation outcomes.

Intestinal Nematodes from Small Mammals Captured near the Demilitarized Zone, Gyeonggi Province, Republic of Korea

A total of 1,708 small mammals (1,617 rodents and 91 soricomorphs), including Apodemus agrarius (n = 1,400), Microtus fortis (167), Crocidura lasiura (91), Mus musculus (32), Myodes (= Eothenomys) regulus (9), Micromys minutus (6), and Tscherskia (= Cricetulus) triton (3), were live-trapped at US/Republic of Korea (ROK) military training sites near the demilitarized zone (DMZ) of Paju, Pocheon, and Yeoncheon, Gyeonggi Province from December 2004 to December 2009. Small mammals were examined for their intestinal nematodes by necropsy. A total of 1,617 rodents (100%) and 91 (100%) soricomorphs were infected with at least 1 nematode species, including Nippostrongylus brasiliensis, Heligmosomoides polygyrus, Syphacia obvelata, Heterakis spumosa, Protospirura muris, Capillaria spp., Trichuris muris, Rictularia affinis, and an unidentified species. N. brasiliensis was the most common species infecting small mammals (1,060; 62.1%) followed by H. polygyrus (617; 36.1%), S. obvelata (370; 21.7%), H. spumosa (314; 18.4%), P. muris (123; 7.2%), and Capillaria spp. (59; 3.5%). Low infection rates (0.1-0.8%) were observed for T. muris, R. affinis, and an unidentified species. The number of recovered worms was highest for N. brasiliensis (21,623 worms; mean 20.4 worms/infected specimen) followed by S. obvelata (9,235; 25.0 worms), H. polygyrus (4,122; 6.7 worms), and H. spumosa (1,160; 3.7 worms). A. agrarius demonstrated the highest prevalence for N. brasiliensis (70.9%), followed by M. minutus (50.0%), T. triton (33.3%), M. fortis (28.1%), M. musculus (15.6%), C. lasiura (13.2%), and M. regulus (0%). This is the first report of nematode infections in small mammals captured near the DMZ in ROK.

Intestinal Nematodes from Small Mammals Captured near the Demilitarized Zone, Gyeonggi Province, Republic of Korea

A total of 1,708 small mammals (1,617 rodents and 91 soricomorphs), including Apodemus agrarius (n = 1,400), Microtus fortis (167), Crocidura lasiura (91), Mus musculus (32), Myodes (= Eothenomys) regulus (9), Micromys minutus (6), and Tscherskia (= Cricetulus) triton (3), were live-trapped at US/Republic of Korea (ROK) military training sites near the demilitarized zone (DMZ) of Paju, Pocheon, and Yeoncheon, Gyeonggi Province from December 2004 to December 2009. Small mammals were examined for their intestinal nematodes by necropsy. A total of 1,617 rodents (100%) and 91 (100%) soricomorphs were infected with at least 1 nematode species, including Nippostrongylus brasiliensis, Heligmosomoides polygyrus, Syphacia obvelata, Heterakis spumosa, Protospirura muris, Capillaria spp., Trichuris muris, Rictularia affinis, and an unidentified species. N. brasiliensis was the most common species infecting small mammals (1,060; 62.1%) followed by H. polygyrus (617; 36.1%), S. obvelata (370; 21.7%), H. spumosa (314; 18.4%), P. muris (123; 7.2%), and Capillaria spp. (59; 3.5%). Low infection rates (0.1-0.8%) were observed for T. muris, R. affinis, and an unidentified species. The number of recovered worms was highest for N. brasiliensis (21,623 worms; mean 20.4 worms/infected specimen) followed by S. obvelata (9,235; 25.0 worms), H. polygyrus (4,122; 6.7 worms), and H. spumosa (1,160; 3.7 worms). A. agrarius demonstrated the highest prevalence for N. brasiliensis (70.9%), followed by M. minutus (50.0%), T. triton (33.3%), M. fortis (28.1%), M. musculus (15.6%), C. lasiura (13.2%), and M. regulus (0%). This is the first report of nematode infections in small mammals captured near the DMZ in ROK.

