A DEADLY disease that can alter sufferers’ personalities shows potential for spreading outside Africa, scientists warn.
Known as ‘sleeping sickness’, or African trypanosomiasis, it causes difficulties sleeping at night.
Early symptoms include fever, weakness, and itching.
While often mild at first, the infection can rapidly worsen if left untreated.
A hallmark of the disease is disrupted sleep patterns, hence the term ‘sleeping sickness,’ as sufferers may sleep during the day and struggle with insomnia at night.
Without treatment, the condition can progress to cause confusion, uncontrollable aggression, psychosis, and ultimately death.
A new study, published in Nature Journal, has revealed that the parasites responsible have evolved, which means the disease could spread beyond Africa.
Until now, they use tsetse flies in sub-Saharan Africa to move around.
The flies carry these parasites and pass infection when they bite a human or animal.
The research, led by scientists at the University of Edinburgh found genetic mutations in the parasites that simplify their life cycle.
This adaptation might allow them to infect animals directly without needing the tsetse fly as a go-between.
Alarmingly, strains of these evolved parasites have already been found in animals in Asia, South America, and southern Europe.
Scientists say this raises the risk of similar changes occurring in forms of the parasite that infect humans.
“Trypanosomes have found ways to expand their geographic range by excluding the tsetse fly from their life cycle,” explained Professor Keith Matthews, who co-led the study.
“The molecular changes they exhibit can allow us to detect the emergence of these virulent parasites that threaten both cattle and, potentially, humans.”
The researchers used gene-editing technology to study over 80 parasite samples collected from people, animals, and tsetse flies.
By mapping a “family tree” of the parasites, they identified multiple mutations in key genes that enable this evolutionary leap.
The findings highlight the role of climate change and human interventions – such as efforts to control tsetse fly populations – in driving these changes.
With the parasites no longer tied to their original insect hosts, their spread could accelerate.
The experts now hope to develop portable diagnostic tools to detect outbreaks early, said co-author Dr Guy Oldrieve.
“We plan to continue this research to facilitate real-time detection of future outbreaks,” he said.
While the prospect of sleeping sickness spreading to humans outside Africa is worrying, the new genetic insights provide a valuable head start in tracking and tackling the disease, they added.
Sleeping sickness, also known as human African trypanosomiasis (HAT), is a deadly tropical disease spread by the tsetse fly.
It primarily affects rural communities in East, West, and Central Africa.
And without treatment, it’s almost always fatal.
In the early stages, symptoms are flu-like and include fever, swollen glands, muscle aches, and headaches.
The disease gets its name from the more advanced stage, where it wreaks havoc on sleep patterns.
Patients may sleep all day and struggle to stay awake at night, resembling a “zombie-like” state.
As the parasites invade the central nervous system, more severe symptoms appear, including:
Treatment, called NECT (nifurtimox-eflornithine combination therapy), is both complex and expensive.
It involves twice-daily injections for seven days and pills three times daily for 10 days.
The treatment itself is very painful. Up to 5 per cent of those who have it die from the medication.
Patients are often hospitaliaed, though medications can sometimes be delivered to remote areas.
Source: WHO/DNDi
