Diarrhea In Beijing Research Articles

Major changes in prevalence and genotypes of rotavirus diarrhea in Beijing, China after RV5 rotavirus vaccine introduction.

To analyze the epidemiological characteristics of group A rotavirus (RVA) diarrhea in Beijing between 2019 and 2022 and evaluate the effectiveness of the RV5 vaccine. Stool specimens were collected from patients with acute diarrhea, and RVA was detected and genotyped. The whole genome of RVA was sequenced by fragment amplification and Sanger sequencing. Phylogenetic trees were constructed using Bayesian and maximum likelihood methods. Descriptive epidemiological methods were used to analyze the characteristics of RVA diarrhea. Test-negative design was used to evaluate the vaccine effectiveness (VE) of the RV5. Compared with 2011-2018, RVA-positive rates in patients with acute diarrhea under 5 years of age and adults decreased significantly between 2019 and 2022, to 9.45% (249/634) and 3.66% (220/6016), respectively. The predominant genotype of RVA had changed from G9-VIP[8]-III between 2019 and 2021 to G8-VP[8]-III in 2022, and P[8] sequences from G8-VP[8]-III strains formed a new branch called P[8]-IIIb. The complete genotype of G8-VP[8]-III was G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. The VE of 3 doses of RV5 was 90.4% (95%CI: 28.8%-98.7%) against RVA diarrhea. The prevalence of RVA decreased in Beijing between 2019 and 2022, and the predominant genotype changed to G8P[8], which may be related to RV5 vaccination. Continuous surveillance is necessary to evaluate vaccine effectiveness and improve vaccine design.

Pathogenic Surveillance of Foodborne Illness-Related Diarrhea - Beijing Municipality, China, 2013-2023.

Foodborne diseases present a significant public health concern, particularly in China, where they represent a significant food safety challenge. Currently, there is a need for a thorough and systematic analysis of the extended epidemiological patterns of foodborne diseases in Beijing Municipality. Monitoring results show that Norovirus and diarrheagenic Escherichia coli (DEC) are the most commonly identified foodborne diarrheal pathogens. Individuals aged 19-30 are at a higher risk of foodborne diarrhea in Beijing, with Salmonella infection being associated with fever symptoms. This study analyzes 11 years of consecutive monitoring data to enhance understanding of the epidemiological and clinical features of foodborne diarrhea in Beijing. It aims to identify high-risk populations, assist in clinical pathogen identification and treatment, and support the development of tailored preventive strategies.

Prevalence and genetic diversity of Parechovirus A in children with diarrhea in Beijing, China, 2017-2019.

We analyzed the prevalence and genotypes of Parechovirus A (PeV-A) in children with diarrhea in Beijing, China, 2017-2019. A total of 1734 stool samples collected from children <5years of age with diarrhea were tested for the presence of PeV-A. Viral RNA was detected by real-time RT-PCR, and then genotyped by nested RT-PCR. We detected PeV-A in 93 (5.4%, 93/1734) samples, of which 87 could be genotyped by amplification of either the complete or partial VP1 region or the VP3/VP1 junction region. The median age of PeV-A infected children was 10months. Most PeV-A infections were observed between August and November, with a peak in September. Seven known genotypes of PeV-A1A, -A1B, -A3, -A4, -A6, -A8 and -A11 were detected and PeV-A1B was the most prevalent genotype. Coinfection with other diarrheal viruses was observed in 30.1% (28/93) of PeV-A positive samples. All strains of PeV-A1A, -A1B, -A4 and -A6 obtained in this study contained the arginine-glycine-aspartic acid (RGD) motif, while all strains of PeV-A3, -A8 and -A11 lacked it. This study revealed a high genetic diversity of PeV-A circulating in Beijing and PeV-A11 was reported for the first time in children with diarrhea in China.

Occurrence of respiratory viruses among outpatients with diarrhea in Beijing, China, 2019-2020.

