Comparing risk factors for primary multidrug-resistant tuberculosis and primary drug-susceptible tuberculosis in Jiangsu province, China: a matched-pairs case-control study.

To find out the reason why some people get infected directly with multidrug-resistant tuberculosis (MDR-TB), whereas some get infected with drug-susceptible tuberculosis (DS-TB), a 1:1:1 matched-pairs case-control study was conducted to identify predictors associated with primary MDR-TB and primary DS-TB against the control in Jiangsu Province, China. All three groups were geographically matched (by neighborhood) and matched on sex and age (±5 years). In total, 110 participants were enrolled in each of three matched groups. Conditional logistic regression analysis showed that predictors independently associated with primary MDR-TB were illiteracy or primary school education, annual per capita income ≤ US$2,000, per capita living space < 40 m(2), and interval ≥ 7 days of eating fruits; predictors with primary DS-TB were body mass index ≤ 20 and feeling higher life pressure. This indicates that there are different predictors impacting the transmission range of primary MDR-TB and primary DS-TB in the general population.

[Epidemiology and etiology of hand-foot-and-mouth disease seen in Jiangsu province from 2008 to 2010].

OBJECTIVE: To analyze the etiological and epidemiological characteristics of hand-foot-and-mouth disease (HFMD) seen in Jiangsu province from 2008 to 2010, and provide evidence for its prevention and control. METHODS: Based on the requirement of supervision program of HFMD, surveillance and report were done according to National Disease Supervision Information Management System. Descriptive epidemiological method, performed between 2008 and 2010, was used to analyze the time, region and population distribution and results of etiologic analysis of HFMD. Nucleic acid of enterovirus (EV) genome was detected by real-time RT-PCR. RESULTS: The average incidence rate of HFMD was 86.70 per million between 2008 and 2010, the peak incidence occurred in April to July. There were significant differences among the incidence in different districts (P<0.05), and the highest incidence was seen in the densely inhabited southern areas of Jiangsu province. Most of the cases were infants and children aged less than 5 years. The number of male cases (2008: 17,008, 2009: 48 768, 2010: 50,231) was much larger than that of the female cases 2008: 9662, 2009: 29 151, 2010: 30,655. The HFMD cases with mild symptoms were caused mainly by enterovirus 71 (EV71) and coxsackievirus A16 (Cox A16) and there was difference among different years. The severe HFMD cases and deaths were mainly caused by EV71 infection. CONCLUSIONS: The epidemiologic characteristics of HFMD in Jiangsu province from 2008 to 2010 had close relationship with season, population and region. The mild cases of HFMD were mainly infected with EV71 and Cox A16. However, EV71 illness seemed to be more severe and had significantly greater frequency of serious complications and fatality than the illness caused by Cox A16.

[A viral meningitis outbreak associated with Echo30 in drinking water].

OBJECTIVE: To study the source of infection, the scope of epidemic and control measures in an outbreak involving students having symptoms as fever, dizziness, headache, vomiting and nausea. METHODS: The suspected-case was defined as fever (armpit temperature ≥ 37°C) and with one or more of the following symptoms: dizziness, headache, vomiting and nausea, among students and teachers at school from Mar 1, 2012. Confirmed-case was among suspected case accompanied by both throat and rectal swabs enterovirus positive by RT-PCR. All the cases were collected through checking the medical records from 4 hospitals as well as through the absence records of students and teachers, from Mar 1, 2012. We conducted a case-control study with ratio of 1:2 and data on the exposures to water among students and teachers was collected prior to the illness. 27 cases' throat and rectal swabs were collected and analyzed by RT-PCR and PCR sequence methods. 2 warm-water samples were collected for testing the counts on total bacteria and E. coli. RESULTS: 103 students' cases were identified in school L, with the attack rate as 4.6% (103/2255). Students from Grade three had the high attack rate as 18.1% (72/397) and 77.7% (80/103) of the cases located in the building with 'multiple-functions'. Epidemic curve of the outbreak showed a pattern with continuous common source of infection. It seemed that the exposure to warm-water appeared to be the major risk factor (OR = 18.3, 95%CI: 2.0 - 169.5) together with the intake of un-boiled water (OR = 15.5, 95%CI: 1.7 - 141.8). Specimens from 27 students (81.5%, 22/27) were identified enterovirus positive by RT-PCR, and 7 of the 9 students were confirmed carrying Echo 30. Bacteria and coli were negative from the 2 warm-water samples. CONCLUSION: This viral meningitis-outbreak was caused by Echo 30, with drinking water as the major risk factor.

