A team from Singapore investigated whether the oro-oral route of transmission between spouses could be an important route of transmission of Helicobacter pylori.
They estimated the prevalence of different genotypes of H. pylori, as distinguished by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, in the local population.
They then compared the genotypes of H. pylori isolated from patients and their spouses.
Gastric biopsies were obtained from 183 dyspeptic patients during endoscopy.
Spouses of H. pylori-positive index cases were screened for the infection using serological testing. If they were found to be positive serologically, endoscopy and gastric biopsies were performed for genotypic study of the microorganism.
For couples with indistinguishable H. pylori strain on RFLP with restriction endonuclease MboI, the process of RFLP was repeated with digestion of the PCR products using restriction endonuclease HhaI.
The PCR technique was 90% sensitive and 96% specific.
| No couples were infected with the same H. pylori strain.
| European Journal of Gastroenterology and Hepatology |
A total of 89 subjects were found to be H. pylori-positive by PCR. According to the RFLP analysis, 8 different genotypic strains were found.
Two genotypes accounted for 81% of the cases.
Some 16 of 31 spouses tested serologically for H. pylori were positive.
All 13 spouses who agreed to undergo endoscopy were PCR-positive for H. pylori.
The researchers found that 5 couples shared indistinguishable H. pylori genotypes as based on RFLP with restriction endonuclease MboI.
However, this was the commonest genotype in the local population.
Further RFLP on the PCR products on these 5 couples, using restriction endonucleases HhaI, showed that the H. pylori isolated from these 5 couples were of different strains.
Author W. Luman, of the Singapore General Hospital, said on behalf of the group, "The oro-oral route of transmission between spouses is unlikely to be an important mode for H. pylori infection."