The bite of the sandfly transmits leishmaniasis to humans. Picture credit James Gathany.
Lack of innovation has long been one of the most lamented problems with neglected tropical disease (NTD) treatment. Most drugs for treating NTDs, though effective, were developed decades ago. The longer a treatment gets used, the greater risk of the disease becoming resistant towards it. A non-NTD example of the risks of drug resistance would be drug-resistant tuberculosis . While there still remains an innovation gap for NTDs, there has been a building effort to develop new, innovative treatments for NTDs. And in one of life’s odd coincidences, the celebration of World Health Day this past week capped a week of breakthroughs which could lead to new, effective treatments for diseases in dire need of them.
Human African trypanosomiasis, better known as African sleeping sickness, is a parasitic disease that affects an estimated 50,000-70,000 people in sub-Saharan Africa and is 100% lethal if untreated . Unfortunately, the two treatments for sleeping sickness are antiquated and insufficient. One treatment requires prolonged hospitalization with limited effectiveness, and the other treatment is based off of arsenic and kills 20% of those treated. However, there may soon be a new treatment for sleeping sickness thanks to a breakthrough by scientists at the Drug Discovery for Tropical Diseases program at Dundee University in England . They’ve successfully isolated a compound which attacks an enzyme necessary for the parasite to survive. Test treatments in lab mice caused rapid and complete elimination of the disease. With human trials beginning in as soon as 18 months, we may be just a few years away from a safe and effective treatment for this horrific disease.
But if such a treatment is a few years away, what can be done in the meanwhile? That’s answered by another breakthrough in the fight against sleeping sickness. Sleeping sickness is spread by the tsetse fly, so trapping the fly would do a great deal too slow to stop the spread of the disease. This past week, research from Burkina Faso and Ivory Coast were able to identify the chemicals which most effectively attract the tsetse fly. Test traps using these chemicals resulted in an up to five-fold increase in the number of flies trapped. This technology will be field tested in the near future and, if successful, would provide an effective, and relatively cheap, means of fighting sleeping sickness. These two breakthroughs combined make the future for sleeping sickness treatment look much brighter than just a week ago.
Leishmaniasis, a lethal parasitic disease transmitted by sandflies, also saw a promising breakthrough. A survey to create a genetic barcode of sandflies in Panama revealed an interesting fact: both species of sandfly which carry the Leishmania parasite also carry the Wolbachia parasite. The importance of this is that Wolbachia affects the reproductive ability of the flies and could be an effective biological control for sandflies.
Together, these three breakthroughs are a promising sign for NTD treatment. Not only do they promise effective ways of combating two horrific NTDs, but they also show that the ongoing push for innovation of NTD treatment is starting to pay dividends and bringing us closer to a future free of NTDs.
