Better tests for sleeping sickness

Health workers use the classical ITG rapid diagnostic test to screen blood on antibodies against sleeping sickness. A better and safer to produce test now is possible, say researchers at the Antwerp Institute of Tropical Medicine. Credit: © ITG

Lies Van Nieuwenhove, researcher at the Antwerp Institute of Tropical Medicine, has produced proteins imitating typical parts of the sleeping sickness parasite. They can be used in more efficient diagnostic tests, without the need for culturing dangerous parasites.

Each year many thousands of Africans contract sleeping sickness. The cause is a unicellular parasite, a trypanosome, which is transmitted by the bite of flies. First the parasite multiplies in blood and lymph, while evading the . It then lodges in organs like heart and kidneys and finally in the brain. Patients become disoriented, their sleeping pattern disintegrates and they get motor and mental problems. This inevitably leads to coma and death. The estimates that sleeping sickness each year claims 10 000 to 20 000 lives.

In an early stage the disease is easy to treat, but once the brain is invaded, the treatment becomes more complex and one must use medicines with dangerous, even deadly, side effects. So it is important to detect the infection early.

In the regions where Trypanosoma brucei gambiense is found, for decades already use a rapid diagnostic test, developed at the Institute of , to screen millions of people each year on the presence of antibodies in their blood.

But diagnostic test are not perfect: they always will miss cases, or on the contrary they see an infection where there isn't. A bit as the at airports: too sensitive and they annoyingly go off on each buckle, earring or coin; a bit less sensitive and pocketknives start slipping trough.

In recent years the number of cases has come down substantially, thanks to campaigns against the disease, so error margins that were acceptable in the old days, because the tests still saved so many lives, now become inadmissible. Research scientist Lies Van Nieuwenhove set out to develop a new and better test.

In such tests one demonstrates the antibodies by presenting them targets they will also recognise and attack on real trypanosomes: typical proteins that cover the parasite as a mantle. When antibody and target react – when the test is 'positive' – this is made visible by for instance a colour change or a clotting. Today those targets are obtained from living parasites that are raised in laboratory animals, and are a constant danger for the laboratory technicians.

Therefore Van Nieuwenhove tried to synthesise artificial targets, 'mimotopes' that mimic only a part of the original target protein, but still are sufficient to react with the patient's antibodies. She indeed could produce mimotopes that are reliable and give alarm with the right patients. These mimotopes now can be the base for a new generation of rapid for .

add to favorites email to friend print save as pdf

Related Stories

Sleeping sickness finding could lead to earlier diagnosis

Apr 14, 2008

Sleeping sickness creates a metabolic 'fingerprint' in the blood and urine, which could enable a new test to be developed to diagnose the disease, according to new research published today in the journal Proceedings of th ...

Recommended for you

Recorded Ebola deaths top 7,000

19 hours ago

The worst Ebola outbreak on record has now killed more than 7,000 people, with many of the latest deaths reported in Sierra Leone, the World Health Organization said as United Nations Secretary-General Ban ...

Liberia holds Senate vote amid Ebola fears (Update)

Dec 20, 2014

Health workers manned polling stations across Liberia on Saturday as voters cast their ballots in a twice-delayed Senate election that has been criticized for its potential to spread the deadly Ebola disease.

Evidence-based recs issued for systemic care in psoriasis

Dec 19, 2014

(HealthDay)—For appropriately selected patients with psoriasis, combining biologics with other systemic treatments, including phototherapy, oral medications, or other biologic, may result in greater efficacy ...

Bacteria in caramel apples kills at least four in US

Dec 19, 2014

A listeria outbreak believed to originate from commercially packaged caramel apples has killed at least four people in the United States and sickened 28 people since November, officials said Friday.

Steroid-based treatment may answer needs of pediatric EoE patients

Dec 19, 2014

A new formulation of oral budesonide suspension, a steroid-based treatment, is safe and effective in treating pediatric patients with eosinophilic esophagitis (EoE), according to a new study in Clinical Gastroenterology and Hepatology, the official clinical practice journal ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.