Risk factors for death in children with severe hand, foot, and mouth disease in Hunan, China.

BACKGROUND: In recent years, outbreaks of hand, foot, and mouth disease (HFMD) have increased throughout East and Southeast Asia, especially in mainland China. The disease now presents as an increasingly serious public health threat in China. METHODS: A case-control study was designed to examine risk factors associated with death from severe HFMD. A total of 553 severe HFMD cases were collected from the National Surveillance System. RESULTS: Multifactorial logistic regression was used to analyse independent associations between potential influence factors and death from severe HFMD. We found that the migrants were more likely to die from severe HFMD than the resident population (OR = 3.07, 95%CI: 1.39-8.32). Additionally, the children whose first visit was to a village-level clinic had a high risk of death from severe HFMD. Patients with EV71 infection or symptoms of convulsion, dyspnoea, cyanosis, coolness of extremities, and vomiting had an increased risk of death from severe HFMD. While breastfeeding children, having a confirmed diagnosis at the first visit to the hospital and with symptom of hyperarousal were identified as protective factors for death from severe HFMD. CONCLUSIONS: To reduce the mortality from severe HFMD, doctors and health care providers need to pay attention to the patients with EV71 infection or with symptoms of convulsion, dyspnoea, cyanosis, coolness of extremities, and vomiting. Health administration departments should pay more attention to the rational allocation of health resources. Furthermore, they should increase financial support and manpower in village-level health institutions.

[The dose-response relationship of chrysotile asbestos exposure and lung cancer in cohort study].

OBJECTIVE: To clarify the dose-response relationship between asbestos dust exposure and lung cancer incidence in chrysotile asbestos miners by fixed cohort study and to investigate the incidence rates of lung cancer in exposure to different concentrations of asbestos dust. METHODS: A retrospective cohort study was conducted in 1932 asbestos miners who registered from January 1, 1981 to December 31, 1988, had worked for at least 1 year, and had no obvious cardiopulmonary diseases; the cohort study began in July 2009 and covered a time span of 29 years (1981 - 2009). The personal information, occupational history, disease history, and health data of these miners were recorded, and the monitoring data on dust concentrations in the mine over the years were collected. The dose-response relationship between asbestos dust concentration and lung cancer incidence was established by the method of life table; a regression equation was fitted to predict the excess incidence rates of lung cancer under the conditions of different working years and dust concentrations. RESULTS: A significant dose-response relationship was observed between cumulative exposure (Ce) and cumulative probability (Px) of lung cancer incidence, and the smokers hada higher Px than nonsmokers. When Ce was less than 2000 mg/m(3)·each year, Px reached 6.58/10000; when Ce was not less than 2000 mg/m(3)·and less than 3000 mg/m(3)·each year, Px reached 91.72/10000; when Ce was more than 5000 mg/m(3)·each year, Px was as high as 141.02/10000. The three models were fitted to obtain the optimal regression equation: Px = -0.0004Ce(2) + 0.0052Ce - 0.0011 (r(2) = 0.9387). In the workshop of asbestos mine in this study, the average dust concentration was 85 times higher than the limit in 2009, so the excess incidence rate of lung cancer was 112.598/10000 if the miners worked under this condition for 40 years, according to the equation. CONCLUSION: There is a significant dose-response relationship between cumulative asbestos exposure and lung cancer incidence in chrysotile asbestos miners. The risk for lung cancer rises as asbestos exposure increases.

[Characteristics and stability of surveillance data on respiratory syndrome, during the Shanghai World Expo in Pudong New District].

OBJECTIVE: To reveal the characteristics and stability of the system through the analyzing the surveillance data of respiratory-feverous syndrome via the syndromic surveillance system which was established during the Shanghai World Expo in Pudong New District and provide references for the development and operation optimization on this Mass Gatherings Surveillance Systems. METHODS: Data used was from the surveillance data of respiratory-feverous syndrome collected from Pudong New District Syndromic Surveillance System, through May 1 to October 31, 2010. On the basis of description of data characteristics, correlation analyses were conducted, when compared to the surveillance data of respiratory-feverous syndrome and Pudong influenza-like illness (ILI) used as reference. Comparison of variances on the surveillance data and the report lag time of the earlier and later surveillance periods were also carried out to evaluate the quality and stability of data. RESULTS: Reports on the respiratory-feverous syndrome showed a peak in late September with day-of-week effects and holiday effects. Correlation between respiratory-feverous syndrome and ILI was the strongest in the same day (r = 0.596, P < 0.05). In the earlier surveillance period from 2010-05-01 to 2010-07-31, the correlation between respiratory-feverous syndrome and ILI was not obvious (r = -0.058, P > 0.05); however, the two-time series showed consistent trend with the correlation coefficient as 0.798 (P < 0.05), in the later period from 2010-08-01 to 2010-10-31. In addition, variability of the surveillance data on respiratory-feverous syndrome was less in the later period than in the earlier one, with quality of the report on related data better in the later period. Analyses on the correlations of reference sequence, variability and quality of report indicated that the stability of the later surveillance period was better than the earlier one. CONCLUSION: Only with the operation of syndromic surveillance system for a certain period of time, could data in the system maintain stability. Surveillance data showed both day-of-week effects and holiday effects, suggesting that there was a need to choose early warning models with short baseline data.

[Effect of magnitude and duration on the performance of Cumulative Sum].

