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Objective: To understand the epidemiological characteristics of diarrheagenic Escherichia ( E. ) coli infection in infectious diarrhea outpatients aged 15 years and older in Shanghai and provide evidence for the development of disease control strategies . Methods: Based on multistage systematic sampling, diarrhea surveillance was conducted in 22 sentinel hospitals in Shanghai, the information about cases' demographic, clinical, and epidemiological characteristics were collected. Stool samples were collected for the detection and typing of diarrheagenic E. coli by local centers for disease control and prevention. The positive rate of diarrheagenic E. coli in different populations and seasons from 2014 to 2021 were analyzed. Statistical analysis was conducted by using χ 2 test. Results: In 15 185 diarrhea cases, 8.05% (1 222/15 185) were positive for diarrheagenic E. coli . The positive rate was higher in men (8.74%, 684/7 824) than in women (7.31%, 538/7 361). The positive rate was highest in age group 15-29 years (9.14%, 335/3 665) and the annual positive rate was highest in 2021 (10.21%, 83/813), the differences were all significant ( P <0.05). In the 1 264 strains of diarrheagenic E. coli analyzed through PCR, enterotoxingenic E. coli was the most frequently identified pathogen (50.24%, 635/1 264), followed by enteroadhesive E. coli (27.93%, 353/1 264), and enteropathogenic E. coli (21.36%, 270/1 264). The positive rate of diarrheagenic E. coli showed obvious seasonality with peak in summer (13.92%, 774/5 562) ( χ 2 =495.73, P <0.001). Conclusions: Diarrheagenic E. coli has become a prominent pathogen in infectious diarrhea cases in Shanghai, the disease can occur all the year round with incidence peak during summer and autumn. Predominant subtypes included enterotoxingenic E. coli , enteroadhesive E. coli and enteropathogenic E. coli . Targeted prevention and control strategies are needed for diarrheagenic E. coli -induced infectious diarrhea in different age groups, seasons and for different types of infections.

Objective: To understand the characteristics and differences of diarrhea-related symptoms caused by different pathogens, and the clinical features of various pathogens causing diarrhea. Methods: Etiology surveillance program was conducted among 20 provinces of China from 2010 to 2016. The acute diarrhea outpatients were collected from clinics or hospitals. A questionnaire was used to survey demographics and clinical features. VFeces samples were taken for laboratory detection of 22 common diarrhea pathogens, to detect and analyze the clinical symptom pattern characteristics of the patient's. Results: A total of 38 950 outpatients were enrolled from 20 provinces of China. The positive rates of Rotavirus and Norovirus were the highest among the five diarrhea-causing viruses (Rotavirus: 18.29%, Norovirus: 13.06%). In the isolation and culture of 17 diarrhea-causing bacterial, Escherichia coli showed the highest positive rates (6.25%). The clinical features of bacterial diarrhea and viral diarrhea were mainly reflected in the results of fecal traits and routine examination, but pathogenic Vibrio infection was similar to viral diarrhea. Conclusion: Infectious diarrhea presents different characteristics due to various symptoms which can provide a basis for clinical diagnosis.

Objective: To analyze the epidemiological characteristics related to Norovirus-associated infectious diarrhea bud events in Shanghai, and to discuss the value of bud events surveillance, so as to help Norovirus-associated infectious diarrhea control, prevention and to improve the surveillance system on bud events. Methods: Data related to 142 Norovirus-associated infectious diarrhea bud events were gathered from 16 districts of Shanghai areas in 2018 and were analyzed. Results: There were 2 peaks, April and November for 142 Norovirus-associated infectious diarrhea bud events reported in 2018. 98.59 % (140/142) of the bud events occurred in schools and kindergartens. 80.28 % (114/142) of the bud events would involve 6-19 cases per each event. The median time duration between the onset date of the first case and the reporting date of the event was 2 days and the median event duration was 7 days. The bud event scale and regional incidence of bud events as well as the reporting timelines were influential factors on the duration of the bud events. Conclusions: Two peaks, spring and winter bud events of the Norovirus-associated infectious diarrhea were seen in Shanghai in 2018. Schools and kindergartens were to be prioritized locations for control and prevention of Norovirus-associated infectious diarrhea bud events. Surveillance system was proved to have contributed to the early detection, reporting and control of bud events.

