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Background. Data on risk factors for severe outcomes from 2009 pandemic influenza A (H1N1) virus infection are limited outside of developed countries. Methods. We reviewed medical charts to collect data from patients hospitalized with laboratory-confirmed 2009 H1N1 infection who were identified across China during the period from September 2009 through February 2010, and we analyzed potential risk factors associated with severe illness (defined as illness requiring intensive care unit admission or resulting in death). Results. Among 9966 case patients, the prevalence of chronic medical conditions (33% vs 14%), pregnancy (15% vs 7%), or obesity (19% vs 14%) was significantly higher in those patients with severe illness than it was in those with less severe disease. In multivariable analyses, among nonpregnant case patients aged ⩾2 years, having a chronic medical condition significantly increased the risk of severe outcome among all age groups, and obesity was a risk factor among those <60 years of age. The risk of severe illness among pregnant case patients was significantly higher for those in the second and third trimesters. The risk of severe illness was increased when oseltamivir treatment was initiated ⩾5 days after illness onset (odds ratio, 1.42; 95% confidence interval, 1.20-1.67). For persons <60 years of age, the prevalence of obesity among case patients with severe illness was significantly greater than it was among those without severe illness or among the general population. Conclusions. Risk factors for severe 2009 H1N1 illness in China were similar to those observed in developed countries, but there was a lower prevalence of chronic medical conditions and a lower prevalence of obesity. Obesity was a risk factor among case patients <60 years of age. Early initiation of oseltamivir treatment was most beneficial, and there was an increased risk of severe disease when treatment was started ⩾5 days after illness onset. [ABSTRACT FROM AUTHOR]

Objective To investigate the contextual risk factors for the regional distribution of Japanese encephalitis (JE) in the People’s Republic of China to enhance the prevention and control of JE. Methods A multilevel Poisson regression model was used to analyse the association between the epidemic of JE and its contextual risk factors with an emphasis on the proportion of rice-planting area, the extent of pig rearing and the proportion of rural population. Results The highest risk of JE was observed in the southwestern and the central areas of P.R. China, characterized by high proportions of rice-planting area, rural population and extent of pig rearing. These contextual determinants seem to govern the risk of JE. Conclusion In P.R. China, an effective surveillance system should be established in the high-risk regions of JE; immunization coverage for the prevention of JE should be expanded in rural areas, and mosquito-control efforts should be made to enhance the prevention and control of JE. [ABSTRACT FROM AUTHOR]

The article presents a study investigating the possibility of person-to-person transmission of the H5N1 strain of the influenza A virus between a father and son in China. Clinical and virological data involving the two cases of H5N1 infection and that of the 91 people who had close contact with both cases were collected and analyzed. All contacts tested negative for H5N1 antibodies, while the isolated H5N1 virus from the father and son were genetically identical. Researchers conclude that limited person-to-person transmission of the H5N1 virus probably occurred between the family members.

We investigated potential sources of infection for 6 confirmed influenza A (H5N1) patients who resided in urban areas of People's Republic of China. None had known exposure to sick poultry or poultry that died from illness, but all had visited wet poultry markets before illness. [ABSTRACT FROM AUTHOR]

Background Malaria transmission is strongly determined by the environmental temperature and the environment is rarely constant. Therefore, mosquitoes and parasites are not only exposed to the mean temperature, but also to daily temperature variation. Recently, both theoretical and laboratory work has shown, in addition to mean temperatures, daily fluctuations in temperature can affect essential mosquito and parasite traits that determine malaria transmission intensity. However, so far there is no epidemiological evidence at the population level to this problem. Methods Thirty counties in southwest China were selected, and corresponding weekly malaria cases and weekly meteorological variables were collected from 2004 to 2009. Particularly, maximum, mean and minimum temperatures were collected. The daily temperature fluctuation was measured by the diurnal temperature range (DTR), the difference between the maximum and minimum temperature. The distributed lag non-linear model (MDLNM) was used to study the correlation between weekly malaria incidences and weekly mean temperatures, and the correlation pattern was allowed to vary over different levels of daily temperature fluctuations. Results The overall non-linear patterns for mean temperatures are distinct across different levels of DTR. When under cooler temperature conditions, the larger mean temperature effect on malaria incidences is found in the groups of higher DTR, suggesting that large daily temperature fluctuations act to speed up the malaria incidence in cooler environmental conditions. In contrast, high daily fluctuations under warmer conditions will lead to slow down the mean temperature effect. Furthermore, in the group of highest DTR, 24-25°C or 21- 23°C are detected as the optimal temperature for the malaria transition. Conclusion The environment is rarely constant, and the result highlights the need to consider temperature fluctuations as well as mean temperatures, when trying to understand or predict malaria transmission. This work may be the first epidemiological study confirming that the effect of the mean temperature depends on temperature fluctuations, resulting in relevant evidence at the population level. [ABSTRACT FROM AUTHOR]

