Helicobacter pylori reinfection after apparent eradication--the Ipswich experience.

The reported rate of Helicobacter pylori reinfection following eradication therapy is highly variable. In Ipswich, the 14C-urea breath test (UBT) has been used since 1986 as a tool to study H. pylori eradication and reinfection. Updated results from 1182 patients in whom the organism had apparently been successfully eradicated, following a number of different eradication regimens between October 1986 and 31 March 1995, are presented. During this period, 57 "reinfections' were observed, of which 45 had occurred within 6 months of treatment. After the first year, the 'reinfection' rate was less than 0.6% per year. The criterion for eradication of the infection was a UBT (2-hour area under curve) of less than 40 at least 1 month after treatment. The treatment regimens were arbitrarily divided into five groups with eradication rates of: less than 20%, 20-39%, 40-59%, 60-79% and over 80%. In these groups, the 6-month 'reinfection' rates were 28.0%, 15.8%, 16.4%, 4.6% and 1.7%, respectively (p < 0.001). These and other data presented in the paper strongly suggest that, in Westernized countries, most so-called reinfections in adults are in fact the late recrudescence of a suppressed infection rather than a true reinfection. Our data also suggest that the true reinfection rate is particularly low if the eradication therapy chosen has an efficacy of more than 85%. Several effective and well-tolerated 1-week triple H. pylori eradication regimens are now available, and we would advocate their use in preference to the less effective dual regimens where initial eradication rates are lower and there is consequently a higher risk of 'reinfection'. We would predict that even in developing countries with a high prevalence of metronidazole-resistant H. pylori, the 'reinfection' rate would be low if a combination of omeprazole, amoxycillin and clarithromycin were to be used.