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Accurate incidence forecasting of infectious disease is critical for early prevention and for better government strategic planning. In this paper, we present a comprehensive study of different forecasting methods based on the monthly incidence of typhoid fever. The seasonal autoregressive integrated moving average (SARIMA) model and three different models inspired by neural networks, namely, back propagation neural networks (BPNN), radial basis function neural networks (RBFNN), and Elman recurrent neural networks (ERNN) were compared. The differences as well as the advantages and disadvantages, among the SARIMA model and the neural networks were summarized and discussed. The data obtained for 2005 to 2009 and for 2010 from the Chinese Center for Disease Control and Prevention were used as modeling and forecasting samples, respectively. The performances were evaluated based on three metrics: mean absolute error (MAE), mean absolute percentage error (MAPE), and mean square error (MSE). The results showed that RBFNN obtained the smallest MAE, MAPE and MSE in both the modeling and forecasting processes. The performances of the four models ranked in descending order were: RBFNN, ERNN, BPNN and the SARIMA model. [ABSTRACT FROM AUTHOR]

Background: syndromic surveillance system has great advantages in promoting the early detection of epidemics and reducing the necessities of disease confirmation, and it is especially effective for surveillance in resource poor settings. However, most current syndromic surveillance systems are established in developed countries, and there are very few reports on the development of an electronic syndromic surveillance system in resource-constrained settings. Objective: this study describes the design and pilot implementation of an electronic surveillance system (ISS) for the early detection of infectious disease epidemics in rural China, complementing the conventional case report surveillance system. Methods: ISS was developed based on an existing platform ‘Crisis Information Sharing Platform’ (CRISP), combining with modern communication and GIS technology. ISS has four interconnected functions: 1) work group and communication group; 2) data source and collection; 3) data visualization; and 4) outbreak detection and alerting. Results: As of Jan. 31st 2012, ISS has been installed and pilot tested for six months in four counties in rural China. 95 health facilities, 14 pharmacies and 24 primary schools participated in the pilot study, entering respectively 74256, 79701, and 2330 daily records into the central database. More than 90% of surveillance units at the study sites are able to send daily information into the system. In the paper, we also presented the pilot data from health facilities in the two counties, which showed the ISS system had the potential to identify the change of disease patterns at the community level. Conclusions: The ISS platform may facilitate the early detection of infectious disease epidemic as it provides near real-time syndromic data collection, interactive visualization, and automated aberration detection. However, several constraints and challenges were encountered during the pilot implementation of ISS in rural China. [ABSTRACT FROM AUTHOR]

Several approaches have been proposed for near real-time detection and prediction of the spread of influenza. These include search query data for influenza-related terms, which has been explored as a tool for augmenting traditional surveillance methods. In this paper, we present a method that uses Internet search query data from Baidu to model and monitor influenza activity in China. The objectives of the study are to present a comprehensive technique for: (i) keyword selection, (ii) keyword filtering, (iii) index composition and (iv) modeling and detection of influenza activity in China. Sequential time-series for the selected composite keyword index is significantly correlated with Chinese influenza case data. In addition, one-month ahead prediction of influenza cases for the first eight months of 2012 has a mean absolute percent error less than 11%. To our knowledge, this is the first study on the use of search query data from Baidu in conjunction with this approach for estimation of influenza activity in China. [ABSTRACT FROM AUTHOR]

Background & Aims: To explore vitamin D status and its dynamic changes during pregnancy in women living in Northeast China. The association between 25-hydroxyvitamin D and serum calcium, phosphate and parathyroid hormone was studied. Because vitamin D deficiency or thyroid dysfunction/autoimmunity during pregnancy may lead to similar adverse events, the relationship between 25-hydroxyvitamin D and thyroid parameters was investigated. Methods: Serum samples of 50 women (aged 22 to 36 years) were selected retrospectively. The samples were collected at gestational 8 weeks ±3 days, 20 weeks ±3 days and 32 weeks ±3 days for measurement of 25-hydroxyvitamin D, calcium, phosphate, parathyroid hormone, and thyroid parameters. Results: The median 25-hydroxyvitamin D levels were 28.29, 39.23 and 40.03 nmol/L, respectively, from the first to the third trimester. The 25-hydroxyvitamin D concentration during the first trimester was significantly lower than the next two trimesters (p<0.01) and was unchanged between the second and the third trimester. Of these women, 96%, 78% and 76% showed 25-hydroxyvitamin D ≤50 nmol/L during each trimester. Season was associated with 25-hydroxyvitamin D during each trimester (p<0.05), and a significant association was found between calcium and 25-hydroxyvitamin D during the first and the second trimesters. Only triiodothyronine was associated with 25-hydroxyvitamin D in the first trimester (p = 0.024), but statistical significance was only a trend (p = 0.063) after excluding abnormal values. No association was observed between 25-hydroxyvitamin D and phosphate, parathyroid hormone, and other thyroid parameters. Conclusions: Vitamin D deficiency during pregnancy was prevalent in women from Northeast China who did not use supplementation. No significant relationships were observed between 25-hydroxyvitamin D and thyroid parameters during pregnancy. [ABSTRACT FROM AUTHOR]