Attempted early detection of influenza A (H1N1) pandemic with surveillance data of influenza-like illness and unexplained pneumonia.

BACKGROUND: To collect disease information and provide data for early detection of epidemics, two surveillance systems were established for influenza-like illness (ILI) and unexplained pneumonia (UP) in Wuxi, People's Republic of China. OBJECTIVES: The current study aims to describe the performance of these surveillance systems during 2004-2009 and to evaluate the value of surveillance data in detection of influenza epidemics. METHODS: Two national ILI sentinel hospitals and three UP sentinel hospitals provided data to the surveillance systems. The surveillance data from hospital-based outpatient clinics and emergency rooms were compared by year. The ILI data of 2009 were further modeled based on previous data using both a control chart method and a moving average regression method. Alarms of potential epidemics would be raised when the input surveillance data surpassed a threshold. RESULTS: In 2009, the proportions of ILI and respiratory illness with fever (one surveillance syndrome of the UP system) to total patient visits (3·40% and 11·76%, respectively) were higher than the previous years. The surveillance data of both systems also showed developing trends similar to the influenza A (H1N1) pandemic in 2009. When the surveillance data of 2009 were fitted in the two detection models, alarms were produced on the occurrence of the first local case of influenza A (H1N1), outbreaks in schools and in general populations. CONCLUSIONS: The results indicated the potential for using ILI and UP surveillance data as syndromic indicators to detect and provide an early warning for influenza epidemics.

[The application of time series analysis in predicting the influenza incidence and early warning].

OBJECTIVE: This research aimed to explore the application of ARIMA model of time series analysis in predicting influenza incidence and early warning in Jiangsu province and to provide scientific evidence for the prevention and control of influenza epidemic. METHODS: The database was created based on the data collected from monitoring sites in Jiangsu province from October 2005 to February 2010. The ARIMA model was constructed based on the number of weekly influenza-like illness (ILI) cases. Then the achieved ARIMA model was used to predict the number of influenza-like illness cases of March and April in 2010. RESULTS: The ARIMA model of the influenza-like illness cases was (1 + 0.785B(2))(1-B) ln X(t) = (1 + 0.622B(2))ε(t). Here B stands for back shift operator, t stands for time, X(t) stands for the number of weekly ILI cases and ε(t) stands for random error. The residual error with 16 lags was white noise and the Ljung-Box test statistic for the model was 5.087, giving a P-value of 0.995. The model fitted the data well. True values of influenza-like illness cases from March 2010 to April 2010 were within 95%CI of predicted values obtained from present model. CONCLUSION: The ARIMA model fits the trend of influenza-like illness in Jiangsu province.

[Serologic survey on pandemic influenza A (H1N1) virus among aged ≥ 3 years population from Jiangsu province in 2009, China].

OBJECTIVE: To understand the antibody levels against pandemic influenza A (H1N1) virus (2009 H1N1) among aged ≥ 3 years population in 2009, from Jiangsu province, and to describe the distribution of 2009 H1N1. METHODS: Serum specimens were collected from natural populations at four different periods in Jiangsu, and tested with hemagglutination-inhibition (HI) assays. Rates of protective antibody against 2009 H1N1 and Geometric mean titers (GMTs) were estimated. RESULTS: The rates of protective antibody against 2009 H1N1 rose with the progress of epidemics in Jiangsu, which were 3.46%, 7.59%, 16.94%, respectively in July, August and November, 2009. There were no significant differences on the rates of protective antibody between males and females at four different cross-sectional periods (P > 0.05), and no significant differences on GMTs were observed at different periods except for November 2009. Significant differences on rates of protective antibody and GMTs among various age groups were observed at four different periods (P < 0.05), and similar results were observed among different periods in various age groups (P < 0.05). There were significant differences on rates of protective antibody and GMTs among different areas (P < 0.05). CONCLUSION: The 2009 H1N1 strain had been widely spread out in Jiangsu province since July 2009. People aged 12 - 17 years became the major victims after August. As of November 2009, the rate of protective antibody against 2009 H1N1 was still low, predicting that the epidemic might continue to exist for a certain period of time.

