Impact of the National Perinatal Hepatitis B Prevention Programme in the Republic of Korea: A retrospective registry-based cohort study.

INTRODUCTION: Hepatitis B is a major preventable cause of morbidity and mortality from chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. We aimed to evaluate the performance and outcomes of the Korean Perinatal Hepatitis B Prevention Programme (PHBPP) and to investigate the impact of the current post-exposure immunoprophylaxis protocol. METHODS: A retrospective cohort study was performed based on electronic data registry of infants born to hepatitis B virus (HBV)-infected mothers between July 2002 and 2013. RESULTS: During the study period, 159,983 Korean infants were registered with the PHBPP, with an overall programme coverage of 92.8%. Despite receiving timely post-exposure immunoprophylaxis, 8.6% of infants born to mothers aged <25 years and hepatitis B e antigen (HBeAg)-positive, and 0.7% of infants born to mothers aged ≥25 years and HBeAg-negative were infected. An estimated 14,123 infants were directly protected from perinatal HBV transmission by the PHBPP during the 11.5-year period, at a cost of 1157 US dollars per case averted. The incidence of paediatric hepatocellular carcinoma declined dramatically during the period. CONCLUSIONS: A substantial number of infants have been prevented from hepatitis B since the PHBPP was launched in the Republic of Korea. Continued efforts to promote the programme, an integrated approach to maximising its coverage, a risk-stratified strategy, and innovations in logistics could further reduce perinatal HBV transmission.

Status of HPV vaccination among HPV-infected women aged 20-60 years with abnormal cervical cytology in South Korea: a multicenter, retrospective study.

OBJECTIVES: Since 2007, human papillomavirus (HPV) vaccines have been administered for the prevention of cervical cancer in Korea. We investigated the status of HPV vaccination among HPV-infected adult women with abnormal cervical cytology before the introduction of National Immunization Program. METHODS: From 2010 to 2016, HPV-positive women (age, 20-60 years) with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion (LSIL) were enrolled from five hospitals across Korea. Their HPV genotype, epidemiologic, and clinical data, including HPV vaccination history, were obtained. We compared the epidemiological characteristics and prevalence of HPV-16/18 genotypes between vaccinated and unvaccinated women. RESULTS: Among the 1,300 women, approximately 26% had a history of vaccination. Vaccinated patients were significantly younger, unmarried, and had a higher education level than unvaccinated women. For HPV-vaccinated individuals by vaccine dose, there was a significant younger age at vaccination initiation (p=0.025), longer duration from HPV vaccination to Pap test date (p=0.001), and lower proportion of HPV-16/18 (p=0.028) in the women with three doses. There was a significantly lower prevalence of HPV-16/18 genotypes in women who were vaccinated at least 12 months prior than in unvaccinated women (adjusted prevalence ratio [aPR]=0.51; 95% confidence interval [CI]=0.29-0.88). For women with LSIL, the prevalence of the HPV-16/18 genotypes was significantly lower in women who were vaccinated more than 12 months prior than in unvaccinated women (aPR=0.35; 95% CI=0.13-0.96). CONCLUSION: This study highlighted the status of HPV vaccination and the prevalence of HPV-16/18 genotypes among HPV-infected women with abnormal cervical cytology according to HPV vaccination. It provides preliminary information regarding the status of HPV vaccination among Korean adult women.

Influence of anonymous HIV testing on national HIV surveillance in the Republic of Korea (2000 to 2015): a retrospective analysis.