To identify optimal cut-off points of fasting plasma glucose for two-step strategy in screening of undiagnosed diabetes in Chinese people, data were selected from two cross-sectional studies of Metabolic Syndrome in Zhejiang Province of China, Zhejiang Statistical Yearbook (2010), and published literatures. Two-step strategy was used among 17437 subjects sampled from population to screen undiagnosed diabetes. Effectiveness (proportion of cases identified), costs (including medical and non-medical costs), and efficiency (cost per case identified) of these different two-step screening strategies were evaluated. This study found the sensitivities of all the two-step screening strategies with further Oral Glucose Tolerance Test (OGTT) at different Fasting Plasma Glucose (FPG) cut-off points from 5.0 to 7.0 (mmol/L) ranged from 0.66 to 0.91. For the FPG point of 5.0 mmol/L, 91 percent of undiagnosed cases were identified. The total cost of detecting one undiagnosed diabetes case ranged from 547.1 to 1294.5 CNY/case, and the strategy with FPG at cut-off point of 6.1 (mmol/L) resulted in the least cost. Considering both sensitivity and cost of screening diabetes, FPG cut-off point at 5.4 mmol/L was optimized for the two-step strategy. In conclusion, different optimal cut-off points of FPG for two-step strategy in screening of undiagnosed diabetes should be used for different screening purposes. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine whether climate factors correlate with variations in the rate of pediatric intussusception cases presenting to the Children’s Hospital in Suzhou, China. Material and Methods: The hospital records of 5,994 pediatric cases of intussusception who had presented between Aug 2006 and Dec 2011 were retrospectively analyzed. Demographic data and air enema reduction data were collected for each case. Results: The monthly rate of new intussusception cases fluctuated throughout the year generally rising from April to September with a peak from May to July. This annual cycling of intussusception incidence was highly significant over the 5 year observation period. Poisson regression analysis showed that the monthly number of intussusception cases was associated with an increase in mean temperature per month (P = 0.0001), sum of sunshine per month (P<0.0001), precipitation per month (P<0.0001), and was marginally associated with increased mean wind speed per month (P = 0.0709). Conclusion: The incidence of intussusception in Suzhou was seasonally variable with a peak in cases presenting during hotter, sunnier, and wetter months demonstrating a positive association with certain climatic factors. [ABSTRACT FROM AUTHOR]

Background: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. Methods: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. Results: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5–11.0%) for chlamydia, 1.5% (0.7–2.9%) for genital wart, 1.9% (1.3–2.7%) for gonorrhoea, 8.9% (7.8–10.2%) for hepatitis B (HBV), 1.2% (1.0–1.6%) for hepatitis C (HCV), 66.3% (57.4–74.1%) for human papillomavirus (HPV), 10.6% (6.2–17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2–5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4–4.7), 5.7 (2.7–12.3), and 2.2 (1.4–3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. Conclusion: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. Trial Registration: PROSPERO No: CRD42013003721 [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) and HIV are two worldwide public health concerns. Co-infection of these two diseases has been considered to be a major obstacle for the global efforts in reaching the goals for the prevention of HIV and TB. Method: A comprehensive cross-sectional study was conducted to recruit TB patients in three provinces (Guangxi, Henan and Sichuan) of China between April 1 and September 30, 2010. Results: A total of 1,032 consenting TB patients attended this survey during the study period. Among the participants, 3.30% were HIV positive; about one quarter had opportunistic infections. Nearly half of the participants were 50 years or older, the majority were male and about one third were from minority ethnic groups. After adjusting for site, gender and areas of residence (using the partial/selective Model 1), former commercial plasma donors (adjusted OR [aOR] = 33.71) and injecting drug users(aOR = 15.86) were found to have significantly higher risk of being HIV-positivity. In addition, having extramarital sexual relationship (aOR = 307.16), being engaged in commercial sex (aOR = 252.37), suffering from opportunistic infections in the past six months (aOR = 2.79), losing 10% or more of the body weight in the past six months (aOR = 5.90) and having abnormal chest X-ray findings (aOR = 20.40) were all significantly associated with HIV seropositivity (each p<0.05). Conclusions: HIV prevalence among TB patients was high in the study areas of China. To control the dual epidemic, intervention strategies targeting socio-demographic and behavioral factors associated with higher risk of TB-HIV co-infection are urgently called for. [ABSTRACT FROM AUTHOR]

Background: Cadmium (Cd) is a heavy metal that can cause renal tubular dysfunction in humans. Women are among the high-risk group for Cd health effects. Determining the thresholds of Cd-induced renal effects is important. Thus, in this article, we aimed to identify the benchmark dose (BMD) and its low limit (BMDL) levels as the Cd thresholds for Chinese women. Methods: Epidemiologic investigation was performed in county A and county B to obtain data on Cd exposure and its renal effect on respondents. Levels of Cd (UCd), β2-microglobulin (UB2M), and N-acetyl-β-D-glucosaminidase (UNAG) were measured in morning urine samples. The BMD approach was mainly performed. Results: Results of the BMD approach were similar whether the method was conducted for the two sets of data (collected in CA and CB, respectively) separately or cooperatively. The BMD/BMDL values of UCd for all subjects were 1.07/0.44 and 2.12/0.53 µg/g cr based on UB2M and UNAG, respectively, given a predetermined BMR of 0.05. Conclusions: The presented thresholds of Cd-induced renal effects (i.e., the BMDLs of UCd) are close to the counterpart values reported in Japan, Sweden and Belguim. [ABSTRACT FROM AUTHOR]