[The feasibility of outpatient data used for respiratory syndromic surveillance in general hospital].

OBJECTIVE: To find out the data sources of respiratory syndromes and their components from the outpatients of general hospitals and to describe the time distribution and mutual relations of different respiratory syndromes. Feasibility of respiratory syndromes used for early warning surveillance on respiratory infectious disease was also under research. METHODS: Retrospective investigation on Hospital Information System (HIS) was implemented in a general hospital in Guangzhou, 2005, and data of outpatients was collected and classified into different syndromes. The respiratory syndromes with its time distribution similar to influenza like illness (ILI), were selected, and cross-correlation analyses were conducted to investigate the feasibility of respiratory syndromes for early warning surveillance on respiratory infection diseases (influenza as an example). RESULTS: Primary sub-classification of respiratory syndromes in outpatient department would include upper respiratory infection (URI) (51.20%), trachitis/bronchitis (18.80%), asthma (17.52%), etc. Pulmonary infection accounted for only 2.26%. Time distributions of URI, trachitis/bronchitis, pulmonary infection, cough and asthma in outpatient department, X-ray tests and pneumonia/acute respiratory distress syndromes (ARDSs) in outpatient X-ray room were similar, with two peaks observed. Cross-correlation functions were calculated with the data sets of 1(st) - 28(th) week. The most significant correlation was detected between the time series of outpatient pulmonary infections and ILIs moved 4 weeks backward (r = 0.739, P < 0.01), and that was detected between URIs and ILIs moved 5 weeks backward (r = 0.714, P < 0.01). Correlation between X-ray tests, pneumonia/ARDSs in outpatient X-ray room and ILIs was the strongest when ILIs time series moved 1 week backward (r = 0.858, P < 0.001;r = 0.821, P < 0.001). CONCLUSION: Outpatient data from HIS system in general hospital could be applied to syndromic surveillance on respiratory diseases. For early warning epidemics or outbreaks of influenza or other respiratory infectious diseases, data of outpatient pulmonary infection appeared to be the most feasible for its specificity and timeliness, followed by URI and cough. X-ray tests and pneumonia/ARDSs in outpatient X-ray findings were important supplementary to verify the respiratory disease epidemics or outbreaks for its good specificity, but with no advantage for early warning.

[An outbreak of human Streptococcus suis serotype 2 infections presenting with toxic shock syndrome in Sichuan, China].

OBJECTIVE: In mid-July 2005, five patients presented with septic shock to a hospital in Ziyang city in Sichuan, China, to identify the etiology of the unknown reason disease, an epidemiological, clinical, and laboratory study were conducted. METHODS: An enhanced surveillance program were established in Sichuan, the following activities were introduced: active case finding in Sichuan of (a) laboratory diagnosed Streptococcus suis infection and (b) clinically diagnosed probable cases with exposure history; supplemented by (c) monitoring reports on meningococcal meningitis. Streptococcus suis serotype 2 infection was confirmed by culture and biochemical reactions, followed by sequencing for specific genes for serotype and virulence factors. RESULTS: From June 10 to August 21, 2005, 68 laboratory confirmed cases of human Streptococcus suis infections were reported. All were villagers who gave a history of direct exposure to deceased or sick pigs in their backyards where slaughtering was performed. Twenty six (38%) presented with toxic shock syndrome of which 15 (58%) died. Other presentations were septicaemia or meningitis. All isolates were tested positive for genes for tuf, species-specific 16S rRNA, cps2J, mrp, ef and sly. There were 136 clinically diagnosed probable cases with similar exposure history but incomplete laboratory investigations. CONCLUSION: An outbreak of human Streptococcus suis serotype 2 infections occurred in villagers after direct exposure to deceased or sick pigs in Sichuan. Prohibition of slaughtering in backyards brought the outbreak to a halt. A virulent strain of the bacteria is speculated to be in circulation, and is responsible for the unusual presentation of toxic shock syndrome with high case fatality.

