Identification of Seoul virus in R.novergicus in Hai phong port

Background: Hantavirus causes two distinct human diseases: Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS). Hantaviruses are maintained in the rodent reservoir and are transmitted to humans via contaminated excreta or bites. Objectives: This study aims to identificate of Seoul virus in R.novergicus in Hai phong port. Material and method: In this study, we trapped 25 of R. novergicus. Results:The results show four R. novergicus are positive for Seoul virus. Partial M segment sequence was recovered from the lung tissue of R. novergicus trapped in Hai Phong port in 2006. M segment of the Seoul virus of Hai Phong sequenced shown is similar to M segment of the Seoul virus of Hanoi. Conclusion:We discovered the Seoul virus in R.novergicus in Hai Phong port in 2006. The sequence belongs to the Seoul virus genotype and is most closely related to the strain B-1 from Japan and the strain AJ620583 from Indonesia.\r\n', u'\r\n', u'

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.

A case of hantavirus pulmonary syndrome with hemorrhagic fever with renal syndrome / 대한내과학회지

Hemorrhagic fever with renal syndrome (HFRS) caused by Hantann virus or Seoul virus frequently occurs in Korea. The prodromal clinical symptoms are flu-like symptoms. Rapidly progressive renal failure and hemorrhage follow. Hantavirus pulmonary syndrome (HPS) is usually found in the U.S.A., caused by the Sin-nombre virus. The prodromal symptoms resemble HFRS. However, during the third to fith hospital day after admission, pulmonary edema or pulmonary hemorrhage acutely develops, which results in acute respiratory failure. We here report a case of HFRS with HPS that developed in a 47 year-old man. The patient had flu-like symptoms and diarrhea on admission. Acute renal failure developed and acute hemodialysis was performed. On the fourth hospital day, an asymmetric bilateral haziness as seen on a chest X-ray rapidly developed with reduced O2 saturation, and mechanical ventilation was applied. On the eighth hospital day, the patient was weaned from the ventilator. When acute respiratory failure develops in patients with HFRS, HPS might be considered.

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.

A Case of Hemorrhagic Fever with Renal Syndrome by Seoul Virus Confirmed by Reverse Transcription-Polymerase Chain Reaction-Restriction Fragment Length Polymorphism / 대한진단검사의학회지

Members of the genus Hantavirus are the etiologic agents of hemorrhagic fever with renal syndrome (HFRS), the diagnosis of which is somewhat difficult because several diseases share similar early clinical presentations such as fever and petechia. In Korea, Hantaan virus and Seoul virus are the causative organisms of HFRS, and the infection caused by Seoul virus is milder than that caused by Hantaan virus. We report a 44-year-old woman, who visited our hospital due to general weakness, fever, myalgia, facial edema and diarrhea. She was diagnosed with HFRS caused by Seoul virus. The antibody against Hantaan virus was positive by an indirect immunofluorescent test and the discrimination between Hantaan and Seoul viruses was done by RT-PCR-RFLP (reverse transcriptionpolymerase chain reaction-restriction fragment length polymorphism) against viral S segment.

Genetics subtypes and distribution of Seoul virus in Henan / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the sub-genotypes and distribution ot Seoul virus in Henan.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>The results indicated that the genetic subtypes of Hantavirus were complicated and widely distributed in Henan.</p>

Passage adaptability of candidate strains for hemorrhagic fever with renal syndrome purified vaccine in Vero cells and their immunogenicity / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To adapt the candidate strains of hemorrhagic fever with renal syndrome (HFRS) purified vaccine to Vero cells and to study their antigenicity and immunogenicity.</p><p><b>METHODS</b>The viral strains H8207 (Hantaan virus, HTN) and Y86013 (Seoul virus, SEO) were continuously propagated in Vero cell by the terminal dilution method and studied the characteristics of virus multiplication, viral titers and the amounts of virus antigen after serial passages. Three batches of crude monovalent inactivated vaccine were developed using the different passages of these 2 viral strains.</p><p><b>RESULTS</b>The strains H8207 and Y86013 adapted to Vero cells and stably grew on the cells with high titers. Rabbits immunized with the crude vaccines of H8207 and Y86013 showed 100% sero-conversion and the neutralizing antibody titers of the rabbit immune sera reached 1?10 at 4 weeks after 2 times of immunization.</p><p><b>CONCLUSIONS</b>The results suggest that these 2 candidate strains had adapted to Vero cells, possessed high titers and good immunogenicity and be feasible to prepare the HFRS purified vaccine in Vero cells.</p>

