• View in gallery

    The geographic distribution of the five network laboratories and 16 sentinel hospitals.

  • View in gallery

    Positive percentage (%) of the main enteropathogens between middle- and high-income levels. *P < 0.05. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic Escherichia coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

  • View in gallery

    Positive percentage (%) of main enteropathogens among different age groups. *P < 0.05. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic E. coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

  • View in gallery

    Seasonal patterns of the main enteropathogens. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic Escherichia coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

  • 1.

    GBD Diarrhoeal Diseases Collaborators, 2017. Estimates of global, regional, and national morbidity, mortality, and aetiologies of diarrhoeal diseases: a systematic analysis for the global burden of disease study 2015. Lancet Infect Dis 17: 909948.

    • Search Google Scholar
    • Export Citation
  • 2.

    Walker CLF, Rudan I, Liu L, Nair H, Theodoratou E, Bhutta ZA, O’Brien KL, Campbell H, Black RE, 2013. Global burden of childhood pneumonia and diarrhoea. Lancet 381: 14051416.

    • Search Google Scholar
    • Export Citation
  • 3.

    Qiao N et al. 2017. Variation analysis of Norovirus among children with diarrhea in rural Hebei Province, North of China. Infect Genet Evol 53: 199205.

    • Search Google Scholar
    • Export Citation
  • 4.

    Wang XY et al. 2005. Incidence of diarrhea caused by Rotavirus infections in rural Zhengding, China: prospective, population-based surveillance. J Infect Dis 192 (Suppl 1): S100S105.

    • Search Google Scholar
    • Export Citation
  • 5.

    Qin S, Duan R, Jing HQ, Wang X, 2018. Etiology of bacterial diarrhea in large cities, mid-sized/small cities and rural areas of China. Zhonghua Liu Xing Bing Xue Za Zhi 39: 651655.

    • Search Google Scholar
    • Export Citation
  • 6.

    Wang X, Wang J, Sun H, Xia S, Duan R, Liang J, Xiao Y, Qiu H, Shan G, Jing H, 2015. Etiology of childhood infectious diarrhea in a developed region of China: compared to childhood diarrhea in a developing region and adult diarrhea in a developed region. PLoS One 10: e0142136.

    • Search Google Scholar
    • Export Citation
  • 7.

    Section on Breastfeeding, 2012. Breastfeeding and the use of human milk. Pediatrics 129: e827e841.

  • 8.

    World Health Organization, 2018. Infant and Young Child Feeding. Geneva, Switzerland: WHO.

  • 9.

    Shane AL et al. 2017. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis 65: 19631973.

    • Search Google Scholar
    • Export Citation
  • 10.

    Management Office of National Science and Technology Major Project of China, 2011. Diarrheal Syndrome Surveillance Protocol (2012 Version). Beijing, China: Chinese Center for Disease Control and Prevention.

    • Search Google Scholar
    • Export Citation
  • 11.

    Yan H, Nguyen TA, Phan TG, Okitsu S, Li Y, Ushijima H, 2004. Development of RT-multiplex PCR assay for detection of adenovirus and group A and C rotaviruses in diarrheal fecal specimens from children in China. Kansenshogaku Zasshi 78: 699709.

    • Search Google Scholar
    • Export Citation
  • 12.

    Liu X et al. 2015. Etiological epidemiology of viral diarrhea on the basis of sentinel surveillance in children younger than 5 years in Gansu, northwest China, 2009–2013. J Med Virol 87: 20482053.

    • Search Google Scholar
    • Export Citation
  • 13.

    Zheng S et al. 2016. Enteropathogens in children less than 5 years of age with acute diarrhea: a 5-year surveillance study in the Southeast Coast of China. BMC Infect Dis 16: 434.

    • Search Google Scholar
    • Export Citation
  • 14.

    Muller D, Greune L, Heusipp G, Karch H, Fruth A, Tschape H, Schmidt MA, 2007. Identification of unconventional intestinal pathogenic Escherichia coli isolates expressing intermediate virulence factor profiles by using a novel single-step multiplex PCR. Appl Environ Microbiol 73: 33803390.

    • Search Google Scholar
    • Export Citation
  • 15.

    Brenner F, Villar R, Angulo F, Tauxe R, Swaminathan B, 2000. Salmonella nomenclature. J Clin Microbiol 38: 24652467.

  • 16.

    Wang X, Cui Z, Jin D, Tang L, Xia S, Wang H, Xiao Y, Qiu H, Hao Q, Kan B, 2009. Distribution of pathogenic Yersinia enterocolitica in China. Eur J Clin Microbiol Infect Dis 28: 12371244.

    • Search Google Scholar
    • Export Citation
  • 17.

    National Bureau of Statistics of China, 2008. Statistic Provisions for Dividing Urban and Rural Areas. Beijing, China: National Bureau of Statistics of China.

    • Search Google Scholar
    • Export Citation
  • 18.

    The World Bank, 2018. World Bank Country and Lending Groups. Washington, DC: The World Bank.

  • 19.

    Li J, Pan H, Xiao WJ, Gong XH, Zhuang Y, Kuang XZ, Wu HY, Yuan ZA, 2017. Epidemiological and etiological surveillance study of infectious diarrhea in Shanghai in 2013–2015. Zhonghua Yu Fang Yi Xue Za Zhi 51: 11131117.

    • Search Google Scholar
    • Export Citation
  • 20.

    Chen C-J, Wu F-T, Huang Y-C, Chang W-C, Wu H-S, Wu C-Y, Lin J-S, Huang F-C, Hsiung CA, 2015. Clinical and epidemiologic features of severe viral gastroenteritis in children: a 3-year surveillance, multicentered study in Taiwan with partial Rotavirus immunization. Medicine 94: e1372.

    • Search Google Scholar
    • Export Citation
  • 21.

    Operario DJ et al. 2017. Etiology of severe acute watery diarrhea in children in the global Rotavirus surveillance network using quantitative polymerase chain reaction. J Infect Dis 216: 220227.

    • Search Google Scholar
    • Export Citation
  • 22.

    Podkolzin AT et al. 2009. Hospital-based surveillance of Rotavirus and other viral agents of diarrhea in children and adults in Russia, 2005–2007. J Infect Dis 200 (Suppl 1): S228S233.

    • Search Google Scholar
    • Export Citation
  • 23.

    Zhang J et al. 2015. Rotavirus-specific and overall diarrhea mortality in Chinese children younger than 5 years: 2003 to 2012. Pediatr Infect Dis J 34: e233e237.

    • Search Google Scholar
    • Export Citation
  • 24.

    Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD, Koopmans M, Lopman BA, 2014. Global prevalence of Norovirus in cases of gastroenteritis: a systematic review and meta-analysis. Lancet Infect Dis 14: 725730.

    • Search Google Scholar
    • Export Citation
  • 25.

    Glass RI, Parashar UD, Estes MK, 2009. Norovirus gastroenteritis. New Engl J Med 361: 17761785.

  • 26.

    O’Brien SJ, Donaldson AL, Iturriza-Gomara M, Tam CC, 2016. Age-specific incidence rates for Norovirus in the community and presenting to primary healthcare facilities in the United Kingdom. J Infect Dis 213 (Suppl 1): S15S18.

