December 6, 2004
HOUSTON - For the first time, scientists have examined the complex causes of acute illness affecting the stomach and intestinal tract and identified the most effective prevention methods. Most intriguing, the research finds no apparent benefit from the popular and commonly used antibacterial soaps. The study, by Daniel M. Musher, M.D., chief, Infectious Disease Section, Michael E. DeBakey VA Medical Center and Benjamin L. Musher, M.D., staff physician, Department of Medicine, University of Pennsylvania School of Medicine, appears in the Dec. 2 New England Journal of Medicine.
Acute gastrointestinal illness is exceedingly common; viruses, bacteria, and protozoa are the principal recognized causes. "In our world, widespread media coverage of infections such as SARS, influenza in Asia, acute gastroenteritis on cruise ships and outbreaks in day-care centers have raised public interest in contagious diseases to new heights," said Daniel Musher.
Unlike agents that cause contagious respiratory infections, which are largely developed by humans, agents that cause acute gastrointestinal illness may spread from person to person or may be acquired from a common food or environmental source, often water. They may also result from exposure to animals.
The likelihood of becoming contagious depends on the age and self-reliance of an infected person, the nature of the social interaction, the intensity of the symptoms, and other, less well-understood factors.
"The immune status of the host undoubtedly plays a role in determining whether disease or infection results, but the nature of such immune factors is poorly understood," said Benjamin Musher.
Within families, young children are the usual source for contagion because of their exposure to other children, their imperfect personal hygiene, and their dependence on adults. Severely affected persons are more contagious because they discharge greater volumes of infective material that contain large numbers of infectious particles.
"Spread of acute gastrointestinal illness is common and problematic in all closed environments such as day-care centers, schools, and cruise ships," said Daniel Musher.
Person-to-person transmission is best prevented by the practice of excellent personal hygiene both by infected persons and by those exposed to them. Fecal-oral transmission is the usual route for spreading acute gastrointestinal illness, but several types of viruses are present in vomit, so kissing or sharing utensils should also be avoided. Dilution by hand washing reduces the number of germs, greatly diminishing the risk of contagion.
"However, our study found there is no apparent benefit from the antibacterial agents in soaps, although the regular use of alcohol-based gels will probably reduce transmission. The use of diluted household bleach on environmental surfaces may be necessary to completely clean them," said Benjamin Musher.
The study was supported by Merit Review Funding from the U.S. Department of Veterans Affairs.
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