New types of drug intended for use in place of antibiotics have been given a cautious welcome by scientists.
Researchers have been probing the long-term effectiveness of drugs currently being developed by the pharmaceutical industry. These work by limiting the symptoms caused by a bug or virus in the body, rather than killing it outright.
These treatments are designed to avoid the problem of infections becoming resistant to treatment, which has become widespread with antibiotics.
This approach is intended to enable 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 created a mathematical model to look at how at how drugs that limit the damage caused by disease could affect how infections spread and evolve.
They 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. They will be useful over longer periods of time.
However, scientists caution that people given damage limitation treatments may appear healthy, but carry high levels of infection and so may be more likely to pass on disease. In addition, people with lesser symptoms could remain undiagnosed and add to the spread of disease. Their study was published in PLoS Biology.
Dr Pedro Vale, of the University of Edinburgh's School of Biological Sciences, said: "In treating infections with drugs, we change their environment, but bacteria and other infectious agents are incredibly good at adapting to their environment.
"Damage limitation therapies may be a useful alternative to antibiotics, but we should be cautious, and investigate their potential long-term consequences. Limiting damage may work for the individual, but could, in some cases, increase disease spread."