Phylogenetics and phylogeographic characteristics of coxsackievirus A16 in hand foot and mouth disease and herpangina cases collected in Beijing, China from 2019 to 2021.

Coxsackievirus A16 (CV-A16) is a significant pathogen responsible for causing hand foot and mouth disease (HFMD) and herpangina (HA). This study aimed to investigate the recent evolution and spread of CV-A16 by monitoring HFMD and HA cases in 29 hospitals across 16 districts in Beijing from 2019 to 2021. The first five cases of HFMD and the first five cases of HA each month in each hospital were included in the study. Real-time reverse transcription polymerase chain reaction was used to identify CV-A16, CV-A6, and EV-A71. From each district, two to four CV-A16 positive samples with a relatively long sampling time interval every month were selected for sequencing. A total of 3344 HFMD cases and 2704 HA cases were enrolled in this study, with 76.0% (2541/3344) of HFMD and 45.4% (1227/2704) of HA cases confirmed to be infected by enterovirus. Among the EV-positive samples, CV-A16 virus was detected in 33.61% (854/2541) of HFMD cases and 13.4% (165/1227) of HA cases, with the predominant cluster being B1a. Both B1a and B1b had a co-circulation of local and imported strains, with different origin time (1993 vs. 1995), different global distribution (14 countries vs. 10 countries), and different transmission centers but mainly distributed in the southern and eastern regions of Beijing. Strengthening surveillance of HFMD in southern and eastern regions will improve the prevention and control efficiency of enterovirus infections.

Genomic Analysis and Antimicrobial Resistance of Campylobacter jejuni Isolated from Diarrheal Patients - Beijing Municipality, China, 2019-2021.

Introduction: Campylobacter jejuni (C. jejuni) is the leading cause of human bacterial gastroenteritis worldwide and has a major impact on global public health. The objective of the present study was to conduct whole genome sequencing (WGS) to determine the genetic diversity, virulence factors, and determinants of antimicrobial resistance of C. jejuni during a 3-year surveillance period in Beijing, China. Methods: A total of 184 clinical isolates were obtained from sentinel hospital surveillance between 2019 and 2021. Antimicrobial susceptibility testing was conducted using the agar dilution method. WGS was employed to characterize the 184 C. jejuni strains. Results: Multilocus sequence typing analysis revealed high genetic diversity among the 184 C. jejuni strains, identifying 71 sequence types (STs) and 19 clonal complexes (CCs). The most prevalent ST was ST760 (6.5%), and the most common CC was CC21 (24.5%), consisting of 11 STs. High resistance rates were observed for ciprofloxacin (76.6%), nalidixic acid (76.1%), and tetracycline (71.2%). A total of 77 C. jejuni isolates (41.8%) exhibited multidrug resistance with 43 resistance patterns. Virulome analysis disclosed the differential distribution of virulence factors related to adherence, colonization, chemotaxis, as well as lipo-oligosaccharide and capsular polysaccharide biosynthesis. Resistome analysis demonstrated widespread resistance to quinolones and tetracycline, but low rates of macrolides resistance. The phylogeny, based on whole genome single nucleotide polymorphisms, indicated a high degree of clonality and grouped the C. jejuni strains into six clades. Closely related isolates that were part of a genetic cluster mostly shared a homogenous clonal complex. Conclusions: The present study emphasizes the rising resistance to quinolones and tetracycline, as well as the virulence potential and diverse genotypes identified among C. jejuni strains isolated from diarrheal patients in Beijing.

Vibrio parahaemolyticus O10:K4: An Emergent Serotype with Pandemic Virulence Traits as Predominant Clone Detected by Whole-Genome Sequence Analysis - Beijing Municipality, China, 2021.

