Q&A: A breakthrough in treatment against tropical disease
Leishmaniasis kills nearly 50,000 people a year, and researchers in Antwerp have made a breakthrough that could potentially lead to improved treatment
Better diagnosis
Leishmaniasis is transmitted through the bites of sand flies (pictured) in the Mediterranean basin as well as Africa, Asia and South America. It’s classified as a neglected tropical disease.
Who is at risk of being infected?
Anybody who comes into contact with an infected sand fly is at risk; essentially people living in rural areas of tropical countries. Worldwide, we are seeing an urbanisation of leishmaniasis, meaning the insects are adapting to urban settings.
Does this disease affect people in Flanders?
Yes and no. Leishmaniasis has existed for decades in southern Europe, but it hasn’t been observed in Flanders. Every year, however, thousands of tourists travel to countries where leishmaniasis exists, and a few dozen return with the disease. Most contract the infection around the Mediterranean basin, but sometimes we have patients infected further away.
This is no cause for panic: there are more victims of traffic accidents than of leishmaniasis. General practitioners might not always think about leishmaniasis when making their diagnosis, but if patients are quickly directed to tropical medicine specialists, they will be diagnosed and treated adequately.
What is this new breakthrough in treatment all about?
Years ago, we were studying leishmaniasis treatment failure in Latin America. The current drugs were ineffective in patients, and not because of drug resistance. Something else was going on.
Recently, Marlene Jara, a Peruvian PhD student, joined our group, and along with other Peruvian researchers she discovered that the parasites were “sleeping” in some phases of their life cycle. Protein synthesis was lower in the parasite living in mammals than in sand flies.
So leishmaniasis “sleeps” in the mammal host, but we don’t yet know if this is responsible for treatment failure. Generally, drugs need active cells to be effective. We are now testing this hypothesis at the Institute of Tropical Medicine.
What are the next steps?
We only have four available drugs, and private companies have little interest in developing new drugs, for economic reasons: leishmaniasis is a disease that mostly affects poor people, and return on investment is low. In our lab, we have considerable experience in drug resistance and now in dormancy. We plan to apply this knowledge to guide further R&D on new drugs. Perhaps we will succeed in designing drugs capable of killing the hibernating parasites.