Background: China's one-child-per-couple policy, introduced in 1979, led to profound demographic changes for nearly a quarter of the world's population. Several decades later, the consequences include decreased fertility rates, population aging, decreased household sizes, changes in family structure, and imbalanced sex ratios. The epidemiology of communicable diseases may have been affected by these changes since the transmission dynamics of infectious diseases depend on demographic characteristics of the population. Of particular interest is influenza because China and Southeast Asia lie at the center of a global transmission network of influenza. Moreover, changes in household structure may affect influenza transmission. Is it possible that the pronounced demographic changes that have occurred in China have affected influenza transmission? Methods and Findings: To address this question, we developed a continuous-time, stochastic, individual-based simulation model for influenza transmission. With this model, we simulated 30 years of influenza transmission and compared influenza transmission rates in populations with and without the one-child policy control. We found that the average annual attack rate is reduced by 6.08% (SD 2.21%) in the presence of the one-child policy compared to a population in which no demographic changes occurred. There was no discernible difference in the secondary attack rate, −0.15% (SD 1.85%), between the populations with and without a one-child policy. We also forecasted influenza transmission over a ten-year time period in a population with a two-child policy under a hypothesis that a two-child-per-couple policy will be carried out in 2015, and found a negligible difference in the average annual attack rate compared to the population with the one-child policy. Conclusions: This study found that the average annual attack rate is slightly lowered in a population with a one-child policy, which may have resulted from a decrease in household size and the proportion of children in the population. [ABSTRACT FROM AUTHOR]

Background: Hepatitis E is caused by two viral genotype groups: human types and zoonotic types. Current understanding of the epidemiology of the zoonotic hepatitis E disease is founded largely on hospital-based studies. Methods: The epidemiology of hepatitis E was investigated in a community-based surveillance study conducted over one year in a rural city in eastern China with a registered population of 400,162. Results: The seroprevalence of hepatitis E in the cohort was 38%. The incidence of hepatitis E was 2.8/10,000 person-years. Totally 93.5% of the infections were attributed to genotype 4 and the rest, to genotype 1. Hepatitis E accounted for 28.4% (102/359) of the acute hepatitis cases and 68.9% (102/148) of the acute viral hepatitis cases in this area of China. The disease occurred sporadically with a higher prevalence during the cold season and in men, with the male-to-female ratio of 3∶1. Additionally, the incidence of hepatitis E increased with age. Hepatitis B virus carriers have an increased risk of contracting hepatitis E than the general population (OR = 2.5, 95%CI 1.5–4.2). Pre-existing immunity to hepatitis E lowered the risk (relative risk  = 0.34, 95% CI 0.21–0.55) and reduced the severity of the disease. Conclusions: Hepatitis E in the rural population of China is essentially that of a zoonosis due to the genotype 4 virus, the epidemiology of which is similar to that due to the other zoonotic genotype 3 virus. [ABSTRACT FROM AUTHOR]

Background: Recent genome-wide association (GWA) studies in Caucasians identified multiple single nucleotide polymorphisms (SNPs) associated with coronary artery disease (CAD). The associations of those SNPs with myocardial infarction (MI) have not been replicated in Asian populations. Among those previously identified SNPs, we selected nine (rs10953541, rs1122608, rs12190287, rs12413409, rs1412444, rs1746048, rs3798220, rs4977574, rs579459, in or near genes 7q22, LDLR, TCF21, CYP17A1, LIPA, CXCL12, LPA, CDKN2A, ABO, respectively) because of the relatively high minor allele frequencies in Chinese individuals and tested the associations of the SNPs with MI and MI related risk factors in Chinese population. Methods and Results: We conducted a case–control association study on a cohort of 2365 MI patients and 2678 unrelated controls from the Chinese population. Genotyping of 9 SNPs were performed by the TaqMan Real Time PCR method. After age, sex, and BMI adjustment, we observed the SNPs rs12190287, rs12413409, rs1412444, rs1746048 and rs4977574, were significantly associated with MI in additive models and rs12190287, rs12413409, rs4977574 were significantly associated with phenotypes of MI at the same time. We also found three SNPs rs1122608, rs3798220 and rs579459 were significantly associated with risk factors of MI, although they had no association with MI in Chinese population. Conclusion: Results of this study indicate that 5 SNPs were associated with MI and 3 SNPs were associated with associated with lipoprotein levels but not with MI in a Chinese population. The present study supports some CAD-related genes in Caucasian as important genes for MI in a Chinese population. [ABSTRACT FROM AUTHOR]

Objectives: Epidemiological data concerning atherosclerotic disease among older people in rural China are sparse. We seek to determine prevalence and cardiovascular risk factor profiles for peripheral artery disease (PAD) and carotid atherosclerosis (CAS) among Chinese older people living in a rural community. Methods: This cross-sectional study included 1499 participants (age ≥60 years, 59.0% women) of the Confucius Hometown Aging Project in Shandong, China. From June 2010–July 2011, data were collected through interviews, clinical examinations, and laboratory tests. PAD was defined as an ankle-brachial index ≤0.9. Carotid intima-media thickness (cIMT) and carotid artery stenosis were assessed by ultrasonography. We defined moderate stenosis as carotid stenosis ≥50%, and severe stenosis as carotid stenosis ≥70%. cIMT≥1.81 mm was considered as an increased cIMT (a measure of CAS). Data were analyzed with multiple logistic models. Results: The prevalence was 5.7% for PAD, 8.9% for moderate stenosis, 1.8% for severe stenosis, and 11.2% for increased cIMT. After controlling for multiple potential confounders, diabetes, an increased low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio, and hypertension were significantly or marginally associated with PAD. Ever smoking, hypertension, and an increased LDL-C/HDL-C ratio were significantly associated with an increased likelihood of increased cIMT. An increasing number of those cardiovascular risk factors were significantly associated with an increasing odds ratio of PAD and increased cIMT, respectively (p for linear trend <0.001). Conclusion: Among Chinese older people living in a rural community, PAD, carotid artery stenosis, and an increased cIMT are relatively uncommon. Cardiovascular risk factor profiles for PAD and CAS are slightly different, with hypertension and an increased LDL-C/HDL-C ratio being associated with an increased likelihood of both PAD and increased cIMT. [ABSTRACT FROM AUTHOR]

