Symptomatic and Asymptomatic SARS-CoV-2 Infection and Follow-up of Neutralizing Antibody Levels.

Objective: To investigate neutralizing antibody levels in symptomatic and asymptomatic patients with coronavirus disease 2019 (COVID-19) at 6 and 10 months after disease onset. Methods: Blood samples were collected at three different time points from 27 asymptomatic individuals and 69 symptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Virus-neutralizing antibody titers against SARS-CoV-2 in both groups were measured and statistically analyzed. Results: The symptomatic and asymptomatic groups had higher neutralizing antibodies at 3 months and 1-2 months post polymerase chain reaction confirmation, respectively. However, neutralizing antibodies in both groups dropped significantly to lower levels at 6 months post-PCR confirmation. Conclusion: Continued monitoring of symptomatic and asymptomatic individuals with COVID-19 is key to controlling the infection.

Coronavirus disease 2019 outbreak in Beijing's Xinfadi Market, China: a modeling study to inform future resurgence response.

BACKGROUND: A local coronavirus disease 2019 (COVID-19) case confirmed on June 11, 2020 triggered an outbreak in Beijing, China after 56 consecutive days without a newly confirmed case. Non-pharmaceutical interventions (NPIs) were used to contain the source in Xinfadi (XFD) market. To rapidly control the outbreak, both traditional and newly introduced NPIs including large-scale management of high-risk populations and expanded severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR-based screening in the general population were conducted in Beijing. We aimed to assess the effectiveness of the response to the COVID-19 outbreak in Beijing's XFD market and inform future response efforts of resurgence across regions. METHODS: A modified susceptible-exposed-infectious-recovered (SEIR) model was developed and applied to evaluate a range of different scenarios from the public health perspective. Two outcomes were measured: magnitude of transmission (i.e., number of cases in the outbreak) and endpoint of transmission (i.e., date of containment). The outcomes of scenario evaluations were presented relative to the reality case (i.e., 368 cases in 34 days) with 95% Confidence Interval (CI). RESULTS: Our results indicated that a 3 to 14 day delay in the identification of XFD as the infection source and initiation of NPIs would have caused a 3 to 28-fold increase in total case number (31-77 day delay in containment). A failure to implement the quarantine scheme employed in the XFD outbreak for defined key population would have caused a fivefold greater number of cases (73 day delay in containment). Similarly, failure to implement the quarantine plan executed in the XFD outbreak for close contacts would have caused twofold greater transmission (44 day delay in containment). Finally, failure to implement expanded nucleic acid screening in the general population would have yielded 1.6-fold greater transmission and a 32 day delay to containment. CONCLUSIONS: This study informs new evidence that in form the selection of NPI to use as countermeasures in response to a COVID-19 outbreak and optimal timing of their implementation. The evidence provided by this study should inform responses to future outbreaks of COVID-19 and future infectious disease outbreak preparedness efforts in China and elsewhere.

Evaluation of the Therapeutic Effect of Bi-Maxillary Osteotomy Using the Stress Distribution on the Temporomandibular Joint When Doing Anterior Teeth Occlusion.

The purpose of this study was to investigate how sagittal split ramus osteotomy (SSRO) and Le Fort 1 osteotomy affected the stress distribution of the temporomandibular joint (TMJ) during an anterior teeth bite using the three-dimensional (3D) finite element (FE) method. Fourteen orthognathic surgery patients were examined with mandibular prognathism, facial asymmetry, and mandibular retraction. They underwent Le Fort 1 osteotomy in conjunction with SSRO. In addition, ten asymptomatic subjects were recruited as the control group. The 3D models of the mandible, disc, and maxilla were reconstructed according to cone-beam computed tomography (CBCT). Contact was used to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. Muscle forces and boundary conditions corresponding to the anterior occlusions were applied on the models. The stresses on the articular disc and condyle in the pre-operative group were significantly higher than normal. The contact stress and minimum principal stress in TMJ for patients with temporomandibular disorder (TMD) were abnormally higher. The peak stresses of the TMJ of the patients under anterior occlusions decreased after bimaxillary osteotomy. No postoperative TMD symptoms were found. Maxillofacial deformity led to excessive stress on the TMJ. Bimaxillary osteotomy can partially improve the stress distributions of the TMJ and relieve the symptoms of TMD.

Outbreak of macrolide-resistant mycoplasma pneumoniae in a primary school in Beijing, China in 2018.

