Will a one-dose drug mean the end of sleeping sickness?

A potential new tool for eradication of sleeping sickness

“This is really an exciting development, which will be useful in the drive for eradication/interruption of transmission of this disease,” Dr. Pépin told this news organization.

Dr. Pépin treated around 1,000 trypanosomiasis patients during an outbreak in Zaire in the early 1980s. Because the asymptomatic incubation period for the disease can be several months or even years, “the core strategy for controlling the disease is active screening,” he said in an interview.

“You try to convince the whole population of endemic villages to show up on a given day, and then you have a mobile team of nurses who examine everybody, trying to find those with early trypanosomiasis. This includes physical examination for lymph nodes in the neck, but also a blood test whose results are available within minutes,” he said.

“Until now, these persons with a positive serology would undergo additional and labor-intensive examinations of blood to try to find trypanosomes and prove that they have the disease. So far those with a positive serology and negative parasitological assays (‘serological suspects’) were left untreated, because the treatments were toxic and cumbersome, and because a substantial but unknown proportion of these ‘suspects’ just have a false positive of their serological test, without having the disease,” Dr. Pépin said.

“Now with acoziborole, which seems to have little serious toxicity ... and can be given as a single-dose oral med, it might be reasonable to treat the ‘serological suspects,’ ” he said.

“Take it one step further, it might be possible to do the serological test only and treat all individuals with a positive serology without bothering to do parasitological assays. This is what they call ‘test-and-treat’ strategy. It would make sense, provided that we are sure that the drug is very well tolerated.”

Dr. Pépin added that he is “just slightly worried” about three patients described in the paper who had psychiatric adverse events 3 months after treatment. “If that happens to patients who indeed have trypanosomiasis, that’s a reasonable price to pay considering the toxicity of other drugs,” he said. “If that happens to serological suspects, many of whom don’t have any disease, this becomes a preoccupation.”

But Dr. Tarral said, “We have no indication that the drug can provoke psychiatric symptoms. In fact, the psychiatric symptoms did not emerge – they re-emerged after 3 months due to some patients’ refusal to be followed up.”

“We included patients in very advanced stages of the disease, and these symptoms are considered disease sequelae,” Dr. Tarral said. “The majority of patients who have such psychiatric symptoms need follow-up after treatment. If not, they can relapse very early. There were a lot of patients who had such symptoms and the investigators proposed they should be followed by a psychiatrist and some of them refused. And due to that only three of our patients had this relapse, and they were cured after psychiatric support.”

The study was funded through the DND initiative and was supported by grants from the Bill & Melinda Gates Foundation; UK Aid; the Federal Ministry of Education and Research through Kreditanstalt für Wiederaufbau, Germany; the Swiss Agency for Development and Cooperation; Médecins Sans Frontières; the Dutch Ministry of Foreign Affairs; the Norwegian Agency for Development Cooperation; the Stavros Niarchos Foundation; the Spanish Agency for International Development Cooperation; and the Banco Bilbao Vizcaya Argentaria Foundation.

A number of study investigators, including Dr. Tarral, report employment at the DND initiative. Other investigators report fees from the DND initiative for the statistical report, consulting fees from CEMAG, D&A Pharma, Inventiva, and OT4B Pharma. The Swiss Tropical and Public Health Institute acted as a service provider for the DND initiative by monitoring the study sites. Dr. Pépin declared no relevant financial relationships.

A version of this article first appeared on Medscape.com.