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In this study, we investigated the associations between cadmium (Cd) and lead (Pb) co-exposure, and serum ion levels in two populations living near a mining/smelting area and a nature reserve (control area), respectively. A total of 445 participants were included in this study. Their blood cadmium (BCd), blood lead (BPb), and serum ion levels were determined, and the association between exposure levels and serum ion levels was analyzed. The exposure levels of subjects living in the polluted area were significantly higher (p

Previous research suggests that heavy metals may be associated with increased susceptibility to

Chronic exposure to environmental cadmium (Cd) and lead (Pb) may have adverse effects on the human health. In this study, we aimed to determine the primary and interactive effects of Cd and Pb exposure on liver function in residents near a mining and smelting area in northwestern China. A total of 451 subjects were recruited, from which blood samples were collected to determine the levels of Cd, Pb, and liver function indices. Additionally, the association between the levels of exposure markers and liver function indices was analysed. Cd and Pb levels were significantly higher in subjects living in the polluted area than in those living in the non-polluted reference area. The liver function levels of subjects in the polluted area were poor compared with those in the reference area. In addition, Cd and Pb levels in the blood were positively associated with gamma glutamyl transpeptidase (GGT) levels and negatively associated with direct bilirubin (DBil) levels. Cd and Pb may be risk factors for abnormal liver function. The risk of abnormal liver function was higher in subjects with moderate Cd and Pb levels, high Cd levels, high Pb levels, and high Cd and Pb levels than in those with low Cd and Pb levels. Our data show that exposure to Cd and/or Pb can cause abnormal liver function. Cd and Pb may have an antagonistic effect on liver function, and high Cd exposure alone has a more profound effect on abnormal liver function compared with co-exposure to Pb and Cd.

Exposure to both cadmium (Cd) and lead (Pb) can promote systemic inflammation. However, the effects of combined exposure to environmental levels of Cd and Pb on systemic immune inflammation have not been fully clarified. A total of 486 subjects (313 women and 173 men) living in either a control area or heavy metal-polluted area were included. Blood Cd and Pb and immune inflammation biomarkers were determined, including the eosinophil-lymphocyte ratio (ELR), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), and systemic immune-inflammation index (SII); moreover, the associations between exposure markers and systemic inflammation markers were analysed. The exposure levels in the polluted area were significantly higher than those in the control area. The NLR, PLR, and SII of subjects in the polluted area were higher and the LMR was lower than in the control area. Blood Pb and Cd levels are associated with elevated or decreased immune inflammation biomarkers in subjects from the exposed and control areas. Furthermore, co-exposure to both Cd and Pb was divided into high, middle, and low exposure groups. The subjects in the high co-exposure group displayed higher levels of ELR, NLR, and SII compared with the middle and low co-exposure group, and LMR levels displayed the opposite trend. Our data demonstrate that Cd and Pb co-exposure is associated with systemic immune inflammation, and the immune inflammatory response is aggravated with an increased co-exposure to Cd and Pb.

SUMMARYDiarrhea is a common cause of morbidity and mortality and the incidence of diarrhea in the world has changed little over the past four decades. To assess the prevalence of and healthcare practices for diarrhea, a cross-sectional study was conducted in Pudong, Shanghai, China. In October 2014, a total of 5324 community residents were interviewed. Respondents were asked if they had experienced diarrhea (defined as ⩾3 passages of watery, loose, bloody, or mucoid stools within a 24-h period) in the previous month prior to the interview. The monthly prevalence of diarrhea was 4·1% (95% CI: 3·3–4·8), corresponding to an incidence rate of 0·54 episodes per person-year. The proportion of individuals with diarrhea who sought healthcare was 21·2% (95% CI: 13·4–29·0). Diarrhea continues to impose a considerable burden on the community and healthcare system in Pudong. Young age and travel were identified as predictors of increased diarrhea occurrence.

Appropriate surveillance and early warning of infectious diseases have very useful roles in disease control and prevention. In 2004, China established the National Notifiable Infectious Disease Surveillance System and the Public Health Emergency Event Surveillance System to report disease surveillance and events on the basis of data sources from the National Notifiable Infectious Disease Surveillance System, China Infectious Disease Automated-alert and Response System in this country. This study provided a descriptive summary and a data analysis, from 2012 to 2014, of these 3 key surveillance and early warning systems of infectious disease in China with the intent to provide suggestions for system improvement and perfection.