BACKGROUND: On 7th June, 2018, a primary school in Beijing, China notified Shunyi CDC of an outbreak of acute respiratory disease characterized by fever and cough among students and resulting in nine hospitalization cases during the preceding 2 weeks. We started an investigation to identify the etiologic agent, find additional cases, develop and implement control measures. METHODS: We defined probable cases as students, teachers and other staffs in the school developed fever (T ≥ 37.5 °C) with cough or sore throat; or a diagnosis of pneumonia during May 1-June 31, 2018. Confirmed cases were probable cases with Mycoplasma pneumoniae detected in oropharyngeal (OP) swabs by quantitative real-time polymerase chain reaction (qPCR). We searched case by reviewing school absenteeism records and interviewing students, teachers and staff in this school. Oropharyngeal swabs were collected from symptomatic students. Two qPCR) assay, a duplex qPCR assay, and sequencing were performed to determine the pathogen, genotype and macrolide resistance at the gene level, respectively. RESULTS: From May 1st to June 31st, 2018, we identified 55 cases (36 probable and 19 confirmed), of whom 25 (45%) were hospitalized for complications. All cases were students, none of the teachers and other staffs in the school were with similar symptoms. The attack rate (AR) was 3.9% (55/1398) for all students. The cases were mainly male (58%), with an age range of 7-8 years (median: 7 years). 72% (18/25) of inpatients had radiograph findings consistent with pneumonia, and some cases were hospitalized for up to 4 weeks. Pathogen detection results indicated that Mycoplasma pneumonia (M. pneumoniae) P1 type 1 was the causative agent in this outbreak, and the strain harbored one point mutation of A to G at position 2063. CONCLUSIONS: The infections by macrolide-resistant M. pneumoniae are not always mild and pneumonia was common and M. pneumoniae could causes serious complications which require long-term hospitalization. In the future infectious disease prevention and control practice, M. pneumoniae should be paid more attention. It is necessary to establish and improve the pathogen and drug resistance surveillance system in order to prevent and control such mutated strains of M. pneumoniae from causing future outbreaks or epidemics in China.

Astragalosideâ £ against cardiac fibrosis by inhibiting TRPM7 channel.

BACKGROUND: Astragaloside Ⅳ (ASG-Ⅳ, (Fig. 1) is the most active component of Chinese sp. Astragalus membranaceus Bunge (Fabaceae) that has showed antioxidant, antiapoptotic and antiviral activities among others. It is reported to play an important role in cardiac fibrosis (CF), but the mechanism remains unclear. PURPOSE: To investigate the mechanism of ASG-Ⅳ on inhibiting myocardial fibrosis induced by hypoxia. STUDY DESIGN: We studied the relationship between anti-fibrotic effect of ASG-Ⅳ and transient receptor potential cation channel, subfamily M, member 7 (TRPM7) by in vivo and in vitro experiments. METHODS: In vivo, CF was induced by subcutaneous isoproterenol (ISO) for 10 days. Rat hearts were resected for histological experiment and reverse transcription real-time quantitative poly merase chain reaction (RT-qPCR). In vitro, molecular and cellular biology technologies were used to confirm the anti-fibrosis effect underlying mechanism of ASG-Ⅳ. RESULTS: Histological findings and the collagen volume fraction showed that ASG-Ⅳ decreased fibrosis in heart tissues. Hypoxia could stimulate the proliferation and differentiation of cardiac fibroblast which indicated that the degree of fibrosis was increased significantly. Anoxic treatment could also obviously up-regulate the expression of TRPM7 protein and current. ASG-Ⅳ groups showed the opposite results. Knock-down TRPM7 experiment further confirmed the role of TRPM7 channel in hypoxia-induced cardiac fibrosis. CONCLUSION: Our results suggest that the inhibition of hypoxia-induced CF in vivo and in vitro by ASG-IV is associated with reduction of the expression of TRPM7. The moderate inhibition of the TRPM7 channel may be a new strategy for treating cardiac fibrosis.

Lyme Borreliosis-associated Risk Factors in Residents of Beijing Suburbs: a Preliminary Case-control Study.

