Objective: To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaV) worldwide. Methods: Literature about the outbreaks on acute gastroenteritis caused by SaV were retrieved from the databases including WanFang, CNKI, PubMed and Web of Science after evaluation. Time, geography, setting and population distributions of outbreaks, transmission mode, SaV genotype and clinical characteristics of the patients were analyzed. Results: A total of 34 papers about SaV were included, involving 146 outbreaks occurred between October 1976 and April 2016. In these papers, 138 outbreaks were reported on the related months. All these outbreaks occurred in northern hemisphere. SaV outbreaks occurred all year around, but mainly in cold season, the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks). Most outbreaks were reported by Japan, followed by Canada, the United States of America and the Netherlands. There were 141 outbreaks for which the occurring settings were reported, child-care settings were most commonly reported setting (48/141, 34.04%), followed by long-term care facility (41/141, 29.08%) and hospital (16/141, 11.35%). Clinical symptoms of 1 704 cases in 31 outbreaks were reported, with the most common symptom was diarrhea (1 331/1 704, 78.12%), followed by nausea (829/1 198, 69.20%), abdominal pain (840/1 328, 63.25%), vomiting (824/1 704, 48.36%) and fever (529/1 531, 34.53%). Genotypes of SaV were determined for 119 outbreaks. GⅠ(51/119, 42.86%) and GⅣ (45/119, 37.82%) were predominant. The outbreaks of GⅣ SaV increased suddenly in 2007, and the outbreaks of GⅠ SaV mainly occurred in 2008 and during 2011-2013. Conclusions: SaV outbreaks were reported mainly by developed countries, with most outbreaks occurred in cold season, in child-care settings and long term care facility. GⅠ and GⅣ were the most common genotypes of SaV. Prevention and control of SaV outbreak in China seemed relatively weak, and it is necessary to conduct related training and to strengthen the SaV outbreak surveillance in areas where service is in need.
Caliciviridae Infections/virology* ; Child ; China/epidemiology* ; Disease Outbreaks ; Feces/virology* ; Gastroenteritis/virology* ; Genotype ; Humans ; Phylogeny ; RNA, Viral/genetics* ; Sapovirus/isolation & purification* ; Sequence Analysis, DNA

Objective: To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province. Methods: Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27, 2016 was reversely transcribed to cDNA, and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR. Amplification products were sequenced for the analysis of genetic characteristics. Results: Based on sequence alignment, the variant shared a high level of identity with the strain GⅡ.g isolated in Spain and Finland (98.7%) in the RNA-dependent RNA polymerase region, and with the strain GⅡ.1 isolated in American (99.4%) in the VP1. The recombination was determined by using software Simplot, and the breakpoint of recombination was located in the ORF1/2 overlap region at position 5 106 of VP1. The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ, but a unique amino acid change was detected at position 132 (N-S). Conclusion: The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant GⅡ.g-GⅡ.1.
Caliciviridae Infections/epidemiology* ; Capsid Proteins ; Disease Outbreaks ; Gastroenteritis/epidemiology* ; Genotype ; Humans ; Norovirus/isolation & purification* ; Phylogeny ; RNA, Viral/genetics* ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

Objective: To investigate the epidemiological characteristics of measles outbreak caused by genotype D8 virus in Pinghu city of Zhejiang province, and provide evidence for the control of the outbreak. Methods: The measles outbreak data were collected through National Measles Surveillance System. The outpatient records and admission records were checked, field investigation and outbreak response were conducted. Blood samples in acute phase and swab specimens were collected from the patients for laboratory testing, including serology test, RNA extraction and amplification, measles virus isolation and genotype identification. Software SPSS 17.0 and Excel 2016 were used for data analysis. Results: A total of 10 confirmed measles cases were reported in Pinghu city, and 8 cases were aged >40 years. Six blood samples were collected, in which 5 were measles D8 virus positive and 1 was negative in measles virus detection. There were epidemiological links among 10 cases which occurred in a factory, a hospital and a family at the same time. There was no statistical difference in symptoms among cases caused by D8 virus and H1a virus. After the emergent measles vaccination, the measles outbreak was effectively controlled. Conclusion: Untimely response due to the uneasy detection of measles cases in the early stage, nosocomial infection and weak barrier of measles immunity in adults might be the main reasons for this outbreak. Measles vaccination is effective in the prevention of measles D8 virus infection. It is necessary to strengthen measles genotype monitoring for the tracing of infection source and control of outbreaks.
Adult ; Amplified Fragment Length Polymorphism Analysis ; Child ; Cross Infection ; Disease Outbreaks ; Genotype ; Hospitalization ; Humans ; Measles/virology* ; Measles virus/isolation & purification* ; Outpatients ; Population Surveillance ; RNA, Viral/genetics* ; Sequence Analysis, DNA