Introduction: Vibrio parahaemolyticus (V. parahaemolyticus) is a common foodborne pathogen which causes gastroenteritis in humans, especially the O3:K6 pandemic clone which is still a prominent serotype in Beijing, China. In this study, we observed a novel serotype O10:K4 isolated from clinical diarrhea cases, which became the most prevalent clone in 2021. Methods: 73 clinical isolates were collected through sentinel hospitals' surveillance in 2021. Serum agglutination testing and antimicrobial susceptibility testing were conducted. Whole genome sequencing was applied to characterize 73 V. parahaemolyticus strains and complete phylogenetic analysis. Results: Seven serotypes were identified among 73 strains. O10:K4 was the most common serotype (83.6%), followed by O2:KUT, O4:KUT, and O1:KUT. Multilocus sequence typing divided the 73 isolates into 10 sequence types (STs) with ST3 as the most prevalent, which covered all O10:K4 strains. Most isolates were sensitive to common antimicrobial agents apart from colistin. All the O10:K4 isolates were positive for the thermostable direct hemolysin gene, toxRS/new, andorf8, and negative for the TDH-related hemolysin gene. The whole genome sequencing-single nucleotide polymorphism phylogenetic analysis revealed O10:K4 strains formed a main genetic lineage, which was genetically distinct from other serotypes. We also demonstrated the presence of two type III secretion system genes (T3SS1 and T3SS2) and ß lactamase resistance gene blaCARB-22 in all O10:K4 strains. Conclusions: The study confirmed the emergence of V. parahaemolyticus O10:K4 possessing virulence factors similar to the O3:K6 pandemic clone, which may have enabled them to become prevalent in Beijing, China.

Epidemiological Investigation of an Inhalational Anthrax Patient Traveling for Medical Treatment in Beijing Municipality, China, August 2021.

What is already known about this topic?: Inhalational anthrax, also known as pulmonary anthrax, is an infectious disease caused by Bacillus anthracis . The patients are usually infected by inhaling aerosolized B. anthracis spores from dead animals or animal products. Compared to cutaneous anthrax, inhalational anthrax is rare and deadly and few cases in China were reported. What is added by this report?: This report covers all information of clinical features, laboratory testing, and epidemiological characteristics as well as exposure history of a recent primary inhalational anthrax patient who was seeking medical treatment in Beijing Municipality in August 2021. New laboratory techniques, including second-generation sequencing, polymerase chain reaction, and rapid test for serum antibody, played an important role in the process. What are the implications for public health practice?: The information provided in this report, including the correct sample type, epidemiological investigation details, and application of the new diagnostic criteria of anthrax, could assist public health professionals in dealing with anthrax epidemics.

Extensively Drug-Resistant (XDR) Salmonella Typhi Outbreak by Waterborne Infection - Beijing Municipality, China, January-February 2022.

What is already known about this topic?: Typhoid fever remains a major public health problem in developing countries. Waterborne typhoid fever affects an estimated 27 million people worldwide each year. Decades of indiscriminate antibiotic usage has driven the emergence and spread of multidrug-resistant (MDR) and even extensively drug-resistant (XDR) Salmonella Typhi (S. Typhi) strains. What is added by this report?: By combining the epidemiological investigations, bacterial isolation from patients and household water, whole genome sequencing and drug resistance analysis, we identified a waterborne typhoid fever outbreak caused by XDR S. Typhi in Beijing municipality. This was the first report of the XDR S. Typhi triggered outbreak in Beijing, which was also rare in China. What are the implications for public health practice?: This report highlights the importance of ensuring access to affordable and safe drinking water, improved sanitation, and waste management systems for resource-constrained urban populations. Typhoid fever caused by XDR S. Typhi is still a severe public health threat.

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

Objectives: To investigate respiratory virus infections in diarrhea cases and identify the risk of respiratory virus transmission through feces. Methods: 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. Results: 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. Conclusion: 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.

Comparison of four commercial RT-PCR diagnostic kits for COVID-19 in China.