Effects of Repeated Steroid Injection at Subacromial Bursa With Different Interval

OBJECTIVE: To evaluate the effects of repeated steroid injection at subacromial bursa with different interval for patient with periarticular shoulder disorder. METHODS: Group A (n=10) received subacromial bursa injection only on their first visit, group C (n=10) received the injection on their first visit and one week later, and group B (n=10) received the injection on their first visit and two weeks later. All injections were done with a combination of 40 mg (1.0 mL) of triamcinolone and 5.0 mL 0.5% lidocaine (6 mL total). We examined the active range of motion (AROM) of the shoulder joint, visual analogue scale (VAS), and shoulder disability questionnaire (SDQ) at baseline at 1, 2, and 4 weeks after the initial injection. RESULTS: In VAS, comparing the changes in VAS between groups, group B showed significant improvements compared with group A or C at 4 weeks after the initial injection (p0.05). In AROM, comparing the changes in AROM of external rotation between groups, group B and C showed significant improvement compared with group A at 4 weeks after the initial injection (p<0.05). CONCLUSION: It may be more effective in pain relief for patients with periarticular disorder to receive subacromial bursa injections twice with 2-week interval, as opposed to once.

Borna Disease Virus Antibody and RNA from Peripheral Blood Mononuclear Cells of Race Horses and Jockeys in Korea

OBJECTIVE: During the last two decades, Borna disease virus (BDV) has received much attention as a possible zoonotic agent, particularly as a cause of psychiatric disease. Although several studies have shown that BDV is present in Asia, BDV has not been detected in Korea. This study was designed to further investigate the presence of BDV infection in Korea. METHODS: Blood samples were taken from 39 race horses and 48 jockeys. Antibody to BDV was detected by indirect immunofluorescence antibody test and RNA of BDV by real time reverse transcriptase PCR (rRT-PCR). RESULTS: No evidence of BDV was detected in either the horses or the jockeys group. CONCLUSION: Our results suggest that BDV infection may not be endemic in Korea. Further studies with novel diagnostic tools are required to clarify the prevalence of BDV infection in Korea.

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.

Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n = 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Failure to Detect Borna Disease Virus Antibody and RNA from Peripheral Blood Mononuclear Cells of Psychiatric Patients

OBJECTIVE: Borna disease virus (BDV) is a highly neurotropic agent causing various neuropsychiatric symptoms in animals. Over the past two decades, it has been suggested that BDV might be associated with human psychiatric diseases. We aimed to investigate whether BDV is associated with psychiatric patients in Korea. METHODS: We recruited 60 normal controls and 198 psychiatric patients (98 patients with depressive disorder, 60 with schizophrenia, and 40 with bipolar disorder). We used an indirect immunofluorescence antibody (IFA) test for the BDV antibody and a real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay for p24 and p40 RNA from peripheral blood mononuclear cells (PBMCs). RESULTS: Neither the BDV antibody nor p24, p40 RNA was detected in controls and patients groups. CONCLUSION: Our results suggest that BDV might not be associated with psychiatric patients in Korea.

Failure to Detect Borna Disease Virus Antibody and RNA from Peripheral Blood Mononuclear Cells of Psychiatric Patients

OBJECTIVE: Borna disease virus (BDV) is a highly neurotropic agent causing various neuropsychiatric symptoms in animals. Over the past two decades, it has been suggested that BDV might be associated with human psychiatric diseases. We aimed to investigate whether BDV is associated with psychiatric patients in Korea. METHODS: We recruited 60 normal controls and 198 psychiatric patients (98 patients with depressive disorder, 60 with schizophrenia, and 40 with bipolar disorder). We used an indirect immunofluorescence antibody (IFA) test for the BDV antibody and a real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay for p24 and p40 RNA from peripheral blood mononuclear cells (PBMCs). RESULTS: Neither the BDV antibody nor p24, p40 RNA was detected in controls and patients groups. CONCLUSION: Our results suggest that BDV might not be associated with psychiatric patients in Korea.

Retraction: Nucleotide Sequence and Phylogenetic Analysis of M and L Segment of Soochong Virus

No abstract available.

Plagiorchis muris infection in Apodemus agrarius from northern Gyeonggi-do (Province) near the demilitarized zone

The small intestines of 6 species of rodents and 1 species of insectivore were examined seasonally for Plagiorchis muris infection in 3 different localities in northern Gyeonggi-do (Province), near the demilitarized zone (DMZ). A total of 1,496 animals, including 1,366 Apodemus agrarius, 54 Crocidura lasiura (insectivore), 32 Mus musculus, 28 Micronytus fortis, 9 Eothenomys regulus, 6 Micronys minutus, and 3 Cricetulus triton, were live-trapped at Yeoncheon-gun (n = 351), Paju-shi (804) and Pocheon-gun (343) at 3-mo intervals from December 2004 to September 2005. A total of 1,647 P. muris were collected from 72 (5.3%) A. agrarius. The infection rate was the highest in Pocheon-gun (8.2%), followed by Yeoncheon-gun (5.0%) and Paju-shi (4.2%). A higher infection rate was observed in A. agrarius captured during September (19.4%) than those captured during December (3.0%), June (2.6%), or April (0%). However, the worm burden was the highest in June (av. 32.1/animal), followed by September (24.7), December (4.0), and April (0). None of the other animal species were found infected with P. muris. The results reveal that A. agrarius is a natural definitive host for P. muris, and infection rates and worm burdens vary seasonally and geographically.