    • Search Google Scholar
    • Export Citation
  • 27.

    Patel MM, Hall AJ, Vinje J, Parashar UD, 2009. Noroviruses: a comprehensive review. J Clin Virol 44: 18.

  • 28.

    Zhang ZK, Lai SJ, Yu JX, Geng QB, Yang WQ, Chen Y, Wu JG, Jing HQ, Yang WZ, Li ZJ, 2017. Etiology of acute diarrhea in the elderly in China: a six-year observational study. Plos One 12: 10.

    • Search Google Scholar
    • Export Citation
  • 29.

    Canizalez-Roman A, Flores-Villaseñor HM, Gonzalez-Nuñez E, Velazquez-Roman J, Vidal JE, Muro-Amador S, Alapizco-Castro G, Díaz-Quiñonez JA, León-Sicairos N, 2016. Surveillance of diarrheagenic Escherichia coli strains isolated from diarrhea cases from children, adults and elderly at Northwest of Mexico. Front Microbiol 7: 1924.

    • Search Google Scholar
    • Export Citation
  • 30.

    Zhou Y et al. 2018. Bacterial pathogen spectrum of acute diarrheal outpatients in an urbanized rural district in Southwest China. Int J Infect Dis 70: 5964.

    • Search Google Scholar
    • Export Citation
  • 31.

    Zhou Y, Zhu X, Hou H, Lu Y, Yu J, Mao L, Mao L, Sun Z, 2018. Characteristics of diarrheagenic Escherichia coli among children under 5 years of age with acute diarrhea: a hospital based study. BMC Infect Dis 18: 63.

    • Search Google Scholar
    • Export Citation
  • 32.

    Chen Y et al. 2014. Serotypes, genotypes and antimicrobial resistance patterns of human diarrhoeagenic Escherichia coli isolates circulating in Southeastern China. Clin Microbiol Infect 20: 5258.

    • Search Google Scholar
    • Export Citation
  • 33.

    Nataro JP, Mai V, Johnson J, Blackwelder WC, Heimer R, Tirrell S, Edberg SC, Braden CR, Morris JG, Hirshon JM, 2006. Diarrheagenic Escherichia coli infection in Baltimore, Maryland, and New Haven, Connecticut. Clin Infect Dis 43: 402407.

    • Search Google Scholar
    • Export Citation
  • 34.

    Zhang S-X et al. 2016. Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China. Infect Dis Poverty 5: 64.

    • Search Google Scholar
    • Export Citation
  • 35.

    Satter SM, Gastanaduy PA, Islam K, Rahman M, Rahman M, Luby SP, Heffelfinger JD, Parashar UD, Gurley ES, 2017. Hospital-based surveillance for Rotavirus gastroenteritis among young children in Bangladesh: defining the potential impact of a Rotavirus vaccine program. Pediatr Infect Dis J 36: 168172.

    • Search Google Scholar
    • Export Citation
  • 36.

    Li Y et al. 2014. Nontyphoidal Salmonella infection in children with acute gastroenteritis: prevalence, serotypes, and antimicrobial resistance in Shanghai, China. Foodborne Pathog Dis 11: 200206.

    • Search Google Scholar
    • Export Citation
  • 37.

    Gorkiewicz G, 2009. Nosocomial and antibiotic-associated diarrhoea caused by organisms other than Clostridium difficile. Int J Antimicrob Agents 33: S37S41.

    • Search Google Scholar
    • Export Citation
  • 38.

    Sears CL, 2009. Enterotoxigenic Bacteroides fragilis: a rogue among symbiotes. Clin Microbiol Rev 22: 349369.

  • 39.

    Woo PC, Lau SK, Teng JL, Que T-L, Yung RW, Luk W-K, Lai RW, Hui W-T, Wong SS, Yau H-H, 2004. Association of Laribacter hongkongensis in community-acquired gastroenteritis with travel and eating fish: a multicentre case-control study. Lancet 363: 19411947.

    • Search Google Scholar
    • Export Citation
  • 40.

    Guo Y, Duan Z, Qian Y, 2013. Changes in human parechovirus profiles in hospitalized children with acute gastroenteritis after a three-year interval in Lanzhou, China. PLoS One 8: e68321.

    • Search Google Scholar
    • Export Citation
  • 41.

    Lasure N, Gopalkrishna V, 2017. Molecular epidemiology and clinical severity of human bocavirus (HBoV) 1–4 in children with acute gastroenteritis from Pune, Western India. J Med Virol 89: 1723.

    • Search Google Scholar
    • Export Citation
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Prevalence of Enteropathogens in Outpatients with Acute Diarrhea from Urban and Rural Areas, Southeast China, 2010–2014

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  • 1 School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China;
  • | 2 Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China;
  • | 3 Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, China;
  • | 4 MOH Key Laboratory of Systems Biology of Pathogens and Dr. Christophe Mérieux Laboratory, CAMS-Fondation Mérieux, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China;
  • | 5 State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China

Acute diarrhea is an important public health issue. Here, we focused on the differences of enteropathogens in acute diarrhea between urban and rural areas in southeast China. Laboratory- and sentinel-based surveillance of acute diarrhea (≥ 3 loose or liquid stools/24 hours) was conducted at 16 hospitals. Fecal specimens were tested for bacterial (Aeromonas sp., Campylobacter sp., diarrheagenic Escherichia coli, Plesiomonas shigelloides, non-typhoidal Salmonella, Shigella sp., Vibrio sp., and Yersinia sp.) and viral (adenovirus, astrovirus, Norovirus, Rotavirus, and Sapovirus) pathogens. Descriptive statistics were used. Between January 1, 2010, and December 31, 2014, 4,548 outpatients with acute diarrhea were enrolled (urban, n = 3,220; rural, n = 1,328). Pathogens were identified in 2,074 (45.6%) patients. Norovirus (25.7%), Vibrio parahaemolyticus (10.2%), enteroaggregative Escherichia coli (EAEC) (8.8%), group A Rotavirus (7.0%), and enterotoxigenic Escherichia coli (ETEC) (5.6%) were the most common pathogens. Enteropathogens were less common in urban than in rural areas (42.0% versus 54.4%, P < 0.001). In urban areas, EAEC and ETEC were more common in high-income than in middle-income regions. Interventions targeting the most common enteropathogens can substantially reduce the burden of acute diarrhea in southeast China.

INTRODUCTION

Diarrhea is a leading cause of morbidity and mortality globally and caused an estimated 1.3 million deaths in 2015.1 China is one of the 15 high-burden countries for diarrhea in the world.2 Understanding the pathogen characteristics of diarrheal diseases is critical to enable the development of more specific disease control strategies.

The differences in pathogen features associated with acute diarrhea among patients of various ages and from different regions have been thoroughly discussed. In addition, previous studies in China have indicated the unique characteristics of some specific enteropathogens associated with acute diarrhea in rural areas.3,4 The enteropathogens of bacterial diarrhea among children was also found to vary in developing and developed regions of China.5,6 However, differences in the features of the enteropathogens of acute diarrhea between urban and rural areas, including both bacteria and viruses, have not been well demonstrated, especially in China.