A population-based case-control study was conducted to evaluate the relative factors in the environments, agricultural works, outdoor activities, and the effectiveness of Lyme borreliosis (LB)- associated personal protective measures in Beijing. Thirty-four cases and 272 controls were personally interviewed by well-trained interviewers. Venous blood samples were taken from each subject. Sowing or harvesting in summer (OR=2.571, 95% CI: 1.109-5.962), living in house with weeding in the yard (OR=2.247, 95% CI: 1.062-4.755), and residence at the plain area (OR=2.630, 95% CI: 1.050-6.588) were the independent relative factors for seropositive LB. Wearing long pants and clothes with cuffs was the only protective behavior against tick bite (OR=0.186, 95% CI: 0.041-0.846). The findings showed that local farmers were easily infected with LB and almost no protective measure was taken against LB infection. Infection with LB was easier in residents of plain regions. Pets raising and outdoor activities were not the risk factors for infection with LB. Further studies are needed to fully understand the risk of infection with LB in China.

[Early detection on the onset of scarlet fever epidemics in Beijing, using the Cumulative Sum].

Based on data related to scarlet fever which was collected from the Disease Surveillance Information Reporting System in Beijing from 2005 to 2011, to explore the efficiency of Cumulative Sum (CUSUM) in detecting the onset of scarlet fever epidemics. Models as C1-MILD (C1), C2-MEDIUM (C2) and C3-ULTRA (C3) were used. Tools for evaluation as Youden's index and detection time were calculated to optimize the parameters and optimal model. Data on 2011 scarlet fever surveillance was used to verify the efficacy of these models. C1 (k = 0.5, H = 2σ), C2 (k = 0.7, H = 2σ), C3 (k = 1.1, H = 2σ) appeared to be the optimal parameters among these models. Youden's index of C1 was 83.0% and detection time being 0.64 weeks, Youden's index of C2 was 85.4% and detection time being 1.27 weeks, Youden's index of C1 was 85.1% and detection time being 1.36 weeks. Among the three early warning detection models, C1 had the highest efficacy. Three models all triggered the signals within 4 weeks after the onset of scarlet fever epidemics. The early warning detection model of CUSUM could be used to detect the onset of scarlet fever epidemics, with good efficacy.

[Analysis on the whole genome of the influenza H1N1 virus of the mild and severe cases in Beijing in 2009].

OBJECTIVE: To explore the characteristics of the whole genome of the influenza H1N1 virus of the mild and severe cases in Beijing. METHODS: A total of 21 samples of throat swabs were collected from surveillance-designated hospitals between June and December in 2009, including 10 severe cases (4 death cases) and 11 mild cases. RNA of the virus were extracted,and the amplified primers of the whole genome were designed.Reverse transcription and PCR were performed to the RNA and then the PCR product was sequenced by software to analyze the evolution of the viral genes and the variation of the amino acids. RESULTS: Compared with the reference vaccine strain A/California/07/2009 (H1N1), the genetic nucleotide homology in the eight segments of the pandemic H1N1 virus in Beijing in 2009 was higher than 99%, without significant variation. Among them,the genetic distance of hemagglutinin (HA), neuraminidase (NA) and nucleoprotein (NP) was comparatively far, separately 0.0050, 0.0040 and 0.0040.The gene of HA, P83S, the gene of NA, N248D, the gene of polymerase (PA), P224S and the gene of NP, V100I and L122Q were found to mutate in all the samples. Genes of HA, NA, NP, PA, PB 2 and nonstructural protein (NS1) in severe cases showed obviously clustered evolution. The mutation of gene S128P and S203T of HA, gene R269R and D547E of PA, gene T588I of PB 2 and gene I123V of NS mainly happened in severe cases, separately counting 6, 9, 6, 7, 9 and 6 cases. The relevance between the mutation happened in S203T of HA, R269K and D547E of PA and the severeness of the cases showed statistical significance (P < 0.05). The mutations of HA gene were mainly on the Ca and Cb antigene domains. No drug resistant mutation was found on NA gene but happened on matrix protein 2 (M2 gene). None of the mutations were found on the virulence related genes. CONCLUSION: A high homology was found between the pandemic H1N1 virus in Beijing in 2009 and the reference vaccine strain A/California/07/2009(H1N1). Mutational sites related with the severe and fatal cases were found, but not the virulence related mutation.

[The genetic features of drug resistance to group A streptococcus and macrolides antibiotics among pediatric patients in Beijing 2012].