Problem In 2003, China's handling of the early stages of the epidemic of severe acute respiratory syndrome (SARS) was heavily criticized and generally considered to be suboptimal. Approach Following the SARS outbreak, China made huge investments to improve surveillance, emergency preparedness and response capacity and strengthen public health institutions. In 2013, the return on these investments was evaluated by investigating China's early response to the emergence of avian influenza A(H7N9) virus in humans. Local setting Clusters of human infection with a novel influenza virus were detected in China--by national surveillance of pneumonia of unknown etiology--on 26 February 2013. Relevant changes On 31 March 2013, China notified the World Health Organization (WHO) of the first recorded human infections with A(H7N9) virus. Poultry markets--which were rapidly identified as a major source of transmission of A(H7N9) to humans--were closed down in the affected areas. Surveillance in humans and poultry was heightened and technical guidelines were quickly updated and disseminated. The health authorities collaborated with WHO in risk assessments and risk communication. New cases were reported promptly and publicly. Lessons learnt The relevant infrastructures, surveillance systems and response capacity need to be strengthened in preparation for future emergencies caused by emerging or existing disease threats. Results of risk assessments and other data should be released promptly and publicly and such release should not jeopardize future publication of the data in scientific journals. Coordination between public health and veterinary services would be stronger during an emergency if these services had already undertaken joint preparedness planning. [ABSTRACT FROM AUTHOR]

Background The association between malaria and meteorological factors is complex due to the lagged and non-linear pattern. Without fully considering these characteristics, existing studies usually concluded inconsistent findings. Investigating the lagged correlation pattern between malaria and climatic variables may improve the understanding of the association and generate possible better prediction models. This is especially beneficial to the south-west China, which is a high-incidence area in China. Methods Thirty counties in south-west China were selected, and corresponding weekly malaria cases and four weekly meteorological variables were collected from 2004 to 2009. The Multilevel Distributed Lag Non-linear Model (MDLNM) was used to study the temporal lagged correlation between weekly malaria and weekly meteorological factors. The counties were divided into two groups, hot and cold weathers, in order to compare the difference under different climatic conditions and improve reliability and generalizability within similar climatic conditions. Results Rainfall was associated with malaria cases in both hot and cold weather counties with a lagged correlation, and the lag range was relatively longer than those of other meteorological factors. Besides, the lag range was longer in hot weather counties compared to cold weather counties. Relative humidity was correlated with malaria cases at early and late lags in hot weather counties. Minimum temperature had a longer lag range and larger correlation coefficients for hot weather counties compared to cold weather counties. Maximum temperature was only associated with malaria cases at early lags. Conclusion Using weekly malaria cases and meteorological information, this work studied the temporal lagged association pattern between malaria cases and meteorological information in southwest China. The results suggest that different meteorological factors show distinct patterns and magnitudes for the lagged correlation, and the patterns will depend on the climatic condition. Existing inconsistent findings for climatic factors' lags could be due to either the invalid assumption of a single fixed lag or the distinct temperature conditions from different study sites. The lag pattern for meteorological factors should be considered in the development of malaria early warning system. [ABSTRACT FROM AUTHOR]