Our research aimed to reveal the characteristics of enteropathogens associated with acute diarrhea in southeastern China between urban and rural areas. The conclusions drawn in our study provide scientific evidence to support the formulation of appropriate public health policies.

METHODS

Study design and participants.

Between January 1, 2010, and December 31, 2014, diarrhea surveillance was conducted at 16 sentinel hospitals in southeast China, covering 25 county-level cities, 59 districts, and 44 counties from the Zhejiang, Jiangsu, and Fujian provinces (Figure 1). The types of hospitals included children’s, general, and urban hospitals, and rural community health service centers.

Figure 1.
Figure 1.

The geographic distribution of the five network laboratories and 16 sentinel hospitals.

Citation: The American Journal of Tropical Medicine and Hygiene 101, 2; 10.4269/ajtmh.19-0171

During each week of the study period, the first 1–5 eligible cases visiting each sentinel hospital were enrolled in our study, with approximately a median of 60 outpatients with acute diarrhea enrolled each year in each hospital; they were primarily enrolled from the enteric, pediatric, infectious disease, emergency, and internal medicine departments. Diarrhea was defined as the passage of three or more loose or liquid stools per day. For breastfed babies (≤ 6 months),7,8 we used the mother’s definition of diarrhea. This study excluded patients with diarrhea lasting more than 14 days,9 patients with comorbid conditions (e.g., hypertension, diabetes mellitus, and cardiovascular disease), patients who had received antibiotics within the preceding 10 days, and patients who had a history of travel (defined as a trip outside of southeast China) in the week preceding the onset of illness.

Information regarding sociodemographic and clinical characteristics was collected using a standardized case reporting form (CRF) during recruitment. Verbal consent was acquired from outpatients or guardians and recorded by the practitioner on the CRF.

Specimen collection and transport.

Fecal specimens were collected and transported to network laboratories for microbiological testing. For each patient, three aliquots of feces were collected under the guidance of a trained nurse at the hospital. For viral testing, 5 g of fresh whole stool was collected in sterilized containers without preservatives and stored at −20°C. For bacterial testing, fresh whole stool was collected using five sterilized cotton swabs and immediately placed in Cary-Blair medium (C-B, Oxoid Ltd., Basingstoke, United Kingdom) at 4°C.

The collected specimens were packed and transported in ice boxes to network laboratories in accordance with the UN3373 transportation requirements within 24 hours for bacterial tests and within 48 hours for viral tests. When the samples arrived, the network laboratories inspected and recorded the quality of the specimens, and unqualified specimens (specimen volume < 5 g or swabs not preserved in Cary-Blair medium) were rejected. In cases of rejected samples, new samples were requested for resubmission.

Microbiological testing.

The network laboratories consisted of the Fujian Provincial Center for Disease Control and Prevention, Huzhou Central Hospital in Zhejiang Province, Jiangsu Provincial Center for Disease Control and Prevention, Zhejiang University, and Zhejiang Provincial Center for Disease Control and Prevention.

A panel of enteropathogens was assayed, including viral (adenovirus, astrovirus, Norovirus, Rotavirus, and Sapovirus) and bacterial (Aeromonas sp., Campylobacter sp., diarrheagenic Escherichia coli (DEC), Plesiomonas shigelloides (P. shigelloides), non-typhoidal Salmonella (NTS), Shigella sp., Vibrio sp., and Yersinia sp.) pathogens. All network laboratories adopted a uniform study protocol, including standardized test methods and operational procedures.10

For Rotavirus testing, an enzyme-linked immunosorbent assay (ProSpecT™ Rotavirus kit, Oxoid Ltd., Basingstoke, United Kingdom) was used to confirm the presence of group A Rotavirus antigens, and reverse transcription–polymerase chain reaction with random primers was used to genotype the ELISA-positive specimens.11 For the other viruses, viral DNA or RNA was extracted from specimens, and the first strand cDNAs were synthesized from the extracted viral RNAs. The multiplex PCR with two sets of specific primers was performed to detect adenovirus, astrovirus, Norovirus (GI and GII), Rotavirus (groups B and C), and Sapovirus.12,13

To isolate Campylobacter sp., the specimens were inoculated on Skirrow selective medium, which added blood and incubated at 42°C in microaerophilic environment for 2–3 days. The suspicious strains were identified following the oxidase, catalase, and hippurate hydrolysis tests.6 To isolate DEC, the specimens were inoculated onto MacConkey (MAC) agar and incubated at 37°C for 16–24 hours. The suspicious colonies were selected to perform biochemical reactions by Kligler iron agar (KIA), motility indole urea (MIU) semisolid medium, and indole/methyl red/Voges-Proskauer/citrate test to identify suspicious presumptive Escherichia coli strains. Multiplex PCR was performed to detect the virulence genes of suspicious presumptive Escherichia coli strains, and the main pathotypes of DEC included enteropathogenic Escherichia coli (EPEC), enteroaggregative Escherichia coli (EAEC), enterotoxigenic Escherichia coli (ETEC), enteroinvasive Escherichia coli (EIEC), and Shiga toxin-producing Escherichia coli (STEC).14 To isolate NTS, the specimens were placed into selenite brilliant green sulfa enrichment broth and incubated at 37°C for 16 hours. Then, the inoculum was placed onto the Salmonella Shigella (SS) agar at 37°C overnight, and the suspicious colonies were selected to conduct ortho-nitrophenyl-beta-D-galactopyranoside test. Finally, the strains were confirmed by Api20E (bioMérieux, France).15 To isolate Shigella sp., specimens were streaked onto the SS agar, MAC agar, or xylose lysine deoxycholate agar, incubated at 37°C for 16–24 hours. The suspicious colonies were chosen to test biochemical reactions by KIA and MIU. The strains were identified and serotyped by the antisera of Shigella. To isolate Vibrio sp., Aeromonas sp., and P. shigelloides, the specimens were cultured by alkaline peptone water at 37°C for 6–8 hours and then inoculated on thiosulfate citrate bile salts sucrose agar, MAC agar, and blood plate. The suspected colonies were tested for oxidase activity, and positive isolates were identified by Api20E/NE. To isolate Yersinia sp., enrichment was performed by using peptone sorbitol bile broth at 4°C for 10–20 days. Then, the strains were inoculated onto Yersinia selective agar (cefsulodin irgasan novobiocin agar) and incubated at 25°C for 24 hours. Suspicious colonies were selected by KIA and MIU, and then identified by Api20E.16

Statistical analysis.

According to the Statistic Provisions for Dividing Urban and Rural Areas from the National Bureau of Statistics and the present addresses of patients, we classified patients residing in cities and towns into urban areas, and those residing in townships and villages into rural areas.17 The income levels of different regions were divided into two categories, high and middle, by adopting the criteria of the World Bank and using the Atlas method.18 Detailed descriptions of the criteria were provided in Supplemental Tables 1 and 2, respectively. The enrolled outpatients were divided into five age groups: < 5, 5–24, 25–44, 45–64, and ≥ 65 years. The onset date of cases was divided into four seasons: spring (March–May), summer (June–August), autumn (September–November), and winter (December–February). As not all specimens underwent a full-range assay of 13 enteropathogens, the prevalence of each pathogen (the proportion of cases that tested positive) was calculated by dividing the number of positive samples by the total number of samples tested for that pathogen. The exact 95% confidence interval (CI) for the prevalence was calculated using a binomial distribution.