BACKGROUND: Characterisation of the severity profile of human infections with influenza viruses of animal origin is a part of pandemic risk assessment, and an important part of the assessment of disease epidemiology. Our objective was to assess the clinical severity of human infections with avian influenza A H7N9 virus, which emerged in China in early 2013. METHODS: We obtained information about laboratory-confirmed cases of avian influenza A H7N9 virus infection reported as of May 28, 2013, from an integrated database built by the Chinese Center for Disease Control and Prevention. We estimated the risk of fatality, mechanical ventilation, and admission to the intensive care unit for patients who required hospital admission for medical reasons. We also used information about laboratory-confirmed cases detected through sentinel influenza-like illness surveillance to estimate the symptomatic case fatality risk. FINDINGS: Of 123 patients with laboratory-confirmed avian influenza A H7N9 virus infection who were admitted to hospital, 37 (30%) had died and 69 (56%) had recovered by May 28, 2013. After we accounted for incomplete data for 17 patients who were still in hospital, we estimated the fatality risk for all ages to be 36% (95% CI 26-45) on admission to hospital. Risks of mechanical ventilation or fatality (69%, 95% CI 60-77) and of admission to an intensive care unit, mechanical ventilation, or fatality (83%, 76-90) were high. With assumptions about coverage of the sentinel surveillance network and health-care-seeking behaviour for patients with influenza-like illness associated with influenza A H7N9 virus infection, and pro-rata extrapolation, we estimated that the symptomatic case fatality risk could be between 160 (63-460) and 2800 (1000-9400) per 100,000 symptomatic cases. INTERPRETATION: Human infections with avian influenza A H7N9 virus seem to be less serious than has been previously reported. Many mild cases might already have occurred. Continued vigilance and sustained intensive control efforts are needed to minimise the risk of human infection. FUNDING: Chinese Ministry of Science and Technology; Research Fund for the Control of Infectious Disease; Hong Kong University Grants Committee; China-US Collaborative Program on Emerging and Re-emerging Infectious Diseases; Harvard Center for Communicable Disease Dynamics; US National Institute of Allergy and Infectious Disease; and the US National Institutes of Health., link_to_subscribed_fulltext

Background Syndromic surveillance has been widely used for the early warning of infectious disease outbreaks, especially in mass gatherings, but the collection of electronic data on symptoms in hospitals is one of the fundamental challenges that must be overcome during operating a syndromic surveillance system. The objective of our study is to describe and evaluate the implementation of a symptom-clicking-module (SCM) as a part of the enhanced hospital-based syndromic surveillance during the 41st World Exposition in Shanghai, China, 2010. Methods The SCM, including 25 targeted symptoms, was embedded in the sentinels’ Hospital Information Systems (HIS). The clinicians used SCM to record these information of all the visiting patients, and data were collated and transmitted automatically in daily batches. The symptoms were categorized into seven targeted syndromes using pre-defined criteria, and statistical algorithms were applied to detect temporal aberrations in the data series. Results SCM was deployed successfully in each sentinel hospital and was operated during the 184-day surveillance period. A total of 1,730,797 patient encounters were recorded by SCM, and 6.1 % (105,352 visits) met the criteria of the seven targeted syndromes. Acute respiratory and gastrointestinal syndromes were reported most frequently, accounted for 92.1 % of reports in all syndromes, and the aggregated time-series presented an obvious day-of-week variation over the study period. In total, 191 aberration signals were triggered, and none of them were identified as outbreaks after verification and field investigation. Conclusions SCM has acted as a practical tool for recording symptoms in the hospital-based enhanced syndromic surveillance system during the 41st World Exposition in Shanghai, in the context of without a preexisting electronic tool to collect syndromic data in the HIS of the sentinel hospitals.