A preliminary genetic reassortment between Hantaan virus and Seoul virus strains / 中华流行病学杂志

<p><b>OBJECTIVE</b>To determine the frequency and characteristics of reassortment among Hantaan and Seoul viruses causing hemorrhagic fever with renal syndrome (HFRS).</p><p><b>METHODS</b>Mixed infections were initiated in tissue culture, using Hantaan virus strain 76 - 118 and Seoul virus strain SR-11. Potential reassortant virus plaques were picked out by multiplex RT-PCR, using primers specific for individual genome segments (L, M, S) of each strain.</p><p><b>RESULTS</b>Most of the progeny virus plaques (68.19% of 44) had parental genotype of 76 - 118 strain or SR-11 strain while 2 of 44 plaques had mixed genotypes that yielded RT-PCR bands for the same segment of both parental strains. Reassortant viruses were detected in 68.19% of 44 progeny plaques tested, involving the M and S segments. In addition, approximately 4.55% of the progeny virus plaques appeared to contain S or M segments originating from both parental virus strains, showing that they were diploid.</p><p><b>CONCLUSION</b>Genetic reassortment can occur between Hantaan virus and Seoul virus strains.</p>

An Immunoserological Study of Vaccine Against Haemorrhagic Fever with Renal Syndrome

Since HantavaxTM, formalin inactivated Hantaan virus vaccine (10,240 ELISA units/ml), has been developed in 1990 to prevent against haemorrhagic fever with renal syndrome (HFRS) caused by Hantaan or Seoul virus, it has been commercially available in Korea. Twenty-one healthy people were booster shot once and twice after primary basic vaccination with HantavaxTM. Seroconversion rates were measured by immunofluorescent antibody technique (IFAT), enzyme-linked immunosorbent assay (ELISA), high density composite particle agglutination (HDPA), and plaque reduction neutralization test (PRNT). Seroconversion rates of 21 vaccinees at one year after primary basic vaccination were 52.3%, 95.2%, 0.0%, 47.6%, and 28.6%, and 13 vaccinees of one month after 1st booster vaccination were 100%, 100%, 30.7%, 100% and 100% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates declined slightly by twenty months, and they were 84.6%, 92.3%, 0.0%, 84.6% and 69.2% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates of 9 vaccinees at three months after 2nd booster vaccination were 100%, 100%, 0.0%, 100%, and 88.9%, and 16 vaccinees at one year after the 2nd booster vaccination were 87.5%, 93.8%, 0.0%, 87.5% and 81.3% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Based on the above result HantavaxTM has proved a vigorous anamnestic response after the 1st and the 2nd booster vaccination and has persisted higher fluorescence, agglutination and neutralizing antibody titers in vaccinees.

Molecular Characterization of the L Segment of Hantann Virus, Strain Howang

Hantaan virus (HTNV), the etiologic agent of hemorrhagic fever with renal syndrome (HFRS), belongs to the genus Hantavirus, and has three single negative straded RNA genome segments. HTNV strain Howang isolated from the blood of severe case of Korean HFRS is more virulent than HTNV 76/118 and the M and S genome segments' nucleotide sequence of Howang strain showed 93.5% and 94% homology to each segment of HTNV 76/118. We have obtained 6533 nucleotides long sequence of the L genome segment of Howang strain using reverse transcriptase in conjunction with PCR amplification and compared to other hantaviruses. The messenger sense of the L segment contains one long single long open reading frame of 2151 amino acids, which encodes a deduced RNA dependent RNA polymerase of 246.4 kDa caculated molecular weight protein. The nucleotide sequence of the Lsegment of Howang strain shows 93%, 74%, 66%,65% homology to HTNV 76/118, Seoul virus 80/39, Puumala virus Hallnas B1 and Sin Nombre virus, respectively. The amino acid sequence of the L segment of Howang strain shows 99%, 85%, 68%, 68% homology to HTNV 76/118, Seoul virus 80/39, Puumala virus Hallnas B1 and Sin Nombre virus, respectively.

