Recurrence of Helicobacter pylori infection after eradication is rare in developed countries, and more frequent in developing countries.
Most recurrent cases are attributed to recrudescence, the recolonization of the same strain within 12 months, rather than to reinfection or colonization with a new strain after more than 12 months.
|The calculated annual recurrence rates was 3% for developed countries|
Dr Niv Yaron and colleagues from Israel analyzed recurrence rates in developed, and developing countries, and deduced the relative roles of recrudescence, and reinfection.
The team searched the PubMed database up to 2007 using the keywords ‘Helicobacter pylori' or ‘H. pylori' and ‘recurrence' or ‘recrudescence', or ‘reinfection'.
Only prospective case studies in adults that used the 13C-urea breath test were included.
Meta-analyses were performed with statdirect statistical software.
The researchers noted that the literature search yielded 10 studies of H. pylori recurrence in developed countries including 3014 patients followed for 24 to 60 months.
The team identified 7 studies in developing countries including 2071 patients followed for 12 to 60 months.
The calculated annual recurrence rates were 3% and 13%, for developed and developing countries, respectively.
A nested meta-analysis of cases with a longer follow-up after eradication revealed an annual recurrence rate of 1% in developed countries and 12% in developing countries.
Dr Yarons' team concluded, "The similarity of the annual recurrence rates during the first year after eradication."
"The annual recurrence rates in the second year after successful eradication in developing countries supports reinfection as the main cause in the second period."
"Therefore, a different approach for follow-up of H. pylori eradication may be needed between developed, and developing countries."