Objective: To understand the epidemiological characteristics of infectious diarrhea pathogens in Pudong New Areas of Shanghai from 2013 to 2017 to provide evidence for control and prevention of the disease. Methods: From Jan 2013 to Dec 2017, active surveillance program on diarrhea was conducted in 14 sentinel hospitals (three tertiary-level and nine secondary-level, and two primary-level hospitals) in Pudong New Areas of Shanghai, based on location, catchment areas and number of patients. All recruited outpatients were interviewed in hospitals, using a standard questionnaire. Stool specimens were collected and tested for five viral and eight bacterial pathogens. Results: A total of 9 301 cases with infectious diarrhea were included, and the overall positive rate was 55.7 % (5 179). Positive rates of single virus, single bacteria and mixed infections were 26.7 % (2 481), 17.0 % (1 579) and 12.0 % (1 119), respectively. For single infection, the most commonly detected viruses appeared as norovirus (15.4 % , 1 428/9 301) and rotavirus (7.2 % , 667/9 301). The most commonly detected bacteria were diarrheagenic Escherichia coli (6.7 % , 619/9 301) and non-typhoid Salmonella (3.3 % , 305/9 301). The most common mixed infections were caused by virus-bacteria (4.9 % , 459/9 301). Norovirus (17.0 % , 838/4 938) showed the highest positive rates, followed by Escherichia coli (7.2 % , 354/4 938), both seen in the age group of 20-59 years old group. Rotavirus (9.4 % , 178/1 896) and non-typhoid Salmonella (4.9 % , 93/1 896) were the most common pathogens found in the age group of 0-4 years old. The prevalence of norovirus peaked both in spring and autumn. The other peaks were seen as: Rotavirus in winter, diarrheagenic Escherichia coli in summer and non-typhoid Salmonella in summer. Conclusions: Our data showed that the positive rates of infectious diarrhea pathogens were high in Pudong New Areas of Shanghai from 2013 to 2017. The dominant pathogens would include norovirus, rotavirus and diarrheagenic Escherichia coli but with differenct distributions in age groups. Obvious seasonal patterns were also observed.

Objective: To investigate the epidemiologic characteristics of Norovirus among adult patients suffering from infectious diarrhea in Shanghai, so as to provide evidence for developing related strategies on prevention and control of the disease. Methods: Diarrheal outpatients were monitored at the 'Intestinal clinic' from 22 hospitals involved in the sentinel surveillance program in Shanghai. Information on demographic and epidemiologic features of the patients was collected while data and clinical, fecal specimens were collected and sent to the district CDC for Norovirus detection. Positive rates of Norovirus were also compared in various populations and seasons during 2013-2018. Multivariate logistic regression model was adopted to fit into the comparisons between non-Norovirus and Norovirus groups. Results: 19.28% of the 12 083 diarrheal cases were found to have carried the Norovirus, with GⅡgroup the most commonly identified genotype. Rates of detection was seen higher in males (20.78%) than in females (17.73%). 30-44 year-old were found having the highest positive rate (21.51%). The positive rates were found the highest (23.60%) in the year of 2015. All the above shown differences were statistically significant ( P <0.05). Diarrheal patients affected with Norovirus would present watery stool (75.94%) and vomiting (35.84%). Data from the multivariate logistic analysis showed that factors as: being males, 30-44 years old, officials/clerks, in winter season and with histories of travelling etc ., were related to higher risks on Norovirus infection. Conclusions: Infectious diarrhea caused by Norovirus occurred all year round, with seasonal peaks seen in winter and spring, in Shanghai. Specific prevention and control measures should be taken on Norovirus- caused infectious diarrhea, according to the difference on age, gender and season.

Objective: To study the lag effect of temperature and the source of heterogeneity on other infectious diarrhea (OID) in Zhejiang province, so as to identify related vulnerable populations at risk. Methods: Data on OID and meteorology in Zhejiang province from 2014 to 2016 were collected. A two-stage model was conducted, including: 1) using the distributed lag non-linear model to estimate the city-specific lag effect of temperature on OID, 2) applying the multivariate Meta- analysis to pool the estimated city-specific effect, 3) using the multivariate Meta-regression to explore the sources of heterogeneity. Results: There were 301 593 cases of OID in Zhejiang province during the study period. At the provincial level, temperature that corresponding to the lowest risk of OID was 16.7 ℃, and the temperature corresponding to the highest risk was 6.2℃ ( RR =2.298, 95 %CI : 1.527- 3.459). 16.7 ℃ was recognized as the reference temperature. P(5) and P(95) of the average daily temperature represented low and high temperature respectively. When the temperature was cold, the risk was delayed by 2 days, with the highest risk found on the 5(th) day ( RR =1.057, 95 %CI : 1.030-1.084) before decreasing to the 23(rd) day. When the temperature got hot, the risk of OID occurred on the first day ( RR =1.081, 95 %CI : 1.045-1.118) and gradually decreasing to the 8(th) day. Differences on heterogeneous sources related to the risks of OID in different regions, presented on urban latitude and the rate of ageing in the population. Conclusions: Both high or low temperature could increase the risk of OID, with a lag effect noticed. Prevention program on OID should be focusing on populations living in the high latitude and the elderly population at the low temperature areas.