We compared the sensitivity and specificity of four commercial coronavirus disease (COVID-19) diagnostic kits using real-time reverse transcription-polymerase chain reaction (RT-PCR). Kits I-IV approved by the State Drug Administration of China were selected, and the detection targets were ORF1ab gene and N gene. Specificity was evaluated by detecting other respiratory viruses. The sensitivity and batch effect of each kit were evaluated by testing 10-fold dilutions of RNA. Clinical application was verified by testing nasopharyngeal swab and sputum specimens from COVID-19 patients. Among the 78 cases infected by other respiratory viruses, no amplification curve was observed using these four COVID-19 RT-PCR kits. The minimum detection limits of kits I-IV were 10-6 , 10-5 , 10-5 , and 10-6 dilutions, respectively, and concentrations were 10 copies/mL (10-5 dilution) and 1 copies/mL (10-6 dilution). The sensitivities of kits I-IV detected using 142 nasopharyngeal swab specimens from COVID-19 patients were 91.55%, 81.69%, 80.28%, and 90.85%, respectively, while they were 92.68%, 85.37%, 82.93%, and 93.90%, respectively, for the 82 sputum samples. The specificity of each kit was 100.00% (77/77). The total expected detection rate using sputum samples was 88.59% (691/780) higher than 86.15% (672/780) of nasopharyngeal swabs. Comparison of nasopharyngeal swab and sputum samples from the same COVID-19 patient led to the detection of ORF1ab and N genes in 16 (100%) sputum samples; only ORF1ab and N genes were detected in 12 (75%) and 14 (87.5%) nasopharyngeal swab specimens, respectively. In conclusion, comparison of commercial COVID-19 RT-PCR kits should be performed before using a new batch of such kits in routine diagnostics.

Molecular Characteristics of Klebsiella pneumoniae Isolates From Outpatients in Sentinel Hospitals, Beijing, China, 2010-2019.

Background:Klebsiella pneumoniae is an opportunistic pathogen associated with community-acquired and nosocomial infections. Since 2010, K. pneumoniae testing has been included into an existing diarrhea-syndrome surveillance system for estimating the prevalence of K. pneumoniae in diarrhea-syndrome patients, assessing antibiotic susceptibility, and investigating molecular characteristics of K. pneumoniae. Methods:Klebsiella pneumoniae strains were isolated from stool specimens from diarrhea-syndrome outpatients in Beijing, China. Isolates were tested for antibiotic susceptibility, and phylogenetic relationships were explored though whole genome sequence analysis. Multi-locus sequence type (MLST) alleles were extracted from the whole genome sequence (WGS) data. A maximum likelihood tree was generated by MEGAX. Genomes were annotated by Prokka; core genes were produced by Roary; a maximum likelihood phylogenetic tree was generated using FastTree. Results: Forty-four K. pnuemoniae strains were isolated from 2010 to July 2019; of these 37 were K. pneumoniae and seven were K. variicola. Antibiotic susceptibility testing showed that all 44 strains were sensitive to gentamicin, imipenem, amikacin, meropenem, kanamycin; 97.73% were sensitive to cefoxitin andlavo-ofloxacin; the highest antibiotic resistance rate was 79.55%, which was to ampicillin. We found three extended-spectrum beta-lactamase (ESBL) producing strains; we identified high-virulence ST types, including ST307 and ST65; and we found that ST23 has been the epidemic clone since 2010. MLST and core genome sequence analysis showed two distinct clusters of 44 K. pnuemoniae; 40 alleles were identified in core genome sequence analysis, while 36 alleles were identified in MLST typing. Conclusions: There is an urgent need for epidemiological and molecular studies to understand the dynamics of antibiotic resistance and virulence gene transmission to guide strategies for K. pneumoniae surveillance. WGS analysis provided high discrimination power and reliable and robust data useful for molecular epidemiology.

[Application, development, and challenges of capillary electrophoresis in disease prevention and control].

