London, Jan 23 (IANS): Damage limitation therapies that control the symptoms caused by a bug or virus in the body rather than killing it at the first place, may not be effective in the long term, scientists have found.

Damage limitation therapies focus on enabling the patient to tolerate disease and buy the immune system valuable time to get rid of the infection naturally.

Researchers at the Universities of Edinburgh and Liverpool in Britain created a mathematical model to look at how damage limitation drugs could affect how infections spread and evolve.

People given damage limitation therapies may appear healthy, but carry high levels of infection and so may be more likely to pass on disease, said the study published in the journal PLoS Biology.

"In treating infections with drugs, we change their environment, but bacteria and other infectious agents are incredibly good at adapting to their environment,” said Pedro Vale of University of Edinburgh's school of biological sciences.

The researchers found that for certain infections, where the symptoms are not linked to the spread of disease, these drugs may prevent disease from evolving too quickly.

However, people with lesser symptoms could remain undiagnosed and add to the spread of disease, the study said.

"Damage limitation therapies may be a useful alternative to antibiotics, but we should be cautious, and investigate their potential long-term consequences,” Vale added.