Sleeping Sickness | Sleeping sickness can now be cured with pills

Sleeping sickness is a parasitic infection which can kill. There are 60 million people at risk.

Sleeping sickness is a parasitic infection that kills

Generally known as sleeping sickness, human African trypanosomiasis is transmitted by tsetse flies.

Tsetse flies are found in 36 countries in sub-Saharan Africa, putting 60 million people at risk. The infection attacks the central nervous system, causing severe neurological disorders. Without treatment the disease is fatal.

According to the World Health Organisation (WHO), more than 95 percent of reported cases are caused by the parasite Trypanosoma brucei gambiense, which is found in western and central Africa.

The other 10 percent of cases are caused by Trypanosoma brucei rhodesiense, which is found in eastern and southern Africa.

Seventy four percent of all cases are reported in the Democratic Republic of Congo.

The reported number of new cases fell by 77 percent between 1999 and 2014 (from around 28,000 to 3,700).

What causes sleeping sickness?

The parasite causing sleeping sickness is transmitted to humans through infected tsetse flies, which breed in warm and humid areas.

Inhabiting the vast savannah across sub-Saharan Africa, tsetse flies come into contact with people, cattle and wild animals, all acting as reservoirs for the Trypanosoma parasites.

Symptoms of sleeping sickness

The first stage of sleeping sickness presents with non-specific symptoms such as fever, headache, weakness, itching and joint pain.

At this stage, sleeping sickness is easy to treat but difficult to diagnose.

If no treatment is given, the parasite will invade the infected person’s central nervous system and the second stage sets in.

The second stage may be characterised by more specific symptoms, such as confusion, violent behavior or convulsions.

Named after one of its most striking symptoms, patients with sleeping sickness experience an inability to sleep during the night but are often overcome by sleep during the day.

Diagnosing sleeping sickness

Diagnosing sleeping sickness before the second stage of the disease is difficult due to the non-specific symptoms of the early stage.

Once the parasite is detected, a painful lumbar puncture must be made to examine the patient’s cerebro-spinal fluid.

This will determine the stage of the disease and the appropriate treatment.

Treating sleeping sickness

The type of treatment depends on the stage of the disease.

Drugs used in the first stage of the disease are of lower toxicity and are easier to administer. However, treatment success in the second stage of the disease depends on a drug that can cross the blood-brain barrier. Nifurtimox-eflornithine combination therapy, or NECT, is now the WHOs recommended course.

NECT is much safer than melarsoprol, the drug previously used to treat the disease. Developed in 1949, melarsoprol is often described by patients as ‘fire in the viens’; between five and 20 percent of those treated die of complications from the toxic drug.

New molecules are currently under clinical trial in the hope of developing a safe, effective treatment for both stages of the disease that can be administered orally.

MSF is currently responsible for the efficient supply and distribution of all sleeping sickness drugs used in the world today.

Prevention efforts such as vector control are crucial to our efforts to keep sleeping sickness at bay. However, exhaustive screenings require a major investment in human and material resources.


Sleeping sickness can now be cured with pills:

For the first time, researchers have cured the deadly neurological disease sleeping sickness using pills instead of a combination of intravenous infusions and pills. The investigators presented the results from final clinical trials on 17 October at the European Congress on Tropical Medicine and International Health in Antwerp, Belgium, providing hope that the treatment will help to eliminate the malady within a decade.

The oral therapy — called fexinidazole — cured 91% of people with severe sleeping sickness, compared with 98% who were treated with the combination therapy. It also cured 99% of people in an early stage of the disease who would typically undergo a spinal tap to determine whether they needed infusions. The relative ease of the treatment with fexinidazole means that if approved, it might save more lives than the current option, say the investigators leading the phase 3 trial, the final phase of testing before the drug goes to regulators for approval.

Sleeping sickness is endemic to Africa and generally infects extremely poor people who live in remote regions. The sick often suffer from the disease for years before seeking treatment, causing them and those caring for them to miss work and spend their savings on traditional medicines. Trekking to a hospital and remaining there for intravenous infusions is costly as well.