To explore the effect of magnitude and duration on the performance of Cumulative Sum (CUSUM), with simulation method used on the subject after the insertion of 11 outbreak events into baseline data with Poisson distribution. Sensitivity fluctuated from 9.1% to 100.0% with specificities higher than 98.6%. Sensitivity was significantly correlated with magnitude, and increased along with the increase of magnitude. However, no significant correlation was observed between sensitivity and duration. A magnitude which was at least 2.6 times higher than that of the mean daily baseline could result in the sensitivity of 100.0%. Time-lag would be improved along with the increase of magnitude. Time between onset and detection of an outbreak was no longer than one day when magnitude was more than 1.8 of the mean daily baseline. In summary, the performance of CUSUM was influenced by magnitude, but not by duration. CUSUM had the advantage of good time-lag and high sensitivity when the outbreak magnitude was more than 2.4 time over the baseline data.

Epidemic features affecting the performance of outbreak detection algorithms.

BACKGROUND: Outbreak detection algorithms play an important role in effective automated surveillance. Although many algorithms have been designed to improve the performance of outbreak detection, few published studies have examined how epidemic features of infectious disease impact on the detection performance of algorithms. This study compared the performance of three outbreak detection algorithms stratified by epidemic features of infectious disease and examined the relationship between epidemic features and performance of outbreak detection algorithms. METHODS: Exponentially weighted moving average (EWMA), cumulative sum (CUSUM) and moving percentile method (MPM) algorithms were applied. We inserted simulated outbreaks into notifiable infectious disease data in China Infectious Disease Automated-alert and Response System (CIDARS), and compared the performance of the three algorithms with optimized parameters at a fixed false alarm rate of 5% classified by epidemic features of infectious disease. Multiple linear regression was adopted to analyse the relationship of the algorithms' sensitivity and timeliness with the epidemic features of infectious diseases. RESULTS: The MPM had better detection performance than EWMA and CUSUM through all simulated outbreaks, with or without stratification by epidemic features (incubation period, baseline counts and outbreak magnitude). The epidemic features were associated with both sensitivity and timeliness. Compared with long incubation, short incubation had lower probability (ß* = -0.13, P < 0.001) but needed shorter time to detect outbreaks (ß* = -0.57, P < 0.001). Lower baseline counts were associated with higher probability (ß* = -0.20, P < 0.001) and longer time (ß* = 0.14, P < 0.001). The larger outbreak magnitude was correlated with higher probability (ß* = 0.55, P < 0.001) and shorter time (ß* = -0.23, P < 0.001). CONCLUSIONS: The results of this study suggest that the MPM is a prior algorithm for outbreak detection and differences of epidemic features in detection performance should be considered in automatic surveillance practice.

[Nested case-control study of chrysotile and lung cancer].

OBJECTIVE: To investigate the relationship between simple exposure to chrysotile and lung cancer. METHODS: The nested case-control study method was used. All of lung cancer cases collected from a male fixed prospective cohort with follow-up of 30 years served as cases and a 1:4 matched proportion was used to select non-cancer case as controls. Controls matched for sex age (+/-5 years old), work time (+/-5 years) and smoking were collected in the same cohort. RESULTS: Forty cases died of lung cancer in the study cohort, and the incidence was higher than the average incidence (SMR =1.77). The top four work types of death density were raw material (741.5), combing and spinning (424.3), weaving (365.0), and repairing (285.5), which was consistent with exposed level. According to the exposed level of chrysotile, the research objects were divided into the high level group and the low level group. The result demonstrated that lung cancer incidence of the high exposed level group of chrysotile was higher (OR = 3.7 95% CI 2.30 approximately 8.16), compared with the low exposed level group. CONCLUSION: Simple exposure to chrysotile can increase the risk of lung cancer for workers who are exposed to chrysotile.

[Paired-control study on the effect of vanadium on neurobehavioral functions].

OBJECTIVE: To investigate the change of neurobehavioral functions of workers with long term exposure to vanadium. METHODS: A total of 106 workers with exposure to vanadium were paired with workers without exposure to vanadium. The WHO-NCTB was employed to assess the neurobehavioral functions. RESULTS: The exposure group had lower scores in the domains measuring positive moods and higher scores in the domains measuring negative moods. The exposure group had poorer performance in Santa Ana dexterity, Benton visual retention and pursuit aiming II than the control group. CONCLUSION: Exposure to vanadium can adversely affect neurobehavioral functions of workers. Workers exposed to vanadium may show mood disorders, decreased vision-memory, and declined motor speed and accuracy.

[Behavioral features of men who have sex with men].

OBJECTIVE: This behavioral surveillance survey in Sichuan province was aimed to gain an insight into the behavioral features related to HIV prevalence among men who have sex with men (MSM). METHODS: The pilot survey was initiated in the year from September to December, 2003. Two cities, Chengdu and Nanchong, were selected as the surveillance sites. All behavioral data were collected by a special questionnaire. Convenience sampling and snowball sampling techniques were applied to recruit participants in 5 types of places where MSM appeared more often. RESULTS: Most of the participants sexed only with male partners, and the most common ways of intercourse for MSM were anal sex, mouth sex and masturbation. The cases of multiple sex partners existed generally in MSM. The median partner numbers for anal sex and mouth sex were 4.4 and 4.2 respectively. There were 491 MSM (84.7%) who had sexed with male partners 6 months before, in which 68.6% of them sexed with non-commercial regular male partners, 66.2% with non-commercial non-regular male partners, and 20.4% with commercial male partners. Condom use with different male partners varied significantly. The proportions of consistent condom use with non-commercial regular, non-commercial non-regular, and commercial male partners were 15.8%, 16.3% and 32.3% respectively. 1.9% of participants reported they had had the experience of injecting drug and 18.3% of participants reported they had been tested for HIV antibody 12 months before. CONCLUSION: High risk behaviors such as multiple sex partners, unprotected anal sex, commercial sex, and injecting drug use among the MSM population in the two cities were unveiled broadly.