ABSTRACT
Objective To investigate the etiology and epidemiological characteristics of diarrhea in Minhang District of Shanghai from 2014 to 2016, so as to provide scientific basis to monitor diarrhea disease and to control cluster epidemics. Methods The diarrhea cases in monitoring hospitals from 2014 to 2016 were analyzed by epidemiological methods.Stool specimens were collected using systematic sampling for etiological examination.All specimens were tested for cholera, Shigella, salmonella, Vibrio parahaemolyticus, rotavirus, norovirus and enteric adenovirus. Results Totally 11 742 cases of diarrhea were reported in Minhang District of Shanghai from 2014 to 2016.The majority of the patients were young and middle aged adults.885 stool samples were detected for pathogen, 454 cases (51.30%) were pathogen positive including 57 cases of bacterial and virus co-infection.The detection rates of bacteria and viruses were respectively 10.36%(92/454)and 34.46%(305/454).Three kinds of bacteria and five kinds of viruses were detected, that were mainly Vibrio parahaemolyticus (n=72), salmonella (n=19), norovirus (n=195) and rotavirus A (n=71).The positive rate of pathogens reached the peak from January to March.There was a significant difference in pathogen positive rate between different seasons, while no difference between different years, gender and age groups.The epidemic peaks of different pathogens were different, with bacteria in summer and virus in winter and spring. Conclusion The positive rate of pathogens that caused diarrhea in Minhang District shows a significant seasonal peak.Norovirus, Vibrio parahaemolyticus and rotavirus A are the three main pathogens.It is necessary to take effective measures for diarrhea disease control according to the epidemiological characteristics.
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.
ABSTRACT
Objective To introduce the establishment of Shanghai Diarrhea Comprehensive Surveillance System ,and to analyze the epidemiological and etiological characteristics of infectious diarrhea outpatients in Shanghai based on data of Shanghai Diarrhea Comprehensive Surveillance System .Methods Diarrhea patients were surveyed according to a unified designed questionnaire ,who visited one of 22 adult sentinel hospitals and 4 children sentinel hospitals of Shanghai Diarrhea Comprehensive Surveillance during September 2013 to August 2016 .Stool specimens were collected according to different sampling intervals and detected for 12 bacteria and 5 viruses .Characteristics of diarrhea patients were compared and analyzed .Chi-square test was used for statistical analysis .Results Of 4497 infectious diarrhea patients ,the detection rate of viral infection was 29 .77％ ,of which norovirus infection (16 .33％ ) , rotavirus infection (7 .90％ ) and sapovirus infection (1 .90％ ) were dominated . The detection rate of bacterial infection was 15 .38％ ,diarrheagenic E .coli (DEC) infection (5 .25％ ) ,V . parahaemolyticus infection (4 .27％ ) and Salmonella spp .infection (3 .13％ ) .Mixed infection accounted for 11 .07％ .The detection rate ,the infection types and the predominant pathogens in different age groups were statistically different (χ= 18 .11 ,61 .86 and 449 .52 ,respectively ,all P< 0 .01) .DEC ranked first in 3 - 14 years age group , and norovirus ranked first in all other age groups .The pathogen spectrum of infectious diarrhea patients≥ 15 years old showed obvious seasonal changes ,with mainly bacterial infection in summer (peaked in August ,accounting for 81 .56％ ) and mainly viral infection in winter (peaked in January ,accounting for 95 .27％ ) .Norovirus ranked first through the year ,except January ,June ,July and August .Among patients ≥ 15 years old , abdominal pain , fever and loose stools were main symptoms in bacterial infections .Vomiting and watery stool were main symptoms in viral infections . Loose stools appeared frequently in patients ≤ 14 years old .Conclusions Diarrhea Comprehensive Surveillance System based on scientific design and rational distribution is beneficial for understanding the epidemic trends and pathogen characteristics of diarrhea .Viral infections are predominant in infectious diarrhea patients in Shanghai . Norovirus and rotavirus are the most common diarrheal pathogens .The pathogen spectrum of infectious diarrhea patients shows obvious seasonal changes .DEC is common in diarrhea patients ≤ 14 years old . The clinical symptoms of infectious diarrhea caused by different pathogens are different . Targeted preventive measures should be taken for infectious diarrhea of different ages ,different pathogens ,and in different seasons .
ABSTRACT
Epidemic surveillance is critical to infectious disease prevention and control .This article describes the evolution and current situation of epidemic surveillance in PLA , systematically analyzes major problems with epidemic surveillance , including incomplete surveillance , simplistic surveillance methods , outdated surveillance technology , inefficient disease diagnosis , poor epidemic prediction , and administrative interference in epidemic reporting .Ways to enhance epidemic surveillance are described here , such as carrying out comprehensive surveillance , and expanding the contents of surveillance , strengthening active surveillance , optimizing surveillance methods , speeding up informatization construction , innovating surveillance technology ,improving disease diagnosis technology , enhancing the ability of epidemic recognition,carrying out the prediction research ,improving the ability of early warning ,perfecting the system construction , and strengthening the awareness of infectious disease reporting .