BACKGROUND: Owing to the continuous increase in the number of new human immunodeficiency virus (HIV) infection in Korea, public health centers (PHCs) have performed anonymous tests since 1989. No study has examined the patterns of anonymous HIV testing performed at PHCs and the characteristics of HIV infection detected in those tests. We aimed to assess the influence of anonymous HIV testing on Korea's national HIV surveillance. METHODS: HIV screening test data from 253 PHCs over a 16-year period were classified into 13 groups based on reason for testing. For anonymous HIV test takers (Anonymous), the HIV positivity per 10,000 tests was calculated, as repetitions could not be distinguished. Those with suspected HIV infection voluntarily underwent HIV testing and revealed their identity (Suspected). HIV prevalence was calculated as the number of HIV-positive persons per 10,000 test takers. Analyses were performed using chi-square and Cochran-Armitage trend test with SAS 9.4. RESULTS: Approximately 400,000 HIV screening tests were performed at PHCs annually, which remained unchanged in the past 10 years. The proportion of anonymous testing increased from < 3.0% before 2014 to 4.8% in 2014 and 6.1% in 2015. While the number of HIV cases increased, the number of anonymous HIV-positive test results per 10,000 tests decreased from 68.8 in 2010 to 41.8 in 2015. The HIV prevalence among the suspected was approximately 20.0 per 10,000 test takers before 2014, which steeply increased to 71.6 in 2015. Those with suspected HIV were predominantly men, aged 20 years, foreigners, and metropolitan city dwellers in the last 6 years. The high prevalence of persons with suspected HIV resulted in a doubling of HIV prevalence at PHCs between 2014 and 2015. CONCLUSIONS: Anonymous and Suspected, which were driven by similar motives, impacted each other. Increase in HIV prevalence among the suspected led to a higher HIV prevalence among all test takers in PHCs and higher proportions of HIV infection nationwide, which could be attributed to the increase in the number of anonymous tests performed in PHCs. HIV positivity among the anonymous and HIV prevalence among the suspected are key indexes of the national HIV surveillance in Korea.

A large healthcare-associated outbreak of hepatitis C virus genotype 1a in a clinic in Korea.

BACKGROUND: In November 2015, reuse of needles and syringes in conjunction with an increase in cases of HCV at a clinic in Korea was reported and investigated by public health authorities. Patients who received injections at the clinic from the first time this infection control breach may have occurred in 2008 through 2015 when the practice was stopped were offered screening for HCV and other blood-borne pathogens such as HIV, HTLV, HBV, syphilis, and malaria. OBJECTIVES: The aim of this study was to assess whether an outbreak of hepatitis C had occurred among the potentially exposed clinic patients due to this infection control breach. STUDY DESIGN: We performed hepatitis C viral RNA load tests and genotyping using plasma from hepatitis C antibody-positive individuals who had visited the clinic between May 2008 and November 2015. We analyzed the core-E2 and NS5B regions of the virus from RNA-positive samples by constructing a phylogenetic tree based on maximum likelihood analysis. To identify transmission risk factors and epidemiological relationships among the patients, we reviewed their medical records, assessed staff infection control practices and performed environmental inspection of the clinic. Environmental samples from medication room surfaces and medication vial contents were tested for HCV RNA. RESULTS AND CONCLUSIONS: Among the 1721 patients tested, 96 were IgG-positive and 70 were viral RNA-positive. Among the 61 patients whose viral loads were greater than the detection limit, 41 (67.2%) were classified as genotype 1a, 1 (1.6%) as genotype 1b, 18 (29.5%) as genotype 1, and one (1.6%) as genotype 2. After sequencing, 12 genotype 1 cases were further classified as genotype 1a (11) or 1b (1). The sequences of the core-E2 and NS5B regions of 45 patients formed a monophyletic cluster distinct from genotype 1a. The hepatitis C virus sequences from patients and environmental specimens were well-matched in the partial E1 gene region. We detected genotype 1a RNA in environmental specimens, indicating a healthcare-associated outbreak caused by reuse of syringes and contaminated multi-dose vials. Our molecular epidemiological investigation of hepatitis C genotype 1a, rare in Korea, will aid investigations of infection sources during future pathogen outbreaks.

Hospital-based surveillance for rotavirus diarrhea in Ulaanbaatar, Mongolia, April 2009 through March 2016.

