Wild animals may be a key contributor to the continuing spread of African sleeping sickness, new research published in PLOS Computational Biology shows. The West African form of the disease, also known as Gambiense Human African trypanosomiasis, affects around 10,000 people in Africa every year and is deadly if left untreated.
The disease is caused by a brain-invading parasite transmitted by bites of the tsetse fly, and gets its name from the hallmark symptoms of drowsiness and altered sleeping patterns that affect late-stage patients, along with other physical and neurological manifestations including manic episodes and hallucinations that eventually lead to coma and death.
Despite numerous previous studies showing that animals can be infected with the parasite, the prevailing view has been that the disease persisted in its traditional areas almost only because of human-to-human transmission. A new study, from an international team of researchers led by the London School of Hygiene & Tropical Medicine, challenges this assumption by using a mathematical model to show that the disease not only can persist in an area even when there are no human cases, but probably requires the presence of infected wild animals to maintain the chain of transmission. The authors' model was based on data collected in active screening campaigns between November 1998 and February 1999 in the Bipindi area of Cameroon. One of the species in the data group was the White-eyelid mangabey, pictured below.
The research provides an attractive explanation for why sleeping sickness survives in places which have undergone intensive efforts to find and treat infected people in the community. It suggests that efforts to eliminate the disease must factor in the wild animal populations.
"This research suggests that targeting human populations alone, the main current control strategy, might not be enough to control the disease," says Sebastian Funk, the lead author of the study. "Maintenance of transmission in wild animal populations could explain the reappearance of sleeping sickness in humans after years without cases."
Public Library of Science: http://www.plos.org
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
The complicated science behind picky eating is giving experts plenty of food for thought
The compound kills disease-causing parasites by popping them like water balloons
The U.S. had planned to build 17 treatment units across Liberia, one in each county's major town. Now that more cases are appearing in remote areas, the Army may need to rethink its strategy.
A woman is thought to be spreading Ebola in a remote village. So health workers spend four hours trekking through the bush to track her down. By the time they make it, it's too late.
Doctors have used perfect replicas of childrens' hearts to uncover and repair hidden defects
An experiment testing people’s altruism in the face of electric shocks is clear on one thing: we are drawn to these little blasts
Researchers gear up tests in West Africa to see whether blood from Ebola survivors can help people who are sick with the disease. This is part of a broader effort to test therapies in West Africa.
The virus's foray into Europe coincides with peak production of Christmas turkeys, the poultry species most vulnerable to bird flu
A novel kind of nanoparticle could lead to more effective cancer treatments.Patients and doctors often don’t know if surgery to remove cancerous tissue was successful until scans are performed months later. A new kind of nanoparticle could show patients if they’re in the clear much earlier.
One challenge in evaluating the effectiveness of different medical procedures, is that patients behave differently after different procedures. Is this true for patients getting heart surgery?