Is the recurrence of Helicobacter pylori infection after eradication therapy resultant from recrudescence or reinfection, in Japan.
BACKGROUND
Reinfection of Helicobacter pylori after eradication is rare in developed countries but most often occurs within 1 year. In the present study, we attempted to differentiate between reinfection and recrudescence of H. pylori strains between 6 months and 6 years after successful eradication in Japan, a country with a high prevalence of H. pylori infection.


METHODS
After successful eradication of H. pylori, 274 patients were followed up by endoscopy and urea breath test. In recurrent patients, H. pylori strains isolated initially and after recurrence were compared using PCR-based restriction fragment length polymorphism (RFLP) analysis.


RESULTS
Recurrence of H. pylori occurred in 15 of 274 patients (5.5%) at 6 months after eradication and the annual recurrence rate was 2.0% per patient year (between 1 and 6 years). PCR-based RFLP analysis of H. pylori strains isolated initially and after recurrence showed that 62.5% (at 6 months) and 100% (after 1 years) of bacteria were of different strains.


CONCLUSIONS
Reinfection of H. pylori was not as rare at 6 months after eradication as reported previously, and up to 6 years after eradication, the annual reinfection rate is 2.0% per patient year in Japan.
Okimoto
Tadayoshi
T
Second Department of Internal Medicine, and Department of General Medicine, Oita Medical University, Oita, Japan.
Murakami
Kazunari
K
Sato
Ryugo
R
Miyajima
Hajime
H
Nasu
Masaru
M
Kagawa
Jiro
J
Kodama
Masaaki
M
Fujioka
Toshio
T
D000328:Adult; D000368:Aged; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000628:therapy*; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012008:Recurrence
D004269:DNA, Bacterial