Background: While human cases of highly pathogenic avian influenza A (H5N1) virus infection continue to increase globally, available clinical data on H5N1 cases are limited. We conducted a retrospective study of 26 confirmed human H5N1 cases identified through surveillance in China from October 2005 through April 2008. Methodology/Principal Findings: Data were collected from hospital medical records of H5N1 cases and analyzed. The median age was 29 years (range 6-62) and 58% were female. Many H5N1 cases reported fever (92%) and cough (58%) at illness onset, and had lower respiratory findings of tachypnea and dyspnea at admission. All cases progressed rapidly to bilateral pneumonia. Clinical complications included acute respiratory distress syndrome (ARDS, 81%), cardiac failure (50%), elevated aminotransaminases (43%), and renal dysfunction (17%). Fatal cases had a lower median nadir platelet count (64.5×109 cells/L vs 93.0×109 cells/L, p = 0.02), higher median peak lactic dehydrogenase (LDH) level (1982.5 U/L vs 1230.0 U/L, p = 0.001), higher percentage of ARDS (94% [n = 16] vs 56% [n = 5], p = 0.034) and more frequent cardiac failure (71% [n = 12] vs 11% [n = 1], p = 0.011) than nonfatal cases. A higher proportion of patients who received antiviral drugs survived compared to untreated (67% [8/12] vs 7% [1/14], p = 0.003). Conclusions/Significance: The clinical course of Chinese H5N1 cases is characterized by fever and cough initially, with rapid progression to lower respiratory disease. Decreased platelet count, elevated LDH level, ARDS and cardiac failure were associated with fatal outcomes. Clinical management of H5N1 cases should be standardized in China to include early antiviral treatment for suspected H5N1 cases. [ABSTRACT FROM AUTHOR]

Scrub typhus, a miteborne rickettsiosis, has emerged in many areas globally. We analyzed the incidence and spatial-temporal distribution of scrub typhus in China during 1952-1989 and 2006-2016 using national disease surveillance data. A total of 133,623 cases and 174 deaths were recorded. The average annual incidence was 0.13 cases/100,000 population during 1952-1989; incidence increased sharply from 0.09/100,000 population in 2006 to 1.60/100,000 population in 2016. The disease, historically endemic to southern China, has expanded to all the provinces across both rural and urban areas. We identified 3 distinct seasonal patterns nationwide; infections peaked in summer in the southwest, summer-autumn in the southeast, and autumn in the middle-east. Persons >40 years of age and in nonfarming occupations had a higher risk for death. The changing epidemiology of scrub typhus in China warrants an enhanced disease control and prevention program. [ABSTRACT FROM AUTHOR]

Background: Measles is among the most highly infectious human diseases. By virtue of increasingly effective childhood vaccination, together with targeted supplemental immunization activities (SIAs), health authorities in the People's Republic of China have reduced measles' reproduction number from about 18 to 2.3. Despite substantial residual susceptibility among young adults, more in some locales than others, sustained routine childhood immunization likely would eliminate measles eventually. To support global eradication efforts, as well as expedite morbidity and mortality reductions in China, we evaluated alternative SIAs via mechanistic mathematical modelling.Methods: Our model Chinese population is stratified by immune status (susceptible to measles infection; infected, but not yet infectious; infectious; and recovered or immunized), age (0, 1-4, 5-9, …, 65+ years) and location (31 provinces). Contacts between sub-populations are either empirical or a mixture of preferential and proportionate with respect to age and decline exponentially with distance between locations at age-dependent rates. We estimated initial conditions and most parameters from recent cross-sectional serological surveys, disease surveillance and demographic observations. Then we calculated the reproduction numbers and gradient of the effective number with respect to age- and location-specific immunization rates. We corroborated these analytical results by simulating adolescent and young adult SIAs using a version of our model in which the age-specific contact rates vary seasonally.Results: Whereas the gradient indicates that vaccinating young adults generally is the optimal strategy, simulations indicate that a catch-up campaign among susceptible adolescent schoolchildren would accelerate elimination, with timing dependent on uptake.Conclusions: These results are largely due to indirect effects (i.e. fewer infections than immunized people might otherwise cause), which meta-population models with realistic mixing are uniquely capable of reproducing accurately. [ABSTRACT FROM AUTHOR]

Multiple clusters of human infections with novel avian influenza A(H7N9) virus have occurred since the virus was first identified in spring 2013. However, in many situations it is unclear whether these clusters result from person-to-person transmission or exposure to a common infectious source. We analyzed the possibility of person-to-person transmission in each cluster and developed a framework to assess the likelihood that person-to-person transmission had occurred. We described 21 clusters with 22 infected contact cases that were identified by the Chinese Center for Disease Control and Prevention from March 2013 through June 2015. Based on detailed epidemiological information and the timing of the contact case patients' exposures to infected persons and to poultry during their potential incubation period, we graded the likelihood of person-to-person transmission as probable, possible, or unlikely. We found that person-to-person transmission probably occurred 12 times and possibly occurred 4 times; it was unlikely in 6 clusters. Probable nosocomial transmission is likely to have occurred in 2 clusters. Limited person-to-person transmission is likely to have occurred on multiple occasions since the H7N9 virus was first identified. However, these transmission events represented a small fraction of all identified cases of H7N9 human infection, and sustained person-to-person transmission was not documented. [ABSTRACT FROM AUTHOR]