OBJECTIVE: To investigate the genetic features of drug resistance to group A streptococcus(GAS) and macrolides antibiotics among pediatric patients in Beijing 2012. METHODS: A total of 199 strains of GAS were collected from 36 hospitals in Beijing between May and July, 2012. All strains were isolated from oropharyngeal swabs. The minimum inhibitory concentrations (MICs) of ten antibiotics (penicillin, ampicillin, erythromycin, clindamycin, tetracycline, levofloxacin, tigecycline, vancomycin, linezolid and streptogramin) were detected by VITEK-2 compact with GPS-67 test kit. The genes encoding macrolides resistance (ermA, ermB and mefA ) were amplified and tested by PCR. The macrolides resistant phenotype of group A streptococcus was detected by double disc test (D-test). RESULTS: Among 199 strains of GAS collected in this study, 101(50.8%) were from suburbs and the other 98(49.2%) were from urban areas. 111(55.8%) strains were collected from scarlet fever patients while the other 88(44.2%) were from oropharyngeal infection cases. All the strains were sensitive to penicillin and ampicillin, and the percentage of resistance to erythromycin, clindamycin and tetracycline were 96.5% (192/199), 95.5% (190/199) and 92.0% (183/199), respectively. All strains were susceptible to levofloxacin, tigecycline, vancomycin, linezolid and streptogramin. The rates of resistance to erythromycin, clindamycin and tetracycline were different in different districts, however, the difference in it between ages and clinical diagnosis did not show statistical significance (P > 0.05) . The detected rate of drug resistance gene ermB was 98.5% (196/199). The gene ermA was only detected out in 5 strains and the gene mefA was not detected out. 199 strains showed A macrolides resistant phenotype cMLS, while the phenotype iMLS was not found in this study. CONCLUSION: This study demonstrates the high level of clindamycin resistance in group A streptococcus collected from children in Beijing, 2012. The macrolides resistance of group A streptococcus was highly prevalent in Beijing, and the dominant phenotype was cMLS mediated by gene ermB.

[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.

[Analysis of status and influence factors of health literacy related to infectious diseases in residents of Beijing].

OBJECTIVE: To assess the status and associated influence factors of health literacy relating to infectious diseases in Beijing. METHODS: A multi-stage stratified sampling method was carried out to select the sample population in Beijing, which were adults aged over 18 years. The questionnaire survey was used to collect the information of adult health literacy relating to infectious diseases, and the answers were scored. Logistic regression model was used to analyze the influence factors of health literacy relating to infectious diseases. RESULTS: The samples were 13 287 people, and the valid questionnaires were 13 001. In the study, 9.9% of the respondents were classified with enough health literacy relating to infectious diseases, and the low level of health literacy was observed among the respondents living in rural area (6.6%), elderly aged over 60 years (6.4%), poor-educated people (0.8%), farmers (4.5%), workers (4.3%), house-holders and people waiting for employment (4.5%). Multiple Logistic analyses indicated that age, educational status, occupation, self-reported health status, and regions (urban or rural area) were the influence factors associated with the level of health literacy. CONCLUSION: The residents living in Beijing were considered to be with low level of health literacy relating to infectious diseases, and more measures should be taken to improve it.

[Exposure to avian influenza virus and the infection status of virus among people breeding or butchering ducks in the suburb of Beijing].

OBJECTIVE: To understand the exposure and the infection status of virus among people engaging in breeding or butchering ducks in the suburb of Beijing. METHODS: People from six districts (Daxing, Fangshan, Huairou, Miyun, Shunyi, Tongzhou) who engaged in breeding or butchering ducks were studied and the status of infecting avian influenza virus was obtained by testing antibody level in serum. Information on demographic characteristics, status of regular exposure and exposure to sick or dead poultry were collected through a self-designed questionnaire. RESULTS: 1741 people were involved in this study in which 313 (18.0%) were workers in duck-breeding enterprise, 562 (32.3%) were workers in duck slaughterhouse, 261 (15.0%) farmers were in individual small-scale duck farms, 605 (34.7%) were farmers raising duck in backyard. Among farmers raising duck in backyard, the percentage of people whose ducks ever contacted with wild birds was higher than the other three groups (66.8%) (P<0.05). Among farmers who bred their ducks in the backyard (35.2%) and those abattoir workers (31.3%), the percentage of people who had contacted ducks but not been vaccinated with avian influenza vaccine was higher than the other two groups (P<0.05). Regarding the status on cleaning and disinfection among the studied farmers who had bred their ducks in the backyard, the percentage of people who had closer contact with ducks would clean the settings more than 4 times per month (8.8%) and disinfected those places more than 12 times per year (27.3%) but still lower than the other three groups (P<0.05). Among those farmers who bred ducks in the backyard, the percentage of people who had ever touched duck with their hands was high (34.4%) (P<0.05). Regarding exposure to sick or dead poultry, higher proportion was found among those who had ever closely contacted sick or dead poultry commercial duck raisers (36.1%) and individuals who raise large amount of ducks (36.0%). 70.8% of the individual duck raisers had never taken any protective measures when closely contacting the sick or dead poultry. Among 1741 samples, 0 were positive to avian influenza virus H5 and H7 subtypes. 12 were positive to H9 subtype (positive rate was 0.7%), in which 10 were farmers raising ducks in backyard (the positive rate of 1.7%). Differences between H9 subtype antibody positive rates difference in 4 population groups were statistically significant (χ2=13.699, P<0.05). CONCLUSION: Farmers who bred their ducks in the backyard had greater risk of contracting the avian influenza. Individual duckers who raise ducks in large scale and the farmers who bred their ducks in the backyard were in lack of protective measures when contacting the sick or dead poultry. Our findings suggested that some intervention measures should be taken to reduce the risk of avian influenza infection.