Since the advent of commercial instruments in 1989, capillary electrophoresis (CE) has advanced considerably, with improvement in reproducibility and accuracy in many application fields. CE is predominantly used in research on disease prevention and control, and hygienic chemical inspection. The applications of CE range from assessment of inorganic anions and cations in drinking water to that of biological macromolecules, such as nucleic acids, in pathogenic microorganisms. Since the analytical capacity of CE ranges from inorganic ions to cell, it has become an indispensable technique in this field, particularly in public health emergency and epidemic management. Universal non-targeted analyses to detect possible pathogens, and the capability of rapid and accurate testing of large numbers of specimens are required. In the analyses of polymerase chain reaction (PCR) products, nucleic acid sequencing, mutation detection and genotyping, food-borne disease pathogens, and vaccine analyses, CE methods characterized by high through-put and sensitivity are necessary. In the public health sector, CE is essential in the analyses of food (including emergency analyses for food poisoning), cosmetics, and disinfectants. Satisfactory results of the FAPAS (Food Analysis Performance Assessment Scheme) and domestic proficiency tests indicated the accuracy of CE in quantitative analyses. Application of CE in disease prevention and control is challenged by a number of new molecular biological methods, as optimizing CE methods may not be feasible, and results are difficult to interpret. CE methods, including transformation of peaks to identification of pathogens, can be an arduous task. Thus, end-users prefer using commercialized CE systems and reagents in their routine work. Alternatively, CE methods for analysis of small molecules in product analyses, such as food safety, cosmetics and disinfectant testing, is commonly performed. A plethora of studies published within the decade, indicate that CE is still an active research area in hygienic chemical inspection. To a large extent, CE has not been used for routine analysis in the centers for disease control and prevention, accredited laboratories in China, nor regulatory agencies worldwide. This may be due to the lack of practical protocols for the standards, and the misconceptions regarding the ease of use of CE, which could have hindered its widespread application. Although CE is an environmental friendly technique with minimal usage of toxic chemicals, few standard methods of CE exist in agriculture, environmental protection, food, beverage, chemical, and pharmaceutical industries in the United States, Britain, Europe, Japan, India, Brazil, Russia, and China. Since 2002, CE was used in our laboratory to analyze a large variety of samples. We found that once the CE method has been fully verified and described in detail, it was easily standardized. It is not necessary to screen the equivalent chromatographic column, or to use a specific liquid chromatographic (LC) column. This can effectively circumvent the challenge of shifting peak orders caused by different LC column selectivity. Once combined with general, high sensitivity detectors, CE can be used in the detection of bacteria or viruses in food safety, and play a greater role in the field of disease prevention and control. In the present review, applications of CE in nucleic acid detection for viruses and bacteria, analysis of vaccines, routine testing on food, dietary supplements, medical foods, cosmetics and disinfectants, proficiency tests, and emergency analyses of food poisoning were summarized. The applications and challenges of CE in the field of disease control and prevention were analyzed, and development of this technique was prospected.

A swimming pool-associated outbreak of pharyngoconjunctival fever caused by human adenovirus type 4 in Beijing, China.

Patients with swimming pool-acquired human adenovirus (HAdV) infections usually manifest characteristic clinical features that include fever, pharyngitis, and conjunctival inflammation, syndromically referred to as pharyngoconjunctival fever (PCF). HAdV types 3, 4, and 7 are most commonly associated with PCF. This article reports an outbreak of PCF that involved 55 students and staff at a university in Beijing, China. Fifty patients had used the same swimming pool 2 weeks before the onset of symptoms. HAdV type 4 was identified from patient eye and throat swabs and concentrated swimming pool water samples. Partial hexon gene sequences obtained from the water samples were 100% identical to the sequences obtained from the swab samples, which clustered with HAdV-4 within species E. Swimming pool water contaminated with HAdV-4 was the most likely source of infection, although one instance of likely person-to-person transmission was noted.

Adenovirus-associated acute conjunctivitis in Beijing, China, 2011-2013.