Background: With the dramatic increase in international travel among Chinese people, the risk of malaria importation from malaria-endemic regions threatens the achievement of the malaria elimination goal of China.Methods: Epidemiological investigations of all imported malaria cases were conducted in nine provinces of China from 1 Nov, 2013 to 30 Oct, 2014. Plasmodium species, spatiotemporal distribution, clinical severity, preventive measures and infection history of the imported malaria cases were analysed using descriptive statistics.Results: A total of 1420 imported malaria cases were recorded during the study period, with P. falciparum (723 cases, 50.9 %) and P. vivax (629 cases, 44.3 %) being the two predominant species. Among them, 81.8 % of cases were in Chinese overseas labourers. The imported cases returned from 41 countries, mainly located in Africa (58.9 %) and Southeast Asia (39.4 %). About a quarter (25.5 %, 279/1094) of counties in the nine study provinces were affected by imported malaria cases. There were 112 cases (7.9 %) developing complicated malaria, including 12 deaths (case fatality rate: 0.8 %). Only 27.8 % of the imported cases had taken prophylactic anti-malarial drugs. While staying abroad, 27.7 % of the cases had experienced two or more episodes of malaria infection. The awareness of clinical manifestations and the capacity for malaria diagnosis were weak in private clinics and primary healthcare facilities.Conclusions: Imported malaria infections among Chinese labourers, returned from various countries, poses an increasing challenge to the malaria elimination programme in China. The risk of potential re-introduction of malaria into inland malaria-free areas of China should be urgently addressed.

To explore the effect of signal strength indictor (SSI) in improving sensitivity of China Infectious Diseases Automated-alert and Response System (CIDARS).Diarrhea cases in 2007-2011 and early warning signals in 2010-2011 were selected by using random digital table method. Then, SSI and event-related ratio (ER) were calculated. The relationship between ER and SSI was analyzed, and the effect of SSI on ER was explored by using multiple logistic regression analysis.9 620 early warning signals in 2010-2011 were generated in two years. Of these, 74, or 0.77% were defined as suspected outbreak signal. The median of SSI related with suspected outbreak signal was 4.0, which was much higher than non-suspected outbreak signal (1.7). ER was significantly correlated with SSI (r=0.917). SSI classification has a good correlation between the ER, ER exceeded 20 after SSI reached 20. The multivariate logistic regression analysis showed OR of SSI related with suspected outbreak signal was 2.52 (95% CI 2.04-3.12). Compared with non-epidemic season, the relationship of SSI and ER in epidemic season was much higher.SSI was closely related with ER. The relationship was much closer in large scale outbreak and epidemic season, and compared to non-epidemic,the effect of epidemic season is more obvious.

Many aberration detection algorithms are used in infectious disease surveillance systems to assist in the early detection of potential outbreaks. In this study, we explored a novel approach to adjusting aberration detection algorithms to account for the impact of seasonality inherent in some surveillance data. By using surveillance data for hand-foot-and-mouth disease in Shandong province, China, we evaluated the use of seasonally-adjusted alerting thresholds with three aberration detection methods (C1, C2, and C3). We found that the optimal thresholds of C1, C2, and C3 varied between the epidemic and non-epidemic seasons of hand-foot-and-mouth disease, and the application of seasonally adjusted thresholds improved the performance of outbreak detection by maintaining the same sensitivity and timeliness while decreasing by nearly half the false alert rate during the non-epidemic season. Our preliminary findings suggest a general approach to improving aberration detection for outbreaks of infectious disease with seasonally variable incidence.

To analyze the viral etiologies of hospitalized pneumonia patients aged less than five years in six provinces during 2009-2012, and to describe the seasonality of the detected viral etiologies.Eight hospitals were selected in six provinces from a national acute respiratory infection surveillance network. Demographic information, clinical history and physical examination, and laboratory testing results of the enrolled hospitalized patients aged less than five years with pneumonia, including respiratory syncytial virus (RSV), human influenza virus, adenoviruses (ADV), human parainfluenza virus (PIV), human metapneumovirus (hMPV), human coronavirus (hCoV)and human bocavirus (hBoV) were analyzed. The viral etiology spectrum of the enrolled patients was analyzed by age-group, year, and seasonality of the detected viral etiologies were described.4 508 hospitalized children less than five years old, with pneumonia from 8 hospitals were included, and 2 688 (59.6%) patients were positive for at least one viral etiology. The most frequent detected virus was RSV (21.3%), followed by PIV (7.1%) and influenza (5.2%), hBoV (3.8%), ADV(3.6%) and hMPV(2.6%). The lowest positive rates in hCoV(1.1%). RSV, influenza, PIV, hBoV and hMPV all showed the nature of seasonality.RSV was a most common viral etiology in the hospitalized young children less than 5 years of age with pneumonia. Prevention measures should be conducted to decrease its severe impact to the young infants and children in China.