Sequence and Phylogenetic Analyses of the M and S Genomic Segments of Hantaan and Seoul Viruses

Hantaan (HTN) and Seoul (SEO) viruses, murid rodent-borne hantaviruses, are known to causes hemorrhagic fever with renal syndrome (HFRS) in Korea. To determine the genomic diversity and molecular phylogeny of HTN and SEO viruses found in Korea, we amplified for part of M and S genomic segments of hantaviruses from sera of HFRS patients and lung tissues of hantavirus seropositive striped-field mice. Both M and S segment of 16 HTN and 2 SEO viruses were amplified by nested reverse transcripton-polymerase chain reaction. Based on 324 nucleotides in the M genomic segment, the HTN and SEO strains showed 93.8~100% and 99.1~99.4% homologies, respectively. Similarly, based on 230 nucleotides in the S genomic segment, HTN and SEO strains showed 90.9~100% and 100% homologies, respectively. Phylogenetic analysis of M and S segments indicated that HTN strains could be divided into at least two main groups in M and S trees and the sequence differences detected among the S and M genomic segments of HTN viruses are consistent with reassortment having taken place between HTN virus strains.

Isolation and Genetic Study of Hantavirus from Apodemus penibsulae Captured in Yeuncheon-gun, Kyunggi-do

Hantaviruses are distributed in rodent population world-widely even in geographical areas where hemorrhagic fever with renal syndrome (HFRS) has not been reported. Va.ictus species of Family Muridae and Arvicolidae serve as the natural reservoirs of hantaviruses. Hantaan virus, Seoul virus, Puumala virus, Prospect Hll virus, Sin Hombre virus and New York virus are members of genus Hantavirus and isolated from lungs of A. agrarius, C glareolus, M. pennsylvanicus, P. maniculatus and P. leucopus respectively. This experiment was intended to find the distribution of hantavirus infection among wild rodents and isolate the hantavirus from lung tissue of seropositve Apodemus peninsulae, and compared the nucleotide and amino acid sequences with prototype of hantaan virus 76-118 strain. Hantaviral sequences were amplified from lung tissues of A. peninsulae by reverse-transcriptase polymerase chain reaction. Alignment and comparison of the 324 nucleotide of G2 region of M-genomic segment diverged 4.6% and 0% at the nucleotide and amino acid levels, and complete N protein-coding region of S-genomic segment diverged 3.7% and 1.4% nucleotide and amino acid levels, respectively. This is the report to spill-over on the hantaan virus from A. peninsulae to A. peninsulae in Korea.

The Multiplex RT-PCR for the Serotyping of Hantaviruses

Hantaviruses are negative-strand RNA viruses that contain three segmented genome and belong to the family Bunyaviridae. Due to such an unique structure of segmented RNA genome, these viruses have a possibility to produce reassortant that have genomic sets mixed with different segments originated from both parental virus during the genetic interaction. To investigate whether this phenomenon occurs actually, Hantaan virus (HTN) could be coinfected with Seoul virus (SEO) to Vero-E6 cell. And also, HTN could be coinfected with Prospect hill virus (PH) to investigate the rate of genetic reassortment according to the genetic distance among the HTN, SEO and PH viruses. As a available method to differentiate the reassortant, we used the multiplex RT-PCR that detect and differentiate the serotype of hantaviruses in mixed infection. Each progeny clone could be screened by multiplex RT-PCR. So, we have constructed the multiplex RT-PCR system that separated amplifications for each segment of Hantaviruses. Our multiplex RT-PCR system provide sensitive, specific and simplified tools for the rapid differentiation of hantaviruses serotypes and also the diagnosis of Hantavirus infections.