We compared the characteristics of cases of highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) A(H7N9) virus infections in China. HPAI A(H7N9) case-patients were more likely to have had exposure to sick and dead poultry in rural areas and were hospitalized earlier than were LPAI A(H7N9) case-patients. [ABSTRACT FROM AUTHOR]

China's hepatitis B virus (HBV) prevention policy has been evaluated through nationally representative serologic surveys conducted in 1992 and 2006. We report results of a 2014 serologic survey and reanalysis of the 1992 and 2006 surveys in the context of program policy. The 2014 survey used a 2-stage sample strategy in which townships were selected from 160 longstanding, nationally representative, county-level disease surveillance points, and persons 1-29 years of age were invited to participate. The 2014 sample size was 31,713; the response rate was 83.3%. Compared with the 1992 pre-recombinant vaccine survey, HBV surface antigen prevalence declined 46% by 2006 and by 52% by 2014. Among children <5 years of age, the decline was 97%. China's HBV prevention program, targeted toward interrupting perinatal transmission, has been highly successful and increasingly effective. However, this progress must be sustained for decades to come, and elimination of HBV transmission will require augmented strategies. [ABSTRACT FROM AUTHOR]

Background: When discussing the relationship between meteorological factors and malaria, previous studies mainly focus on the interaction between different climatic factors, while the possible interaction within one particular climatic predictor at different lag periods has been largely neglected. In this study, this issue was investigated by exploring the interaction of lagged rainfalls and its impact on malaria epidemics, which is a typical example of those meteorological variables. Methods: The weekly data of malaria cases and three climatic variables of 30 counties in southwest China from 2004 to 2009 were analysed with the varying coefficient-distributed lag non-linear model. The correlation patterns of the 6th, 9th and 12th week lags would vary over different rainfall levels at the 4th-week lag. Results: The non-linear patterns for rainfall at different rainfall levels are distinct from each other. In the low rainfall level at the 4th week lag, the increasing rainfall may promote the transmission of malaria. However, for the high rainfall level at the 4th week lag, evidence shows that the excessive rainfall decreases the risk of malaria. Conclusion: This study reports for the first time that the interaction effect between lagged rainfalls on malaria exists, and highlights the importance of integrating the interaction between lagged predictors in relevant studies, which could help to better understand and predict malaria transmission. [ABSTRACT FROM AUTHOR]

In mainland China, most avian influenza A(H7N9) cases in the spring of 2013 were reported through the pneumonia of unknown etiology (PUE) surveillance system. To understand the role of possible underreporting and surveillance bias in assessing the epidemiology of subtype H7N9 cases and the effect of live-poultry market closures, we examined all PUE cases reported from 2004 through May 3, 2013. Historically, the PUE system was underused, reporting was inconsistent, and PUE reporting was biased toward A(H7N9)-affected provinces, with sparse data from unaffected provinces; however, we found no evidence that the older ages of persons with A(H7N9) resulted from surveillance bias. The absolute number and the proportion of PUE cases confirmed to be A(H7N9) declined after live-poultry market closures (p<0.001), indicating that market closures might have positively affected outbreak control. In China, PUE surveillance needs to be improved. [ABSTRACT FROM AUTHOR]

Objective To estimate influenza-associated mortality in urban China. Methods Influenza-associated excess mortality for the period 2003-2008 was estimated in three cities in temperate northern China and five cities in the subtropical south of the country. The estimates were derived from models based on negative binomial regressions, vital statistics and the results of weekly influenza virus surveillance. Findings Annual influenza-associated excess mortality, for all causes, was 18.0 (range: 10.9-32.7) deaths per 100 000 population in the northern cities and 11.3 (range: 7.3-17.8) deaths per 100 000 in the southern cities. Excess mortality for respiratory and circulatory disease was 12.4 (range: 7.4-22.2) and 8.8 (range: 5.5-13.6) deaths per 100 000 people in the northern and southern cities, respectively. Most (86%) deaths occurred among people aged ≥ 65 years. Influenza-associated excess mortality was higher in B-virus-dominant seasons than in seasons when A(H3N2) or A(H1N1) predominated, and more than half of all influenza-associated mortality was associated with influenza B virus. Conclusion Between 2003 and 2008, seasonal influenza, particularly that caused by the influenza B virus, was associated with substantial mortality in three cities in the temperate north of China and five cities in the subtropical south of the country. [ABSTRACT FROM AUTHOR]