Injuries are a growing public health concern in China, accounting for more than 30% of all Person Years of Life Lost (PYLL) due to premature mortality. This study analyzes the trend and disease burden of injury deaths in Chinese population from 2004 to 2010, using data from the National Disease Surveillance Points (DSPs) system, as injury deaths are classified based on the International Classification of Disease-10th Revision (ICD-10). We observed that injury death accounted for nearly 10% of all deaths in China throughout the period 2004–2010, and the injury mortality rates were higher in males than those in females, and higher in rural areas than in urban areas. Traffic crashes (33.79–38.47% of all injury deaths) and suicides (16.20–22.01%) were the two leading causes of injury deaths. Alarmingly, suicide surpassed traffic crashes as the leading cause of injury mortality in rural females, yet adults aged 65 and older suffered the greatest number of fatal falls (20,701 deaths, 2004–2010). The burden of injury among men (72.11%) was about three times more than that of women's (28.89%). This study provides indispensible evidence that China Authority needs to improve the surveillance and deterrence of three major types of injuries: Traffic-related injury deaths should be targeted for injury prevention activities in all population, people aged 65+ should be encouraged to take individual fall precautions, and prevention of suicidal behavior in rural females should be another key priority for the government of China. [ABSTRACT FROM AUTHOR]

Background/Objective: Several studies have described the epidemiological distribution of blaOXA-58-harboring Acinetobacter baumannii in China. However, there is limited data concerning the replicon types of blaOXA-58-carrying plasmids and the genetic context surrounding blaOXA-58 in Acinetobacter spp. in China. Methodology/Principal Findings: Twelve non-duplicated blaOXA-58-harboring Acinetobacter spp. isolates were collected from six hospitals in five different cities between 2005 and 2010. The molecular epidemiology of the isolates was carried out using PFGE and multilocus sequence typing. Carbapenemase-encoding genes and plasmid replicase genes were identified by PCR. The genetic location of blaOXA-58 was analyzed using S1-nuclease method. Plasmid conjugation and electrotransformation were performed to evaluate the transferability of blaOXA-58-harboring plasmids. The genetic structure surrounding blaOXA-58 was determined by cloning experiments. The twelve isolates included two Acinetobacter pittii isolates (belong to one pulsotype), three Acinetobacter nosocomialis isolates (belong to two pulsotypes) and seven Acinetobacter baumannii isolates (belong to two pulsotypes/sequence types). A. baumannii ST91 was found to be a potential multidrug resistant risk clone carrying both blaOXA-58 and blaOXA-23. blaOXA-58 located on plasmids varied from ca. 52 kb to ca. 143 kb. All plasmids can be electrotransformed to A. baumannii recipient, but were untypeable by the current replicon typing scheme. A novel plasmid replicase named repAci10 was identified in blaOXA-58-harboring plasmids of two A. pittii isolates, three A. nosocomialis isolates and two A. baumannii isolates. Four kinds of genetic contexts of blaOXA-58 were identified. The transformants of plasmids with structure of IS6 family insertion sequence (ISOur1, IS1008 or IS15)-ΔISAba3-like element-blaOXA-58 displayed carbapenem nonsusceptible, while others with structure of intact ISAba3-like element-blaOXA-58 were carbapenem susceptible. Conclusion: The study revealed the unique features of blaOXA-58-carrying plasmids in Acinetobacter spp. in China, which were different from that of Acinetobacter spp. found in European countries. The diversity of the genetic contexts of blaOXA-58 contributed to various antibiotics resistance profiles. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of risk reduction interventions on HIV knowledge, attitudes and behaviors among men who have sex with men (MSM) in China. Methods: We performed a systematic review and meta-analysis of HIV risk reduction intervention studies among Chinese MSM. The summary difference of standardized mean differences (SMD) between both study arms or between pre- and post-intervention assessments were defined as the effect size (ES); ES was calculated using standard meta-analysis in random effects models. Results: Thirty-four eligible studies were included in the analysis, including two randomized clinical trials (RCT), six quasi-experimental studies, six pre-and-post intervention studies, and twenty serial cross-sectional intervention studies. These studies showed an increase in consistent condom use with any male sexual partners (mean ES, 0.46; 95% confidence interval [CI], 0.35–0.56), with regular sexual partners (mean ES, 0.41; 95% CI, 0.18–0.63), and casual sexual partners (mean ES, 0.52; 95% CI, 0.24–0.79). The analysis of ten studies that measured the impact on uptake of HIV testing also showed a positive result (mean ES, 0.55; 95% CI, 0.38–0.71). The risk reduction interventions also improved HIV/AIDS-related knowledge (mean ES, 0.77; 95% CI, 0.60–0.94) and attitudes (mean ES, 1.35; 95% CI, 0.91–1.79), but did not reduce prevalence of HIV (mean ES, 0.23; 95% CI, 0.02–0.45) and syphilis infections (mean ES, −0.01; 95% CI, −0.19–0.17). There was significant heterogeneity among these studies. Conclusions: On aggregate, HIV risk reduction interventions were effective in reducing risky behaviors and improving knowledge and attitudes among Chinese MSM, but were not associated with a change in the prevalence of HIV and syphilis. Future studies should use incidence as definitive study outcome. [ABSTRACT FROM AUTHOR]

