Researchers say they have paved the way for the development of a drug for human African trypanosomiasis (sleeping sickness).
The team, from Canada and the United Kingdom, inhibited an enzyme crucial for the survival of the Trypanosoma brucei parasite and successfully cured mice of the disease.
At the moment, there are no safe or effective drugs for sleeping sickness — one of Africa's deadliest diseases and spread by the tsetse fly — despite "more than a century of study".
One drug has fatal side effects in one in 20 patients, and the other requires lengthy hospital treatment and does not work against all forms of the disease.
This new method for tackling the disease could eventually yield better treatments, say the researchers.
However, there is still work to be done. So far, the compound is only effective against the first stage of infection — which occurs before the parasites infect a person's nervous system — so further work is needed before a safe drug becomes available for treating stage two of the disease.