BACKGROUND: Human adenovirus (HAdV)-associated acute conjunctivitis is a common infectious disease and causes significant morbidity among residents in Beijing, China. However, little is known about the epidemiology and type distribution of acute adenoviral conjunctivitis in Beijing. METHODS: Acute conjunctivitis surveillance was conducted in 18 hospitals in Beijing from July through October during 2011-2013. HAdVs were detected by PCR from eye swab and types were determined by partial hexon and fiber gene sequencing. Risk factors associated with adenoviral conjunctivitis were analyzed. RESULTS: Of 876 conjunctivitis cases, 349 (39.8%) were HAdV positive. HAdV detection was most common in conjunctivitis patients aged 18-40 years; patients with contact history with a conjunctivitis case; patients with specimen collected on days 4-6 post symptom onset and patients who worked in food service as catering attendants. Fifteen types were identified among adenoviral conjunctivitis cases. Five HAdV types (HAdV-4, - 37, - 53, - 64 and - 8) accounted for 81.1% of all adenoviral conjunctivitis cases. HAdV-37, - 4 and - 53 were the most common types associated with adenoviral conjunctivitis in 2011, 2012 and 2013, respectively. CONCLUSION: Multiple HAdV types were associated with acute conjunctivitis in Beijing. Predominant types associated with adenoviral conjunctivitis circulating in Beijing varied from year to year.

Prevalence and factors associated with different pathogens of acute diarrhea in adults in Beijing, China.

INTRODUCTION: Only a small proportion of patients with diarrhea are diagnosed with laboratory tests in China, and most are diagnosed based on clinical symptoms. Therefore, understanding the prevalence of different diarrheal pathogens and their specific symptoms is important. METHODOLOGY: Data from a prospective study in Beijing of acute diarrhea and the related pathogens were used to study the association between different pathogen groups and the infected patients' characteristics. A total of 355 patients with acute diarrhea, clinically diagnosed with infectious or noninfectious diarrhea by general practitioners (GPs), were recruited from three districts. RESULTS: Different species of diarrheal pathogens were detected in 133 (37.5%) patients. The most prevalent pathogen was calicivirus (42.9%), followed by rotavirus (30.1%), Vibrio parahaemolyticus (13.5%), and Salmonella spp. (10.5%). The detection rates in patients diagnosed with infectious or noninfectious diarrhea by GPs did not differ significantly (c2 = 0.026, p = 0.873). Abdominal pain correlated negatively with viral pathogens, whereas nausea, living in the suburbs, and winter infection correlated positively with viral infection. Abdominal pain and leukocytosis were positively associated with bacterial infections, whereas winter infection correlated negatively with them. CONCLUSION: In this study, we found that the detection rates in patients diagnosed with infectious or noninfectious diarrhea by GPs was the same. We also revealed the improper prescription of antibiotics by GPs based simply on clinical diagnoses. A further analysis of diagnostic accuracy and methods is required to assist GPs in improving their diagnoses when insufficient laboratory tests are available and budgets are limited.

Weight and prognosis for influenza A(H1N1)pdm09 infection during the pandemic period between 2009 and 2011: a systematic review of observational studies with meta-analysis.

BACKGROUND: In 2009, a novel influenza A(H1N1)pdm09 virus was detected and caused influenza pandemic. It is important to identify the risk factors for severe outcomes. However, inconsistent results regarding the effect of obesity were reported in previous studies. METHODS: We conducted a systematic review to assess the association between obesity and poor prognosis for laboratory-confirmed A(H1N1)pdm09 influenza. We searched three English databases and three Chinese databases for relevant studies from April 2009 to October 2015: PubMed, the Cochrane library, Embase, CNKI, CBM, and Wanfang. Two investigators independently identified eligible articles, assessed quality using NOS, and extracted data. We performed meta-analyses and meta-regressions to estimate the association between weight and poor prognosis for influenza A(H1N1)pdm09 infection, when data were available. RESULTS: We identified 22 articles enrolling 25,189 laboratory confirmed patients. The pooled estimates indicated obesity significantly increased the risk of fatal and critical complications of influenza A(H1N1)pdm09 infection (for fatal, OR = 1.81, 95% CI: 1.23-2.65; for critical complications, OR = 1.67, 95% CI: 1.13-2.47). However, we found significant interaction between early antiviral treatment and obesity (ß = -0.28). After adjustment for early antiviral treatment, relationship between obesity and poor outcomes disappeared (OR = 1.14, 95% CI: 0.94-1.39). CONCLUSIONS: The results of the meta-analyses showed obesity significantly increased the risk of death, critical complications, and severe complications for influenza A(H1N1)pdm09 infection, especially among high-quality studies and in Asia region. Importantly, the result from our meta-regression indicated that the conclusion should be interpreted with caution, because early antiviral treatment might be a key confounding factor.