Background. Glucocorticoids increase the risk of developing critical disease from viral infections. However, primary care practitioners in China use them as antipyretics, potentially exposing hundreds of millions to this risk. Methods. We enrolled all patients with confirmed pandemic influenza A (pH1N1) virus infection aged ⩾3 years with available medical records at 4 Shenyang City hospitals from 20 October to 30 November 2009. A critical patient was any confirmed, hospitalized pH1N1 patient who developed ⩾1 of the following: death, respiratory failure, septic shock, failure or insufficiency of ⩾2 nonpulmonary organs, mechanical ventilation, or ICU admission. In a retrospective cohort study, we evaluated the risk of developing critical illness in relation to early (⩽72 hours of influenza-like illness [ILI] onset) glucocorticoids treatment. Results. Of the 83 hospitalized case-patients, 46% developed critical illness, 17% died, and 37% recovered and were discharged. Critically ill and other patients did not differ by underlying conditions and severity, median temperature at first clinic visit, and other measured risk factors. Of 17 patients who received early glucocorticoid treatment, 71% subsequently developed critical disease compared with 39% of 66 patients who received late (>72 hours) or no glucocorticoid treatment (RRM-H 5 1.8, 95% CI 5 1.2-2.8, after adjusting for 2 summary variables; ie, presence of underlying diseases and presence of underlying risk factors). Proportional hazards modeling showed that use of glucocorticoids tripled the hazard of developing critical disease (hazard ratio [HR] 5 2.9, 95% CI 5 1.3-6.2, after adjusting for the same summary variables). Conclusions. Early use of parenteral glucocorticoids therapy for fever reduction and pneumonia prevention increases the risk for critical disease or death from pH1N1 infection. We recommend that guidelines on glucocorticoid use be established and enforced. [ABSTRACT FROM AUTHOR]

Background: Mainland China experienced pandemic influenza H1N1 (2009) virus (pH1N1) with peak activity during November-December 2009. To understand the geographic extent, risk factors, and attack rate of pH1N1 infection in China we conducted a nationwide serological survey to determine the prevalence of antibodies to pH1N1. Methodology/Principal Findings: Stored serum samples (n = 2,379) collected during 2006-2008 were used to estimate baseline serum reactogenicity to pH1N1. In January 2010, we used a multistage-stratified random sampling method to select 50,111 subjects who met eligibility criteria and collected serum samples and administered a standardized questionnaire. Antibody response to pH1N1 was measured using haemagglutination inhibition (HI) assay and the weighted seroprevalence was calculated using the Taylor series linearization method. Multivariable logistic regression analyses were used to examine risk factors for pH1N1 seropositivity. Baseline seroprevalence of pH1N1 antibody (HI titer ≥40) was 1.2%. The weighted seroprevalence of pH1N1 among the Chinese population was 21.5%(vaccinated: 62.0%; unvaccinated: 17.1%). Among unvaccinated participants, those aged 6-15 years (32.9%) and 16-24 years (30.3%) had higher seroprevalence compared with participants aged 25-59 years (10.7%) and ≥60 years (9.9%, P<0.0001). Children in kindergarten and students had higher odds of seropositivity than children in family care (OR: 1.36 and 2.05, respectively). We estimated that 207.7 million individuals (15.9%) experienced pH1N1 infection in China. Conclusions/Significance: The Chinese population had low pre-existing immunity to pH1N1 and experienced a relatively high attack rate in 2009 of this virus. We recommend routine control measures such as vaccination to reduce transmission and spread of seasonal and pandemic influenza viruses. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Huai et al. (2010) A primary school outbreak of pandemic 2009 influenza A (H1N1) in China. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2010.00150.x. Background We investigated the first known outbreak of pandemic 2009 influenza A (H1N1) at a primary school in China. Objectives To describe epidemiologic findings, identify risk factors associated with 2009 H1N1 illness, and inform national policy including school outbreak control and surveillance strategies. Methods We conducted retrospective case finding by reviewing the school’s absentee log and retrieving medical records. Enhanced surveillance was implemented by requiring physicians to report any influenza-like illness (ILI) cases to public health authorities. A case–control study was conducted to detect potential risk factors for 2009 H1N1 illness. A questionnaire was administered to 50 confirmed cases and 197 age-, gender-, and location-matched controls randomly selected from student and population registries. Results The attack rate was 4% (50/1314), and children from all grades were affected. When compared with controls, confirmed cases were more likely to have been exposed to persons with respiratory illness either in the home or classroom within 7 days of symptom onset (OR, 4·5, 95% CI: 1·9–10·7). No cases reported travel or contact with persons who had traveled outside of the country. Conclusions Findings in this outbreak investigation, including risk of illness associated with contacting persons with respiratory illness, are consistent with those reported by others for seasonal influenza and 2009 H1N1 outbreaks in school. The outbreak confirmed that community-level transmission of 2009 H1N1 virus was occurring in China and helped lead to changes in the national pandemic policy from containment to mitigation. [ABSTRACT FROM AUTHOR]

Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008. [ABSTRACT FROM AUTHOR]

Background The next influenza pandemic will create a surge in demand for health resources in China, with its current population of >1·3 billion persons and under-developed medical care and public health system. However, few pandemic impact data are available for China. Objectives We estimated the effects of a future influenza pandemic in China by examining pandemic scenarios of varying severity and described the time distribution of cases during a first wave. Methods  We used a Monte-Carlo simulation model and death rates, hospitalizations and outpatient visits for 1918- and 1968-like pandemic scenarios and data from the literature or experts’ opinion to estimate four health outcomes: deaths, hospitalizations, outpatient medical visits and clinical illness for which medical care was not sought. For each of the two scenarios we estimated outcomes by week using a normal distribution. Results We estimated that a 1968 scenario in China would result in 460 000–700 000 deaths, 1·94–2·27 million hospitalizations, 111–117 million outpatient visits and 192–197 million illnesses for which medical care was not sought. Fifty-two percent of hospitalizations occurred during the two-peak weeks of the first wave. We estimated that patients at high-risk of influenza complications (10–17% of the population) would account for 61–75% of all deaths. For a 1918 scenario, we estimated that 4·95–6·95 million deaths, 20·8–22·7 million hospitalizations and 101–108 million outpatient visits could occur. Conclusion Even a 1968 pandemic scenario will pose substantial challenges for the medical and public health system in China, and planning to manage these challenges is essential. [ABSTRACT FROM AUTHOR]

Background. In China, 30 human cases of avian influenza A (H5N1) virus infection were identified through July 2008. We conducted a retrospective case-control study to identify risk factors for influenza H5N1 disease in China. Methods. A questionnaire about potential influenza H5N1 exposures was administered to 28 patients with influenza H5N1 and to 134 randomly selected control subjects matched by age, sex, and location or to proxies. Conditional logistic regression analyses were performed. Results. Before their illness, patients living in urban areas had visited wet poultry markets, and patients living in rural areas had exposure to sick or dead backyard poultry. In multivariable analyses, independent risk factors for influenza H5N1 were direct contact with sick or dead poultry (odds ratio [OR], 506.6 [95% confidence interval {CI}, 15.7-16319.6]; P < .001), indirect exposure to sick or dead poultry (OR, 56.9 [95% CI, 4.3-745.6]; P = .002), and visiting a wet poultry market (OR, 15.4 [95% CI, 3.0-80.2]; P = .001). Conclusions. To prevent human influenza H5N1 in China, the level of education about avoiding direct or close exposures to sick or dead poultry should be increased, and interventions to prevent the spread of influenza H5N1 at live poultry markets should be implemented. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the origin and nosocomial transmission of human granulocytic anaplasmosis (HGA) in the Anhui Provence in China. The authors explain that HGA is a tick-borne infectious disease. A laboratory diagnosis to test for serum IgG to A phagocytophium was performed on patients who were suspected of HGA exposure to an index patient. A discussion of the epidemiological investigation is included. Results of the serological and molecular diagnosis are also included. Researchers found HGA in China and likely nosocomial transmission of HGA from direct contact with respiratory secretions or blood. A discussion of the contact investigation and risk factors for the disease are included.

A scarlet fever outbreak caused by Streptococcus pyogenes occurred in China in 2011. To determine the genomic features of the outbreak strains, we deciphered genomes of two strains isolated from the regions with the highest incidence rates. The sequences will provide valuable information for comprehensive study of mechanisms related to this outbreak. [ABSTRACT FROM AUTHOR]