An outbreak detection and response system, using time series moving percentile method based on historical data, in China has been used for identifying dengue fever outbreaks since 2008. For dengue fever outbreaks reported from 2009 to 2012, this system achieved a sensitivity of 100%, a specificity of 99.8% and a median time to detection of 3 days, which indicated that the system was a useful decision tool for dengue fever control and risk-management programs in China.

Providing evidences for further modification of China Infectious Diseases Automated-alert and Response System (CIDARS) via analyzing the outbreak detection performance of Moving Percentile Method (MPM) by optimizing thresholds in different provinces.We collected the amount of MPM signals, response results of signals in CIDARS, cases data in nationwide Notifiable Infectious Diseases Reporting Information System, and outbreaks data in Public Health Emergency Reporting System of 16 infectious diseases in 31 provinces in Chinese mainland from January 2011 to October 2013. The threshold with the optimal sensitivity, the shortest time to detect outbreak and the least number of signals was considered as the best threshold of each disease in Chinese mainland and in each province.Among all the 16 diseases, the optimal thresholds of 10 diseases, including dysentery, dengue, hepatitis A, typhoid and paratyphoid, meningococcal meningitis, Japanese encephalitis, scarlet fever, leptospirosis, hepatitis, typhus in country level were the 90(th) percentile (P90), which was the same as provincial level for those diseases.For the other 6 diseases, including other infectious diarrhea, influenza, acute hemorrhagic conjunctivitis, mumps, rubella and epidemic hemorrhagic fever, the nationwide optimal thresholds were the 80th percentile (P80), which was different from that by provinces for each disease. For these 6 diseases, the number of signals generated by MPM with the optimal threshold for each province was decreased by 23.71% (45 557), 15.59% (6 124), 14.07% (1 870), 9.44% (13 881), 8.65% (1 294) and 6.03% (313) respectively, comparing to the national optimal threshold, while the sensitivity and time to detection of CIDARS were still the same.Optimizing the threshold by different diseases and provinces for MPM in CIDARS could reduce the number of signals while maintaining the same sensitivity and time to detection.

For providing evidences for further modification of China Infectious Diseases Automated-alert and Response System (CIDARS) by comparing the early-warning performance of the temporal model and temporal-spatial model in CIDARS.The application performance for outbreak detection of temporal model and temporal-spatial model simultaneously running among 208 pilot counties in 20 provinces from 2011 to 2013 was compared; the 16 infectious diseases were divided into two classes according to the disease incidence level; cases data in nationwide Notifiable Infectious Diseases Reporting Information System was combined with outbreaks reported to Public Health Emergency Reporting System, by adopting the index of the number of signals, sensitivity, false alarm rate and time for detection.The overall sensitivity of temporal model and temporal-spatial model for 16 diseases was 96.23% (153/159) and 90.57% (144/159) respectively, without significant difference (Z = -1.604, P = 0.109), and the false alarm rate of temporal model (1.57%, 57 068/3 643 279) was significantly higher than that of temporal-spatial model (0.64%, 23 341/3 643 279) (Z = -3.408, P = 0.001), while the median time for detection of these two models was not significantly different, which was 3.0 days and 1.0 day respectively (Z = -1.334, P = 0.182).For 6 diseases of type I which represent the lower incidence, including epidemic hemorrhagic fever,Japanese encephalitis, dengue, meningococcal meningitis, typhus, leptospirosis, the sensitivity was 100% for both models (8/8, 8/8), and the false alarm rate of both temporal model and temporal-spatial model was 0.07% (954/1 367 437, 900/1 367 437), with the median time for detection being 2.5 days and 3.0 days respectively. The number of signals generated by temporal-spatial model was reduced by 2.29% compared with that of temporal model.For 10 diseases of type II which represent the higher incidence, including mumps, dysentery, scarlet fever, influenza, rubella, hepatitis E, acute hemorrhagic conjunctivitis, hepatitis A, typhoid and paratyphoid, and other infectious diarrhea, the sensitivity of temporal model was 96.03% (145/151), and the sensitivity of temporal-spatial model was 90.07% (136/151), the number of signals generated by temporal-spatial model was reduced by 59.36% compared with that of temporal model. Compared to temporal model, temporal-spatial model reduced both the number of signals and the false alarm rate of all the type II diseases;and the median of outbreak detection time of temporal model and temporal-spatial model was 3.0 days and 1.0 day, respectively.Overall, the temporal-spatial model had better outbreak detection performance, but the performance of two different models varies for infectious diseases with different incidence levels, and the adjustment and optimization of the temporal model and temporal-spatial model should be conducted according to specific infectious disease in CIDARS.