“It’s not just the person with sleeping sickness, it’s the family that takes care of them during years of this neurological, very serious disease,” says Philippe Büscher, a sleeping-sickness specialist at the Institute of Tropical Medicine in Antwerp, Belgium, who was not involved in the study. “Whatever money they have, they’ll spend on this instead of anything else.”

Büscher commends the team for conducting a quality clinical trial under extraordinary circumstances in countries hit hardest by the disease, the Democratic Republic of the Congo and the Central African Republic. Investigators had to carry equipment to remote clinics over rugged terrain; one study site was repeatedly robbed; and early on in the trial, some participants fled armed conflict. “I need to congratulate them for beautiful work,” Büscher says.

A better way
Sleeping sickness — also known as human African trypanosomiasis — is spread through the bite of tsetse flies carrying parasites, most commonly Trypanosoma brucei gambiense. The organism infects the central nervous system, and patients can experience confusion, daytime sleepiness, night-time insomnia and various psychiatric symptoms, including manic episodes and aggression. If left untreated, they enter a coma and die. For decades, the only treatment was a toxic arsenic-based drug that killed one in 20 patients.

In 2009, researchers introduced a safer option: nifurtimox–eflornithine combination therapy, or NECT, which consists of pills and 14 intravenous infusions. For the first time in 50 years, the incidence of sleeping sickness slipped below 10,000 new cases per year; it’s currently around 2,200, according to the World Health Organization. But the need for infusions, along with the spinal tap required to qualify a patient for the treatment, still present obstacles in regions where sterile equipment, electricity and doctors are in short supply.

The group that developed NECT — a non-profit research organization based in Geneva, Switzerland, called the Drugs for Neglected Diseases initiative (DNDi) — continued searching for a better therapy. In 2007, it discovered fexinidazole, a compound that had been shelved by Paris-based pharmaceutical company Sanofi. With the firm's agreement, the DNDi took the drug through clinical trials. It estimates that developing the therapy through to approval will cost a total of around US$50 million — a fraction of what pharmaceutical companies often spend on new drugs.

Just the beginning
Sanofi will soon submit an application for drug approval through the European Medicines Agency, whose sign-off could pave the way for regulators in the Democratic Republic of the Congo. The drug might get a green light by the end of next year, says Nathalie Strub Wourgraft, the DNDi’s medical director. Because it is a simple oral treatment, she suggests that patients might even be treated at home, which would save them and their families the expense of hospital stays.

However, Büscher argues that home treatments could be dangerous because people who don’t respond to fexinidazole could die of the disease if not seen immediately by medical staff. It’s imperative that patients follow up with health workers, he says, and he suggests offering people incentives to return to the clinic, such as money or staples including salt or sorghum. “This is a success,” he says, “but it is not the end.”

DNDi researchers and their colleagues are currently working on what they hope will be an even better oral treatment to cure the disease in a single dose, and more reliably than fexinidazole.

Water evaporation could be a promising source of renewable energy

Solar and wind power get all the attention, but harvesting energy from evaporation could go a long way toward solving our power problems — at least in theory.'

This device sits on the surface of water and uses evaporation to harness energy. The shutters control how much energy is stored.

Photo by Ozgur Sahin

This method of harvesting energy is in very early stages. Unlike solar and wind power, evaporation technology is not commercialized yet and won’t be for a while. So is it worth pursuing further? Scientists wrote a model to figure this out, and predicted that the energy potentially available from evaporation is comparable to that of wind and solar power. The research was published today in the journal Nature Communications.

If we were able to harvest evaporation energy from the existing lakes and reservoirs in the US — excluding the Great Lakes in the Midwest — we could generate 325 gigawatts (2.85 million megawatt hours per year). That’s about 70 percent of the total US electrical energy generation in 2015. Energy from evaporation, unlike solar or wind, is less dependent on the weather. Of course, it’s not likely that we’d be able to use the water from every lake, and the authors do note that this could affect freshwater resources. But the paper suggests that evaporation-based energy could have a big impact.

How do you harvest energy from evaporation? Study author and Columbia University biophysicist Ozgur Sahin first developed the “evaporation engine” in a 2015 paper. Imagine you have a material that changes size when there’s a lot of water inside it. (In Sahin’s case, the material were tiny spores.) The spores absorb water and get bigger. When it’s hot, the water evaporates and the spores shrink.

Now, if you think of the spores as a muscle that contracts and elongates, says Sahin, you can connect it to a generator that produces electricity from motion, and then harvest energy from that process.
The spores are attached to tiny plastic strips, and expand and contract depending on whether it’s humid or dry.

The spores are attached to tiny plastic strips, and expand and contract depending on whether it’s humid or dry.

Photo by Ozgur Sahin

Sahin’s tiny “evaporation engine” sits on the surface of water. As water from the surface enters the device, it changes the shape of the spores, which create electricity. The spores are also connected to shutters that control how much water evaporates. This means that you can control how much energy is generated, and even store and release it over time to create continuous power. Other forms of renewable energy are more dependent on the amount of sun or wind. (Remember the solar eclipse? It disrupted power generated from solar panels.)

The same team also created a mill with spores on it, half in a humid environment and half in a dry environment. When attached to a tiny wheels, the device powered the wheels using evaporation.
This “moisture mill” was attached to a tiny platform with wheels, like a toy car. It powered the tiny car.

 Image by Ozgur Sahin

There are a lot of steps before this method can be put to use. The team is working to develop materials that can be manufactured on a large scale, and want to test their engine on a larger body of water, like a pool. But they could one day have a lot of impact — after all, the Earth is 70 percent water.

Do you know about Cancer-Detecting Pen

This cancer-detecting pen could one day help surgeons better remove tumors

The pen can identify cancerous tissue in 10 seconds

The MasSpec Pen

Photo by Vivian Abagiu / University of Texas at Austin

Scientists have developed a “pen” that can help surgeons identify cancer cells within 10 seconds. The tool could one day be used during surgeries to quickly determine what tissue should be cut in order to remove tumors completely.

The device, called MasSpec Pen, isn’t perfect yet, however; it can distinguish between cancerous and healthy tissue with about 96 percent accuracy. But the team behind the device, described this week in the journal Science Translational Medicine, hopes that the pen will be tested in surgeries as early as next year.

When a patient undergoes surgery to get rid of a tumor, a surgeon tries to remove all cancerous tissue while preserving the healthy tissue. In the case of breast cancer, for instance, the task is particularly delicate, as the surgeon tries to remove the tumor while preserving the rest of the breast. Right now, surgeons can send tissue samples to a lab for analysis, which can take days. Tissue can also be frozen and analyzed during the operation, but that takes 15 to 20 minutes. (The more time-consuming method is more accurate than the so-called “frozen section,” according to the National Cancer Institute.)

In search for a quicker but still accurate tool, researchers in Texas developed a handheld “pen” that gets the job done in 10 seconds. It uses a tiny amount of water — 10 microliters — to extract molecules from a person’s tissue. The water-molecules combo is then sent through tubes to an instrument that can identify the molecular fingerprint of cancer, telling the surgeon whether the tissue is healthy or cancerous.
An illustration of the pen and the instrument, called a mass spectrometer, that analyzes the tissue.

 Illustration: University of Texas at Austin

The researchers tested the device on 253 human tissue samples of breast, lung, thyroid, and ovarian cancer, as well as healthy tissue. The pen was accurate 96 percent of the time, the study says. The researchers also tested the MasSpec Pen while operating on mice with tumors, finding that the device didn’t damage tissue or stress the animals.

Before the pen is adopted, it needs to be tested on more tissue samples, as well as during actual surgeries in clinical trials. It also needs to be approved by the US Food and Drug Administration. The instrument that actually analyzes the tissue takes up a lot of space for now, but the team is already testing a smaller one, according to STAT.

Still, the pen seems to be a big improvement on current methods, and the researchers hope to start testing it during surgeries in 2018.