BACKGROUND: Diarrheal disease is one of the leading causes of illness and death in young children in the world, especially the developing countries. Diarrheal disease results in about half a million childhood death per year, ranking second among all causes worldwide. Diarrheal disease due to rotavirus infection is currently the most common cause of severe diarrhea in infants and young children worldwide. Rotavirus immunization of infants is a safe and effective public health intervention for rotavirus infection control and expected to lead to a reduction of childhood morbidity and mortality. METHODS: We conducted hospital-based surveillance at two representative hospitals in Mongolia to estimate the burden of hospitalizations for rotavirus diarrhea among children aged <5 years and to describe strain distribution patterns during 6-year study period. Fecal specimens were tested by rotavirus antigen detection enzyme immunoassay (EIA). Specimens that tested positive for rotavirus were further characterized to determine the genotype of strains by reverse-transcriptase polymerase chain reaction. RESULTS: Between April 2009 and March 2016, among 7076 eligible children with diarrhea 6078 patients were enrolled nationally. Forty-six percent (2794/6078) of EIA a specimens were positive for rotavirus. Ninety-three percent (5649/6078) of hospitalizations for diarrhea involved children less than 2 years. No deaths were recorded due to rotavirus diarrhea. The most common genotype was G3P [8] (47.7%) followed by G9P [6] (14.4%), G2P [4] (12%), and G9P [8] (7.1%). CONCLUSIONS: This study found a relatively high prevalence of severe rotavirus-associated diarrhea disease in Mongolia and infants were the most affected. It highlights the urgent need for introduction of rotavirus vaccine into the national immunization program. Continued surveillance is crucial and pre-vaccine introduction rotavirus genotype patterns in Mongolia are valuable and can be followed post-introduction to assess vaccine impact.

Viral and serological kinetics in Zika virus-infected patients in South Korea.

Zika virus is a mosquito-borne flavivirus that causes clinical symptoms similar to those observed in dengue and chikungunya virus infections. The Korea Centers for Disease Control and Prevention initiated laboratory testing using a real-time reverse transcription-polymerase chain reaction in January 2016. More than 1,000 suspected cases of infection were tested and nine were confirmed as imported cases of Zika virus infection from January to July 2016. The travel destinations of the infected individuals were Brazil, Philippines, Viet Nam, Guatemala, Puerto Rico, and the Dominican Republic. Phylogenetic analysis based on the partial envelope gene indicated that the viruses belonged to the Asian genotype circulating in South America. We further investigated the duration for which the viral RNA and virus-specific antibodies were detectable after the symptom onset. After the day of symptom onset, Zika virus was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen. Immunoglobulin M against Zika virus was detected as early as 2 days after the symptom onset and was maintained at these levels until 41 days, whereas Immunoglobulin G was detectable from 8 days after the symptom onset and was maintained until 52 days. These findings would help diagnostic laboratories improve their testing programs for Zika virus infection.

Multiplicative synergistic risk of hepatocellular carcinoma development among hepatitis B and C co-infected subjects in HBV endemic area: a community-based cohort study.

BACKGROUND: There has been limited study on the effect of infection with different hepatitis C virus (HCV) genotypes on the risk of hepatocellular carcinoma (HCC) in hepatitis B virus (HBV) endemic regions of Asia. METHODS: Hazard ratios of HCC development were estimated for HBV and HCV co-infected subjects among a community-based prospective cohort. HCV genotype was determined in HCV RNA-positive samples. Incident HCC cases were identified through linkage to the cancer registry. RESULTS: HCC incidence was 79 per 100,000 person-years in the study population (50 incident cases among 6,694 individuals within 63,170 person-years with an average of 9.4 years of follow-up); seroprevalence of HBsAg and anti-HCV was 5.2% and 5.6%. Adjusted hazard ratios of HCC by HBsAg positivity and anti-HCV positivity were 13.3 (CI: 7.3-24.4) and 6.7 (CI: 3.6-12.6). HRs of HBV and HCV monoinfection, and HBV/HCV coinfection were 17.1 (CI: 8.4-34.8), 10.4 (CI: 4.9-22.1) and 115.0 (CI: 32.5-407.3). Multiplicative synergistic effect of HBV/HCV coinfection on HCC risk was also observed (synergy index: 4.5, CI: 1.3-15.5). Infection with HCV genotype 1 (HR: 29.7, CI: 13.6-46.8) and mixed infection with genotype 1 and 2 (HR: 68.7, CI: 16.4-288.4) significantly elevated HCC risk, much higher than HBV infection. CONCLUSIONS: The effect of differences in HCV genotype and the multiplicative synergistic effect of HBV/HCV coinfection on HCC risk shown in the present study underline the need for comprehensive identification of hepatitis infection status in order to prevent and control HCC in this HBV endemic area.