To investigate respiratory virus infections in diarrhea cases and identify the risk of respiratory virus transmission through feces. Fecal specimens were collected from diarrhea cases in enteric disease clinics in Beijing, China, from 2019 to 2020. Cases that tested negative for norovirus, rotavirus, sapovirus, astrovirus, and enteric adenovirus were included in the study. Real-time RT-PCR was used to detect 16 groups of respiratory viruses, and the major viruses were genotyped. Viruses isolation and digestion of clinical specimens and nucleic acid by artificial gastric acid or artificial bile/pancreatic juice were used to evaluate the risk of respiratory virus transmission through feces. A total of 558 specimens were collected and 47 (8.42%) specimens were detected positive, 40 (13.33%, 40/300) in 2019, and 7 (2.71%, 7/258) in 2020, including 20 (3.58%) for human rhinovirus (HRV), 13 (2.32%) for Bocavirus (BoV), 6 (1.08%) for parainfluenza virus I (PIV), 4 (0.72%) for coronavirus (CoV) OC43, 3 (0.54%) for respiratory syncytial virus (RSV) A, and 1 (0.18%) for both BoV and CoV OC43. Syndrome coronavirus 2 (SARS-CoV-2) and other viruses were not detected in this study. Eight genotypes were identified in the 13 HRV specimens. BoVs 1 and 2 were identified in nine BoV specimens. HRV infectious virions were successfully isolated from 2 clinical specimens and clinical specimens of HRV, RSV, PIV, and CoV could not be detected after 4 h of digestion and their nucleic acid could not be detected after 2 h of digestion by artificial gastric acid or artificial bile/pancreatic juice. There may be a risk of respiratory virus transmission from diarrhea cases, and interventions against SARS-COV-2 epidemics are also effective for other respiratory viruses.

Group A rotavirus prevalence and genotypes among adult outpatients with diarrhea in Beijing, China, 2011-2018.

Group A rotavirus (RVA) is one of the most common causes of severe diarrhea in children worldwide. However, RVA is also an important pathogen causing adult diarrhea, with higher infection rates in older patients. To provide evidence for rotavirus epidemic control and to inform vaccine development, we analyzed the molecular epidemiology of RVA among adult outpatients with diarrhea in Beijing from 2011 to 2018. Stool specimens were collected monthly from 14 districts. RVA was detected using enzyme-linked immunosorbent assay and real-time reverse-transcription polymerase chain reaction (RT-PCR). Genotyping of rotavirus was performed using multiplex semi-nested RT-PCR. Phylogenetic analysis was performed using maximum likelihood methods implemented in MEGA software (version 6.06). Logistic regression and chi-square tests were used to assess differences among age groups, districts, years, and genotype distributions. The prevalence of rotavirus was 10.16% (1310 of 12,893) among adult outpatients with diarrhea from 2011 to 2018 in Beijing. The highest prevalence (13.74%, 600 of 4367) was observed among those aged 41 to 65 years. November, December, and January had the highest positive detection rates. In 2011, G3P[8] and G9P[8] were the dominant genotypes. Starting from 2012, G9P[8] became the dominant genotype. Most G9 strains belonged to the G9-VI clade. Most P[8] strains belonged to the P[8]-III clade. RVA is a major cause of adult diarrhea in Beijing. Continuous molecular surveillance is needed, and transmission of rotavirus between children and adults should be investigated further.

Prevalence and genotypes of group A rotavirus among outpatient children under five years old with diarrhea in Beijing, China, 2011\u20132016

BackgroundRotavirus is a leading cause of severe diarrheal disease, and one of the common causes of death in children aged under five years old. The dominant epidemic strains may change in different years in the same area. In order to provide evidence for rotavirus epidemic control and inform vaccine development, we analyzed epidemiological patterns and genetic characteristics of rotavirus in Beijing during 2011–2016.MethodsStool specimens of outpatient children under five years old were collected from three children’s hospitals on a weekly basis. Group A rotavirus antigens were detected using enzyme-linked immunosorbent assay (ELISA) kit. The partial VP4 genes and VP7 genes of rotavirus were both amplified and sequenced. Genotyping and phylogenetic analyses were performed. Logistic regression and Chi-square tests were performed to determine differences across age groups, districts and years in rotavirus prevalence and genotype distribution.ResultsA total of 3668 stool specimens from children with acute diarrhea identified through hospital-based surveillance were collected from 2011 to 2016 in Beijing. A total of 762 (20.8%) specimens tested positive for rotavirus. The rotavirus-positive rate was highest among the 1–2 years old age group (29.0%, 310/1070). November, December and January were the highest rotavirus-positive rate months each year. G9 was the most common G genotype (64.4%, 461/716), and P [8] was the most common P genotype (87.0%, 623/716) among the 716 rotavirus-positive specimens. G9P [8], G3P [8] and G2P [4] were the most common strains. The rotavirus-positive rates of samples in 2012 and 2013 were higher than that in 2011, and the dominant genotype changed from G3P [8] to G9P [8] in 2012 and 2013. VP7 gene sequences of G9 strains in this study clustered into two main lineages. Most of the G9 strains exhibited the highest nucleotide similarity (99.1%~ 100.0%) to the strain found in Japan (MI1128). VP4 gene sequences of P [8] strains were almost P[8]b.ConclusionsRotavirus accounted for more than one fifth of childhood diarrhea in Beijing during the study period. Targeted measures such as immunization with effective rotavirus vaccines should be carried out to reduce the morbidity and mortality due to rotavirus.

