title: Associations between Helicobacter pylori infection, co-morbid infections, gastrointestinal symptoms, and circulating cytokines in African children.
abstract: BACKGROUND
  Refugee children have complex medical needs and often have multiple infections. The relationship between infection, gastrointestinal symptoms, and systemic inflammation is poorly understood. We investigated these parameters in refugee children with a high prevalence of Helicobacter pylori, helminth, and malaria infection.
  
  
  METHODS
  African refugee children were recruited at resettlement health screening. Data were collected on demography, gastrointestinal symptoms, co-morbid infection, and serum for peripheral cytokine levels. Helicobacter pylori infection was diagnosed by a fecal-based immunoassay.
  
  
  RESULTS
  Data from 163 children were analyzed, of which 84.0% were positive for H. pylori. Infected children were significantly older (9.2 years +/- 3.7 vs 7.1 years +/- 3.9, p = .01). Half the cohort (84/163, 51.5%) described gastrointestinal symptoms but these were not strongly associated with co-morbid infections. Helicobacter pylori-infected children had significantly lower circulating log-interleukin-8 (IL-8) (odds ratio 0.61, 95% confidence interval (CI) 0.40, 0.94, p = .025). Helminth infections were common (75/163, 46%) and associated with elevated log-IL-5 (beta: 0.42, 95% CI 0.077, 0.76). Children with malaria (15/163, 9.2%) had elevated log-tumor necrosis factor-alpha (TNFalpha) and log-IL-10 (beta: 0.67, 95% CI 0.34, 1.0 and beta: 1.3, 95% CI 0.67, 1.9, respectively). IL-10 : IL-12 ratios were increased in H. pylori-infected children with malaria or helminth infections. Symptoms were generally not associated with levels of circulating peripheral cytokines irrespective of co-morbid infection diagnosis.
  
  
  CONCLUSIONS
  There is a high prevalence of asymptomatic H. pylori infection in recently resettled African refugee children. Gastrointestinal symptoms were not predictive of H. pylori nor of helminth infections. Serum cytokines, particularly IL-5, IL-10, and TNFalpha, were significantly elevated in children with malaria and helminth infections but not in those with H. pylori infection.
authors.affiliation: School of Pediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cherian
authors.forename: David Paul
authors.initials: DP
authors.lastname: Burgner
authors.forename: Angus George
authors.initials: AG
authors.lastname: Cook
authors.forename: Frank Mario
authors.initials: FM
authors.lastname: Sanfilippo
authors.forename: David Alan
authors.initials: DA
authors.lastname: Forbes
mesh_terms: D000349:Africa / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D016207:Cytokines / Q000097:blood*; D005243:Feces / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D006373:Helminthiasis / Q000453:epidemiology; D006801:Humans; D007118:Immunoassay; D007223:Infant; D007231:Infant, Newborn; D008288:Malaria / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012036:Refugees
chemical_list: D016207:Cytokines