The chi-squared test or Fisher’s exact test was used to compare proportions as appropriate. A two-sided P-value < 0.05 was considered statistically significant. All statistical tests were performed using the Statistical Package for Social Science (SPSS, version 13.0, SPSS Inc., Chicago, IL) and Microsoft Excel 2013 (version 15.0, Microsoft Inc., Redmond, WA). A geographic map was processed using ArcGIS (version 9.3, ESRI Inc., Redlands, CA).

Ethics approval and consent to participate.

This study was approved by the Ethics Committee of the Chinese Center for Disease Control and Prevention. Verbal consent was acquired from outpatients or guardians and recorded by the practitioner on the CRF.

RESULTS

Characteristics of the study participants.

Between January 1, 2010, and December 31, 2014, 4,548 outpatients with acute diarrhea were enrolled, including 3,220 patients from urban areas and 1,328 patients from rural areas. Although gender, age, and the receipt of oral rehydration before treatment were similar between the patients in urban and rural areas, other characteristics (e.g., income level, season, and the percentages of vomiting, fever, and dehydration) differed (Table 1).

Table 1

Sociodemographic and clinical characteristics of outpatients with acute diarrhea in southeast China, 2010–2014

CharacteristicAll patients, n = 4,548Urban, n = 3,220Rural, n = 1,328P-value
Gender0.059
 Male2,439 (53.6)1,698 (52.7)741 (55.8)
 Female2,109 (46.4)1,522 (47.3)587 (44.2)
Age (years)0.808
 < 51,302 (28.6)916 (28.4)386 (29.1)
 5–24636 (14.0)442 (13.7)194 (14.6)
 25–441,340 (29.5)961 (29.8)379 (28.5)
 45–64889 (19.5)626 (19.4)263 (19.8)
 ≥ 65381 (8.4)275 (8.5)106 (8.0)
Income level*< 0.001
 High3,532 (79.9)2,748 (85.3)784 (65.2)
 Middle890 (20.1)472 (14.7)418 (34.8)
Season of illness onset< 0.001
 Spring698 (15.3)402 (12.5)296 (22.3)
 Summer2,165 (47.6)1,628 (50.6)537 (40.4)
 Autumn1,211 (26.6)875 (27.2)336 (25.3)
 Winter474 (10.4)315 (9.8)159 (12.0)
Clinical symptoms/signs
 Vomiting1,054 (23.2)671 (20.8)383 (28.8)< 0.001
 Fever430 (9.5)356 (11.1)74 (5.6)< 0.001
 Dehydration148 (3.3)121 (3.8)27 (2.0)0.003
Oral rehydration before treatment*77 (3.7)37 (3.1)40 (4.6)0.076

The results in the table are presented as the no (%). Bold characters indicate significant (P < 0.05) values.

* The numbers in the column were not summated for a total because of missing data.

The prevalence of enteropathogens.

Overall, 2,074 (45.6%) outpatients were positive for at least one pathogen, including 1,878 patients with mono-infections and 196 patients with coinfections. Among the 13 identified enteropathogens, Norovirus was the most prevalent (25.7%, 787/3,061), followed by Vibrio parahaemolyticus (V. parahaemolyticus) (10.2%, 328/3,222), EAEC (8.8%, 245/2,788), group A Rotavirus (7.0%, 225/3,194), ETEC (5.6%, 155/2,788), NTS (3.5%, 115/3,266), Aeromonas sp. (3.2%, 102/3,200), EPEC (2.2%, 62/2,788), Sapovirus (1.5%, 47/3,060), P. shigelloides (0.7%, 23/3,199), Vibrio flurialis (0.7%, 15/2,200), Vibrio cholerae (0.6%, 20/3,221), Shigella sp. (0.6%, 19/3,238), group B Rotavirus (0.6%, 18/3,111), adenovirus (0.6%, 17/3,068), astrovirus (0.5%, 16/3,062), group C Rotavirus (0.5%, 14/3,076), STEC (0.3%, 8/2,788), Yersinia sp. (0.2%, 6/3,201), Campylobacter sp. (0.1%, 3/3,177), and EIEC (0.1%, 2/2,788).

In total, 1878 (43.2%) of 4,352 patients were positive for mono-infections, and the major pathogens included Norovirus (23.3%, 690/2,964), V. parahaemolyticus (9.2%, 294/3,188), EAEC (8.0%, 197/2,474), ETEC (5.6%, 134/2,411), and group A Rotavirus (5.2%, 163/3,132) (Table 2).

Table 2

Microbiological findings of outpatients with acute diarrhea

EnteropathogensNo. positive/no. tested (%)P-value
All patients, n = 4,548Urban, n = 3,220Rural, n = 1,328
Mono-infection1,878/4,352 (43.2)1,245/3,114 (40.0)633/1,238 (51.1)< 0.001
Bacterial954/3,428 (27.8)600/2,469 (24.3)354/959 (36.9)< 0.001
 Diarrheagenic Escherichia coli415/2,692 (15.4)259/1,764 (14.7)156/928 (16.8)0.146
  EAEC197/2,474 (8.0)116/1,621 (7.2)81/853 (9.5)0.041
  EHEC5/2,282 (0.2)4/1,509 (0.3)1/773 (0.1)0.855
  EIEC0/2,277 (0.0)0/1,505 (0.0)0/772 (0.0)/
  EPEC47/2,324 (2.0)25/1,530 (1.6)22/794 (2.8)0.065
  ETEC134/2,411 (5.6)96/1,601 (6.0)38/810 (4.7)0.187
  Untyped32/2,309 (1.4)18/1,523 (1.2)14/786 (1.8)0.243
 Non-typhoidal Salmonella107/3,258 (3.3)60/2,266 (2.6)47/992 (4.7)0.002
Shigella sp.13/3,232 (0.4)11/2,254 (0.5)2/978 (0.2)0.386
Aeromonas sp.71/3,169 (2.2)47/2,192 (2.1)24/977 (2.5)0.583
Plesiomonas shigelloides14/3,190 (0.4)9/2,203 (0.4)5/987 (0.5)0.922
Campylobacter sp.1/3,175 (0.0)0/2,192 (0.0)1/983 (0.1)0.310
Vibrio sp.322/2,239 (14.4)206/1,713 (12.0)116/526 (22.1)< 0.001
  V. cholerae (serogroup O1 and O139)1/3,202 (0.0)1/2,211 (0.0)0/991 (0.0)1.000
  V. cholerae (serogroup non-o1/o139)14/3,215 (0.4)11/2,221 (0.5)3/994 (0.3)0.631
  V. parahaemolyticus294/3,188 (9.2)184/2,211 (8.3)110/977 (11.3)0.008
  V. flurialis13/2,198 (0.6)10/1,692 (0.6)3/506 (0.6)1.000
Yersinia sp.4/3,199 (0.1)2/2,205 (0.1)2/994 (0.2)0.781
 Other bacteria*7/1,532 (0.5)6/1,028 (0.6)1/504 (0.2)0.517
Viral924/3,398 (27.2)645/2,514 (25.7)279/884 (31.6)0.001
Rotavirus (groups A, B, and C)167/3,013 (5.5)98/2,268 (4.3)69/745 (9.3)< 0.001
  Group A rotavirus163/3,132 (5.2)95/2,369 (4.0)68/763 (8.9)< 0.001
  Group B rotavirus3/3,096 (0.1)3/2,305 (0.1)0/791 (0.0)0.575
  Group C rotavirus1/3,063 (0.0)0/2,283 (0.0)1/780 (0.1)0.255
Norovirus690/2,964 (23.3)500/2,223 (22.5)190/741 (25.6)0.079
  G I48/2,322 (2.1)34/1,757 (1.9)14/565 (2.5)0.430
  G II642/2,916 (22.0)466/2,189 (21.3)176/727 (24.2)0.100
Sapovirus34/3,047 (1.1)20/2,261 (0.9)14/786 (1.8)0.039
 Astrovirus8/3,054 (0.3)3/2,270 (0.1)5/784 (0.6)0.047
 Adenovirus11/3,062 (0.4)10/2,273 (0.4)1/789 (0.1)0.357
 Other viruses†14/2,993 (0.5)14/2,226 (0.6)0/767 (0.0)0.058
Coinfection196/2,670 (7.3)106/1,975 (5.4)90/695 (12.9)< 0.001
 Viral–viral54/2,528 (2.1)32/1,901 (1.7)22/627 (3.5)0.006
 Bacterial–bacterial63/2,537 (2.5)36/1,905 (1.9)27/632 (4.3)0.001
 Viral–bacterial79/2,553 (3.1)38/1,907 (2.0)41/646 (6.3)< 0.001
Total2,074/4,548 (45.6)1,351/3,220 (42.0)723/1,328 (54.4)< 0.001