It is critical to distinguish events that are temporarily associated with, but not caused by, vaccination from those caused by vaccination during mass immunization. We performed a literature search in China National Knowledge Infrastructure and Pubmed databases. The number of coincident events was calculated based on its incidence rate and periods after receipt of a dose of hypothesized vaccine. We included background incidences of Guillain-Barré syndrome, anaphylaxis, seizure, sudden adult death syndrome, sudden cardiac death, spontaneous abortion, and preterm labour or delivery. In a cohort of 10 million individuals, 7.71 cases of Guillain-Barré syndrome would be expected to occur within six weeks of vaccination as coincident background cases. Even for rare events, a large number of events can be expected in a short period because of the large population targeted for immunization. These findings may encourage health authorities to screen the safety of vaccines against unpredictable pathogens. [ABSTRACT FROM AUTHOR]

Objectives: This investigation was undertaken in response to an outbreak of suspected shellfish poisoning in Zhejiang Province, China. The objectives of this project were to confirm the outbreak and to identify the aetiology, source and mode of transmission. Methods: A probable case was defined as an individual with diarrhea (≥3 times/day) plus at least one of the following symptoms: fever (≥37.5°C), vomiting, or abdominal pain after consuming seafood between May 23rd and May 28th, 2011. Using a case-control study design, we compared exposures to suspected seafood items and cooking methods between 61 probable cases and 61 controls. Results: Over 220 suspected or probable cases of diarrhetic shellfish poisoning (DSP) were identified (incidence of 18 cases per 100,000). The case control study revealed that 100% of cases and 18% of controls had eaten mussels during the exposure period (OR = ∞, χ2 = 84.72,P = 0.000). The number of mussels consumed was related to DSP risk (P = 0.004, χ2 test for trend). Consumption of other seafood items was not associated with disease. The frequency of diarrhea and vomiting were positively correlated with the number of mussels consumed (r = 0.424 and r = 0.562, respectively). The frequency of vomiting and the incubation period were significantly correlated with the total time the mussels were boiled (r = 0.594 and r = −0.336, respectively). Mussels from 3 food markets and one family contained Okadaic acid (OA) and Dinophysistoxin-1 (DTX-1). Conclusions: This outbreak was attributed to the consumption of mussels contaminated by DSP-toxins (OA and DTX-1) which are produced by different species of dinoflagellates (toxic microalgae) from the genus Dinophysis or Prorocentrum. Suspension of mussel sales and early public announcements were highly effective in controlling the outbreak, although oversight of seafood quality should be a priority to prevent future contamination and outbreaks. [ABSTRACT FROM AUTHOR]

Background: In the evaluation of a healthcare system, it is of interest to identify factors associated with the usage of different healthcare facilities and with different levels of medical expenditure. Methods: A survey was conducted in January and February of 2012 in China. It focused on the middle-aged and elderly with age of 45 and above. A total of 2,093 people from 1,152 households were surveyed. Results: For inpatient treatment, the probability of using grade III hospitals, which had the highest level of care, was positively associated with age, being married, living in urban areas, and having higher income. For outpatient treatment, the probability of using grade III hospitals was positively associated with age, being married, working in enterprises, living in urban areas, living in central and western regions, and having higher income, and negatively associated with being farmers. The total and out-of-pocket (OOP) medical expenses were analyzed separately. It was found that the expense level was associated with age, education, occupation, living in urban areas, type of hospital used, insurance being used, and per capita income. Conclusion: The access to healthcare and level of medical expenditure were found as associated with demographic characteristics. In addition, differences between areas and regions were observed. Such results may be useful for identifying vulnerable population and for tuning future healthcare development policies. [ABSTRACT FROM AUTHOR]

Background: Improvement of quality of life has been one of goals in health care for people living with HIV/AIDS (PLWHA). In China, the epidemic characteristics have changed and transmission is now most commonly sexual contact. However, the assessment of quality of life of PLWHA under new characteristics has limited reporting. This study was designed to assess the quality of life among PLWHA who contracted disease mainly via sexual contact and to clarify the associated factors. Methods: A cross-sectional study was performed in Liaoning Province. Sample size (800) was calculated based on the fatality rate and enlarged with consideration on the loss of response. Participants were sampled by tables of random numbers among all registered PLWHA. Questionnaires pertaining to quality of life (SF-36) and related factors (demographic characteristics, social support and network, HIV/AIDS awareness, and behavior factors) were distributed during December 2010-April 2011. 783 effective responses were obtained. Results: The average scores of physical component summary (PCS), mental component summary (MCS), and total score (TS) were 66.8±21.9 (Mean±SD), 62.2±20.9, and 64.5±20.2. General linear model analysis revealed that, in standardized estimate (β) sequence, PCS was significantly associated with monthly income, perceived social support, antiretroviral therapy, transmission, and ethnicity; MCS was associated with perceived social support, antiretroviral therapy, condom use, monthly income, transmission, ethnicity, and alcohol consumption; whereas TS was associated with perceived social support, antiretroviral therapy, monthly income, transmission, condom use, and ethnicity. Conclusions: Quality of life for PLWHA who contracted HIV mainly via sexual contact was worse and both physical conditions and social integration were impacted. Under current epidemic characteristics, efforts to increase social support and enhance the implementation of supporting policy are necessary to improve the quality of life of PLWHA. [ABSTRACT FROM AUTHOR]

