Infections may be spread faster in those who eat well, a study has suggested.
Scientists at the University of Edinburgh said research into water-fleas has shown that increasing the supply of food can accelerate the rate in which bacterial infections are passed.
They found that when a population of parasite-infected water-fleas was well-fed, some of them became highly contagious, compared with when food was limited.
The research could help find ways to control the spread of infections in large populations.
Some well-fed water-fleas were more infectious than others because they were able to survive for longer with the parasite, giving it more time to multiply, the team said. Among those that were well-fed, some were carrying more parasites than others, and so were more prone to spreading the disease.
Researchers said their study highlighted the need to consider the impact of environmental conditions, such as nutrition, on individuals in large populations at risk of disease.
Dr Pedro Vale, of the University of Edinburgh, who led the study, said: “If we have an idea of which individuals transmit a lot of disease, we will be better able to stop its spread.”