Objective: To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province. Methods: RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017. Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package. Results: Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8%-99.2% and 99.2% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO, respectively. Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2%-99.3% and 97.6%-98.8% similarities with vaccine strain A/Hunan/02650/2016, respectively. Other 6 stains detected in 2017 shared 99.1%-99.4% and 98.9%-99.3% similarities with strain A/Guangdong/17SF003/2016, respectively. Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch, but they were derived from different small branch. PEVPKRKRTAR↓GLF was found in 6 of 24 strains cleavage site sequences of HA protein, indicating the characteristic of highly pathogenic avian influenza virus. Mutations A134V, G186V and Q226L at the receptor binding sites were found in the HA. All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein, and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/18980/2017. In addition, potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains. Conclusions: HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017. The mutations of key sites might enhance the virulence of the virus, human beings are more susceptible to it. Hence, the risk of infection is increasing.
Animals ; Base Sequence ; Birds ; China/epidemiology* ; Genome, Viral ; Hemagglutinin Glycoproteins, Influenza Virus/immunology* ; Hemagglutinins/genetics* ; Humans ; Influenza A Virus, H7N9 Subtype/isolation & purification* ; Influenza in Birds ; Influenza, Human/virology* ; Neuraminidase/genetics* ; Phylogeny ; RNA, Viral/genetics* ; Sequence Analysis, DNA

There has been increasing interest in standardized and quantitative Epstein-Barr virus (EBV) DNA testing for the management of EBV disease. We evaluated the performance of the Real-Q EBV Quantification Kit (BioSewoom, Korea) in whole blood (WB). Nucleic acid extraction and real-time PCR were performed by using the MagNA Pure 96 (Roche Diagnostics, Germany) and 7500 Fast real-time PCR system (Applied Biosystems, USA), respectively. Assay sensitivity, linearity, and conversion factor were determined by using the World Health Organization international standard diluted in EBV-negative WB. We used 81 WB clinical specimens to compare performance of the Real-Q EBV Quantification Kit and artus EBV RG PCR Kit (Qiagen, Germany). The limit of detection (LOD) and limit of quantification (LOQ) for the Real-Q kit were 453 and 750 IU/mL, respectively. The conversion factor from EBV genomic copies to IU was 0.62. The linear range of the assay was from 750 to 10⁶ IU/mL. Viral load values measured with the Real-Q assay were on average 0.54 log₁₀ copies/mL higher than those measured with the artus assay. The Real-Q assay offered good analytical performance for EBV DNA quantification in WB.
DNA, Viral/*blood/metabolism ; Epstein-Barr Virus Infections/diagnosis/virology ; Herpesvirus 4, Human/*genetics/isolation & purification ; Humans ; Limit of Detection ; Reagent Kits, Diagnostic ; Real-Time Polymerase Chain Reaction

BACKGROUND: Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are increasingly important in immunocompromised patients. Nucleic acid extraction methods could affect the results of viral nucleic acid amplification tests. We compared two automated nucleic acid extraction systems for detecting CMV and EBV using real-time PCR assays. METHODS: One hundred and fifty-three whole blood (WB) samples were tested for CMV detection, and 117 WB samples were tested for EBV detection. Viral nucleic acid was extracted in parallel by using QIAsymphony RGQ and QIAcube (Qiagen GmbH, Germany), and real-time PCR assays for CMV and EBV were performed with a Rotor-Gene Q real-time PCR cycler (Qiagen). Detection rates for CMV and EBV were compared, and agreements between the two systems were analyzed. RESULTS: The detection rate of CMV and EBV differed significantly between the QIAsymphony RGQ and QIAcube systems (CMV, 59.5% [91/153] vs 43.8% [67/153], P=0.0005; EBV, 59.0% [69/117] vs 42.7% [50/117], P=0.0008). The two systems showed moderate agreement for CMV and EBV detection (kappa=0.43 and 0.52, respectively). QIAsymphony RGQ showed a negligible correlation with QIAcube for quantitative EBV detection. QIAcube exhibited EBV PCR inhibition in 23.9% (28/117) of samples. CONCLUSIONS: Automated nucleic acid extraction systems have different performances and significantly affect the detection of viral pathogens. The QIAsymphony RGQ system appears to be superior to the QIAcube system for detecting CMV and EBV. A suitable sample preparation system should be considered for optimized nucleic acid amplification in clinical laboratories.
Automation ; Cytomegalovirus/*genetics/isolation & purification ; Cytomegalovirus Infections/diagnosis/*virology ; DNA, Viral/*blood/isolation & purification/metabolism ; Herpesvirus 4, Human/*genetics/isolation & purification ; Humans ; Reagent Kits, Diagnostic ; Real-Time Polymerase Chain Reaction

