China ; epidemiology ; Epidemiologic Studies ; Human bocavirus ; isolation & purification ; Humans ; Molecular Epidemiology ; Parvoviridae Infections ; epidemiology ; Respiratory Tract Infections ; epidemiology ; virology

Child ; China ; epidemiology ; Female ; Human bocavirus ; Humans ; Infant ; Infant, Newborn ; Male ; Parvoviridae Infections ; epidemiology ; virology ; Respiratory Tract Infections ; epidemiology ; virology

Human bocavirus (HBoV) is classified in the family of parvovirdae, genus bocavirus. Besides parvovirus B19 and human parvovirus 4 (PARV4), HBoV isone of the parvoviruses currently known to infect and cause illness in human. So far, four different HBoVs (HBoV1-4) have been successively reported. The incidence of HBoVs infection varies widely, the clinical presentations of patients are different, and HBoVs are often co-detected with other pathogens. There are already quite a few report of HBoVs infection, and this article reviews and discusses the biological characters, epidemic characters, pathogenic mechanism, phylogenetic analyses of HBoVs and the epidemiological situation in China.
China ; epidemiology ; Gastrointestinal Diseases ; etiology ; Human bocavirus ; classification ; genetics ; immunology ; isolation & purification ; Humans ; Parvoviridae Infections ; epidemiology ; Phylogeny

This study aimed to study the epidemiological and clinical characteristics of human bocavirus 1-4 (HBoV1-4) in children with acute diarrhea in Lanzhou and to investigate the association between HBoV and acute gastroenteritis. A total of 331 stool samples were collected from children aged under 5 years with acute diarrhea at the Department of Pediatrics, the First Hospital, Lanzhou University, between July 2012 and June 2013. Nested PCR was used to screen for HBoV and a general PCR was employed to screen other common diarrhea viruses. We found human bocavirus 1, 2, 3 and 4 in 26, 15, 7 and 1 cases, respectively. There was no specific seasonal distribution of HBoV, with infections occurring throughout the year. HBoV was mostly found in children aged between 7 and 12 months, with a mean age of 11.04 months (+/- 6.92 months), and 93.88% of affected children were aged under 2 years. Overall, 71.3% of mixed infections were mixed and the majority of other infections were caused by rotavirus. There was no statistical difference in the incidence of fever and vomiting associated with HBoV infection. A rare virus strain, HBoV4 (LZFB086), was identified, which showed highest levels of nucleotide sequence identity (99.0%) with a single Thai HBoV strain (JQ267789). No case of HBoV2B was found. In conclusion, HBoV1 was a major etiological pathogen of HBoV in pediatric cases in Lanzhou. HBoV4 was detected in feces for the first time in China. The rate of mixed infections was high and rotavirus was dominant. The data presented suggests that HBoV is not a major causative agent of gastroenteritis.
China ; epidemiology ; Diarrhea ; epidemiology ; virology ; Feces ; virology ; Human bocavirus ; classification ; genetics ; isolation & purification ; Humans ; Infant ; Molecular Sequence Data ; Parvoviridae Infections ; epidemiology ; virology ; Phylogeny ; Seasons

OBJECTIVETo explore the risk factors of human parvovirus B19 infection in pregnancy and to provide guidelines for its prevention and control strategy.

METHODSFour hundred and eighty-six cases of gravida serum were detected for parvovirus B19 DNA by nested-polymerase chain reaction assay. Factors associated with parvovirus B19 infection in pregnancy were investigated and analyzed, using multiple logistic regression and factor analysis.

RESULTSMultiple logistic regression analysis suggested that there were 16 agents associated with parvovirus B19 infection during pregnancy, which were dominated by 6 potential factors listed as follows: countryside and bad hygienic habit, mental factor, occupational exposure to hospital and environmental condition, health and illness, bad behavior and health education and blood type.

CONCLUSIONThe prevention strategy of parvovirus B19 infection in pregnancy should include reasonable allocation of public health resources between city and countryside, and to promote health education and occupational health during pregnancy.

Adult ; China ; epidemiology ; DNA, Viral ; analysis ; Factor Analysis, Statistical ; Female ; Humans ; Parvoviridae Infections ; epidemiology ; Parvovirus B19, Human ; isolation & purification ; Pregnancy ; Pregnancy Complications, Infectious ; epidemiology ; Prevalence ; Risk Assessment

BACKGROUNDHuman bocavirus (HBoV) is a newly identified human parvovirus that was originally detected in the respiratory secretions of children with respiratory infections. This study aimed to learn about the importance of HBoV infections by revealing the prevalence of serum antibodies against HBoV in Beijing population.

METHODSTwo batches of serum specimens collected in different periods were tested by Western blotting for specific IgG against HBoV using recombinant VP2 as antigen.

RESULTSOut of 677 serum specimens collected during April 1996 to March 1997, 400 (59.1%) were positive and antibody positive rate for another batch of 141 serum specimens collected in August, 2005 from adults aged from 20 years to over 60 years was 78.7% (111/141). Comparison of the sero-prevalence profiles for serum specimens collected during 1996 - 1997 to those collected in 2005 indicated that the antibody positive rate for specimens collected in 2005 was higher than that of the corresponding age groups collected during 1996 - 1997.