To analyze the implement performance of China Infectious Diseases Automated-alert and Response System (CIDARS) of 31 provinces in mainland China, and to provide the evidences for further promoting the application and improvement of this system.The amount of signals, response situation and verification outcome of signals related to 32 infectious diseases of 31 provinces in mainland China in CIDARS were investigated from 2011 to 2013, the changes by year on the proportion of responded signals and timeliness of signal response were descriptively analyzed.A total of 960 831 signals were generated nationwide on 32 kinds of infectious diseases in the system, with 98.87% signals (949 936) being responded, and the median (the 25(th) percentile to the 75(th) percentile (P25-P75) ) of time to response was 1.0 (0.4-3.3) h. Among all the signals, 242 355 signals were generated by the fixed-value detection method, the proportion of responded signals was 96.37% (62 349/64 703), 98.75% (68 413/69 282) and 99.37% (107 690/108 370), respectively, and the median (P25-P75) of time to response was 1.3 (0.3-9.7), 0.8(0.2-4.9) and 0.7 (0.2-4.2) h, respectively. After the preliminary data verification, field investigation and laboratory test by local public health staffs, 100 232 cases (41.36%) were finally confirmed.In addition, 718 476 signals were generated by the temporal aberration detection methods, and the average amount of signal per county per week throughout the country were 1.53, and 8 155 signals (1.14%) were verified as suspected outbreaks. During these 3 years, the proportion of signal response was 98.89% (231 149/233 746), 98.90% (254 182/257 015) and 99.31% (226 153/227 715), respectively, and the median (P25-P75) of time to response was 1.1 (0.5-3.3), 1.0 (0.5-2.9) and 1.0 (0.5-2.6) h, respectively.From 2011 to 2013, the proportion of responded signals and response timeliness of CIDARS maintained a rather high level, and further presented an increasing trend year by year. But the proportion of signals related to suspected outbreaks should be improved.