Molecular and epidemiological characterization of enteroviruses isolated in Chungnam, Korea from 2005 to 2006.

Enteroviruses were identified and characterized from patients with aseptic meningitis and other enterovirusrelated diseases in Chungnam, Korea from 2005 to 2006. Enteroviruses were isolated from 79 of 519 cases (15.2%) in 2005, and 37 of 386 cases (9.6%) in 2006. Based on partial VP1 sequencing, a total of 116 enterovirus isolates were resolved into 13 types. Prevalent among the Chungnam isolates were echovirus 18 and coxsackievirus B5 in 2005, and echoviruses 5 and 25 in 2006. This is the first time echoviruses 5 and 18 have been identified in Korea since enterovirus surveillance began there in 1993. The temporal distribution of enterovirus epidemics in Chungnam showed a remarkable seasonal pattern, with cases occurring during most of the three months of the summer from June to August. The highest rate of enterovirus-positive cases occurred in patients less than 1 year of age. The ratio of male to female enterovirus-positive patients was approximately 1.8:1. Comparison of the VP1 amino acid sequences of the 15 coxsackievirus B5 isolates with reference strains revealed that all Chungnam isolates are substituted at positions 23 (V23I), 19 (S19G), 75 (Y75F), and 95 (N95S). Upon comparing the nine ECV5 isolates with foreign strains, it was found that only the Chungnam isolates, with the exception of Kor06-ECV5-239cn, have P at position 153 and F at position 146. The three ECV9 isolates from 2006 show alterations at amino acids 36, 148, and 154 outside of the BC-loop and at position 84 in the BC-loop, whereas the seven isolates from 2005 and the other ECV9 strains in the database only show the alteration at position 84 (D, I, N, S). The five ECV25 isolates have an S residue at position 134, whereas most of the foreign strains have an N residue.

Hepatitis B virus X mutations occurring naturally associated with clinical severity of liver disease among Korean patients with chronic genotype C infection.

Few reports have detailed mutation frequencies and mutation patterns in the entire X region according to clinical status. The aims of this study were to elucidate the relationships between mutation patterns and their frequencies in the X region and clinical status in a Korean cohort and determine specific X mutation types, related closely with liver disease progression. All X mutations were determined by direct sequencing in 184 patients with different clinical features. Mutation rates in the X region in patients with more severe liver disease, hepatocellular carcinoma (HCC) (3.6%) or liver cirrhosis (4%) were always significantly higher than in patients with corresponding less severe forms, chronic hepatitis (2.9%) or asymptomatic carriers (2.1%), but no significant difference in mutation rates was found in terms of HBeAg serostatus. All five mutation types (V5M/L, P38S, H94Y, I127T/N, and K130M and V131I) affecting the six codons were found to be related significantly to clinical severity. Among these, two mutation types (V5M/L and K130M and V131I) were observed more frequently in HBeAg negative patients than in HBeAg positive patients. In conclusion, the results suggest that an accumulation of mutations in the X region contributes to disease progression in chronic patients, at least Korean patients with genotype C. Specific mutation types appears to be related more to severe liver diseases such as HCC or liver cirrhosis. In particular, a novel mutation type (V5M/L) discovered firstly during the present study was found to be associated significantly with HCC.

The prevalence of hepatitis B virus preS deletions occurring naturally in Korean patients infected chronically with genotype C.