Characterization of Coxsackievirus A6- and Enterovirus 71-Associated Hand Foot and Mouth Disease in Beijing, China, from 2013 to 2015.

BACKGROUND: Etiology surveillance of Hand Foot and Mouth disease (HFMD) in Beijing showed that Coxsackievirus A6 (CVA6) became the major pathogen of HFMD in 2013 and 2015. In order to understand the epidemiological characteristics and clinical manifestations of CVA6-associated HFMD, a comparison study among CVA6-, EV71- (Enterovirus 71), and CVA16- (Coxsackievirus A16) associated HFMD was performed. METHODS: Epidemiological characteristics and clinical manifestations among CVA6-, EV71- and CVA16-associated mild or severe cases were compared from 2013 to 2015. VP1 gene of CVA6 and EV71 from mild cases, severe cases were sequenced, aligned, and compared with strains from 2009 to 2015 in Beijing and strains available in GenBank. Phylogenetic tree was constructed by neighbor-joining method. RESULTS: CVA6 became the predominant causative agent of HFMD and accounted for 35.4 and 36.9% of total positive cases in 2013 and 2015, respectively. From 2013 to 2015, a total of 305 severe cases and 7 fatal cases were reported. CVA6 and EV71 were responsible for 57.5% of the severe cases. Five out six samples from fatal cases were identified as EV71. High fever, onychomadesis, and decrustation were the typical symptoms of CVA6-associated mild HFMD. CVA6-associated severe cases were characterized by high fever with shorter duration and twitch compared with EV71-associated severe cases which were characterized by poor mental condition, abnormal pupil, and vomiting. Poor mental condition, lung wet rales, abnormal pupil, and tachycardia were the most common clinical features of fatal cases. The percentage of lymphocyte in CVA6-associated cases was significantly lower than that of EV71. High percentage of lymphocyte and low percentage of neutrophils were the typical characteristics of fatal cases. VP1 sequences between CVA6- or EV71-associated mild and severe cases were highly homologous. CONCLUSION: CVA6 became one of the major pathogens of HFMD in 2013 and 2015 in Beijing. Epidemiological characteristics, clinical manifestations of CVA6-, EV71- and CVA16-associated cases in this study enriched the definition of HFMD caused by different pathogens and shed light to accurate diagnosis, appropriate treatment and effective prevention of HFMD.

[Infection status of enterovirus 71 and coxsackievirus A16 among children receiving health examination for child care setting entrance in Beijing and their related medical care seeking practice].

OBJECTIVE: To understand the infection status of enterovirus 71 (EV71) and coxsackievirus A16 (Cox A16) among children receiving health examination for child care setting entrance in Beijing and their related medical care seeking practice and provide evidence for the estimation of disease burden caused by hand foot and mouth disease (HFMD). METHODS: Serological survey was conducted in the local children receiving health examination for child care setting entrance. Enzyme-linked immunosorbent assay (ELISA) was conducted to detect anti-EV71 and anti-Cox A16 IgG and IgM. RESULTS: A total of 813 children were surveyed (mean age: 3.5 ± 1.0 year old). The seropositive rate was 61.9% and 4.4% for anti-Cox A16 IgG and IgM. The seropositive rate was 9.3% and 1.1% for anti-EV71 IgG and IgM. No significant difference was observed in sex specific seropositive rate (P > 0.05). However, significant differences were found in seropositive rate among different age groups (P < 0.05). Among the children who were anti-Cox A16 positive, 7.8% had ever had rashes on their hands and feet, mouth or buttocks (HFMD-like rashes). Among the children who were anti-EV71 positive, 10.7% had ever had HFMD-like rashes. For the children who were anti-Cox A16 or anti-EV71 positive, only 7.1% were brought to see doctors by their parents. However, among the seropositive children with rashes, 80.5% were brought to see doctors. CONCLUSION: In the healthy children at the age to go to child care setting in Beijing, most had ever infected with Cox A16. The anti-EV71 positive rate was much lower than the anti-Cox A16 positive rate. It was necessary to strengthen the prevention and control of EV71 infection in child cares settings.

