College of Medicine & Veterinary Medicine

Malaria parasites fight effects of drugs

New insights into how malaria parasites survive and thrive may help to explain how they resist the effects of drugs.

A University study suggests that malaria parasites can detect when they are being threatened and change their behaviour in order to increase their chances of survival.

Researchers hope that the study, funded by the Wellcome Trust, may inform strategies to control the disease, which causes one million deaths each year.

Blood infection

The disease is caused when malaria parasites replicate in the bloodstream of patients.

During infections, however, some parasites do not replicate and instead develop into a specialised transmission form - a process that enables the disease to be spread by mosquitoes.

Parasites must produce the right balance of replicating and transmission forms to ensure that they are not only able to survive, but also able to spread infection.

With parasites having access to only limited resources, it is a delicate balancing act.

Safety in numbers

The new study shows that when drug-sensitive strains of the human malaria parasite are exposed to low doses of anti-malarial drugs, the balance of types of forms is upset.

Instead, the parasites opt for increasing their chances of surviving the medicines through a ‘safety in numbers’ strategy.

The parasites achieve this by producing fewer transmission forms, which enables them to invest more in replication.

The findings are published in the journal Proceedings of the Royal Society B.

This study uncovers a new way that parasites are able to resist the effects of drugs. This is also likely to have important implications for human disease control strategies.

Dr Sarah ReeceSchool of Biological Sciences