Prevalence of intestinal parasites in companion dogs with diarrhea in Beijing, China, and genetic characteristics of Giardia and Cryptosporidium species.

Companion animals including dogs are one of the important components in One Health. Parasites may cause not only diseases in pet animals but also many zoonotic diseases infecting humans. In this study, we performed a survey of intestinal parasites in fecal specimens (n = 485) collected from outpatient pet dogs with diarrhea in Beijing, China, for the entire year of 2015 by microscopic examination (all parasites) and SSU rRNA-based nested PCR detection (Giardia and Cryptosporidium). We observed a total of 124 (25.6%) parasite-positive specimens that contained one or more parasites, including Giardia duodenalis (12.8%), Cryptosporidium spp. (4.9%), Cystoisospora spp. (4.3%), trichomonads (4.3%), Toxocara canis (3.5%), Trichuris vulpis (0.6%), and Dipylidium caninum (0.2%). Among the 55 dog breeds, infection rates were significantly higher in border collies and bulldogs, but lower in poodles (p < 0.05). Risk factor analysis suggested that age was negatively correlated with the infection rate (p < 0.00001), while vaccination and deworming in the past 12 months could significantly reduce the parasite infections (p < 0.01). Among the 62 Giardia-positive specimens, 21 were successfully assigned into assemblages using glutamate dehydrogenase (gdh) and/or beta-giardin (bg) genes, including assemblage D (n = 15), C (n = 5), and F (n = 1). Among the 24 Cryptosporidium-positive specimens by SSU rRNA PCR, 20 PCR amplicons could be sequenced and identified as Cryptosporidium canis (n = 20). Collectively, this study indicates that parasites are a significant group of pathogens in companion dogs in Beijing, and companion dogs may potentially transmit certain zoonotic parasites to humans, particularly those with weak or weakened immunity.

Seasonality of clustering of fever and diarrhea in Beijing, 2009-2015

Objective: To understand the seasonal distribution of the clustering of fever and diarrhea. Methods: Concentration degree and circular distribution methods were used to analyze the seasonal distribution of the clustering of fever and diarrhea in Beijing from 2009 to 2015. The information were collected from the Infectious Disease Surveillance Information System of Beijing. Results: The M values of the clustering of fever and diarrhea were 0.57 and 0.47. Circular distribution results showed that the clustering of fever and diarrhea angle dispersion index R values were 0.57 and 0.46 respectively, the sample average angle of Rayleigh' s test Z values were 414.14, 148.09 respectively (all P<0.01). The clustering of fever and diarrhea had seasonality. The incidence peak of fever was on October 13, and the epidemic period was during August 13-December 14. The incidence peak of diarrhea was on July 31, and the epidemic period was during May 20-October 11. Conclusion: The clustering of fever had obvious seasonality in Beijing, which mainly occurred in autumn and winter. The cluster of diarrhea had certain seasonality, which mainly occurred in summer and autumn.

Prevalence and antibiotic resistance of bacterial pathogens isolated from childhood diarrhea in Beijing, China (2010-2014).