Seroprevalence of Lyme disease and associated risk factors in rural population of Beijing.

A seroepidemiological survey of 801 local residents from 28 villages was conducted to assess the seroprevalence of Lyme disease and to identify the risk factors of becoming seropositive for Lyme disease in the northern suburb of Beijing. Forty-one serum samples were positive for IgG against B burgdorferi and the seroprevalence was 5.1% (41/801), indicating that Lyme disease is endemic in the rural population. In the multivariable analysis, sowing and harvesting in summer (OR, 2.377, 95% CI, 1.233-4.583), weed in the yard (OR, 1.914, 95% CI, 1.003-3.655) were positively associated with Lyme disease, while wearing protective clothes (OR, 0.173, 95% CI, 0.041-0.732) was negatively associated with Lyme disease. People living in the area are easily infected just near the house or in the cropland. They were barely diagnosed and cured. Without clear tick knowledge, the people are at high risk of exposure to tick bite and Lyme disease.

Etiology of acute conjunctivitis due to coxsackievirus A24 variant, human adenovirus, herpes simplex virus, and Chlamydia in Beijing, China.

Acute conjunctivitis is a common disease associated with high morbidity and economic burden. To clarify the etiological characteristics of acute conjunctivitis in Beijing, surveillance of acute conjunctivitis was conducted from July to October during 2007-2012 by collecting eye swabs from patients treated at surveillance hospitals affiliated with a surveillance program of 18 districts Center for Disease Prevention and Control in Beijing. Coxsackievirus A24 variant (CA24v), enterovirus 70 (EV70), human adenovirus (HAdV), herpes simplex virus (HSV), and chlamydia were identified by PCR. Phylogenetic analysis of the VP1 region of CA24v was conducted. Comparisons of proportions and statistical significance were performed using the chi-square test. HAdV was found to be the most prevalent pathogen, followed by CA24v, chlamydia, and HSV. Significant differences in the symptoms of ocular pain, photophobia, and epiphora were identified among the 4 agents. The prevalence of HAdV- and CA24v-mediated conjunctivitis peaked in July or August and September or October, respectively. Nucleotide sequences of the VP1 regions among the isolated CA24v strains shared 92.8%-100% homology. In conclusion, HAdV followed by CA24v, chlamydia, and HSV were the most common causative agents of acute conjunctivitis in Beijing. Comprehensive, continuous surveillance and advanced laboratory techniques are needed for further studies.

A case-control study to identify environmental risk factors for hand, foot, and mouth disease outbreaks in Beijing.

A matched case-control study was conducted in Beijing to identify the relative importance of major environmental risk factors for outbreaks of hand, foot, and mouth disease (HFMD). A case was defined as a kindergarten class with at least 1 HFMD outbreak. As a control, a kindergarten class that did not experience an HFMD outbreak was used. To identify potential transmission factors, the control group was divided into 2 subgroups: a sporadic group and an HFMD-negative group. We collected data for 8 environmental factors and basic information of each class. The correlations between the suspected environmental factors and HFMD outbreaks were analyzed. Thirty outbreak classes, 19 sporadic classes, and 30 HFMD-negative classes were enrolled. Class grade, indoor solar radiation, and ultraviolet (UV) radiation revealed significant differences among the 3 groups. After controlling for other factors, UV radiation (adjusted ß = -0.42) and class grade (adjusted ß = -0.46) as protective factors and temperature (adjusted ß = 0.31) as a risk factor were significantly associated with the attack rate by multiple linear regression analysis. Logistic regression analysis showed that the probability of an HFMD outbreak in the lower grade was 6-fold greater than that in the higher grade (P = 0.0380, odds ratio = 0.157, 95% confidence interval = 0.027-0.903). We identified UV radiation and class grade as protective factors that were associated with the epidemic intensity in Beijing. However, more data is needed to evaluate the relationship between these factors and HFMD outbreaks.