EAEC = enteroaggregative Escherichia coli; EHEC = enterohaemorrhagic Escherichia coli; EIEC = enteroinvasive Escherichia coli; EPEC = enteropathogenic Escherichia coli; ETEC = enterotoxigenic Escherichia coli. Bold characters indicate significant (P < 0.05) values.

* The full range of eight bacteria tested (n = 1,532) was used to calculate the prevalence of other bacteria (e.g., Vibrio vulnificus; Sphingomonas paucimobilis).

† The full range of five viruses tested (n = 2,993) was used to calculate the prevalence of other viruses (e.g., Enterovirus 71, poliovirus).

In total, 196 (7.3%) of 2,670 patients were positive for coinfection, and the main combinations of pathogens involved were Norovirus and DEC coinfection (1.4%, 35/2,553), Norovirus and group A Rotavirus coinfection (1.1%, 27/2,528), DEC and V. parahaemolyticus coinfection (0.5%, 12/2,537), and DEC and Aeromonas sp. coinfection (0.4%, 11/2,537).

The detection rate of at least one pathogen-positive specimen was lower in urban areas than in rural areas (42.0% versus 54.4%, P < 0.001), including mono-infections (40.0% versus 51.1%, P < 0.001) and coinfections (5.4% versus 12.9%, P < 0.001). More specifically, in instances of mono-infection, some enteropathogens differed between urban and rural areas, including EAEC (7.2% versus 9.5%, P = 0.041), NTS (2.6% versus 4.7%, P = 0.002), V. parahaemolyticus (8.3% versus 11.3%, P = 0.008), group A Rotavirus (4.0% versus 8.9%, P < 0.001), Sapovirus (0.9% versus 1.8%, P = 0.039), and astrovirus (0.1% versus 0.6%, P = 0.047) (Table 2).

In regions with middle-income level, the percentage of EAEC-infected patients was lower in urban areas than in rural areas, and the same pattern was observed for V. parahaemolyticus–infected patients. In regions with high-income level, the percentages of EAEC, V. parahaemolyticus, group A Rotavirus, and Norovirus were lower in urban areas than in rural areas (Figure 2). Moreover, the percentage of EAEC-positive patients was lower in regions with middle-income level than in regions with high-income level (urban: 3.8% versus 9.0%, P = 0.012), and the same pattern was observed for ETEC (urban: 2.9% versus 7.6%, P = 0.014) and Norovirus (rural: 23.0% versus 33.4%, P = 0.008).

Figure 2.
Figure 2.

Positive percentage (%) of the main enteropathogens between middle- and high-income levels. *P < 0.05. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic Escherichia coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

Citation: The American Journal of Tropical Medicine and Hygiene 101, 2; 10.4269/ajtmh.19-0171

In both urban and rural areas, Norovirus was the leading pathogen among all age groups. In patients aged < 5 years, the percentage of EAEC-positive cases was lower in urban areas than in rural areas (2.7% versus 8.3%, P < 0.001), and the same pattern was observed for group A Rotavirus (11.4% versus 22.9%, P < 0.001) and Norovirus (27.8% versus 37.5%, P = 0.002). In patients aged 25–44 years, the percentage of V. parahaemolyticus infections was lower in urban areas than in rural areas (13.0% versus 19.3%, P = 0.009), and the same pattern was observed for group A Rotavirus (2.5% versus 6.3%, P = 0.011). In patients aged 45–64 years, the percentage of V. parahaemolyticus infections was lower in urban areas than in rural areas (8.6% versus 15.0%, P = 0.010), and the same pattern was observed for group A Rotavirus (0.9% versus 5.8%, P = 0.002) and Norovirus (18.2% versus 30.8%, P = 0.003). However, in patients aged 5–24 years, the percentage of ETEC-positive cases was higher in urban areas than in rural areas (15.6% versus 6.6%, P = 0.015) (Figure 3).

Figure 3.
Figure 3.

Positive percentage (%) of main enteropathogens among different age groups. *P < 0.05. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic E. coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

Citation: The American Journal of Tropical Medicine and Hygiene 101, 2; 10.4269/ajtmh.19-0171

In urban areas, Norovirus was the most prevalent pathogen during all seasons, except for July (ETEC) and August (V. parahaemolyticus). In rural areas, aside from July (V. parahaemolyticus), August (V. parahaemolyticus), November (group A Rotavirus), and January (group A Rotavirus), the most prevalent pathogen was Norovirus (Figure 4). The percentage of EAEC-positive patients in April was lower in urban areas than in rural areas (0.0% versus 11.1%, P = 0.049), the same pattern was observed for ETEC (September: 6.7% versus 15.6%, P = 0.016), V. parahaemolyticus (July: 8.7% versus 21.6%, P < 0.001; August: 13.0% versus 23.9%, P < 0.001; October: 4.7% versus 25.6%, P < 0.001), group A Rotavirus (January: 23.8% versus 44.4%, P = 0.043; March: 6.1% versus 27.6%, P < 0.001; April: 2.2% versus 17.3%, P = 0.004), and Norovirus (August: 9.6% versus 22.3%, P < 0.001; October: 42.6% versus 66.0%, P = 0.003). However, the opposite pattern was observed in ETEC (July: 14.1% versus 5.0%, P = 0.007) and Norovirus (January: 55.0% versus 22.2%, P = 0.002; March: 63.5% versus 39.5%, P = 0.004; November: 57.7% versus 26.2%, P < 0.001) (Figure 4).

