title: Follow up of serial urea breath test results in patients after consumption of antibiotics for non-gastric infections.
abstract: OBJECTIVE
  The widespread use of antibacterial therapy has been suggested to be the cause for the decline in the prevalence of Helicobacter pylori infection. This study examine the serial changes of urea breath test results in a group of hospitalized patients who were given antibacterial therapy for non-gastric infections.
  
  
  METHODS
  Thirty-five hospitalized patients who were given antibacterial therapy for clinical infections, predominantly chest and urinary infections, were studied. Most (91 %) patients were given single antibiotic of either a penicillin or cephalosporin group. Serial (13)C-urea breath tests were performed within 24 hours of initiation of antibiotics, at one-week and at six-week post-therapy. H. pylori infection was diagnosed when one or more urea breath tests was positive.
  
  
  RESULTS
  All 35 patients completed three serial urea breath tests and 26 (74 %) were H. pylori-positive. Ten (38 %) H. pylori-infected patients had at least one negative breath test results during the study period. The medium delta (13)C values were significantly lower at baseline (8.8) than at one-week (20.3) and six-week (24.5) post-treatment in H. pylori-positive individuals (P=0.022). Clearance of H. pylori at six-week was only seen in one patient who had received anti-helicobacter therapy from another source.
  
  
  CONCLUSIONS
  Our results suggested that one-third of H. pylori-infected individuals had transient false-negative urea breath test results during treatment with antibacterial agent. However, clearance of H. pylori infection by regular antibiotic consumption is rare.
authors.affiliation: Department of Medicine Therapeutics, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China. wkleung@cuhk.edu.hk
authors.forename: Wai-Keung
authors.initials: WK
authors.lastname: Leung
authors.forename: Lawrence Cheung-Tsui
authors.initials: LC
authors.lastname: Hung
authors.forename: Carrie Ka-Li
authors.initials: CK
authors.lastname: Kwok
authors.forename: Rupert Wing-Loong
authors.initials: RW
authors.lastname: Leong
authors.forename: Daniel Kwok-Keung
authors.initials: DK
authors.lastname: Ng
authors.forename: Joseph Jao-Yiu
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D005188:False Negative Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D014508:Urea / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D014508:Urea