Apodemus agrarius as a new definitive host for Neodiplostomum seoulense

A total of 1,496 rodents and insectivores were live-trapped at Yeoncheon-gun (n = 351), Paju-shi (804), and Pocheon-gun (343), Gyeonggi-do (Province), and examined for intestinal helminths, including Neodiplostomum seoulense, seasonally from December 2004 to September 2005. Six species of rodents, including Apodemus agrarius (1,366), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutus (6), and Cricetulus triton (3), and 1 species of insectivores Crocidura lasiura (54) were collected. A total of 321 adult N. seoulense were collected from 19 (1.4%) A. agrarius. The worm burden ranged from 1 to 101 per A. agrarius (mean; 16.9). No N. seoulense was observed in other rodent or insectivore species examined. The infection rate during autumn (4.5%) was higher than those during spring (0.8%), summer (0.8%), and winter (0.5%). The average number of N. seoulense in infected A. agrarius was the highest in spring (66.0 specimens), followed by autumn (15.2), winter (4.5), and summer (3.3). This study first confirms that A. agrarius is a natural definitive host for N. seoulense, and demonstrates that the infection rates and intensities vary seasonally and geographically.

Nucleotide Sequence and Phylogenetic Analysis of M and L Segment of Soochong Virus

Hantaan virus (HTNV) and Seoul virus (SEOV) have mainly been known as the cause of hemorrhagic fever with renal syndrome (HFRS) in Korea since HTNV has been isolated from Korean field mouse, Apodemus agrarius in 1976 and SEOV has been isolated from Rattus norvegicus in 1980. Soochong virus-1, -2, -3, -4 (SOOVs) were isolated from lung tissues of four Apodemus peninsulae captured on 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. Apodemus peninsulae is the second-most dominant field rodent species found throughout Korea. To determine phylogenetic analysis of SOOVs, we entirely identified nucleotide sequences of M and L segments. The length of M segment was 3,615 bp and L segment was 6,533 bp. SOOVs were diverged from HTNV by 22.7~23.3% and SEOV by 36.3~37.2%, in M segment. In addition, L segment was diverged from HTNV by 21.8~22.0% and SEOV by 30.3~30.5%. SOOVs sequence compared with Amur virus (AMRV) in M segment showed that SOOVs were different with AMRV about 14.6~16.2% in nucleotide sequences. Neighbor-joining phylogenetic analysis based on entire sequences of the M and L segment indicated that the SOOVs sequences present a separate lineage with HTNV, SEOV and AMRV. SOOVs constituted an individual cluster on the phylogenetic tree and they composed a phylogenic lineage separately. According to these data, SOOVs could be classified as a new hantavirus.

Detection of Bartonella species from ticks, mites and small mammals in Korea

We investigated the prevalence of Bartonella infections in ticks, mites and small mammals (rodents, insectivores and weasels) collected during 2001 through 2004, from various military installations and training sites in Korea, using PCR and sequence analysis of 16S rRNA, 23S rRNA and groEL heat shock protein genes. The prevalence of Bartonella spp. was 5.2% (n = 1, 305 sample pools) in ticks, 19.1% (n = 21) in mesostigmatid mites and 13.7% (n = 424 individuals) in small mammals. The prevalence within the family Ixodidae was, 4.4% (n = 1, 173) in Haemaphysalis longicornis (scrub tick), 2.7% (n = 74) in H. flava, 5.0% (n = 20) in Ixodes nipponensis, 11.1% (n = 9) in I. turdus, 33.3% (n = 3) in I. persulcatus and 42.3% (n = 26) in Ixodes spp. ticks. In rodents, the prevalence rate was, 6.7% (n = 373) in Apodemus agrarius (striped field mouse) and 11.1% (n = 9) in Eothenomys regulus (Korean red-backed vole) and in an insectivore, Crocidura lasiura, 12.1% (n = 33). Neither of the two weasels were positive for Bartonella spp. Phylogenetic analysis based on amino acid sequence of a portion of the groEL gene amplified from one A. agrarius spleen was identical to B. elizabethae species. We demonstrated the presence of Bartonella DNA in H. longicornis, H. flava and I. nipponensis ticks, indicating that these ticks should be added to the growing list of potential tick vectors and warrants further detailed investigations to disclose their possible roles in Bartonella infection cycles.