To evaluate the performance of China's infectious disease automated alert and response system in the detection of outbreaks of hand, foot and mouth (HFM) disease.We estimated size, duration and delay in reporting HFM disease outbreaks from cases notified between 1 May 2008 and 30 April 2010 and between 1 May 2010 and 30 April 2012, before and after automatic alert and response included HFM disease. Sensitivity, specificity and timeliness of detection of aberrations in the incidence of HFM disease outbreaks were estimated by comparing automated detections to observations of public health staff.The alert and response system recorded 106,005 aberrations in the incidence of HFM disease between 1 May 2010 and 30 April 2012 - a mean of 5.6 aberrations per 100 days in each county that reported HFM disease. The response system had a sensitivity of 92.7% and a specificity of 95.0%. The mean delay between the reporting of the first case of an outbreak and detection of that outbreak by the response system was 2.1 days. Between the first and second study periods, the mean size of an HFM disease outbreak decreased from 19.4 to 15.8 cases and the mean interval between the onset and initial reporting of such an outbreak to the public health emergency reporting system decreased from 10.0 to 9.1 days.The automated alert and response system shows good sensitivity in the detection of HFM disease outbreaks and appears to be relatively rapid. Continued use of this system should allow more effective prevention and limitation of such outbreaks in China.Évaluer les résultats du système automatisé d'alerte et d'action pour les maladies infectieuses de la Chine en matière de détection des épidémies de maladie des mains, pieds et bouche (MMPB).Nous avons estimé la taille, la durée et le retard du signalement des épidémies de MMPB à partir des cas notifiés entre le 1er mai 2008 et le 30 avril 2010 et entre le 1er mai 2010 et le 30 avril 2012, c'est-à-dire avant et après l'intégration de la MMPB dans le système automatisé d'alerte et d'action. La sensibilité, la spécificité et la rapidité de la détection des aberrations dans l'incidence des épidémies de MMPB ont été estimées en comparant les détections automatisées aux observations du personnel des services de santé publique.Le système d'alerte et d'action a enregistré 106 005 aberrations dans l'incidence de la MMPB entre le 1er mai 2010 et le 30 avril 2012 – une moyenne de 5,6 erreurs pour 100 jours dans chaque comté qui avait signalé la MMPB. Le système d'action avait une sensibilité de 92,7% et une spécificité de 95,0%. Le retard moyen entre le signalement du premier cas d'une épidémie et la détection de cette épidémie par le système d'action était de 2,1 jours. Entre les périodes de la première et de la seconde étude, la taille moyenne d'une épidémie de MMPB a diminué de 19,4 à 15,8 cas, et l'intervalle moyen entre le début et le signalement initial d'une telle épidémie au système de notification d'urgence des services de santé publique a diminué, passant de 10,0 à 9,1 jours.Le système automatisé d'alerte et d'action présente une bonne sensibilité en matière de détection des épidémies de MMPB et semble être relativement rapide. L'utilisation continue de ce système devrait permettre de prévenir et de limiter plus efficacement ces épidémies en Chine.Evaluar el rendimiento del sistema de alerta y respuesta automática a enfermedades infecciosas de China en la detección de brotes de la enfermedad boca-mano-pie (EBMP).Calculamos la magnitud, la duración y la demora en la notificación de brotes de la enfermedad BMP a partir de casos notificados entre el 1 de mayo de 2008 y el 30 de abril de 2010, y entre el 1 de mayo de 2010 y el 30 de abril 2012, antes y después de que el sistema de alerta y respuesta automáticas incluyera la enfermedad BMP. Se estimó la sensibilidad, especificidad y oportunidad de la detección de aberraciones en la incidencia de los brotes de enfermedad BMP mediante la comparación de las detecciones automáticas con las observaciones del personal de salud pública.El sistema de alerta y respuesta registró 106 005 aberraciones en la incidencia de la EBMP entre el 1 de mayo de 2010 y el 30 de abril de 2012 - una media de 5,6 aberraciones por cada 100 días en cada condado que notificó dicha enfermedad. El sistema de respuesta tuvo una sensibilidad del 92,7 % y una especificidad del 95,0 %. La demora media entre la notificación del primer caso de un brote y la detección de ese brote por el sistema de respuesta fue de 2,1 días. Entre el primer y el segundo período de estudio, las dimensiones medias de un brote de EBMP disminuyeron de 19,4 a 15,8 casos, y el intervalo medio entre el comienzo de un brote y el primer informe en el sistema de notificación de emergencia de salud pública se redujo de 10,0 a 9,1 días.El sistema de alerta y respuesta automática muestra una buena sensibilidad en la detección de los brotes de EBMP y parece ser relativamente rápido. El uso continuado de este sistema debería permitir una prevención y limitación más eficaces de dichos brotes en China.