Few comprehensive studies have investigated viraemia caused by human parvoviruses (HPAVs) in China. A total of 1626 of blood samples were collected from non-HBV and HBV infected Chinese subjects (adults, N = 1279; children, N = 347) from south-western and south-eastern China. DNA from three HPAVs was detected in blood samples using PCR-based assays. The epidemiological profiles and association with HBV co-infection were also analysed. Of the 1626 blood samples tested, 138 (8.49%) were found to exhibit HPAV viraemia, including 3.51% with B19, 3.75% with HBoV and 2.52% with PARV4. The presence of B19 DNA in both child and adult, as well as that of PARV4 DNA in adult,from the south-western region was significantly higher than that from the south-eastern region (P = 0.006 for B19 in children; P = 0.026 for B19 in adults; and P = 0.014 for PARV4 in adult).However, the frequency of HBoV DNA in adults from the south-western region was significantly lower than that observed in adults from the south-eastern region (P = 0.001). Furthermore, HBoV was more prevalence in male (4.9%) than in female (1.4%) individuals. In addition, no significant correlation between HBV and HPAV co-infection was found using serum samples from Chinese adults. In conclusions,the molecular prevalence of three HPAVs in blood samples exhibited variation among different populations depending on area, age and gender; No association between HPAV and HBV infection in adults was found. Our data provide a basis for improving blood safety and preventing HPAV infection in China. [ABSTRACT FROM AUTHOR]

To investigate the risk factors of scrub typhus infection in Beijing, China, a case-control study was carried out. Cases (n = 56) were defined as persons who were diagnosed by PCR and serological method within three years. Three neighborhood control subjects were selected by matching for age and occupation. Living at the edge of the village, living in the houses near grassland, vegetable field or ditch, house yard without cement floor, piling weeds in the house or yard, all of these were risk factors for scrub typhus infection. Working in vegetable fields and hilly areas, and harvesting in autumn posed the highest risks, with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.7 (1.1–11.9), 8.2 (1.4–49.5), and 17.2 (5.1–57.9), respectively. These results would be useful for the establishment of a detail control strategy for scrub typhus infection in Beijing, China. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prevalence and visual acuity (VA) outcomes of cataract surgery in adults of the Bai Nationality populations in rural China. Methods: We conducted a population-based cross-sectional survey (from randomly selected block groups) of Chinese Bai Nationality aged ≥50 years in southwestern China. Presenting visual acuity (PVA), best corrected visual acuity (BCVA) were recorded and a detailed eye examination was carried out. For all aphakic and pseudophakic subjects identified, information on the date, setting, type, and complications of cataract surgery were recorded. In eyes with VA <20/63, the principal cause of visual impairment was identified. Results: Of 2133 (77.8% of 2742) subjects, 99 people (129 eyes) had undergone cataract surgery. The prevalence of cataract surgery was 4.6%. Surgical coverage among those with PVA <20/200 in both eyes because of cataract was 52.8%. Unoperated cataract was associated with older age. The main barrier to cataract surgery was lack of awareness and knowledge, cost, and fear. Among the 129 cataract-operated eyes, 22.5% had PVA of ≥20/32, 25.6% had PVA of 20/40 to 20/63, 23.3% had PVA <20/63 to 20/200, and 28.7% had PVA<20/200. With BCVA, the percentages were 42.6%, 23.3%, 10.9%, and 23.3%, respectively. Aphakia (odds ratio [OR], 8.49; P<0.001) and no education (OR, 10.18; P = 0.001) or less education (OR, 6.49; P = 0.014) were significantly associated with postoperative visual impairment defined by PVA, while aphakia (OR, 8.49; P<0.001) and female gender (OR, 4.19; P = 0.004) were significantly associated with postoperative visual impairment by BCVA. The main causes of postoperative visual impairment were refractive error, retinal disorders and glaucoma. Conclusions: Half of those with bilateral visual impairment or blindness because of cataract remain in need of cataract surgery in Bai population. Surgical uptake and visual outcomes should be further improved in the future. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess whether Chinese men who have sex with men (MSM) had a significantly elevated prevalence of psychiatric disorders compared to urban males in China. Methods: 807 MSM were recruited using a respondent-driven sampling (RDS) method in urban area of northeast China. Psychiatric disorders were assessed employing the Composite International Diagnostic Interview (CIDI. Version 1.0) according to the criteria of the DSM-III-R. Results: Chinese MSM had a significantly elevated standardized prevalence ratios (SPR) for lifetime prevalence of any disorder (SPR = 2.8; 95%CI: 2.5–3.2), mood disorder (SPR = 3.0; 95%CI: 2.3–3.7), anxiety disorder (SPR = 5.5; 95% CI: 4.6–6.5), alcohol use disorder (SPR = 2.4, 95%CI: 2.0–2.8), and combination of disorders (SPR = 4.2; 95%CI: 3.4–5.1). Conclusions: Chinese MSM had significantly elevated prevalence and comorbidity of psychiatric disorders. RDS is a suitable sampling method for psychiatric epidemiological survey in MSM population. [ABSTRACT FROM AUTHOR]

Aims: It is well-established that lipid disorder is an important cardiovascular risk factor, and failure to reach optimal lipid levels significantly contributes to the residual cardiovascular risks. However, limited information is available on the management and the attainment of recommended cholesterol targets in real-world practice in China. Methods and Results: A nationally representative sample of 12,040 patients with dyslipidemia from 19 provinces and 84 hospitals across China were consecutively enrolled in this survey. Risk stratification and individual cholesterol target was established for all participants. This survey identified a high-risk cohort, with over 50% of patients had hypertension, 37.5% had coronary artery disease, and more than 30% had peripheral artery disease. Thirty-nine percent of all participants received lipid lowering medications. And the majority of them (94.5%) had statins (42.5% with atorvastatin, 29.0% with simvastatin, and 15.2% with rosuvastatin). However, the overall attainment for low-density lipoprotein cholesterol (LDL-C) target is low (25.8%), especially, in female (22.2%), and in patients with increased body mass index (BMI) (38.3% for BMI<18.5, 28.1% for BMI 18.5–24.9, 26.0% for BMI 25.0–29.9, and 17.4% for BMI≥30, P<0.0001). Subgroup analysis also showed the attainment is significantly lower in patients who were stratified into high (19.9%) and very high (21.1%) risk category. In logistic regression analysis, eight factors (BMI, gender, coronary artery disease, systolic and diastolic blood pressure, hypertension, family history of premature coronary artery disease and current smoking) were identified as independent predictors of LDL-C attainment. Conclusions: Despite the proven benefits of lipid-lowering therapies, current management of dyslipidemia continues to be unsatisfied. A considerable proportion of patients failed to achieve guideline-recommended targets in China, and this apparent treatment gap was more pronounced among patients with increased BMI, higher risk stratification and women. [ABSTRACT FROM AUTHOR]