[Multilocus variable-number tandem-repeat analysis for molecular subtypes of Shigella isolates in Beijing].

OBJECTIVE: Selecting variable-number tandem-repeat (VNTR) loci for different serogroups of Shigella spp to explore and establish multilocus variable-number tandem-repeat analysis (MLVA) method, in order to study the molecular characteristic of the isolated strains. METHODS: Of the Shigella strains found by dysentery surveillance in Beijing from 2001 to 2009, 180 strains were selected for this study, according to the number and serotypes of the surveillant strains, at the ratio of 15%; including 50 strains of Shigella sonnei and 130 strains of Shigella flexneri. After screening the polymorphism of the 18 VNTR loci, 10 VNTR loci (sh1-sh10) were retained and constructed three groups of multi-PCR methods to detect all he 180 strains and analyze MLVA molecular subtypes using capillary segments. RESULTS: A range of 2 to 11 alleles were found on the 10 VNTR loci among the 180 Shigella strains, with a diversity index value between 0.158 and 0.766. The 10 loci showed diversity in different serogroups, such as only one allele found in sh6 of Shigella flexneri, sh2 and sh3 of Shigella sonnei individually. The isolated 180 strains were divided into 84 MLVA subtypes, with a resolution ratio D value at 0.967 (95%CI: 0.956 - 0.978). The 130 strains of Shigella flexneri were divided into 63 subtypes, named as TF001-TF063; among which TF001, TF002 and TF 005 were the dominant subtypes, accounting to 17, 16 and 15 strains respectively. The 50 strains of Shigella sonnei were divided into 21 subtypes, named as TS001-TS021; among which TS002 (14 strains) and TS001 (7 strains) were the dominant subtypes. CONCLUSION: MLVA subtyping method including 10 VNTR loci was preliminarily developed. The MLVA cluster analysis revealed that the subtypes of Shigella strains isolated in Beijing were diverse, and suggested the possibility of multiple-clone source.

[Application of EARS in early-warning of influenza pandemic in Beijing].

OBJECTIVE: To illustrate the efficiency of cumulative sum (CUSUM) in pre-warning of the influenza peak in Beijing. METHODS: CUSUM was used to analyze the data of influenza like illness (ILI), and the results of the influenza laboratory surveillance was regarded as the gold standard to judge the approaching of the influenza peak. RESULTS: The surveillance was launched in 421 hospitals in Beijing during the 2009 to 2010 influenza season, while the influenza laboratory surveillance was launched by 7 collaborative laboratories. From Jun. 2009 to Apr. 2010, the average ILI percentage in the 421 hospitals was 2.56%. In the study, 19 262 pharyngeal swab samples were collected from the ILI cases in 11 hospitals and 5 045 of them were tested positive for the influenza virus, with the novel swine-origin influenza A H1N1 virus dominating. After analyzing of the ILI surveillance data with CUSUM, it was found that the ILI surveillance in Beijing could make a satisfactory early warning for the approaching of the influenza peak referring to the gold standard based on the influenza laboratory results. CONCLUSION: It could give the prediction and early warning for the influenza peak efficiently and precisely, by using CUSUM to analyze the influenza surveillance data of Beijing.

[Study on the index system in evaluating the adult health literacy situation related to infectious disease in Beijing].