Detection of Puumala and Hantaan Viruses among Bats in Korea by Nested RT-PCR

Hantavirus is a genus of the Bunyaviridae family consisting following serotype groups: Hantaan, Seoul, Puumala, Prospect Hill, Thailand, Belgrade, Thotta palayam, Sin Hombre. Most of Hantavirus group have been associated with many clinically similar disease known collectively as hemorrhagic fever with renal syndrome (HFRS). Hantaan virus is the prototype of the genus hantavirus, originally isolated from Apodemus agrarius. Bat was found as a natural host for Hantaan virus in Lee's lab for the first time. Then, Hantaan-like virus was isolated Hantaan-like virus from bat. To identify hantaviruses that are present in Korea among bats, bats were collected from Jeong-Sun, Won-Joo, Chung-Ju and Hwa-Cheon area, RNA was isolated from lung and serum. RT-PCR was performed with a universal primer from M segment. Nested RT-PCR was carried out to differentiate Hantaan, Seoul and Puumala virus using serotype specific primers. As we expected, Hantaan viruses were detected in bats and Seoul virus was not detected. Interestingly, Puumala viruses were also detected in bats from won-Ju, but not in other areas. Puumala virus is originally isolated from Clethrinomys glareolus, and cause light HFRS. Recently, Paradoxomis webbiana, a wild bird turn out to be a reservoir for Puumala virus in Korea. These data indicate that bat is a new natural reservoir of Puumala virus.

Production and Characterization of Monoclonal Antibodies Against Seoul Virus

Hantaviruses are members of the family Bunyaviridae, the etiologic agents of Hemorrhagic fever with renal syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS). They are negative-sense, single-stranded RNA viruses possessing a large (L), medium (M) and small (S) genomic segment which encodes a viral polymerase, envelope glycoproteins (G1 and G2) and a nucleocapsid (N) protein, respectively. Seoul (SEO) virus, the causative agent of clinically mild HFRS in worldwide, was isolated from lung tissues of urban rat (Rattus norvegicus) captured in Seoul, Korea, 1982. To clarify the antigenic characteristics and the differentiation of serotypes of hantavirus, 8 hybridoma cell lines secreting monoclonal antibodies (MAbs) against SEOV 80-39 strain were produced by fusion of SP2/0-Ag14 mouse myeloma cells with spleen cells of BALB/c mice, immunized with SEOV. Reactivities of these MAbs were examined by the indirect immunofluorescence assay (IFA), enzyme linked immunosorbent assay (ELISA), immunoblot, high density particle agglutination (HDPA) and plaque reduction neutralization test (PRNT). Eight out of 235 hybridomas secreted MAbs of Seoul virus 80-39 continuously, and these eight MAbs were all IgG. The isotypes of these 8 MAbs are; one clone (F3-3C) was IgG1, six (F1-1B9B, F1-3B, F1-3D, F4-1E, F4-3F, F4- 6C) were IgG2a and one (F1-1B9F) was IgG2b. Seven MAbs (F1-1B9B, F1-1B9F, F1-3B, F1- 3D, F3-3C, F4-1E, F4-3F) reacted with nucleocapsid protein (M.W. 50K) of SEOV by immunoblot. All eight MAbs were cross-reacted with Hantaan (HTN) virus, one (F4-3F) was cross-reacted with Puumala (PUU) virus and two (F1-1B9B, F1-3B) were cross-reacted with Prospect Hill (PH) virus by IFAT. None of these 8 MAbs had neutralizing activity.