CONCLUSIONSThe data suggest that HBoV has been circulating in Beijing population for at least over 10 years, and most of children had been exposed to HBoV by age of 7 years. Higher HBoV antibody positive rate shown in the serum specimens collected in 2005 suggested that infections by HBoV have been increased in Beijing population in recent years.

Adult ; Antibodies, Viral ; blood ; Blotting, Western ; Bocavirus ; pathogenicity ; China ; epidemiology ; Humans ; Immunoglobulin G ; immunology ; Middle Aged ; Parvoviridae Infections ; blood ; epidemiology ; immunology ; Seroepidemiologic Studies ; Viral Proteins ; immunology ; Young Adult

OBJECTIVEThe aim of this study was to explore the prevalent characteristics of HBoV1 and its co-infection.

METHODSPCR was used to detect HBoV1-DNA (HBoV1) and other viruses. A multivariate logistic regression model was used to explore possibility of co-detected for related viruses.

RESULTSThe positivity rates in Nanjing and Lanzhou were 9.38% (74/789) and 11.62% (161/1386), respectively (P>0.05). The HBoV1 positive group was younger than negative group (P<0.05). Seasonal differences were noted, with a higher frequency of infection in December and July. HBoV1-positive children [72.34% (169/235)] were co-infected with other respiratory viruses. Multifactorial analysis showed no correlations between HBoV1 and the clinical classification, region, gender, age, or treatment as an outpatient or in a hospital. Correlations were identified between HBoV1 infections with ADV (OR=1.53, 95% CI 1.03-2.28), RSV (OR=0.71, 95% CI 0.52-0.98), and IFVA (OR=1.77, 95% CI 1.00-3.13).

CONCLUSIONPresence of HBoV1 in nasopharyngeal aspirates did not correlate with region or gender, although the prevalence of HBoV1 was higher in younger children. There were no correlations between HBoV1 and other variables, except for the season and ADV, RSV, or IFVA infections.

Acute Disease ; Child, Preschool ; China ; epidemiology ; Comorbidity ; DNA, Viral ; genetics ; Female ; Human bocavirus ; genetics ; isolation & purification ; Humans ; Logistic Models ; Male ; Multivariate Analysis ; Parvoviridae Infections ; epidemiology ; virology ; Prevalence ; Respiratory Tract Infections ; epidemiology ; virology

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; DNA, Viral/analysis ; Female ; Human bocavirus/*isolation & purification ; Humans ; Infant ; Male ; Middle Aged ; Nasopharynx/virology ; Parvoviridae Infections/diagnosis/*epidemiology/virology ; Polymerase Chain Reaction ; Prevalence ; Respiratory Tract Infections/diagnosis/*epidemiology/virology ; Viral Load

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; DNA, Viral/analysis ; Female ; Human bocavirus/*isolation & purification ; Humans ; Infant ; Male ; Middle Aged ; Nasopharynx/virology ; Parvoviridae Infections/diagnosis/*epidemiology/virology ; Polymerase Chain Reaction ; Prevalence ; Respiratory Tract Infections/diagnosis/*epidemiology/virology ; Viral Load

OBJECTIVETo find out the importance of human bocavirus (HBoV) as an infectious agent for population in Beijing, China, seroprevalence study was conducted by using expressed recombinant major capsid VP2 protein as an antigen.

METHODSSerum specimens collected from infants and children who visited the Children's Hospital Affiliated to the Capital Institute of Pediatrics for health check up and adults visited the Xuanwu Hospital, Beijing for diseases other than respiratory infections from April 1996 to March 1997 were used for investigation. The major capsid protein VP2 from HBoV was expressed in E. coli strain BL21 (DE3) with the transformed PET30b vector inserted with full-length VP2 gene of HBoV and the specific antigenicity of this expressed protein was validated by previous study. Western blot was used to detect specific IgG antibody against HBoV in collected serum specimens diluted to 1:200. Mock expressed protein was E. coli cells strain BL21 (DE3) with the transformed PET30b vector without insert. Anti-His monoclonal antibody and rabbit anti-HBoV VP2 polypeptides hyper-immune serum were used as positive control for antibody detection.

RESULTSOut of 677 serum specimens tested, 400 (59.1%) were positive by Western blot. About 45.3% (34/75) of the newborns under 1 month of age had anti-HBoV antibodies, and antibody positive rates were lower in the age groups of 1 and 2 months (41.4% and 31.3%, respectively) and were higher in the following ages from 6 months to 7 years (from 45.6% to 69.7%). The antibody positive rates were at a relatively constant level (about 70%) in the age groups from 7 years to 40 years and became lower (61.8% - 62.8%) in groups of age over 50 years.

CONCLUSIONThe high seroprevalence against recombinant HBoV VP2 protein and early age antibody acquisition indicate that HBoV has been circulating in Beijing, China as early as in 1996 and most of children had been exposed to HBoV by the age of 7 years. Infants under the age of 6 months were susceptible to infection with this virus.

Adolescent ; Adult ; Antibodies, Viral ; blood ; Blotting, Western ; Bocavirus ; immunology ; Capsid Proteins ; immunology ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Immunoglobulin G ; blood ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Parvoviridae Infections ; epidemiology ; immunology ; Prevalence ; Seroepidemiologic Studies ; Young Adult