OBJECTIVE: To establish and assess a comprehensive index system on adult health literacy which related to infectious disease. METHODS: A multi-stage stratified sampling method was carried out among adults aged over 18 years, in Beijing. A questionnaire survey was used to collect the information on adult health literacy situation related to infectious disease, with answers scored. Degrees of difficulty and difference together with confirmatory factor analysis were used to screen the indications from the questionnaires so as to establish a comprehensive index system. Methods as Cronbach alpha coefficient, split-half reliability, confirmatory factor analysis and cluster analysis methods were used to assess the reliability and validity of the index system. RESULTS: The sample size was 13,287 with valid questionnaires as 13,001. There were 30 indexes selected to establish the comprehensive index system on adult health literacy related to infectious disease. The Cronbach a coefficient was 0.777, and the split-half reliability was 0.609. Data from Confirmatory factor analysis revealed that each of the standardized regression coefficient was significant, and there were significant differences between the groups of being clustered by Q cluster analysis method (P<0.001). 9.9% of the residents were classified as having enough knowledge on health. CONCLUSION: The index system set for adult health literacy that related to infectious disease showed good reliability and validity thus could be used as a good tool to evaluate the levels of health literacy which related to infectious diseases, in Beijing.

[Study on the risk factors of diarrhea-related behaviors among adults in Beijing].

OBJECTIVE: To study the risk behaviors on diarrhea among the adults of Beijing. METHODS: 13 287 adults aged over 18 years in Dongcheng, Xicheng, Haidian, Changping, Huairou and Tongzhou districts in Beijing were selected with a multi-stage stratified sampling method. Information on the demographic characteristics, with or without symptoms on diarrhea in the last year, and behaviors related to diarrhea, were collected through a self-designed questionnaire. RESULTS: The reported total prevalence of diarrhea symptoms in the last year was 17.6% and, in urban areas as 16.8%, in rural areas as 18.2% respectively. The differences on the reported prevalence rates of diarrhea in different age groups, background of education and occupations groups among urban residents were statistically significant (P < 0.05). Items as eating raw seafood or freshwater products, using the same chopping block and knife at the time when processing raw and cooked food, not being used to regular physical exercise etc. were the risk factors to diarrhea among adults from urban areas, with OR (95%CI) as 1.26 (1.07 - 1.48), 1.37 (1.16 - 1.63) and 1.38 (1.20 - 1.59), respectively. The reported diarrhea prevalence rates related to sex, age, education background and occupations among rural residents did not show significant differences (P > 0.05). Without hand-washing habit before eating or after toilet-using, eating raw seafood or freshwater products, using the same chopping block and knife at the time when processing raw and cooked food, not being used to regular physical exercise etc. seemed to be the risk factors on diarrhea among adults in the rural areas with the OR (95%CI) as 1.85 (1.51 - 2.25), 1.39 (1.17 - 1.67), 1.44 (1.24 - 1.67) and 1.46 (1.27 - 1.67), respectively. CONCLUSION: The prevalence reported on diarrhea symptoms among adults from the rural areas was higher than the urban adults. Diarrhea was related to health-related habits, eating habits and regularity of taking physical exercises.

[Etiological detection of severe hand-food-mouth disease and related genetic characteristics of enterovirus type 71 infection in Beijing, 2010].

OBJECTIVE: To study the etiological detection on samples from severe hand-foot-mouth disease (HFMD) cases and the genetic characteristics of enterovirus type 71 (EV71) isolates from severe patients in Beijing, 2010. METHODS: Real-time RT-PCR was used to detect EV71 and Coxsackievirus A16 (CoxA16) and RD cells were used to separate virus strains from samples. Homogeneity of EV71 isolated strains were also analyzed. RESULTS: Four hundred and fourty-two severe cases were detected and 253 were positive, taking up 57.24% of the total (253/442). The overall positive detection rate on EV71 was 54.55% (138/253), with CoxA16 as 5.93% (15/253), and with other enterovirus group was 39.53% (100/253). The nucleotide homogeneity of VP1 within these 12 strains was 97.2% - 100.0%, and with Beijing strains in 2007 - 2010, Shandong strains in 2007 and Anhui Fuyang strains in 2008 and the Guangdong strains in 2008 as 94.0% - 99.9%. CONCLUSION: Severe HFMD cases were most oftenly caused by EV71 but less caused by CoxA16 or other enterovirus. The HFMD in 2010 in Beijing was mainly caused by EV71 subgenotype C4a with 4 transmission chains. Twelve isolated EV71 strains had high homogeneity with strains isolated from severe cases in Anhui Fuyang in 2007.