BackgroundDiarrhea is one of the main causes of morbidity and mortality among children less than 5 years of age worldwide, and its causes vary by region. This study aimed to determine the etiologic spectrum, prevalent characteristics and antimicrobial resistance patterns of common enteropathogenic bacteria from diarrheagenic children in Beijing, the capital of China.MethodsStool samples were collected from 2524 outpatients who were aged 0–5 years in Beijing, China during 2010–2014. Microbiological methods, real-time PCR and antimicrobial susceptibility test were used to identify the bacterial causes and antimicrobial resistance patterns in the isolates.ResultsOf the 2524 patients screened, we identified the causes of 269 cases (10.7 %) as follows: diarrheagenic Escherichia coli (4.6 %), Salmonella (4.3 %), Shigella (1.4 %) and Vibrio parahaemolyticus (0.4 %). Atypical EPEC, Salmonella enteritidis, Shigella sonnei and serotype O3:K6 were the most common serogroups or serotypes of the four etiological bacteria. The prevalence of pathogens was correlated with age, season and clinical symptoms. The highest proportion of all causative bacteria was found in children aged 3–5 years and in summer. The clinical symptoms associated with specific bacterial infection, such as fever; abdominal pain; vomiting; and watery, mucus, and bloody stool, were observed frequently in diarrheal patients. Salmonella showed moderate rates of resistance (40–60 %) to ampicillin, nalidixic acid, streptomycin and sulfisoxazole. Resistance to at least three antimicrobials was found in 50 % of isolates. Of the top three serotypes in Salmonella, high-level antimicrobial resistance to single and multiple antibiotics was more common among Salmonella typhimurium and Salmonella 1, 4, [5], 12:i:- than among S. enteritidis. More than 90 % of Shigella isolates showed more alarming resistance to most antibiotics, with a widened spectrum compared to Salmonella.ConclusionConstant antibiotic surveillance is warranted because the bacteria were highly resistant to various antimicrobials. Our study contributes to the strengthening of the existing surveillance system and provides aid for effective prevention and control strategies for childhood diarrhea.Electronic supplementary materialThe online version of this article (doi:10.1186/s13099-016-0116-2) contains supplementary material, which is available to authorized users.

A seventeen-year observation of the antimicrobial susceptibility of clinical Campylobacter jejuni and the molecular mechanisms of erythromycin-resistant isolates in Beijing, China

To investigate the dynamic development of the antimicrobial resistance of Campylobacter jejuni isolated from human diarrhea in Beijing, China, between 1994 and 2010, and to further analyze the molecular mechanisms of erythromycin-resistant strains. Susceptibility tests were performed on 203 non-duplicate clinical C. jejuni strains against eight common antibiotics using the standard agar dilution method. The molecular determinants were further studied in the erythromycin (ERY) non-susceptible strains. The analysis focused on the 23S rRNA gene, the rplD and rplV ribosomal genes, the ermB gene, and the regulatory region of the CmeABC efflux pump. The rates of resistance of C. jejuni to ciprofloxacin (CIP), nalidixic acid (NAL), doxycycline (DOX), tetracycline (TET), florfenicol (FFC), and chloramphenicol (CHL) increased significantly over the period studied (all p<0.05). Similarly, the proportions of resistant patterns (CIP-NAL-DOX-TET, CIP-NAL-DOX-TET-FFC, and CIP-NAL-DOX-TET-CHL) increased remarkably. In this study, 4.4% (9/203) of C. jejuni strains were ERY non-susceptible. The A2075G mutation in the 23S rRNA was found in all of the resistant strains except cj8091, which harbored the ermB gene. Interestingly, the ermB gene was also detected in intermediately resistant isolates, and the earliest ermB-positive strain cj94473 was derived in 1994. Moreover, none of the ribosomal rplD or rplV genes harbored mutations that have been described to confer resistance to macrolides. Different mutations affecting the regulatory region of the CmeABC efflux pump were also found. This is the first comprehensive study on the recent trend in antimicrobial resistance and the molecular mechanisms of macrolide resistance in clinical C. jejuni strains isolated in China. More stringent monitoring and regulation of human and animal antimicrobial use are warranted.

Human calicivirus occurrence among outpatients with diarrhea in Beijing, China, between April 2011 and March 2013.

