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Objective@#To conduct a viral pathogen surveillance program on pediatric inpatients less than five years old with acute gastroenteritis in Shanghai and to better understand the pathogenic spectrum and molecular features in the target population, for setting up programs on control, prevention, medication and vaccine applications of the diseases.@*Methods@#Fecal samples were collected from inpatients less than 5 years old who were admitted to a pediatric hospital for having acute gastroenteritis. Information related to demographic, clinical and epidemiological features of the patients was also collected. Laboratory assays including ELISA, real-time PCR and nested PCR, were performed to detect the presence of pathogens as rotavirus, calicivirus, astrovirus and adenovirus.@*Results@#A total of 1 018 samples were collected (male 671 and 347 female), with the positive detection rate as 40.57% which peaked from autumn till winter, annually. Calicivirus and rotavirus A presented with the highest detection rates (24.75% and 13.95% respectively). The lowest detection rate was found in the 0-6 month-olds (32.20%). 65% of the patients with positive virus had received antibiotic treatment prior to the hospitalization. However, no statistically significant difference was seen, regarding the rates of antibiotic medication in the virus positive or negative populations (P>0.05). Data from the Rotavirus genotype analysis revealed that G9P[8] genotype was the predominant strain, and causing majority of rotavirus infections in all the age groups.@*Conclusions@#Among the inpatients under 5 years of age in Shanghai, the positive detection rate for Calicivirus was higher than that for rotavirus group A, suggesting the necessity to carefully monitor the changes regarding the pathogenic spectrum and subtypes of the virus. Antibiotics should also be attentively administered, together with the development of suitable vaccine.
ABSTRACT
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.
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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.
ABSTRACT
Objective@#To analyze the pathogen spectrum and epidemiological characters of infectious diarrhea cases in Shanghai from July 2013 to June 2015.@*Methods@#From July 2013 to June 2015, using multi-stage sampling to select 22 hospitals as adult diarrhea surveillance sentinels, and 3 district central hospitals together with Shanghai municipal children's hospital as children diarrhea surveillance sentinels. A total of 6 267 diarrhea cases were sampled. The demographic characters, main clinical manifestations and signs of cases were investigated, and stool specimens were collected to conduct the bacteria culture and virus nucleic acid detection. The difference of positive rate of bacteria and virus in different seasons, and age difference of relevant pathogens were compared.@*Results@#Among 6 267 cases, 3 262 (52.05%) were male, and most of them were in 50-69 years group (1 999 cases, 31.90%) and 30-49 years group (1 691 cases, 26.98%). Totally, 2 783 positive specimens were detected out of 6 267 specimens with the positive rate being 44.41%. A total of 7 kinds of bacteria and 5 kinds of viruses were detected. The positive rate for bacterium was 12.61%(790 cases), mainly being vibrio parahaemolyticus (256 cases), diarrheagenic E.coli (239 cases) and salmonella (209 cases). The positive rate for virus was 31.80% (1 993 cases), mainly being norovirus (1 172 cases) and rotavirus (546 cases). The positive rates of viruses in winter of 2013 and 2014 were 57.89%(429 cases) and 62.14%(522 cases) respectively, higher than those of bacterium in the same periods which were 2.43% (18 cases) and 2.86% (24 cases) respectively. The positive rates of bacterium in summer of 2013, 2014 and 2015 were 14.56% (97 cases), 25.29%(258 cases) and 21.21% (49 cases), also higher than those of viruses in the same periods which were 7.51% (50 cases), 8.43%(86 cases) and 11.69% (27 cases) respectively, all of the above differences were statistically significant (P<0.05). The cases of 50-69 years group had the highest positive rate of pathogen, which was 47.57% (951/1 999). Secondly was those of 30-49 years group with 47.13% (797/1 691). Positive rate of pathogen for cases of 0-2 years group was 35.74% (213/596).@*Conclusion@#The pathogen spectrumes of infectious diarrhea in Shanghai are mainly vibrio parahaemolyticus, diarrheagenic E.coli, salmonella, norovirus and rotavirus. The summer and winter season peak was obvious. Specific etiological surveillance and control strategies should be strengthened aiming at focus groups including children and the elderly in different seasons.