Figure 4.
Figure 4.

Seasonal patterns of the main enteropathogens. EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic Escherichia coli; NoV = Norovirus; RVA = group A Rotavirus; VP = Vibrio parahaemolyticus.

Citation: The American Journal of Tropical Medicine and Hygiene 101, 2; 10.4269/ajtmh.19-0171

Clinical symptoms of major enteropathogens.

Norovirus-infected outpatients were younger than noninfected outpatients, but their clinical symptoms were similar, except for higher percentages of patients with vomiting and dehydration among Norovirus-infected outpatients. EAEC-infected outpatients were older than noninfected outpatients, and the clinical characteristics of the outpatients were similar, aside from a lower percentage of fever among EAEC-infected outpatients. The percentage of outpatients with vomiting was higher among V. parahaemolyticus–infected outpatients than among noninfected outpatients. Group A Rotavirus-infected outpatients were significantly younger than noninfected outpatients, and the clinical signs differed between the two groups, including a higher percentage of vomiting, more episodes of vomiting in 24 hours, a higher percentage of fever, and a higher percentage of dehydration among group A Rotavirus-infected outpatients than the corresponding parameters among noninfected outpatients (Table 3).

Table 3

Ages and clinical characteristics of outpatients infected with major enteropathogens

CharacteristicsEAECETECVibrio parahaemolyticusGroup A rotavirusNorovirus
Negative, n = 1,475Positive, n = 197P-valueNegative, n = 1,475Positive, n = 134P-valueNegative, n = 1,853Positive, n = 294P-valueNegative, n = 1,721Positive, n = 163P-valueNegative, n = 1,622Positive, n = 690P-value
Age, years, median (IQR)30.0 (4.0–51.0)33.0 (21.5–55.5)0.00930.0 (4.0–51.0)33.0 (24.0–51.0)0.02032.0 (19.0–52.0)32.5 (25.0–49.0)0.10026.0 (1.0–48.0)1.0 (0.0–17.0)< 0.00127.0 (1.0–49.0)24.0 (1.0–42.0)< 0.001
Duration of diarrhea, days, median (IQR)1.0 (1.0–2.0)1.0 (1.0–2.0)0.0141.0 (1.0–2.0)1.0 (1.0–1.0)< 0.0011.0 (1.0–2.0)1.0 (0.0–1.0)< 0.0011.0 (1.0–2.0)1.0 (1.0–2.0)0.9611.0 (1.0–2.0)1.0 (1.0–2.0)< 0.001
No. of stools in 24 hours, median (IQR)5.0 (4.0–6.0)5.0 (4.0–6.0)0.6435.0 (4.0–6.0)5.0 (3.0–6.0)0.1645.0 (4.0–6.0)5.0 (4.0–6.0)0.0055.0 (3.0–6.0)5.0 (4.0–7.0)0.0035.0 (3.0–6.0)5.0 (3.0–6.0)0.094
Vomiting present, %19.816.20.23619.817.20.46217.733.3< 0.00118.244.2< 0.00117.134.1< 0.001
Duration of vomiting, days, median (IQR)1.0 (0.0–1.0)1.0 (0.0–1.0)0.2981.0 (0.0–1.0)1.0 (1.0–1.0)0.5451.0 (0.0–1.0)1.0 (0.0–1.0)0.0091.0 (0.0–1.0)1.0 (0.5–2.0)0.1911.0 (0.0–1.0)1.0 (0.0–1.0)0.005
No. of vomiting episodes in 24 hours, median (IQR)1.0 (1.0–3.0)1.0 (1.0–2.75)0.6761.0 (1.0–3.0)1.0 (1.0–3.0)0.8591.0 (1.0–2.0)2.0 (1.0–3.0)< 0.0011.0 (1.0–3.0)3.0 (1.0–4.0)< 0.0011.0 (1.0–2.0)2.0 (1.0–3.0)< 0.001
Fever present, %6.11.50.0086.17.50.5326.87.80.52111.719.00.00610.210.90.615
Temperature of fever, °C, median (IQR)38.3 (38.0–38.8)38.5 (38.0–/)0.99238.3 (38.0–38.8)38.0 (38.0–38.525)0.42538.3 (38.0–38.7)38.1 (37.7–38.5)0.15238.4 (38.0–39.0)38.5 (38.0–39.0)0.61438.4 (38.0–38.8)38.0 (38.0–38.9)0.275
Dehydration present, %3.53.00.7653.53.00.9683.03.40.6871.24.30.0041.04.2< 0.001

EAEC = enteroaggregative Escherichia coli; ETEC = enterotoxigenic Escherichia coli. IQR = interquartile range. Bold characters indicate significant (P < 0.05) values.

DISCUSSION

The results of this diarrhea surveillance study on the epidemiology of enteropathogens in southeast China showed differences in characteristics of enteropathogens between urban and rural areas, and indicated a higher positive percentage of enteropathogens in rural areas than in urban areas. Norovirus, V. parahaemolyticus, EAEC, group A Rotavirus, and ETEC were the most common enteropathogens in this study.

Overall, 45.6% of the enrolled patients were positive for at least one pathogen, which is similar to the results of a diarrhea surveillance study in Shanghai, China.19 In contrast to most studies that focused on patients aged < 5 years, this surveillance study enrolled patients in all age groups. Thus, Norovirus was the predominant pathogen in this study rather than rotavirus, as identified in other studies12,2023; however, group A Rotavirus was still a leading pathogen among patients aged < 5 years in this study. Norovirus plays an important role in sporadic diarrheal cases across all age groups.2427 Moreover, previous studies have reported that the most prevalent enteropathogen in adults was Norovirus.6,22,28 DEC is a main cause of bacterial diarrhea in developing countries,2931 and in this study, EAEC was predominant among the pathotypes of DEC, which is in line with the results of previous studies.32,33 In total, 7.3% of patients with acute diarrhea were positive for more than one pathogen; this detection rate is much lower than those reported previously.34

In patients infected with Norovirus, V. parahaemolyticus, and group A Rotavirus, the percentage of patients with vomiting was higher than the corresponding percentage of noninfected patients, suggesting that if vomiting were included in the “case definition,” the positive percentages of specific pathogens may improve. Some studies have incorporated this idea in the surveillance of Norovirus and Rotavirus.35

Unlike other major pathogens, in urban areas, EAEC and ETEC exhibited a higher positive percentage in regions with high-income level than in those with middle-income level. The specific reason for this observation requires further investigation, especially in the context of rapid urbanization.