Human caliciviruses (HuCVs), including noroviruses (NoVs) and sapoviruses (SaVs), are the most common cause of diarrhea in adults and the second most common cause of diarrhea in children. Between April 2011 and March 2013, 3,832 fecal specimens were collected from outpatients with diarrhea from 17 hospitals in Beijing, China, and 669 specimens (17.5%) were positive for HuCV. Of the 287 HuCV-positive specimens, 263 (91.6%) were identified to be NoV, 23 (8.0%) were identified to be SaV, and one (0.3%) was identified to be a mixed infection of NoV and SaV. Of the 263 NoV-positive specimens, 237 (90.1%) were NoV GII, 21 (8.0%) were NoV GI, and 5 (1.9%) were a combination of NoV GI and GII. Among the 216 sequenced GII-positive samples, GII.4 was the most common genotype (70.4%, 152/216), followed by GII.13 (9.3%, 20/216). GII.4 Sydney_2012 was first detected in August 2012 and replaced GII.4 Den Haag_2006b as the predominant variant between September 2012 and March 2013. With the emergence of the GII.4 Sydney_2012 variant, 44.6% more patients with diarrhea visited the 17 hospitals (9,931 cases) than in the previous year (6,866 cases) between October and December 2012.

Draft genomes of four enterotoxigenic Escherichia coli (ETEC) clinical isolates from China and Bangladesh.

BackgroundEnterotoxigenic Escherichia coli (ETEC) is an important pathogen that causes childhood and travelers’ diarrhea. Here, we present the draft genomes of four ETEC isolates recovered from stool specimens of patients with diarrhea in Beijing, China and Dhaka, Bangladesh, respectively.ResultsWe obtained the draft genomes of ETEC strains CE516 and CE549 isolated in China, and E1777 and E2265 isolated in Bangladesh with a length of 5.1 Mbp, 4.9 Mbp, 5.1 Mbp, and 5.0 Mbp, respectively. Phylogenetic analysis indicated that the four strains grouped with the classical Escherichia coli phylogenetic groups A and B1 and three of them including a multi drug-resistant Chinese isolate (CE549) belonged to two major ETEC lineages distributed globally. The heat stable toxin (ST) structural gene (estA) was present in all strains except in strain CE516, and the heat labile toxin (LT) operon (eltAB) was present in all four genomes. Moreover, different resistance gene profiles were found between the ETEC strains.ConclusionsThe draft genomes of the two isolates CE516 and CE549 represent the first genomes of ETEC reported from China. Though we revealed that ETEC is uncommon in Beijing, China, however, when it does occur, multi-drug resistance and ESBL positive isolates might pose a specific public health risk. Furthermore, this study advances our understanding of prevalence and antibiotic resistance of ETEC in China and adds to the number of sequenced strains from Bangladesh.

Multiple Genomic Recombination Events in the Evolution of Saffold Cardiovirus

BackgroundSaffold cardiovirus (SAFV) is a new human cardiovirus with 11 identified genotypes. Little is known about the natural history and pathogenicity of SAFVs.Methodology/Principal FindingsWe sequenced the genome of five SAFV-1 strains which were identified from fecal samples taken from children with viral diarrhea in Beijing, China between March 2006 and November 2007, and analyzed the phylogenetic and phylodynamic properties of SAFVs using the genome sequences of every known SAFV genotypes. We identified multiple recombination events in our SAFV-1 strains, specifically recombination between SAFV-2, -3, -4, -9, -10 and the prototype SAFV-1 strain in the VP4 region and recombination between SAFV-4, -6, -8, -10, -11 and prototype SAFV-1 in the VP1/2A region. Notably, recombination in the structural gene VP4 is a rare event in Cardiovirus. The ratio of nonsynonymous substitutions to synonymous substitutions indicates a purifying selection of the SAFV genome. Phylogenetic and molecular clock analysis indicates the existence of at least two subclades of SAFV-1 with different origins. Subclade 1 includes two strains isolated from Pakistan, whereas subclade 2 includes the prototype strain and strains isolated in China, Pakistan, and Afghanistan. The most recent common ancestor of all SAFV genotypes dates to the 1710s, and SAFV-1, -2, and -3 to the 1940s, 1950s, and 1960s, respectively. No obvious relationship between variation and pathogenicity exists in the critical domains of the CD and EF loops of viral capsid proteins or the multi-functional proteins L based on animo acid sequence identity comparison between SAFV genotypes.Conclusions/SignificanceOur findings suggest that intertypic recombination plays an important role in the diversity of SAFVs, highlighting the diversity of the five strains with the previously described SAFV-1 strains.