تقييم أداء نظام الإنذار والاستجابة الآلي للأمراض المعدية في اكتشاف فاشيات مرض اليد والقدم والفم في الصين.قمنا بتقدير الحجم والمدة والتأخير في الإبلاغ عن فاشيات مرض اليد والقدم والفم من الحالات التي تم الإخطار بها بين 1 أيار/مايو 2008 و30 نيسان/أبريل 2010 وبين 1 أيار/مايو 2010 و30 نيسان/أبريل 2012، قبل إدراج داء اليد والقدم والفم في الإنذار والاستجابة الآلية وبعده. وتم تقدير حساسية اكتشاف الانحرافات ونوعيتها وتوقيتها في معدل الإصابة بفاشيات مرض اليد والقدم والفم عن طريق مقارنة الاكتشافات والملاحظات الآلية من قبل موظفي الصحة العمومية.سجل نظام الإنذار والاستجابة 106005 انحرافاً في معدل الإصابة بمرض اليد والقدم والفم بين 1 أيار/مايو 2010 و30 نيسان/أبريل2012 - المتوسط 5.6 انحرافاً لكل 100 يوم في كل مقاطعة أبلغت عن مرض اليد والقدم والفم. وكانت حساسية نظام الاستجابة 92.7 % ونوعيته 95.0 %. وكان متوسط التأخير بين الإبلاغ عن الحالة الأولى لإحدى الفاشيات واكتشاف تلك الفاشية عن طريق نظام الاستجابة 2.1 يوم. وانخفض متوسط حجم فاشية مرض اليد والقدم والفم بين الفترتين الدراسيتين الأولى والثانية من 19.4 حالة إلى 15.8 حالة وانخفض متوسط الفاصل بين بداية هذه الفاشية والإبلاغ الأولي عنها إلى نظام الإبلاغ عن حالات الطوارئ في الصحة العمومية من 10.0 إلى 9.1 يوماً.يشير نظام الإنذار والاستجابة الآلي إلى حساسية جيدة في اكتشاف فاشيات مرض اليد والقدم والفم ويبدو أنه سريع نسبياً. وينبغي أن يسمح الاستخدام المتواصل لهذا النظام بزيادة فعالية الوقاية وتقييد هذه الفاشيات في الصين.评价中国传染病自动预警与响应系统在探测手足口疾病（HFM）爆发方面的表现。我们利用2008年5月1日和2010年4月30日之间以及2010年5月1日和2012年4月30日之间（即自动预警与响应系统将手足口病纳入之前和之后）报告的病例估算了手足口病病爆发的规模、持续时间和报告延迟时间。将预警与响应系统自动探测的结果与公共卫生工作人员的观察结果进行比较，评估该系统用于探测手口足病爆发的灵敏度、特异度和及时性。在2010年5月1日至2012年4月30日期间，预警和响应系统发出了106005条预警信号，——在每个有手足口病病例报告的县，平均每100天产生5.6条手足口病预警信号。响应系统敏感度为92.7%，特异度为95.0%。从爆发的第一例病例报告至自动预警与响应系统探测到爆发之间的平均时间间隔是2.1天。在自动预警与响应系统将手足口病纳入之前和之后，手足口病爆发的平均规模从19.4例下降到15.8例，从爆发首例病例发病至向突发公共卫生事件报告系统进行报告之间的平均时间间隔从10.0天下降到9.1天。自动预警与响应系统在探测手足口病爆发方面具有良好的灵敏度和及时性。持续使用该系统应该能够更有效地预防和控制中国手足口病的爆发。Оценить эффективность автоматизированной системы оповещения и реагирования в Китае, используемой для обнаружения вспышек вирусной пузырчатки полости рта и конечностей (HFM — от англ. hand, foot and mouth disease).Размер, продолжительность вспышек и задержка сообщений о вспышках HFM оценивались на основе случаев, зарегистрированных в период с 1 мая 2008 года по 30 апреля 2010 года и в период с 1 мая 2010 года по 30 апреля 2012 года, как до, так и после начала использования системы автоматического оповещения и реагирования о данном заболевании. Чувствительность, специфичность и своевременность обнаружения отклонений в уровне заболеваемости HFM оценивались путем сравнения данных автоматизированной системы обнаружения с наблюдения специалистов общественного здравоохранения.Системой оповещения и реагирования было зарегистрировано 106 005 отклонений в уровне заболеваемости HFM в период с 1 мая 2010 года по 30 апреля 2012 года, что составило в среднем 5,6 отклонений на 100 дней в каждом округе, сообщившем о случаях заболевания HFM. Чувствительность и специфичность системы реагирования составляли 92,7% и 95,0% соответственно. Средняя задержка между сообщением о первом случае вспышки заболевания и выявлением данной вспышки системой реагирования составила 2,1 дня. Между первым и вторым периодами исследования средний размер вспышки HFM уменьшился с 19,4 до 15,8 случаев, а средний интервал между началом вспышки и первоначальным сообщением о данной вспышке в систему аварийной отчетности здравоохранения уменьшился с 10,0 до 9,1 дней.Автоматизированная система оповещения и реагирования продемонстрировала хорошую чувствительность при обнаружении вспышек вирусной пузырчатки полости рта и конечностей и относительно высокую скорость реагирования. Дальнейшее использование этой системы должно обеспечить более эффективное предотвращение и ограничение вспышек данного заболевания в Китае.