Objective: To understand the seasonality and etiological characteristics of infectious diarrhea in adults from Shanghai. Methods: Adult patients with diarrhea who had visited the enteric disease clinics in 22 hospitals that carrying on the Diarrhea Comprehensive Surveillance sentinel programs in Shanghai during 2014-2017, were surveyed. Stool specimens were collected according to the different intervals of sampling and detected for 12 bacteria and 5 viruses. Concentration ratio and circular distribution method were used for data analysis. Results: From 2014 to 2017, a total of 9 573 stool specimens were collected from the targeted diarrhea patients ≥18 years old ( n =96 067), through the Shanghai Diarrhea Comprehensive Surveillance program. The positive rate of detection was 46.44%. Seasonal peaks of infectious diarrhea were both seen in summer (bacteria peak, diarrheagenic Escherichia coli and Vibrio parahaemolyticus , etc .) and in winter (virus peak, Norovirus, etc .). Both bacterial and viral infections presented seasonal concentration (Raleigh's test P <0.001) but more obvious with bacterial infection. Viral infection accounted for 60.19% of the cause of infectious diarrhea. The top five predominant pathogens appeared as Norovirus, Rotavirus, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, and Salmonella spp.. Conclusions: Among the adult outpatients with infectious diarrhea in Shanghai, obvious seasonality was seen, with peaks in both summer and winter. Viral infection with Norovirus in particular, appeared as the predominant source of infection. Active, continuous and comprehensive diarrhea-related surveillance programs would be able to monitor the changing dynamic of pathogen spectrum, and lead to the adoption of targeted preventive measures.

Objective: To understand the etiological characteristics of bacterial diarrhea in different areas, including large cities, mid-sized/small cities and rural area, in China. Methods: A cross-sectional surveillance was conducted in 17 provinces of China from 2010 to 2014. The acute diarrhea outpatients were selected from clinics or hospitals in large cities, mid-sized/small cities, including rural-urban fringe zones, and rural areas. The demographical and clinical characteristics of the patients were collected by using questionnaire, and stool samples were taken from them for laboratory detection of 17 kinds of bacteria. The differences in pathogen positive rates (PPR) and pathogen spectrum across the cases from three-type areas were compared. The different infection risk in different cases were analyzed with unconditional logistic regression model. Results: In our study, we enrolled 9 253 cases from large cities, 5 138 cases from rural areas and 13 683 cases from midsized/small cites. The pathogen with largest differences in infection rate across the three-type areas was Shigella ( S .) flexneri (rural area: 5.81 % , mid-sized/small city: 2.78 % , large city: 0.46 % ), followed by Aeromonas ( A .) hydrophila (rural area: 2.14 % , mid-sized/small city: 0.96 % , large city: 0.48 % ). Compared with cases in large cities, the cases in mid-sized/small cities and rural areas had higher infection risks for S. flexneri (mid-sized/small city: OR =6.481, 95 %CI : 4.666-9.002, rural area: OR =11.304, 95 %CI : 8.018-15.938) and A . hydrophila (mid-sized/small city: OR =1.992, 95 %CI :1.401-2.832, rural area: OR =4.083, 95 %CI : 2.833-5.884). The constituent ratio of diarrheagenic Escherichia coli and Salmonella increased with the urbanization development, while the ratios of Shigella and A . hydrophila had an opposite trend. S. sonnei (60.00 % ) was the predominant serogroup of Shigella in urban infections, while S. flexneri (77.37 % ) was the predominant serogroup in rural infections. Conclusion: The differences in pathogen spectrum of bacterial diarrhea were obvious across large cities, mid-sized/small cities and rural areas in China, especially the differences in the infection rates of S. flexneri and A. hydrophila.

