title: Prevalence and molecular characterisation of human adenovirus in diarrhoeic children in Tanzania; a case control study.
abstract: BACKGROUND
  Human adenovirus (HAdV) causes acute diarrhoea sporadically, as well as in outbreaks. Understanding the prevalence and types of HAdV in diarrhoea is important for control and preventive measures, especially in the African region where there is a high burden of diarrhoeal disease. The present study assessed the prevalence, molecular characteristics, seasonality and associated clinical features of HAdV infection Tanzanian children below two years of age with and without diarrhoea between 2010-2011.
  
  
  METHODS
  Stool specimens, demographic and clinical information were collected in 690 cases and 545 controls. All stool samples were screened for HAdV-antigen using ELISA. Positive samples subsequently underwent real-time PCR and sequencing for molecular typing.
  
  
  RESULTS
  HAdV was detected in 37 children, corresponding to a prevalence of 3.5% (24/690) in diarrhoeic and 2.4% (13/545) in non-diarrhoeic children (P > 0.05). Among HAdV-infected children, the median age was significantly lower in diarrhoeic than in non-diarrhoeic children (10 vs. 14 months, P˂0.001). More than half of HAdV infected (54.2%) were dehydrated as compared to diarrhoeic children without HAdV (45.8%, P = 0.01). The proportion of the enteric HAdV type 40/41 in diarrhoeic and non-diarrhoeic children was (50.0%, 12/24) and (46.2%, 6/13) respectively. Other HAdV types detected were; 1, 2, 7, 18, 19 and 31. The prevalence of adenovirus was not significantly different between rainy and dry seasons. HAdV was not detected in the 33 known HIV positive children. There was no significant association between HAdV infection and gender, nutritional status of the child and parent educational level.
  
  
  CONCLUSIONS
  The present study provides further evidence of the contribution of adenovirus in causing gastroenteritis in young children, with symptomatic infection being significantly more prevalent in children below one year. We found similar prevalence of adenovirus in non-diarrhoeic children and in diarrhoeic children. This first report on molecular epidemiology of human adenovirus in Tanzania observed diversity of HAdV types that circulate the study setting. The study findings suggest that HAdV is not an important cause of diarrhoea in young HIV-positive children.
authors.affiliation: Department of Clinical Science, University of Bergen, Bergen, Norway. Sabrina.moyo@med.uib.no.
authors.forename: Sabrina John
authors.initials: SJ
authors.lastname: Moyo
authors.forename: Kurt
authors.initials: K
authors.lastname: Hanevik
authors.forename: Bjørn
authors.initials: B
authors.lastname: Blomberg
authors.forename: Oyvind
authors.initials: O
authors.lastname: Kommedal
authors.forename: Svein Arne
authors.initials: SA
authors.lastname: Nordbø
authors.forename: Samuel
authors.initials: S
authors.lastname: Maselle
authors.forename: Nina
authors.initials: N
authors.lastname: Langeland
mesh_terms: D000258:Adenovirus Infections, Human / Q000453:epidemiology*; D000260:Adenoviruses, Human / Q000235:genetics; D000956:Antigens, Viral / Q000235:genetics; D016022:Case-Control Studies; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology / Q000821:virology; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D025202:Molecular Diagnostic Techniques; D017720:Molecular Epidemiology; D010802:Phylogeny; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D012621:Seasons; D013636:Tanzania / Q000453:epidemiology
chemical_list: D000956:Antigens, Viral