BACKGROUND/AIMS: Clear indicators for stopping antiviral therapy in chronic hepatitis B (CHB) patients are not yet available. Since the level of hepatitis B surface antigen (HBsAg) is correlated with covalently closed circular DNA, the HBsAg titer might be a good indicator of the off-treatment response. This study aimed to determine the relationship between the HBsAg titer and the entecavir (ETV) off-treatment response. METHODS: This study analyzed 44 consecutive CHB patients (age, 44.6±11.4 years, mean±SD; men, 63.6%; positive hepatitis B envelope antigen (HBeAg) at baseline, 56.8%; HBV DNA level, 6.8±1.3 log₁₀ IU/mL) treated with ETV for a sufficient duration and in whom treatment was discontinued after HBsAg levels were measured. A virological relapse was defined as an increase in serum HBV DNA level of >2000 IU/mL, and a clinical relapse was defined as a virological relapse with a biochemical flare, defined as an increase in the serum alanine aminotransferase level of >2 × upper limit of normal. RESULTS: After stopping ETV, virological relapse and clinical relapse were observed in 32 and 24 patients, respectively, during 20.8±19.9 months of follow-up. The cumulative incidence rates of virological relapse were 36.2% and 66.2%, respectively, at 6 and 12 months, and those of clinical relapse were 14.3% and 42.3%. The off-treatment HBsAg level was an independent factor associated with clinical relapse (hazard ratio, 2.251; 95% confidence interval, 1.076–4.706; P=0.031). When patients were grouped according to off-treatment HBsAg levels, clinical relapse did not occur in patients with an off-treatment HBsAg level of ≤2 log10 IU/mL (n=5), while the incidence rates of clinical relapse at 12 months after off-treatment were 28.4% and 55.7% in patients with off-treatment HBsAg levels of >2 and ≤3 log₁₀ IU/mL (n=11) and >3 log₁₀ IU/mL (n=28), respectively. CONCLUSION: The off-treatment HBsAg level is closely related to clinical relapse after treatment cessation. A serum HBsAg level of <2 log₁₀ IU/mL is an excellent predictor of a sustained off-treatment response in CHB patients who have received ETV for a sufficient duration.
Adult ; Alanine Transaminase/blood ; Antiviral Agents/*therapeutic use ; DNA, Viral/blood ; Female ; Follow-Up Studies ; Guanine/*analogs & derivatives/therapeutic use ; Hepatitis B Surface Antigens/blood ; Hepatitis B virus/genetics/isolation & purification ; Hepatitis B, Chronic/*drug therapy ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Polymerase Chain Reaction ; Recurrence ; Treatment Outcome

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Aged ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis/metabolism ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Guanine/*analogs & derivatives/therapeutic use ; Hepatitis B virus/genetics/isolation & purification ; Hepatitis B, Chronic/*drug therapy/virology ; Humans ; Male ; Middle Aged ; Organophosphonates/*therapeutic use ; Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Tenofovir/*therapeutic use ; Treatment Outcome

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Aged ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis/metabolism ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Guanine/*analogs & derivatives/therapeutic use ; Hepatitis B virus/genetics/isolation & purification ; Hepatitis B, Chronic/*drug therapy/virology ; Humans ; Male ; Middle Aged ; Organophosphonates/*therapeutic use ; Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Tenofovir/*therapeutic use ; Treatment Outcome

Further understanding of male human papillomavirus (HPV) infection is necessary to prevent infection in men, as well as transmission to women. In our current study, we investigated patterns of HPV infection and genotype distributions in male genital warts using the Anyplex II HPV28 Detection kit. We reviewed the medical records of 80 male patients who presented to 5 neighborhood clinics in Ulsan, Korea, for the treatment of genital warts between April 2014 and January 2015. All patients underwent HPV genotyping. The prevalence and characteristics of HPV infection were analyzed, and the patterns of HPV infection according to age were assessed. Among the study patients, 13 (16.3%) were negative for HPV infection, 46 (57.3%) were infected with low-risk HPV, and 21 (26.3%) were infected with high-risk HPV. Patients with multiple HPV infection were more likely to have high-risk HPV infection (P = 0.001). The prevalence of HPV infection was much higher in samples obtained by tissue excision due to a definite lesion (P = 0.001). There were no differences in high-risk HPV infection (P = 0.459), multiple HPV infection (P = 0.185), and recurrence at diagnosis (P = 0.178) according to age. HPV-6 and HPV-11 were the most common type overall (39.7% and 13.8%, respectively). HPV-16 and HPV-18 were the most common high-risk infections (both 3.4%). HPV infection is not only commonly encountered in male genital warts, but is also accompanied by high-risk HPV and multiple infections.
Adult ; Condylomata Acuminata/epidemiology/*pathology/virology ; DNA, Viral/genetics/metabolism ; Genotype ; Human papillomavirus 11/*genetics/isolation & purification ; Human papillomavirus 16/genetics/isolation & purification ; Human papillomavirus 18/genetics/isolation & purification ; Human papillomavirus 6/*genetics/isolation & purification ; Humans ; Male ; Middle Aged ; Prevalence ; Real-Time Polymerase Chain Reaction ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors