A public health official holds up three Triatoma dimidiatas in San Pedro Sula Thomson Reuters Diseases you've never heard of affect millions of people around the world.

These so-called neglected tropical diseases are mostly parasitic infections that have very few treatments and affect some of the hardest-hit communities.

But, there might be a glimmer of hope. Researchers at the Genomics Institute of the Novartis Research Foundation said in a letter published Monday in Nature that they have identified a new drug that could treat three of these debilitating diseases.

For now, the treatment has only been tested in mice, but ideally it could make a dent in the combined 20 million people affected by the diseases every year.

Chagas disease, leishmaniasis, and sleeping sickness lead to 500,000 deaths a year. They're all fairly similar diseases: Chagas disease is a parasitic infection that comes from the kissing bug that got its name for biting people on the face; leishmaniasis is a parasitic infection spread by sand flies that leads to skin sores; sleeping sickness (or trypanosomiasis) is a parasitic infection that's spread by the tsetse fly, which at first can lead to headaches, fever, joint pain, and itchiness, but later can lead to some serious neurological problems.

So, the scientists figured out a compound, which they dubbed GNF6702, that might be able to treat all three.

Starting out with leishmaniasis, they found that the drug worked better in mice than miltefosine, the treatment that's currently used to treat leishmaniasis. They made it work in mice, which is a good first step.

After that, they pitted it against the main drug for Chagas disease, benznidazole , which is being developed by KaloBios after then-CEO Martin Shkreli acquired the rights to the drug. They found that the new compound did just as well as benznidazole at making the mice parasite-free.

which is being developed by KaloBios after then-CEO Martin Shkreli acquired the rights to the drug. They found that the new compound did just as well as benznidazole at making the mice parasite-free. For sleeping sickness, the new drug did a better job of clearing out the parasite in mice than the existing treatment.

Finding one drug that could treat all three could be a major move in getting the treatment advanced into later trials that could one day change the way we treat these neglected diseases. The researchers noted, "There are only scarce resources for drug development in these diseases, and identification of a common target and chemical scaffold with potential across multiple indications provides new hope for improved treatment options for some of the world’s poorest people."