title: Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China.
abstract: BACKGROUND
  Acute diarrhea is a global health problem, resulting in high morbidity and mortality in children. It has been suggested that enteric pathogen co-infections play an important role in gastroenteritis, but most research efforts have only focused on a small range of species belonging to a few pathogen groups. This study aimed to assess the impact of co-infections with a broad range of enteric pathogens on children aged below five years who suffer from acute diarrhea in southwest China.
  
  
  METHODS
  A total of 1020 subjects (850 diarrhea cases and 170 healthy controls) were selected from four sentinel hospitals in Kunming, Yunnan province, southwest China, from June 2014 to July 2015. Stool specimens were collected to detect five virus (rotavirus group A, RVA; norovirus, NoV; Sapovirus, SaV; astrovirus, As; and adenovirus, Ad), seven bacterial (diarrheagenic Escherichia coli, DEC; non-typhoidal Salmonella, NTS; Shigella spp.; Vibrio cholera; Vibrio parahaemolyticus; Aeromonas spp.; and Plesiomonas spp.), and three protozoan (Cryptosporidium spp., Giardia lamblia, and Blastocystis hominis, B. hominis) species using standard microbiologic and molecular methods. Data were analyzed using the partial least square regression technique and chi-square test.
  
  
  RESULTS
  At least one enteric pathogen was detected in 46.7 % (n = 397) of acute gastroenteritis cases and 13.5 % (n = 23) of healthy controls (χ(2) = 64.4, P < 0.05). Single infection with RVA was associated with acute diarrhea (26.5 % vs. 5.8 %, P < 0.05). The prevalence of a single infection with B. hominis in diarrhea cases was higher than in healthy controls (3.1 % vs. 0.5 %, OR = 4.7, 95 % CI: 1.01-112.0). Single infection with NoV GII was not associated with diarrhea (4.4 % vs. 3.5 %, OR = 1.2, 95 % CI: 0.5-3.3). Single infections with bacterial species were not observed. The prevalence of co-infections with two enteric pathogens in diarrhea cases was higher than in asymptomatic children (20.1 % vs. 5.3 %, P < 0.05). RVA-NoV GII was the most common co-infection in symptomatic children (4.4 %), with it aggravating the severity of diarrhea.
  
  
  CONCLUSIONS
  Although it is clear that RVA has an overwhelming impact on diarrhea illnesses in children, co-infection with other enteric pathogens appears to also aggravate diarrhea severity. These findings should serve as evidence for public health services when planning and developing intervention programs.
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China.
authors.forename: Shun-Xian
authors.initials: SX
authors.lastname: Zhang
authors.affiliation: Yunnan Provincial Center for Disease Control and Prevention, Kunming, People's Republic of China.
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Zhou
authors.affiliation: Yunnan Provincial Center for Disease Control and Prevention, Kunming, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China.
authors.forename: Li-Guang
authors.initials: LG
authors.lastname: Tian
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China.
authors.forename: Jia-Xu
authors.initials: JX
authors.lastname: Chen
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China.
authors.forename: Shao-Hong
authors.initials: SH
authors.lastname: Chen
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China.
authors.forename: Zhi-Sheng
authors.initials: ZS
authors.lastname: Dang
authors.affiliation: Yunnan Provincial Center for Disease Control and Prevention, Kunming, People's Republic of China.
authors.forename: Wen-Peng
authors.initials: WP
authors.lastname: Gu
authors.affiliation: Yunnan Provincial Center for Disease Control and Prevention, Kunming, People's Republic of China.
authors.forename: Jian-Wen
authors.initials: JW
authors.lastname: Yin
authors.affiliation: Centre for Environmental and Marine Studies, Departamento de Biología, Universidade de Aveiro, Aveiro, Portugal.|Servei d'Ecopatologia de Fauna Salvatge, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Serrano
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, People's Republic of China. ipdzhouxn@sh163.net.|Key Laboratory for Parasite and Vector Biology, Ministry of Health of China, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, People's Republic of China. ipdzhouxn@sh163.net.
authors.forename: Xiao-Nong
authors.identifier: http://orcid.org/0000-0003-1417-8427
authors.initials: XN
authors.lastname: Zhou
mesh_terms: D000208:Acute Disease; D001424:Bacterial Infections / Q000150:complications / Q000453:epidemiology; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D060085:Coinfection / Q000150:complications / Q000453:epidemiology; D003967:Diarrhea / Q000150:complications / Q000453:epidemiology; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D011528:Protozoan Infections / Q000150:complications / Q000453:epidemiology; D014777:Virus Diseases / Q000150:complications / Q000453:epidemiology
keywords: Bacteria; Children; China; Co-infection; Diarrhea; Intestinal protozoa; Kunming; Severity; Virus; Yunnan