Reinfection rate following effective therapy against Helicobacter pylori infection in Japan.
OBJECTIVE
In developed countries, reinfection of Helicobacter pylori (H. pylori) after eradication of the bacterium is unusual, while the reinfection rate in developing countries is variable. In this study, we determined the reinfection rate after successful H. pylori eradication in Japan, a country with a high prevalence of H. pylori infection.


METHODS
After successful eradication, 377 patients were followed up by endoscopy and urea breath test annually. In reinfected patients, H. pylori strains isolated initially and after reinfection were compared by using random amplification of polymorphic DNA fingerprinting.


RESULTS
H. pylori became positive in four of 337 patients (1.2) 1 year after eradication and in two of 133 patients (1.5) 2 years after eradication. One patient experienced an ulcer relapse 2 years after eradication therapy. Random amplification of polymorphic DNA fingerprinting of the isolated strains from four of the six patients showed two had identical strains (at 1 year) while the other two had different strains (one at 1 year and one at 2 years). When infection in the two patients reinfected with identical strains is considered a recrudescence, the true reinfection rate is < 0.8 per patient year.


CONCLUSIONS
The reinfection rate after eradication of H. pylori is low in Japan despite the country's high prevalence of H. pylori infection.
Adachi
Masayasu
M
Department of Medicine and Medical Science, Okayama University Graduate School of Medicine and Dentistry, Japan.
Mizuno
Motowo
M
Yokota
Kenji
K
Miyoshi
Masatsugu
M
Nagahara
Yasuhiro
Y
Maga
Toshirou
T
Ishiki
Kunihara
K
Inaba
Tomoki
T
Okada
Hioyuki
H
Oguma
Keiji
K
Tsuji
Takao
T
D000328:Adult; D000368:Aged; D001944:Breath Tests; D016172:DNA Fingerprinting / Q000379:methods; D004381:Duodenal Ulcer / Q000382:microbiology; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016480:Helicobacter pylori / Q000145:classification / Q000302:isolation & purification; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012008:Recurrence; D013276:Stomach Ulcer / Q000382:microbiology; D014510:Urease / Q000032:analysis
D014510:Urease