Excretion of enterovirus 71 in persons infected with hand, foot and mouth disease.

BACKGROUND: Hand, foot and mouth disease (HFMD) is a common illness in young children. It also can be seen in adults occasionally. Enterovirus 71 (EV71), a pathogen that causes not only HFMD but also neurological complications and even death, has caused many HFMD outbreaks in China. However, till now the data about the duration of EV71 shedding is very limited. RESULTS: A total of 136 throat swabs and fecal samples were collected from 27 children and 3 adults, which includs 7 close contacts, 9 mild cases and 14 severe cases,. The participants were divided into three groups namely, severe case group, mild case group and close contact group. All the samples were assayed with real-time polymerase chain reaction (PCR). Kruskal-Wallis Test was employed to compare the difference in duration of viral RNA shedding among three groups. The results showed that significant difference in duration of EV71 shedding was found among three groups (P < 0.01). The longest duration of EV71 shedding in fecal samples is 54 days and 30 days in throat swabs. CONCLUSIONS: HFMD is characterized by extended excretion of EV71. Our results suggest that the duration of EV71 shedding is correlated with the severity of the disease. EV71 shedding through feces can persist more than 54 days. Prolonged virus shedding is a potential risk factor of proliferating HFMD epidemic.

[Prevalence of hepatitis B in Chaoyang district, Beijing in 2010].

OBJECTIVE: To study the prevalence of hepatitis B infections and carrier status among general population in Chaoyang district, Beijing in 2010. METHODS: From May to December 2010, 14 491 subjects over 12 months old were selected by multistage random cluster sampling method from residents in Chaoyang district, Beijing. Five millilitre venous blood specimens were collected from these subjects to test hepatitis B virus antigens and antibodies. Status of hepatitis B infections were analyzed in different age, sex and registered permanent residence groups. RESULTS: The overall positive rate of surface antigen (HBsAg) was 2.66% (383/14 410). The lowest rate of 0.56% (9/1603) was found in the 1 to 14 years old group and the 35 to 44 years old group had the highest rate of 4.27% (92/2154). The rate in subjects younger than 24 years old was 1.03% (31/2986). The overall positive rate of surface antibody (anti-HBs) was 40.21% (5798/14 421). The highest positive rate of anti-HBs (80.59%, 407/505) was found in the 1 to 4 years old group. The overall positive rate of core antibody (anti-HBc) was 30.26% (4364/14 424). The overall hepatitis B virus infection rate was 30.32% (4364/14 393). For male and female groups, the positive rates of HBsAg were 2.93% (179/6108) and 2.44% (202/8287) respectively (χ² = 3.32, P > 0.05); anti-HBs were 41.93% (2563/6113) and 38.96% (3231/8293) respectively (χ² = 12.88, P < 0.01); and anti-HBc were 31.39% (1919/6114) and 29.39% (2438/8295) respectively (χ² = 6.65, P = 0.01). For local residents group and mobile population group, the positive rates of HBsAg were 2.46% (283/11 510) and 3.60% (98/2719) respectively (χ² = 11.08, P < 0.01); anti-HBs were 37.11% (4293/11 568) and 53.07% (1445/2723) respectively (χ² = 233.51, P < 0.01); and anti-HBc were 30.83% (3567/11 570), and 28.41% (774/2724) respectively (χ² = 6.08, P < 0.05). CONCLUSION: The positive rate of HBsAg in population younger than 24 years old has reached a relatively low level. The mobile population has significantly higher positive rate of HBsAg than local residents, indicating the need for enhancing prevention and control measures for hepatitis B for the mobile population and local residents over 25 years old.