Objective: To analyze the current situation on infectious diarrhea other than cholera, dysentery, typhoid and paratyphoid (hereinafter referred to as Other Infectious Diarrheal Diseases) under the current monitoring program in China from 2014 to 2015, to provide evidence for developing strategies related to the control of these diseases. Methods: All the reported infectious diarrhea cases and information on public health emergencies relevant to infectious diarrhea were collected from the "Chinese Information System for Disease Control and Prevention" . Analytic method was carried out to describe the etiological and epidemiological characteristics of all the infectious diarrhea cases. Results: In 2014, a total of 867 545 infectious diarrhea cases were reported, with the incidence rate as 64.0/100 000. While in 2015, a total of 937 616 infectious diarrhea cases were reported, and the incidence rate was 68.8/100 000. Cases distributed in all provinces of the country, with incidence rates between 3.8/100 000 and 506.7/100 000. Cases involved in all the age groups, with 53.7 % (968 984/1 805 161) of the total reported cases below 5 years of age. Reported cases showed two peaks of incidence, in summer (from June to August) and winter (from November to next January). Laboratory-confirmed cases accounted for 9.5 % (82 285/867 545) of the total and 9.3 % (86 975/937 616) of the cases reported in 2014 and 2015 respectively. Among cases reported in the two years, viral infection accounted for 92.4 % (76 045/82 285) and 91.0 % (79 176/86 975) while bacterial infection accounted for 7.4 % (6 062/82 285) and 8.8 % (7 614/86 975), respectively. Among the death cases, only three were laboratory confirmed, with two of them caused by rotavirus. Conclusions: Children under 5 years old appeared both higher incidence and mortalities for infectious diarrhea. Most laboratory-confirmed cases were viral-born, with pathogenic spectrums varied in different provinces. Capabilities related to testing and case-reporting on infectious diarrheal diseases differed greatly among areas that called for urgent improvement.

This paper summaries the application of adaptive kernel density algorithm in the spatial relative risk estimation of communicable diseases by using the reported data of infectious diarrhea (other than cholera, dysentery, typhoid and paratyphoid) in Ludian county and surrounding area in Yunnan province in 2013. Statistically significant fluctuations in an estimated risk function were identified through the use of asymptotic tolerance contours, and finally these data were visualized though disease mapping. The results of spatial relative risk estimation and disease mapping showed that high risk areas were in southeastern Shaoyang next to Ludian. Therefore, the spatial relative risk estimation of disease by using adaptive kernel density algorithm and disease mapping technique is a powerful method in identifying high risk population and areas.

Objective: To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county., Methods: HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients., Results: Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand., Conclusion: Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.

Objective: To provide information on epidemiology of rotavirus infection in Beijing, China., Methods: An ongoing hospital-based surveillance was conducted among children < 5yr old with acute diarrhea according to WHO generic protocol (CID-98). During a 3-year study (Apr. 1998 to Mar. 2001), a total of 484 stool samples were collected from 1 457 patients, including 275 samples from 1 048 outpatients and 209 samples from 409 inpatients., Results: The overall detection rate of rotavirus infection was 25.4%. Rotavirus was responsible for 27.3% of diarrhea inpatients on a yearly base, and 46.2% during rotavirus season. Two peaks of diarrhea were observed each year, one in the summer (June-Sep.) due to bacterial dysentery (16.7%) and another in fall winter (Oct.-Dec.) due to rotavirus infection (23.0%). The detection rate on rotavirus was the highest in age group of 6 - 11 months (38.2%), followed by 1 - 2 years old (28.5%). Ninety six point eight percentage of children were infected under 3 years of age. The number of deaths, possibly caused by rotavirus diarrhea were accounted for 40% of all diarrhea deaths and 11.1% of the total deaths. Serotyping of 123 rotavirus isolates showed that serotype G1 (55.3%) was predominant, followed by G2 (26.8%), G3 (9.8%), G4 (0.8%), and 10 isolates (8.1%) remained non-typeable. Mixed infections (0.8%) seemed to be rare., Conclusion: Rotavirus diarrhea was an important infectious disease among children in Beijing. Safe and effective rotavirus vaccines for the prevention of severe diarrheas and the reduction of treatment costs are of significant importance to China.

The incidence rates of infectious diseases were selected and analysed according to data from the Beijing Railway Area during 1981-1991. We put forward the mathematical model to forecast the incidence rate of dysentery each quarter in 1992. The best mathematical model was selected from analysis of precision, and very useful in the prevention and treatment of seasonal infectious diseases.