Although anaplasmosis cases have been nationally identified in China, no human isolates of A. phagocytophilum have been obtained, which limits the analysis of any molecular and genetic contributions to patients' severe clinical manifestations and the study of the bacteria's pathogeneses in China. Given this situation, a joint project was conducted in 2009–2010. A total of 421 febrile cases of unknown etiology were collected and the patients' blood samples were collected for laboratory diagnoses including serologic diagnosis based on the four-fold rise in the anti- A. phagocytophilum IgG titer by indirect micro-immunofluorescence assay (IFA), positive PCR assay and confirmation of A. phagocytophilum DNA and positive culture of A. phagocytophilum and confirmed by amplification and sequencing of the 16S rRNA and ank A genes of the A. phagocytophilum isolates. A total of 570 ticks were collected from the patients' domestic animals (456) and from wild fields (114) for culturing and amplifying and sequencing the 16S rRNA gene of A. phagocytophilum. Phylogenetic analyses were performed on the 16S rRNA and ank A gene sequences of the isolates and the ticks tested in the study. A total of 46 (10.9%) confirmed and 16 (3.8%) probable cases were diagnosed and severe clinical features and higher mortality rates were observed in these Chinese patients. Five isolates were obtained and the 16S rRNA genes of the 5 isolates were conserved but variety for ank A genes. Two human isolates and 1 tick isolate from Shandong Peninsula, where all patients exhibited severe clinical manifestations, were grouped as one clan based on the phylogenetic analyses, while 2 other human isolates were clustered in a second clan. 43.5% of H. longicornis were infected with A. phagocytophilum.The present study is the first to obtain clinical isolates of A. phagocytophilum in China. The diversity of the ank A genes of Chinese isolates will help us to further discern the relationship between the variations in the ank A genes and the severity of the disease's clinical manifestations in China. [ABSTRACT FROM AUTHOR]

Background: Due to the possible involvement of Glutathione S-transferase Mu-1 (GSTM1) and Glutathione S-transferase theta-1 (GSTT1) in the detoxification of environmental carcinogens, environmental toxins, and oxidative stress products, genetic polymorphisms of these two genes may play important roles in the susceptibility of human being to hepatocellular carcinoma. However, the existing research results are not conclusive. Methods: A systematic literature search using databases (PubMed, Scopus, Embase, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, Wanfang Data, etc.) for the eligible studies meeting the inclusion criteria including case-control studies or cohort studies is evaluated using an updated systematic meta-analysis. Results: Significant increase in the risk of HCC in the Chinese population is found in GSTM1 null genotype (OR = 1.47, 95% CI: 1.21 to 1.79, P<0.001) and GSTT1 null genotype (OR = 1.38, 95% CI: 1.14 to 1.65, P<0.001). Analysis using the random-effects model found an increased risk of HCC in GSTM1-GSTT1 dual null population (OR = 1.79, 95% CI: 1.26 to 2.53, P<0.001). In addition, subgroup analyses showed a significant increase in the association of GST genetic polymorphisms (GSTM1, GSTT1, and GSTM1-GSTT1) with HCC in southeast and central China mainland. However, available data collected by this study fail to show an association between GST genetic polymorphisms and HCC in people from the Taiwan region (for GSTM1: OR = 0.78, 95% CI: 0.60 to 1.01, P = 0.06; for GSTT1: OR = 0.94, 95% CI: 0.78 to 1.14, P = 0.546; for GSTM1-GSTT1: OR = 1.04, 95% CI: 0.81 to 1.32, P = 0.77). Sensitivity analysis and publication bias diagnostics confirmed the reliability and stability of this meta-analysis. Conclusions: Our results indicate that both GSTM1 and GSTT1 null genotypes are associated with an increased HCC risk in Chinese population. Peoples with dual null genotypes of GSTM1-GSTT1 are more susceptible to developing HCC. In conclusion, GST genetic polymorphisms play vital roles in the development of HCC in the Chinese population. [ABSTRACT FROM AUTHOR]

Objective: Hand, foot, and mouth disease (HFMD) has posed a great threat to the health of children and become a public health priority in China. This study aims to investigate the epidemiological characteristics, spatial-temporal patterns, and risk factors of HFMD in Guangdong Province, China, and to provide scientific information for public health responses and interventions. Methods: HFMD surveillance data from May 2008 to December 2011were provided by the Chinese Center for Disease Control and Prevention. We firstly conducted a descriptive analysis to evaluate the epidemic characteristics of HFMD. Then, Kulldorff scan statistic based on a discrete Poisson model was used to detect spatial-temporal clusters. Finally, a spatial paneled model was applied to identify the risk factors. Results: A total of 641,318 HFMD cases were reported in Guangdong Province during the study period (total population incidence: 17.51 per 10,000). Male incidence was higher than female incidence for all age groups, and approximately 90% of the cases were children years old. Spatial-temporal cluster analysis detected four most likely clusters and several secondary clusters (P<0.001) with the maximum cluster size 50% and 20% respectively during 2008–2011. Monthly average temperature, relative humidity, the proportion of population years, male-to-female ratio, and total sunshine were demonstrated to be the risk factors for HFMD. Conclusion: Children years old, especially boys, were more susceptible to HFMD and we should take care of their vulnerability. Provincial capital city Guangzhou and the Pearl River Delta regions had always been the spatial-temporal clusters and future public health planning and resource allocation should be focused on these areas. Furthermore, our findings showed a strong association between HFMD and meteorological factors, which may assist in predicting HFMD incidence. [ABSTRACT FROM AUTHOR]