Genetic Analysis of Hantaviral M Segment Isolated from Patients with Korean Hemorrhagic Fever / 대한신장학회잡지

Hemorrhagic fever with renal syndrome(HFRS) is an infectious disease showing diverse clinical manifestations according to different serotypes of hantavirus. Korean hemorrhagic fever(KHF), HFRS caused by Hantaan or Seoul virus in Korea, shows diverse clinical manifestations even in the same serotype of hantavirus. On the assumption that the antigenicity, nucleotide and amino acid sequence diversity of hantaviruses, as well as immune response diversity of individual KHF patient may be present, this study was performed to analyse the genetic diversity of hantaviruses isolated from patients with KHF. In the 13 samples(9 strains of hantavirus isolated from bloods, urines or autopsy tissue of KHF patients and 4 serums of KHF patients), hantaviral RNAs were extracted, cDNAs of partial M segment were amplified by RT-PCR using genus-reactive primer, amplified cDNAs were analysed by direct sequencing method, and then the nucleotide and deduced amino acid sequences were compared with previously known sequences of four serotypes of hantavirus isolated from rodent hosts and each other by the computer assistance. The results were as follows. The nucleotide and amino acid sequences of 11 samples among the 13 human isolates showed 90.3-95.5%, 86.7-97.9%, the other 1 sample 82.7%, 71.9% homology respectively to those of Hantaan virus 76-118 strain, and another 1 sample showed 83.7%, 75.3% homology respectively to those of Seoul virus B1 strain isolated from rodent host. The nucleotide and amino acid sequences of 7 among 12 Hantaan samples showed differences within 5%, 10% respectively each other and high genetic similarities, but those of the other 5 among 12 Hantaan samples showed low genetic similarities each other. In conclusion, hantaviruses isolated from KHF patients showed genetic diversity compared with previously known hantaviruses isolated from rodent hosts.

Nucleotide Sequence and phylogenetic Analysis of Hantaviruses Isolated from Patients with Hemorrhagic Fever with Renal Syndrome (HFRS) in Korea

Eleven hantavirus isolates were obtained by innoculation of viremic blood, urine, or autopsy tissue specimens from ten HFRS patients, and sera were obtained from five patients with HFRS. The disease was diagnosed by clinical manifestations and indirect immunofluorescent antibody technique. We obtained 6 hantaviruses from gene bank. So, we analyzed 22 hantavirus samples to elucidate the genetic diversity. The hantaviral RNAs were extracted and 365 base-pair complementary DNAs of M segment were obtained by reverse transcriptase polymerase chain reaction (RT-PCR) and 326 base-pair by nested PCR. The nucleotide sequences of amplified cDNA fragments were determined by the direct sequencing method using automatic DNA sequence analyzer. We got full M segment sequences of 28 reported hantaviruses with medline searching, and aligned them with our 22 samples, and the phylogenetic analysis for nucleotide and amino acid sequences were done by the Clustal method. The nucleotide and amino acid sequences of Hantaan virus 17 samples showed high (above 90%) homology with 76-118 strain, but 2 samples showed significant differences with 76-118 strain and with other 17 samples. The 3 Seoul virus samples showed high intraspecies differences in 1 sample, and showed singnificant differences with SR-11 strain. In phyogenetic tree analysis, Puumala virus and Hantavirus pulmonary syndrome viruses showed high homology, but Hantaan and Seoul viruses showed significant genetic diversity among strains. In conclusion, hantaviruses isolated from HFRS patients showed genetic diversity compared with those isolated from rodent hosts.

Immune Response and Antibody Persistence against Hantaan Virus of Vaccinees with Hantavax(TM) / 감염