LIMITATIONS OF THIS STUDY

However, this study had several limitations. First, this study lacked a case–control design. Hospital-based surveillance was not representative of the overall population. Because of the limited capacity of laboratories, most specimens were not assayed for the full range of enteropathogens. For example, unlike the previously reported positive percentage (7.1%) in Shanghai, China,36 Campylobacter sp. in this study may have been underestimated. Therefore, some stool specimens should be tested again with improved technology or appropriate selective enrichment. Alternatively, the negative results of some stool specimens may have been due to the absence of the enteropathogens in our surveillance scheme. Some “new” agents of diarrhea have been described, including bacterial (Klebsiella oxytoca,37 enterotoxigenic Bacteroides fragilis,38 and Laribacter hongkongensis39) and viral (Parechovirus40 and bocavirus41) pathogens. Moreover, the information regarding the subtypes of enteropathogens was not complete. Finally, long-term trends were not observed in this study as the period of 5 years was too short. Further continuous surveillance will be able to clarify such trends.

CONCLUSION

In conclusion, precise interventions targeting the five most common pathogens (Norovirus, V. parahaemolyticus, EAEC, group A Rotavirus, and ETEC) can substantially reduce the burden of acute diarrhea in southeast China. The differences between urban and rural areas should be emphasized in future surveillance and intervention efforts. Moreover, further studies are needed to explore the risk factors for enteropathogen infection and acute diarrhea.

Supplementary Material

Acknowledgments

We would like to thank the patients, nurses, and clinicians who participated in this study and the laboratory and administration staff at all sites for their assistance.

REFERENCES

  • 1.

    GBD Diarrhoeal Diseases Collaborators, 2017. Estimates of global, regional, and national morbidity, mortality, and aetiologies of diarrhoeal diseases: a systematic analysis for the global burden of disease study 2015. Lancet Infect Dis 17: 909948.

    • Search Google Scholar
    • Export Citation
  • 2.

    Walker CLF, Rudan I, Liu L, Nair H, Theodoratou E, Bhutta ZA, O’Brien KL, Campbell H, Black RE, 2013. Global burden of childhood pneumonia and diarrhoea. Lancet 381: 14051416.

    • Search Google Scholar
    • Export Citation
  • 3.

    Qiao N et al. 2017. Variation analysis of Norovirus among children with diarrhea in rural Hebei Province, North of China. Infect Genet Evol 53: 199205.

    • Search Google Scholar
    • Export Citation
  • 4.

    Wang XY et al. 2005. Incidence of diarrhea caused by Rotavirus infections in rural Zhengding, China: prospective, population-based surveillance. J Infect Dis 192 (Suppl 1): S100S105.

    • Search Google Scholar
    • Export Citation
  • 5.

    Qin S, Duan R, Jing HQ, Wang X, 2018. Etiology of bacterial diarrhea in large cities, mid-sized/small cities and rural areas of China. Zhonghua Liu Xing Bing Xue Za Zhi 39: 651655.

    • Search Google Scholar
    • Export Citation
  • 6.

    Wang X, Wang J, Sun H, Xia S, Duan R, Liang J, Xiao Y, Qiu H, Shan G, Jing H, 2015. Etiology of childhood infectious diarrhea in a developed region of China: compared to childhood diarrhea in a developing region and adult diarrhea in a developed region. PLoS One 10: e0142136.

    • Search Google Scholar
    • Export Citation
  • 7.

    Section on Breastfeeding, 2012. Breastfeeding and the use of human milk. Pediatrics 129: e827e841.

  • 8.

    World Health Organization, 2018. Infant and Young Child Feeding. Geneva, Switzerland: WHO.

  • 9.

    Shane AL et al. 2017. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis 65: 19631973.

    • Search Google Scholar
    • Export Citation
  • 10.

    Management Office of National Science and Technology Major Project of China, 2011. Diarrheal Syndrome Surveillance Protocol (2012 Version). Beijing, China: Chinese Center for Disease Control and Prevention.

    • Search Google Scholar
    • Export Citation
  • 11.

    Yan H, Nguyen TA, Phan TG, Okitsu S, Li Y, Ushijima H, 2004. Development of RT-multiplex PCR assay for detection of adenovirus and group A and C rotaviruses in diarrheal fecal specimens from children in China. Kansenshogaku Zasshi 78: 699709.

    • Search Google Scholar
    • Export Citation
  • 12.

    Liu X et al. 2015. Etiological epidemiology of viral diarrhea on the basis of sentinel surveillance in children younger than 5 years in Gansu, northwest China, 2009–2013. J Med Virol 87: 20482053.

    • Search Google Scholar
    • Export Citation
  • 13.

    Zheng S et al. 2016. Enteropathogens in children less than 5 years of age with acute diarrhea: a 5-year surveillance study in the Southeast Coast of China. BMC Infect Dis 16: 434.

    • Search Google Scholar
    • Export Citation
  • 14.

    Muller D, Greune L, Heusipp G, Karch H, Fruth A, Tschape H, Schmidt MA, 2007. Identification of unconventional intestinal pathogenic Escherichia coli isolates expressing intermediate virulence factor profiles by using a novel single-step multiplex PCR. Appl Environ Microbiol 73: 33803390.

    • Search Google Scholar
    • Export Citation
  • 15.

    Brenner F, Villar R, Angulo F, Tauxe R, Swaminathan B, 2000. Salmonella nomenclature. J Clin Microbiol 38: 24652467.

  • 16.

    Wang X, Cui Z, Jin D, Tang L, Xia S, Wang H, Xiao Y, Qiu H, Hao Q, Kan B, 2009. Distribution of pathogenic Yersinia enterocolitica in China. Eur J Clin Microbiol Infect Dis 28: 12371244.

    • Search Google Scholar
    • Export Citation
  • 17.

    National Bureau of Statistics of China, 2008. Statistic Provisions for Dividing Urban and Rural Areas. Beijing, China: National Bureau of Statistics of China.

    • Search Google Scholar
    • Export Citation
  • 18.

    The World Bank, 2018. World Bank Country and Lending Groups. Washington, DC: The World Bank.

  • 19.

    Li J, Pan H, Xiao WJ, Gong XH, Zhuang Y, Kuang XZ, Wu HY, Yuan ZA, 2017. Epidemiological and etiological surveillance study of infectious diarrhea in Shanghai in 2013–2015. Zhonghua Yu Fang Yi Xue Za Zhi 51: 11131117.

    • Search Google Scholar
    • Export Citation
  • 20.

    Chen C-J, Wu F-T, Huang Y-C, Chang W-C, Wu H-S, Wu C-Y, Lin J-S, Huang F-C, Hsiung CA, 2015. Clinical and epidemiologic features of severe viral gastroenteritis in children: a 3-year surveillance, multicentered study in Taiwan with partial Rotavirus immunization. Medicine 94: e1372.

    • Search Google Scholar
    • Export Citation
  • 21.

    Operario DJ et al. 2017. Etiology of severe acute watery diarrhea in children in the global Rotavirus surveillance network using quantitative polymerase chain reaction. J Infect Dis 216: 220227.

    • Search Google Scholar
    • Export Citation
  • 22.

    Podkolzin AT et al. 2009. Hospital-based surveillance of Rotavirus and other viral agents of diarrhea in children and adults in Russia, 2005–2007. J Infect Dis 200 (Suppl 1): S228S233.

    • Search Google Scholar
    • Export Citation
  • 23.

    Zhang J et al. 2015. Rotavirus-specific and overall diarrhea mortality in Chinese children younger than 5 years: 2003 to 2012. Pediatr Infect Dis J 34: e233e237.