Detection of a Bocavirus Circular Genome in Fecal Specimens from Children with Acute Diarrhea in Beijing, China

To determine if human bocavirus 2 (HBoV2) has a circular genome similar to the head-to-tail sequence of HBoV1 and the episomal form of HBoV3, 15 HBoV2 positive samples identified from 553 stool specimens from children with acute diarrhea were tested for a head-to-tail sequence using TaqMan-based real-time PCR. A circular genome with a head-to-tail sequence was identified in one (BJQ435) out of 15 samples tested by nested PCR. The complete circular genome of HBoV2-C1 (BJQ435) was 5307 nt in length and was flanked with a 520 nt-long terminal non-coding region (NCR). The secondary structure of HBoV2 -C1 had some differences compared to HBoV3-E1 (JN086998). Our study indicates that the HBoV genome exists in the form of a head-to-tail monomer and provides more information for understanding the HBoV replication mechanism.

Etiology of acute diarrhea due to enteropathogenic bacteria in Beijing, China

Acute diarrhea is of great concern due to considerable morbidity and mortality worldwide. The causative bacteria leading to acute diarrhea in general population remains unclear in China. This study was conducted to determine the etiology of acute diarrhea using a sentinel hospital-based surveillance network in Beijing. Active surveillance was implemented from April 2010 to December 2011 on two random days per week by enrolling every tenth diarrheal patients admitted to seventeen intestinal clinics. Shigella spp., Vibrio spp, Salmonella spp., diarrheagenic Escherichia coli and other genera of bacteria, were investigated from 4803 outpatients with acute diarrhea by microbiological methods. The pathogenic bacteria recovered out from fecal samples of 968 (20.2%) patients had the following profile: Shigella spp. (5.9%) was the most prevalent pathogen, Vibrio parahaemolyticus (5.2%), Salmonella spp. (3.9%) and enteropathogenic E. coli (EPEC) (0.9%) had from the second to fourth highest prevalence, respectively. Of the 55 co-infections detected, V. parahaemolyticus was the most common pathogen from 28 cases (50.9%), with the main combination of V. parahaemolyticus and Salmonella. The highest proportion of all causative bacteria was found in adults aged 20-39 year and in summer as well as early autumn. The clinical symptoms associated with specific bacterial infection, such as fever, abdominal pain, tenesmus, nausea, vomiting, and watery and bloody stool, were observed frequently in diarrheal patients. Shigella spp., V. parahaemolyticus, Salmonella spp., and EPEC are important enteropathogenic bacteria causing acute diarrhea in Beijing. To execute reasonable interventions, the comprehensive and continuous surveillance is needed to identify the prevalence of different enteropathogeic bacteria.

Detection of Cryptosporidium infection among HIV/AIDS patients with chronic diarrhea in Beijing, Henan and Xinjiang of China

To investigate the Cryptosporidium infection and its epidemiological characteristics in HIV/AIDS patients with chronic diarrhea. Stool samples collected from HIV/AIDS confirmed patients with chronic diarrhea who lived in Beijing, Henan and Xinjiang. Samples were concentrated by Formalin-Ethyl Acetate Sedimentation technique and stained by modified acid-fast stain (AFS) for the identification of oocysts by microscopy. CD4(+)T cells count was performed by Flow Cytometry. The overall infection rate of Cryptosporidium in AIDS patients was 12.6% (32/253). The infection rates of oocysts in the area of Beijing, Henan and Xinjiang were 5.97% (4/67), 16.1% (24/149) and 10.8% (4/37) respectively. The infection rate of oocysts in the urban areas was 6.5% (7/104) while in the countryside it was 16.8% (25/149) and the difference was significantly different. However, there were no any differences discovered between the infection rates on patient's gender or on infection occurred in different seasons. The infectious rates of oocyst in patients on different stages of the disease were also significantly different (P < 0.01). AIDS patients infected by Cryptosporidium were not rarely seen in northern China. The rate of infection was not associated with patient's gender but was associated with patient's living environments. Patients living in the countryside, with lower lever of CD4(+)T cells counts and at the middle/late stage of the disease, Cryptosporidium infection appeared to be high.