BACKGROUND: Hantavax(TM) was developed for preven-tion of hemorrhagic fever with renal syndrome caused by Hantaan or Seoul virus in 1990, and has been commer-cially available in Korea since then. Because Hantavax (TM) has such short usage history, the duration of antibody persistency in vaccinees has not been well studied. METHODS: 61 healthy people were immunized subcu-taneously with Hantavax (TM) twice at one month intervals as primary vaccination. 21 vaccinees were tested at 1 ~4 months after primary vaccination and 40 vaccinees were tested at one year after primary vaccination and then one month and 1 ~2 years after booster vaccination. Antibody titers were measured by immunofluorescent assay(IFA), Hantaan virus antigen-coated high density particle agglu-tination assay(HDPA), and plaque reduction neutralization test(PRNT). RESULTS: Seroconversion rates of 21 vaccinees at 1 ~ 4 months after primay vaccination were 20/21(95.2%), 19/21(90.5%) and 14/21(66.7%); seropositivity of 40 vaccinees at one year after primary vaccination was 25/40 (62.5%), 18/40(45.0%), and 9/40(22.5%) by IFA, HDPA, and PRNT, respectively. Seroconversion rates of 8 vaccinees at one month after booster vaccination were 8/ 8(100 %), 8/ 8(100%); antibody persistence rate of 11 vaccinees at 20 months after booster vaccination were 11/ 12 (91.7%), 9/ 12(75.0%), and seroconversion rates of 7 vaccinees at 3 months after second booster vaccination were 7/7(100%) and 6/7(85.7%) by IFA and PRNT, respectively. Geometric mean antibody titers of 21 vaccinees at 1-4 months after primary basic vaccination were 262, 248, 120; and those of 40 vaccinees at one year after primary vaccination were 90, 56, and 24 by IFA, HDPA, and PRNT, respectively. Geometric mean antibody titers of 8 vaccinees at one month after booster vaccination were 852, 183, of 12 vaccinees at 20 months after booster vaccination were 296, 33, and of 7 vaccinees at 3 months after second booster vaccination were 549 and 46 by IFA and PRNT, respectively. CONCLUSION: The booster vaccination is necessary at 12 months after primary vaccination to maintain high levels of antibodies which persist at least two years after booster vaccination.

Detection of Hantaan and Seoul Viruses by Reverse Transcriptase-Polymerase Chain Reaction(RT-PCR) and Restriction Fragment Length Polymorphism(RFLP) in Korean Hemorrhagic Fever Patients / 대한신장학회잡지

BACKGROUND: Korean hemorrhagic fever(KHF), a severe from of hemorrhagic fever with renal syndrome(HFRS), is the most common cause of acute renal failure in far east. Two serotypes of hantavirus, Hantaan and Seoul viruses, were identified as pathogens for KHF in Korea. To elucidate the diagnostic applicability for the serotype diagnosis in KHF patients, using a nested reverse transcriptase-PCR and restriction fragment length polymorphism(nRT-PCR /RFLP), we screened 4 prototype viruses, 11 virus isolates from KHF patients, and 69 specimens obtained from 30 KHF patients. METHODS: The nRT-PCR was performed using serotype specific primers for G1 segments for Hantaan(HF3 1140-1163, HB14 1363-1342) and Seoul(SF2 809-832, SB3 1200-1177) viruses. The PCR product was further amplified using nested primers for Hantaan(HF4, 1141-1164, HB13, 1360-1339) and Seoul(SF7 863-884, SB1 1165-1142) viruses. Amplified segments were digested with restriction enzymes specific for either Hantaan(Cla I) or Seoul(Sac I) virus sequences. In all cultured viruses, serotypes identified by nRT-PCR/RFLP were consistent with those of PRNT. RESULTS: In KHF patients, nRT-PCR/RFLP results were compatible with Hantaan virus in 10 patients and with Seoul virus in 13 patients. In 3 patients both Hantaan and Seoul specific amplified bands were visualized in serially collected samples, and in 4 patients no detectable amplicons were detected. Among 69 specimens, 55 specimens obtained from 3 to 33 day of illness were positive. The positive rate was affected by the hospital where specimens were collected, but not by clinical phases, the day of illness, or severity of HFRS. CONCLUSIONS: In general, nRT-PCR/RFLP was a rapid and convenient method for serotype diagnosis in most of the KHF patients. The presented method also make it possible to detect genetic variation of hantavirus within the same serotype. But unlike the viruses in culture, in testing patients' sera, the sensitivity of this methods needed to be improved especially by adequate sample handling.