    • Search Google Scholar
    • Export Citation
  • 24.

    Ahmed SM, Hall AJ, Robinson AE, Verhoef L, Premkumar P, Parashar UD, Koopmans M, Lopman BA, 2014. Global prevalence of Norovirus in cases of gastroenteritis: a systematic review and meta-analysis. Lancet Infect Dis 14: 725730.

    • Search Google Scholar
    • Export Citation
  • 25.

    Glass RI, Parashar UD, Estes MK, 2009. Norovirus gastroenteritis. New Engl J Med 361: 17761785.

  • 26.

    O’Brien SJ, Donaldson AL, Iturriza-Gomara M, Tam CC, 2016. Age-specific incidence rates for Norovirus in the community and presenting to primary healthcare facilities in the United Kingdom. J Infect Dis 213 (Suppl 1): S15S18.

    • Search Google Scholar
    • Export Citation
  • 27.

    Patel MM, Hall AJ, Vinje J, Parashar UD, 2009. Noroviruses: a comprehensive review. J Clin Virol 44: 18.

  • 28.

    Zhang ZK, Lai SJ, Yu JX, Geng QB, Yang WQ, Chen Y, Wu JG, Jing HQ, Yang WZ, Li ZJ, 2017. Etiology of acute diarrhea in the elderly in China: a six-year observational study. Plos One 12: 10.

    • Search Google Scholar
    • Export Citation
  • 29.

    Canizalez-Roman A, Flores-Villaseñor HM, Gonzalez-Nuñez E, Velazquez-Roman J, Vidal JE, Muro-Amador S, Alapizco-Castro G, Díaz-Quiñonez JA, León-Sicairos N, 2016. Surveillance of diarrheagenic Escherichia coli strains isolated from diarrhea cases from children, adults and elderly at Northwest of Mexico. Front Microbiol 7: 1924.

    • Search Google Scholar
    • Export Citation
  • 30.

    Zhou Y et al. 2018. Bacterial pathogen spectrum of acute diarrheal outpatients in an urbanized rural district in Southwest China. Int J Infect Dis 70: 5964.

    • Search Google Scholar
    • Export Citation
  • 31.

    Zhou Y, Zhu X, Hou H, Lu Y, Yu J, Mao L, Mao L, Sun Z, 2018. Characteristics of diarrheagenic Escherichia coli among children under 5 years of age with acute diarrhea: a hospital based study. BMC Infect Dis 18: 63.

    • Search Google Scholar
    • Export Citation
  • 32.

    Chen Y et al. 2014. Serotypes, genotypes and antimicrobial resistance patterns of human diarrhoeagenic Escherichia coli isolates circulating in Southeastern China. Clin Microbiol Infect 20: 5258.

    • Search Google Scholar
    • Export Citation
  • 33.

    Nataro JP, Mai V, Johnson J, Blackwelder WC, Heimer R, Tirrell S, Edberg SC, Braden CR, Morris JG, Hirshon JM, 2006. Diarrheagenic Escherichia coli infection in Baltimore, Maryland, and New Haven, Connecticut. Clin Infect Dis 43: 402407.

    • Search Google Scholar
    • Export Citation
  • 34.

    Zhang S-X et al. 2016. Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China. Infect Dis Poverty 5: 64.

    • Search Google Scholar
    • Export Citation
  • 35.

    Satter SM, Gastanaduy PA, Islam K, Rahman M, Rahman M, Luby SP, Heffelfinger JD, Parashar UD, Gurley ES, 2017. Hospital-based surveillance for Rotavirus gastroenteritis among young children in Bangladesh: defining the potential impact of a Rotavirus vaccine program. Pediatr Infect Dis J 36: 168172.

    • Search Google Scholar
    • Export Citation
  • 36.

    Li Y et al. 2014. Nontyphoidal Salmonella infection in children with acute gastroenteritis: prevalence, serotypes, and antimicrobial resistance in Shanghai, China. Foodborne Pathog Dis 11: 200206.

    • Search Google Scholar
    • Export Citation
  • 37.

    Gorkiewicz G, 2009. Nosocomial and antibiotic-associated diarrhoea caused by organisms other than Clostridium difficile. Int J Antimicrob Agents 33: S37S41.

    • Search Google Scholar
    • Export Citation
  • 38.

    Sears CL, 2009. Enterotoxigenic Bacteroides fragilis: a rogue among symbiotes. Clin Microbiol Rev 22: 349369.

  • 39.

    Woo PC, Lau SK, Teng JL, Que T-L, Yung RW, Luk W-K, Lai RW, Hui W-T, Wong SS, Yau H-H, 2004. Association of Laribacter hongkongensis in community-acquired gastroenteritis with travel and eating fish: a multicentre case-control study. Lancet 363: 19411947.

    • Search Google Scholar
    • Export Citation
  • 40.

    Guo Y, Duan Z, Qian Y, 2013. Changes in human parechovirus profiles in hospitalized children with acute gastroenteritis after a three-year interval in Lanzhou, China. PLoS One 8: e68321.

    • Search Google Scholar
    • Export Citation
  • 41.

    Lasure N, Gopalkrishna V, 2017. Molecular epidemiology and clinical severity of human bocavirus (HBoV) 1–4 in children with acute gastroenteritis from Pune, Western India. J Med Virol 89: 1723.

    • Search Google Scholar
    • Export Citation

Author Notes

Address correspondence to Zhong-Jie Li, Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China, E-mail: lizj@chinacdc.cn or Yu Chen, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China, E-mail: chenyu_zy@163.com.

Financial support: This work was supported by the National Science and Technology Major Project [grant numbers: 2017ZX10103-008, 2012ZX10004-201, 2012ZX10004-210, 2009ZX10004-201, and 2009ZX10004-210] and the National Natural Science Foundation of China [grant numbers: 81802067 and 81803290]. The funding source for the study had no role in the study design, data collection, data analysis, data interpretation, or writing of the article. The corresponding authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Disclosure: The data used to support the findings of this study are available from the corresponding author on request.

Authors’ addresses: Chong Chen and Si-Jia Liu, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China, Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China, and Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, Zhejiang, China, E-mails: chenchong_1991@163.com and liusijia94@outlook.com. Li-Ping Wang and Zhong-Jie Li, Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China, E-mails: wanglp@chinacdc.cn and lizj@chinacdc.cn. Jian-Xing Yu, Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China, and MOH Key Laboratory of Systems Biology of Pathogens and Dr. Christophe Mérieux Laboratory, CAMS-Fondation Mérieux, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China, E-mail: interconnect-yu@163.com. Xiao Chen and Shu-Fa Zheng, Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, Zhejiang, China, and State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China, E-mails: zsfchx80@163.com and zsfzheng@163.com. Ruo-Nan Wang, Xian-Zhi Yang, Fei Yu, and Zi-Ke Zhang, Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, Zhejiang, China, E-mails: wrnsilvia0809@sina.com, yayayang1984@126.com, yufei2013@aliyun.com, and zhangzike2006@sina.com. Yu Chen, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China, Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, Zhejiang, China, and State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China, E-mail: chenyu_zy@163.com.

These authors contributed equally to this work.

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