A U.S.-funded study in China might have
accidentally exposed participants to the
bacterium that causes stomach ulcers,
prompting National Cancer Institute doctors to
help administer antibiotics to up to 500 people.
It's still unclear if the research was to blame,
cautioned Dr. Susan Nayfield, chief of the NCI
unit that oversees international research safety.
China already had one of world's highest rates of
infection with the H. pylori bacterium.
But NCI and Chinese scientists are investigating
whether study participants were infected by
dirty endoscopes, tubes snaked down the throat
to inspect the stomach, Nayfield said Thursday.
The NCI funded two studies in the rural
Shandong province starting in 1989, to examine
the prevalence of stomach cancer and H. pylori
and to see if certain nutritional supplements
affected either condition. H. pylori causes
stomach ulcers, and is suspected to play a role
in stomach cancer. China also has high rates of
stomach cancer, relatively rare in this country.
Part of the first study, between 1989 and 1994,
used endoscopes to examine participants'
When the second study began in the late 1990s,
scientists recorded more H. pylori infections than
expected--a possible increase of 40 percent,
Unknown to the NCI, Chinese health officials in
the early 1990s declared endoscopes could be
cleaned by wiping them with a special cloth
instead of soaking them in a sterilizer, the
method U.S. officials recommend when
disposable endoscopes can't be used.
The question: Could dirty endoscopes be to
blame, did infections rise overall in Shandong, or
was there a testing error?
The NCI and an independent safety board
couldn't say, but NCI scientists departed for
China a few weeks ago to help provide
antibiotics to clear up the infections.
Also, the scientists will test-clean endoscopes
using the wiping method to see if H. pylori could
survive that way, something no one yet knows,