Background: Many studies have found extreme temperature can increase the risk of mortality. However, it is not clear whether extreme diurnal temperature range (DTR) is associated with daily disease-specific mortality, and how season might modify any association. Objectives: To better understand the acute effect of DTR on mortality and identify whether season is a modifier of the DTR effect. Methods: The distributed lag nonlinear model (DLNM) was applied to assess the non-linear and delayed effects of DTR on deaths (non-accidental mortality (NAD), cardiovascular disease (CVD), respiratory disease (RD) and cerebrovascular disease (CBD)) in the full year, the cold season and the warm season. Results: A non-linear relationship was consistently found between extreme DTR and mortality. Immediate effects of extreme low DTR on all types of mortality were stronger than those of extreme high DTR in the full year. The cumulative effects of extreme DTRs increased with the increment of lag days for all types of mortality in cold season, and they were greater for extreme high DTRs than those of extreme low DTRs. In hot season, the cumulative effects for extreme low DTRs increased with the increment of lag days, but for extreme high DTR they reached maxima at a lag of 13 days for all types of mortality except for CBD(at lag6 days), and then decreased. Conclusions: Our findings suggest that extreme DTR is an independent risk factor of daily mortality, and season is a modifier of the association of DTR with daily mortality. [ABSTRACT FROM AUTHOR]

Background: Influenza A (H1N1)pdm09 (2009 H1N1) re-circulated as the predominant virus from January through February 2011 in China. National surveillance of 2009 H1N1 as a notifiable disease was maintained to monitor potential changes in disease severity from the previous season. Methodology/Principal Findings: To describe the characteristics of hospitalized cases with 2009 H1N1 infection and analyze risk factors for severe illness during the 2010–2011winter season in China, we obtained surveillance data from hospitalized cases with 2009 H1N1 infection from November 2010 through May 2011, and reviewed medical records from 701 hospitalized cases. Age-standardized risk ratios were used to compare the age distribution of patients that were hospitalized and died due to 2009 H1N1 between the 2010–2011winter season to those during the 2009–2010 pandemic period. During the 2010–2011 winter season, children less than 5 years of age had the highest relative risk of hospitalization and death, followed by adults aged 65 years or older. Additionally, the relative risk of hospitalized cases aged 5–14 and 15–24 years was lower compared to children less than 5 years of age. During the winter season of 2010–2011, the proportions of adults aged 25 years or older for hospitalization and death were significantly higher than those during the 2009–2010 pandemic period. Being male, having a chronic medical condition, delayed hospital admission (≥3 days from onset) or delayed initiation of antiviral treatment (≥5 days from onset) were associated with severe illness among non-pregnant patients ≥2 years of age. Conclusions/Significance: We observed a change in high risk groups for hospitalization for 2009 H1N1 during the winter months immediately following the pandemic period compared to the high risk groups identified during the pandemic period. Our nationally notifiable disease surveillance system enabled us to understand the evolving epidemiology of 2009 H1N1 infection after the pandemic period. [ABSTRACT FROM AUTHOR]

The apolipoprotein A5 (APOA5) gene −1131T>C (rs662799) has been suggested to be involved in the pathway of lipid homeostasis and the development of metabolic syndrome (MetS). However, the findings are not consistent. To systematically evaluate the associations between −1131T>C polymorphism and fasting lipid parameters and the risk of MetS, we conducted a case-control study in a Chinese population and a meta-analysis. The findings from 1840 Chinese participants indicated that the C allele carriers had significantly higher fasting total cholesterol (TC), triglycerides (TG) and lower HDL-cholesterol (HDL-C) than the TT homozygotes carriers. The −1131C allele was also found to be significantly associated with increased risk of MetS (OR  =  1.40, 95% confidence interval (CI)  =  1.15, 1.69) compared to the TT homozygotes. In the meta-analysis of 51,868 participants from 46 East Asian studies, 26 European studies and 19 studies of other ethnic groups, the −1131C allele was associated with higher fasting TC (weighted mean difference (WMD)  =  0.08 mmol/L, 95% CI  =  0.05, 0.10, P = 1.74×10−9), TG (WMD  =  0.30 mmol/L, 95% CI  =  0.26, 0.33, P =  1.87×10−55), LDL-cholesterol (LDL-C) (WMD  =  0.04 mmol/L, 95% CI  =  0.02, 0.07, P = 0.002), and lower HDL-C (WMD  =  −0.05 mmol/L, 95% CI  =  −0.06,−0.04, P = 1.88×10−21), respectively. Based on 12 studies with 5,573 MetS cases and 8,290 controls from 5 East Asian studies, 5 European studies and 2 studies of other ethnic groups, the −1131C allele was associated with increased risk of MetS with an OR (95% CI)  =  1.33 (1.16, 1.53) in the overall population, 1.43 (1.29, 1.58) in East Asian and 1.30 (0.94, 1.78) in European populations. In conclusion, the −1131C allele may be associated with elevated levels of fasting TG, TC, LDL-C and decreased HDL-C, and increased risk of MetS, especially in East Asians. [ABSTRACT FROM AUTHOR]