Although Korea is one of the endemic areas for hepatitis B virus infection (HBV), the prevalence of deletions in HBV preS region occurring naturally have not been determined. In the present study, the prevalence of preS deletions was determined in terms of clinical state and HBeAg serostatus in 120 patients with different clinical features [59 HBeAg positive, 61 HBeAg negative; 38 asymptomatic carriers, 21 patients with chronic hepatitis, 21 patients with liver cirrhosis, 40 patients with hepatocellular carcinoma (HCC)]. A total of 37 strains (30.8%) harbored deletions in the preS region. Overall, the frequencies of preS deletions tended to increase gradually according to the degree of the clinical severity of liver disease. The prevalence of preS1 deletions in HCC patients tended to be higher than in patients with liver cirrhosis (32.5% vs. 19%). The prevalence of preS2 deletions in HBeAg negative patients was significantly higher than in HBeAg positive patients (23% vs. 6.8%). The type of deletion encountered most frequently was one disrupting the preS1 start codon [14/37 strains (37.8%)], which showed a very high prevalence in HCC patients (9/40, 22.5%; HCC vs. asymptomatic carriers, P=0.048). These results suggest that there might be the discrepancy between preS1 and preS2 mutations in the mechanism of enhancing the progression of chronic liver disease, especially the development of HCC and to maintain tolerance during the stage of immune tolerance. Specific deletion of the type disrupting preS1 start codon may play important roles in hepatocarcinogenesis, at least in Korean patients with chronic HBV infection.

Recombinant lentivirus-delivered short hairpin RNAs targeted to conserved coxsackievirus sequences protect against viral myocarditis and improve survival rate in an animal model.

Coxsackieviruses are important human pathogens that induce myocarditis and pancreatitis. However, there are no vaccines or therapeutic reagents for their clinical treatment. Although RNA interference (RNAi)-based approaches to the prevention of viral production have been developed recently, limitations to the in vivo delivery systems and variations in the viral target sequences still hamper the strategy. In this study, to overcome these limitations, we have constructed recombinant lentivirus-delivered short hairpin RNAs (shRNAs) against sequences in highly conserved cis-acting replication element (CRE) within the 2C protein of coxsackievirus B3 (CVB3), designated MET-2C. A recombinant lentivirus, designated Met-2C lenti, was constructed that contains the MET-2C sequence, which acts as a shRNA. Met-2C lenti clearly reduced viral production in CVB3-infected cells in vitro. Moreover, the mice injected intraperitoneally with Met-2C lenti had significant reductions in viral titers, viral myocarditis, and proinflammatory cytokines after challenge with CVB3, compared with those in GFP lenti infected control mice. Moreover, Met-2C lenti improved survival rate compared with that of the GFP lenti infected control group. Therefore, Met-2C lenti is potentially a clinical therapeutic agent for the treatment of viral myocarditis.

Primary neurons become less susceptible to coxsackievirus B5 following maturation: the correlation with the decreased level of CAR expression on cell surface.

Coxsackievirus B (CVB) is one of the major pathogens of aseptic meningitis and meningioencephalitis, particularly in newborn infants. To analyze the influence of neural maturation on susceptibility to CVB infection, we prepared immature and mature neurons from 16-day-old BALB/c embryonic cortex. In contrast to immature neurons, mature neurons were less susceptible to CVB5 infection, as indicated by the decrease of cytopathic features. In mature neurons, progeny virus production was significantly hindered, and virus capsid protein VP1 synthesis and virus genome amplification were concomitantly reduced. In addition, the expression of coxsackievirus and adenovirus receptor (CAR), the major receptor of CVB5, was down-regulated in mature neurons. The antibody treatment specific to CAR significantly attenuated CVB5 susceptibility of immature neurons. These findings demonstrate that mature neurons become less susceptible to CVB by the decrease of CAR level. Thus, the data strongly support the idea that the level of virus receptor in neurons is one of the crucial determinants in the age-dependency of CVB virulence in central nervous system.

Comparison of full genome sequences between two hepatitis B virus strains with or without preC mutation (A1896) from a single Korean hepatocellular carcinoma patient.

This report describes the full-length sequences of 2 HBV clones from a hepatocellular carcinoma (HCC) patient, one with preC mutation (1896A) and the other without preC mutation. The high level of discrepancy in mutation frequency between these 2 strains was observed in the Core (C) region among 4 ORFs. These data support previous results that Korean HBV strains, belonging to genotype C2, are prone to mutations. It is possible that the mutations (BCP and preC mutations) associated with the HBeAg defective production might contribute to the diversity of mutations related to HBV persistence, playing an important role in hepatocarcinogenesis in this patient.

Production of cross-reactive peptide antibodies against viral capsid proteins of human enterovirus B to apply diagnostic reagent.