[Anlysis on features of dead cases with human Streptococcus suis infections].

OBJECTIVE: To describe the clinical and epidemiological features of dead cases with human Streptococcus suis infections, and to find the target population for preventing death and the related indicators. METHODS: Epidemiological investigation on human Streptococcus suis infections was implemented used unified questionnaires. Analysis on dead cases and survival cases (as contrast) was done. RESULTS: The population with highest fatality rate was in 40-49 age group. 97.37% of dead cases had toxic shock syndrome. The mean interval from onset to admission was 0.76 days, and the mean course was 2.11 days. The progression among dead cases was faster than that among survival cases. Chief clinical manifestations of dead cases that are more frequent than survival cases are purpura (73.68%), diarrhea (50.0%), dyspnea (21.05%), conjunctival congestion (34.21%), etc. Renal impairment and liver involvement in dead cases were more significant than that in survival cases. No significant difference between mean incubation period, exposure rates of main risk factors in dead cases and in survival cases was found. CONCLUSION: Preventing toxic shock syndrome might reduce the fatality rate. The target population for preventing death is aged > or = 40. Liver function and renal function testing might be indicators for monitoring the progression of human Streptococcus suis infections.

[Matched case-control study for risk factors of human Streptococcus suis infection in Sichuan Province, China].

OBJECTIVE: To study the potential risk factors of human infecting with Streptococcus suis. METHODS: 1: M matched case-control study was conducted. 29 human cases of Streptococcus suis infection in the early phase were included in the case group, Patients' family members, neighbors and peoples who had worked together with patients to handle deceased or sick pigs in the last week were recruited as matched controls. There were 147 controls in total. Both cases and controls received questionnaire investigation including the ways to contact sick/dead pigs. Conditional logistic regression was employed to analyze matching data. RESULTS: According to the results of multivariate analysis, slaughtering (OR = 11.978, 95% CI: 3.355-42.756), carcasses cutting and processing (OR = 3.008, 95% CI: 1.022-8.849) sick/dead pigs were associated with cases related to human Streptococcus suis infection. The attributable risk proportion were 91.65% and 66.76% respectively. The other types of exposures to sick/ dead pigs, including feeding, selling, burying and eating, were not associated with the human Streptococcus suis infection in our study population. CONCLUSION: Slaughtering, carcasses cutting and processing sick/dead pigs were important risky behavior for humans to be infected by Streptococcus suis.

[Surveillance on hemorrhagic fever with renal syndrome in Jiangsu province from 1996 to 2000].

OBJECTIVE: To analyze the incidence rate, animal hosts, and human inapparent infection rate from surveillance data collected in Jiangsu province from 1996 to 2000 and the risk factors of hemorrhagic fever with renal syndrome (HFRS). METHODS: Data on the incidence rate was collected from the whole province to describe the epidemiologic characteristics of HFRS. Data on the density of rats, proportion of rats with virus, index of rats with virus and the human inapparent infection rate were collected in special areas according to the standardised protocol in the project. RESULTS: The incidence rate of HFRS reduced continuously in Jiangsu province, with a 42.17% reduction from 1996 to 2000. The ratio between the incidence rate of autumn-winter peak and spring peak had also reduced. The main host in spring was Rattus norvegicus (with a density of 3.07%), while that in autumn was Apodemus agrarius (with a density of 4.64%). The density of main hosts and mixed species of rats had all reduced during the five years of observation. The proportions of Rattus norvegicus, Apodemus agrarius, Mus musculus with virus were relatively high in spring and autumn. The index of Rattus norvegicus and Mus musculus with virus in spring were 0.025 5 and 0.028 4 respectively, while that of Apodemus agrarius with virus in autumn was 0.030 2. The average human inapparent infection rate was 4.73% in the five years. CONCLUSION: The incidence rate of HFRS in Jiangsu reduced significantly from 1996 to 2000, but the risk factors still widely existed. Suggesting that the surveillance program needs to be carried out steadily in Jiangsu.