NEW YORK (Reuters Health) - Mother-to-child transmission appears to be the most common route of Helicobacter pylori infection in Japan.

In The Pediatric Infectious Disease Journal, Dr. Mutsuko Konno and colleagues at Sapporo Kosei General Hospital in Sapporo note that previous studies have suggested that children are at high risk for H. pylori acquisition and that their mothers are the likely sources.

H. pylori is a bacterium passed from person to person and infection is usually contracted during childhood. Chronic H. pylori infection is responsible for most cases of ulcers and many cases of chronic gastritis. While it affects up to half of the world's population, many people who harbor the pathogen never develop an ulcer or gastritis.

To further investigate the route of transmission in childhood, the researchers analyzed H. pylori DNA from 42 children with H. pylori gastritis and 66 family members who were also infected with the organism.

Overall, 32 children (76 percent) had an H. pylori "DNA fingerprint" identical to the one in at least one family member. In 29 children (69 percent), the patterns were identical to the pattern seen in the mother. In 6 children, H. pylori DNA patterns matched those of both parents. One child's H. pylori DNA fingerprint pattern matched only the father's.

Recognizing this mode of transmission "may be useful in identifying a high-risk population, especially in countries such as Japan that have high rates of gastric cancer," the authors conclude.

SOURCE: The Pediatric Infectious Disease Journal, November 2008.

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