20100415
allafrica

Sleeping sickness, a disease that is prevalent in sub-Saharan Africa and affects some of the poorest people in the world, may finally have a cure thanks to The Drug Discovery for Tropical Diseases program at the University of Dundee.

Tsetse flies carry the sleeping sickness infection, which is spread through bites leaving behind a parasite that attacks the central nervous system. Sleep becomes uncontrollable as the disease gets worse, and eventually leads to coma, which is fatal without treatment, according to the World Health Organization (WHO).

Professor Paul Wyatt and fellow researchers at the Drug Discovery for Tropical Diseases program have identified an enzyme that exploits a weakness in the parasite. "If we inhibit this enzyme it will have significant effects on many processes within the parasite, leading to the rapid death we see on treatment with our compounds," Wyatt told MediaGlobal. "We think the major effect though is on the process of replacement of the parasite's cell surface, which is rapidly replaced as part of its defense mechanism against the host immune system."

According to the WHO, sleeping sickness is an epidemic in 36 African countries and affects 60,000 people annually, and is part of a group of diseases known as "neglected tropical diseases." One sixth of the world's population suffers from one or more of the neglected diseases. These diseases have a low profile and low status amongst public health priorities.

Explaining why sleeping sickness goes overlooked Wyatt said, "Many of the countries are not politically stable so have multiple issues, have poor health care infrastructure, and are not set up to lobby for help." He also said that in recent years most of the focus has been on HIV, tuberculosis, and malaria. "Sleeping sickness is not the only neglected disease which requires greater attention and more drug discovery effort."

Although a clinical trial for a drug developed from the discovery is still 1.5 to 2 years away, Wyatt believes it will have significant advantages over current treatments. "Almost all of the current treatments are given by injection, either by infusion or into muscle," said Wyatt. "In addition, the current drugs are associated with significant toxicity, one causes deaths in 5 percent of patients, ...[and] deaths and complications are caused by infection due to the use of needles."

The new drug will be administered through an oral tablet, which "will be more suitable for areas with little or no health care infrastructure," Wyatt said. Sleeping sickness mostly affects people in isolated and remote areas and an affordable cure will make it easier to treat people in these secluded places. "A cure which will need limited resource to administer, a pill rather than injections...will be more attractive to charitable organizations [which will donate pills] for clinical use. Therefore the sufferers will not have to pay for the drug."

Once Wyatt and his team have an optimized compound, they will partner with Drugs for Neglected Diseases initiative (DNDi, Geneva) to carry out the pre-clinical and clinical development. "DNDi have experience taking sleeping sickness compounds through clinical development," he said. "Our efforts are focused on developing compounds which are simple and cheap to make, keeping down the cost of the final drug." Wyatt explained, "If we come up with a drug which is both efficacious and safe in the early and late stage, where parasites have entered the brain, a diagnosis through taking a sample of spinal fluid through a lumber puncture will not be needed, making treating the disease both easier and more attractive to the patients."

Making an inexpensive drug is important for Wyatt. "[People] cannot afford to pay for their drugs, so it is not an attractive disease for companies which need to make a profit to satisfy their shareholders."

MediaGlobal is an independent international media organization, based in the United Nations, creating awareness in the global media on social justice and development issues in the world's least developed countries.