Molecular characterization of astrovirus infection in children with diarrhea in Beijing, 2005–2007

Human astroviruses (HAstVs) have been recognized as one of the major causes of acute gastroenteritis in children. To provide more insight into the prevalence of HAstV gastroenteritis in China, 664 fecal samples were collected from children affected with acute gastroenteritis in Beijing from March 2005 to November 2007. The samples were analyzed genetically. All eight serotypes (genotypes) of HAstVs were screened using RT‐PCR assays targeting the ORF2 region in the study. The assays detected HAstVs in 52 (7.8%) of the patients, with HAstV‐1 (50/52) being the dominant genotype during the study period. Two minor genotypes, HAstV‐6 and HAstV‐3, were also detected. Partial sequencing of the 50 HAstV‐1 strains showed that the homology of the nucleotide sequence of the ORF1a region between these strains was 88.4–100%, whereas the homology of the amino acid sequences was 95.6–100%. In the ORF2 partial region, the nucleotide identities ranged from 91.5% to 100%, and amino acid identities ranged from 97.3% to 100%. The identity of the whole genome sequence between four randomly examined HAstV‐1 strains was 91–99%. No recombination events were observed in HAstVs in this study. The findings of this study will provide baseline data for HAstVs surveillance and control. J. Med. Virol. 82:415–423, 2010. © 2010 Wiley‐Liss, Inc.

Analysis on VP7 and VP4 genes of human rotavirus G9 identified from children with diarrhea in Beijing, from 2007 to 2008

To characterize the outer capsid protein VP7 and VP4 encoding genes of human rotavirus G9 strains detected in Beijing, from 2007 to 2008. Full length of VP7 genes of G9 rotaviruses from 12 fecal specimens previously detected by dot-blot hybridization assay were amplified by RT-PCR and sequenced after being cloned into T vector. The sequences of these VP7s were compared to VP7 genes of rotavirus G9 prototype strains and recently circulating strains around the world. VP4 genes of these 12 G9 strains were amplified by nested-PCR for P genotyping. Sequence analysis for the full length of VP7 genes from these 12 specimens confirmed that they were G9 rotaviruses. P genotyping for VP4 genes revealed that both P[8]G9 and P[6]G9 were circulating in Beijing in the last 2 years. Sequence and phylogenetic analysis demonstrated that VP7 genes of G9 strains from Beijing in this study were clustered in the lineage III which resembled the G9 strains circulating in other places around the world, indicated by high identities of nucleotide and deduced amino acid sequences and were distant with the first reported G9 strain T203 identified in China in 1994. It was found that there were some consistent amino acid substitutes at the corresponding positions among VP7s from these 12 specimens and from Xinjiang and Wuhan, both in G9P[8] and G9P[6] strains. The rotavirus G9 strains both in combination of G9P[8] and G9P[6] were circulating in Beijing in the past years. It seemed that rotavirus G9 should be included in the list of surveillance for rotavirus in China.

Etiology of childhood diarrhea in Beijing, China

To determine the role of recently recognized enteropathogens in childhood diarrhea in China, 221 children with diarrhea and 108 controls seen at the Beijing Children's Hospital were studied during April and May 1989. Stools were examined for ova, parasites, and rotavirus, cultured for bacterial pathogens, and probed for enterotoxigenic Escherichia coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), and enteropathogenic adherence factor-positive (EAF+) E. coli. Pathogens were identified in 56.5% of children with diarrhea and 43.5% of controls (P = 0.04). Detection of enteropathogens was significantly greater in patients examined within 1 week of symptom onset (65%) than in patients examined later (39%; P = 0.01). ETEC was the most frequently detected pathogen in children with diarrhea, accounting for 20% of the cases. Other agents identified in patients included the following: salmonellae, 12%; rotavirus, 7%; EIEC, 7%; EHEC, 7%; members of the Aeromonas hydrophila group, 6%; EAF+ E. coli, 5%; Ascaris lumbricoides, 3%; shigellae, 3%; campylobacters, 2%; and Vibrio spp., 0.5%. The isolation rates of salmonellae (P = 0.02), EAF+ E. coli (P = 0.04), and mixed pathogens (P = 0.05) were significantly greater for diarrhea patients than for controls. Resistance to multiple antimicrobial agents occurred in 39% of the Salmonella isolates, 22% of the Aeromonas isolates, and 17% of the Shigella isolates. Multiresistant salmonellae (P = 0.05) and shigellae were recovered from diarrheal stools only. Ciprofloxacin, cefotaxime, and imipenem were the only agents tested to which all bacterial isolates were susceptible in vitro. These results suggest that both traditional and newly recognized agents are important causes of childhood diarrhea in Beijing and that therapy may be complicated by indigenous antimicrobial resistance.