The coxsackievirus group B (CVB) of the genus Enterovirus and the species human enterovirus B is a nonenveloped virus containing a single-stranded positive-sense RNA genome. Coxsackievirus has icosahedral symmetry and four capsid proteins, VP1, VP2, VP3, and VP4. Specific antibodies against each viral protein are prerequisites for various studies. In this study, we developed seven peptide-derived antibodies directed against coxsackievirus VP1 (NO1-NO5), VP2 (B3), and VP3 (GL3). We developed a type-specific antibody (NO1) and broadly cross-reactive antibodies (NO3 and NO5) to VP1. Anti-VP2 and anti-VP3 antibodies (B3 and GL3, respectively) are also cross-reactive to human enterovirus B such as CVB and echoviruses. Their sensitivities and reactivities are likely to be better than those of the commercial VP1 monoclonal antibody (MAb). The dot-blot analysis also showed that NO5 against VP1 is able to detect less than 1 microg [2x10(6) plaque-forming unit (pfu) of CVB3] of viruses, suggesting that it could be used to develop a diagnostic kit that can directly detect human enterovirus B. The antibodies produced here may allow us to undertake several studies, such as those involving viral trafficking, expression kinetics, and the roles of viral proteins in infection, and the development of diagnostic kits.

Characterization of two hepatitis B virus populations in a single Korean hepatocellular carcinoma patient with an HBeAg-negative serostatus: a novel X-Gene-deleted strain with inverted duplication sequences of upstream enhancer site II.

OBJECTIVES: The aim of the study was to elucidate mutation patterns related to hepatocarcinogenesis in a Korean hepatocellular carcinoma (HCC) patient. METHODS: We analyzed full genome sequences of 6 hepatitis B virus (HBV) clones from an HCC patient. RESULTS: This patient harbored 2 HBV populations with genomes of different lengths (3,221 and 2,212 bp). In addition, we found 2 characteristic features not described so far in the full-genome sequence of deleted strains. First, 3 large deletion events (847, 144 and 48 bp) and a premature termination of the 182th codon of the surface antigen could lead to truncated or possibly nonfunctional forms of all HBV proteins. Second, these showed a novel mutation type not reported to date, which is a complex of an inverted duplication of 36-bp sequences containing an upstream enhancer site II (UEII), a remote insertion, and a large deletion event of the X region by homologous recombination. CONCLUSION: The fact that UEII is a binding site of liver-specific nuclear factor, which is expressed only in highly differentiated liver cells such as cancerous HepG2, strongly suggests a relationship between this novel mutation and hepatocarcinogenesis in this patient.

Cell-mediated immune responses to smallpox vaccination.

We report that vaccine dilution (1:1 or 1:10) and previous vaccinia virus vaccination status had no significant effect on cell-mediated immune responses (i.e., the immediate vaccinia virus-specific gamma interferon-producing T-cell response measured by enzyme-linked immunospot assay) 1 month after smallpox vaccination (Lancy-Vaxina; Berna Biotech, Switzerland).

Isolation and molecular identification of echovirus 13 isolated from patients of aseptic meningitis in Korea, 2002.

During 2002, several epidemics of aseptic meningitis were attributed to echovirus 13 in Korea. The causative agents of these outbreaks were isolated and identified using rhabdosarcoma cells, HEp-2 and Buffalo green monkey kidney cells, and a neutralization test using monospecific antiserum. Fifty-four echovirus 13 isolates were isolated from patients with aseptic meningitis in the provinces, Seoul, Kyonggi, Gwangju, Jeonju, Busan, and Ulsan. Symptoms associated with aseptic meningitis infection in patients included the occurrence of headaches and mild fever. Molecular characterization of echovirus 13 samples was achieved by sequence and phylogenetic analyses on partial VP1 sequences from 20 Korean isolates and 10 foreign isolates listed in Genbank. Minor variation was observed among the Korean isolates, which formed a unique cluster with isolates of German and Japanese origin. The marked similarities between isolates could be attributed to a relatively recent arrival of the virus in Korea. This is the first such investigation of aseptic meningitis caused by echovirus 13 on the Korean peninsula.