In vivo characterization of the integrin beta3 as a receptor for Hantaan virus cellular entry

Binding of viruses to cell surface molecules is an essential step in viral infection. In vitro studies suggested that the alpha v beta3 integrin receptor is the epithelial cell receptor for Hantaan virus (HTNV). Whether beta3 is in vivo the only or central cellular receptor for HTNV infection is not known. To investigate the role of beta3 integrin for cellular entry of HTNV, we established an HTNV infection model in newborn murine pups. Infected pups died at an average age of 14.2 +/- 1.1 days with high levels of viral antigen detected in their brain, lung, and kidney. Pre-injection of blocking monoclonal antibodies (mAb) specific for either beta3 or av prolonged survival significantly to a maximal average survival of 19.7 +/- 1.5 days (P<0.01) and 18.4 +/- 0.9 days (P<0.01), respectively. XT-199, a chemical blocker of the alpha v beta3 receptor also prolonged survival to 19.5 +/- 1.3 days (P<0.01). In contrast to these receptor blockades, anti-HTNV antibody was not only able to prolong survival, but 20% of infected pups achieved long-term survival. An anti-murine beta1 antibody comparatively prolonged survival (19.0 +/- 1.2 days), suggesting that HTNV infection is partly mediated through integrin beta1 receptors as well as through beta3 receptors in vivo. Our data demonstrate that the beta3 receptor is important for HTNV infection in vivo, but also suggest that HTNV may utilize additional receptors beyond beta3 for cellular entry within an organism.

Serological Characterization of Soochong and Muju Virus as New Serotype of Hantavirus

Apodemus agrarius, which accounts for three-fourths of the wild rodents, mainly inhabits in cultivated fields of Korea. Apodemus peninsulae and Eothenomys regulus are the second and third dominant species, respectively. Soochong virus (SOOV) from A. peninsulae and Puumala-related Muju virus (MUJV) from E. regulus were isolated in 1997 and 1998 in Korea, respectively. But serological characterizations of SOOV and MUJV were not identified clearly. Thus, in order to determine the serotypic classification, simultaneous cross-indirect immunofluorescent antibody (IFA) assay and cross-plaque reduction neutralization (PRN) test against four different hantaviruses were conducted with sera from 17 A. agrarius, 19 A. peninsulae, and 8 E. regulus strains. IFA titers of sera from A. agrarius and A. peninsulae were the highest to Hantaan virus (HTNV) and SOOV, respectively. However, most sera showed similar IFA titers to Seoul virus (SEOV). Therefore it was difficult to do serotyping using the sera from A. agrarius and A. peninsulae by IFA. In case of sera of E. regulus, IFA titers to Puumala virus (PUUV) were higher than HTNV, SOOV and SEOV. Cross-PRN result of A. agrarius to HTNV, SOOV, SEOV and PUUV was 6,890, 5,120, 110 and 30, respectively. In case of A. peninsulae, the mean PRN titer was the highest to SOOV (1:6,820) and those to HTNV, SEOV and PUUV were 1,580, 100 and 30, respectively. The mean PRN titers of E. regulus to HTNV, SOOV, SEOV and PUUV were 70, 10, 80 and 640. SOOV and MUJV could be distinguished from HTNV and SEOV by cross-PRNT. These results demonstrate that SOOV and MUJV could be classified as new serotype of hantavirus.

Epidemilogical Study on Orientia tsutsugamushi Infection of Wild Rodents in Korea

This study was carried out to determine the seropositivity for Orientia tsutsugamushi infection among wild rodents captured in farms and mountains of Korea. A total 965 wild rodents of 7 species and 48 Crocidura laciura were captured in farms and mountains of 6 province during 1997~2000 in Korea. Serological evidence for O. tsutsugamushi infection was obtained using O. tsutsugamushi antigens by indirect immunofluorescent antibody technique (IFA). Four hundred eighty four Apodemus agrariusus, 246 Apodemus peninsulae, 179 Eothenomys regulus, 44 Microtus fortis, 6 Micromys minutus, 5 Mus musculus, and 1 Cricetula triton were captured in Gyeonggi, Gangwon, Chungnam, Gyeongbuk, Gyeongnam, and Jeonbuk province. Among them, 59 (12.2%) A. agrariusus, 22 (8.9%) A. peninsulae, 12 (6.7%) E. regulus, 5 (11.4%) M. fortis and 1 (16.7%) M. minutus were IF antibody positive against O. tsutsugamushi Gilliam or Karp strain.