We evaluated a novel strategy to improve the performance of outbreak detection algorithms, namely setting the alerting threshold separately in each region according to the disease incidence in that region. By using data on hand, foot and mouth disease in Shandong province, China, we evaluated the impact of disease incidence on the performance of outbreak detection algorithms (EARS-C1, C2 and C3). Compared to applying the same algorithm and threshold to the whole region, setting the optimal threshold in each region according to the level of disease incidence (i.e., high, middle, and low) enhanced sensitivity (C1: from 94.4% to 99.1%, C2: from 93.5% to 95.4%, C3: from 91.7% to 95.4%) and reduced the number of alert signals (the percentage of reduction is C1∶4.3%, C2∶11.9%, C3∶10.3%). Our findings illustrate a general method for improving the accuracy of detection algorithms that is potentially applicable broadly to other diseases and regions.

Introduction Each year there are approximately 390 million dengue infections worldwide. Weather variables have a significant impact on the transmission of Dengue Fever (DF), a mosquito borne viral disease. DF in mainland China is characterized as an imported disease. Hence it is necessary to explore the roles of imported cases, mosquito density and climate variability in dengue transmission in China. The study was to identify the relationship between dengue occurrence and possible risk factors and to develop a predicting model for dengue’s control and prevention purpose. Methodology and Principal Findings Three traditional suburbs and one district with an international airport in Guangzhou city were selected as the study areas. Autocorrelation and cross-correlation analysis were used to perform univariate analysis to identify possible risk factors, with relevant lagged effects, associated with local dengue cases. Principal component analysis (PCA) was applied to extract principal components and PCA score was used to represent the original variables to reduce multi-collinearity. Combining the univariate analysis and prior knowledge, time-series Poisson regression analysis was conducted to quantify the relationship between weather variables, Breteau Index, imported DF cases and the local dengue transmission in Guangzhou, China. The goodness-of-fit of the constructed model was determined by pseudo-R2, Akaike information criterion (AIC) and residual test. There were a total of 707 notified local DF cases from March 2006 to December 2012, with a seasonal distribution from August to November. There were a total of 65 notified imported DF cases from 20 countries, with forty-six cases (70.8%) imported from Southeast Asia. The model showed that local DF cases were positively associated with mosquito density, imported cases, temperature, precipitation, vapour pressure and minimum relative humidity, whilst being negatively associated with air pressure, with different time lags. Conclusions Imported DF cases and mosquito density play a critical role in local DF transmission, together with weather variables. The establishment of an early warning system, using existing surveillance datasets will help to control and prevent dengue in Guangzhou, China.

BACKGROUND: Dengue has been a notifiable disease in China since 1 September 1989. Cases have been reported each year during the past 25 years of dramatic socio-economic changes in China, and reached a historical high in 2014. This study describes the changing epidemiology of dengue in China during this period, to identify high-risk areas and seasons and to inform dengue prevention and control activities.METHODS: We describe the incidence and distribution of dengue in mainland China using notifiable surveillance data from 1990-2014, which includes classification of imported and indigenous cases from 2005-2014.RESULTS: From 1990-2014, 69,321 cases of dengue including 11 deaths were reported in mainland China, equating to 2.2 cases per one million residents. The highest number was recorded in 2014 (47,056 cases). The number of provinces affected has increased, from a median of three provinces per year (range: 1 to 5 provinces) during 1990-2000 to a median of 14.5 provinces per year (range: 5 to 26 provinces) during 2001-2014. During 2005-2014, imported cases were reported almost every month and 28 provinces (90.3%) were affected. However, 99.8% of indigenous cases occurred between July and November. The regions reporting indigenous cases have expanded from the coastal provinces of southern China and provinces adjacent to Southeast Asia to the central part of China. Dengue virus serotypes 1, 2, 3, and 4 were all detected from 2009-2014.CONCLUSIONS: In China, the area affected by dengue has expanded since 2000 and the incidence has increased steadily since 2012, for both imported and indigenous dengue. Surveillance and control strategies should be adjusted to account for these changes, and further research should explore the drivers of these trends. Please see related article: http://dx.doi.org/10.1186/s12916-015-0345-0.

BackgroundIn China, the national malaria elimination programme has been operating since 2010. This study aimed to explore the epidemiological changes in patterns of malaria in China from intensified control to elimination stages.MethodsData on nationwide malaria cases from 2004 to 2012 were extracted from the Chinese national malaria surveillance system. The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed.ResultsIn total, 238,443 malaria cases were reported, and the proportion of Plasmodium falciparum increased drastically from ConclusionsThis study demonstrated that malaria has decreased dramatically in the last five years, especially since the Chinese government launched a malaria elimination programme in 2010, and areas with reported falciparum malaria cases have expanded over recent years. These findings suggest that elimination efforts should be improved to meet these changes, so as to achieve the nationwide malaria elimination goal in China in 2020.