The term “vector-borne disease” usually brings to mind a familiar list of names: malaria, West Nile virus, dengue, chikungunya, onchocerciasis, yellow fever. But there’s another name that is too often left off the list of public health threats—Chagas disease.
The World Health Organization estimates that between six and seven million people are infected with Chagas disease around the world, with most infections occurring in rural/underdeveloped areas of Latin America.1
While the mortality rate of Chagas disease is relatively low compared to the more familiar vector-borne illnesses, up to 30% of people with chronic infection will develop cardiac, digestive, or neurological complications, many of which can be fatal if left untreated.
Largely considered to be a disease of poverty, Chagas also plays a role in perpetuating poverty—because complications from the disease often occur when people are in the prime of their lives, working and caring for children, which can present significant challenges for already impoverished populations.
HIDING IN THE SHADOWS
As Dr. Rick Tarleton, founder and president of the Chagas Disease Foundation in Athens, Georgia, describes it, Chagas disease is “the most neglected of the neglected diseases.” His interest in the disease began with the desire to study a complex host-parasite interaction, but as he discovered how little was being done, it became a passion to make a difference for people and communities affected by the disease. The foundation he started works closely with groups throughout Latin America developing education and prevention strategies.
Chagas disease is caused by a parasitic protozoan, Trypanosoma cruzi, which is carried by triatomine insects (the “kissing” bug). The parasites are passed from a host (primarily mammals, including humans) to the insect during feeding, and then passed to the next host when feces from the insect are introduced to the bite area or nearby mucous membrane, usually by the new host rubbing or scratching the bite.
Triatomine insects live anywhere they can find a host, usually the burrow or nest of an animal. The mud walls and thatched roofs found in rural or underdeveloped regions are also susceptible to infestation.2 It’s this proximity of parasite reservoirs, vector infestation, and human habitation that leads to infection.
BRINGING CHAGAS SOLUTIONS TO LIGHT
There is no vaccine for Chagas disease, but anti-parasitic medicines can resolve the infection more easily if it is caught early. That’s what makes screening for Chagas disease so important. “Routine screening of young people can make an immediate difference in terms of addressing the disease, but it also tells us where transmission is occurring,” said Dr. Tarleton. “In places where transmission occurs, you need to incorporate a variety of tactics-insecticides, treated bed nets, insect collars for domestic animals-it all needs to be meshed with early screening.”
To help patients and clinical researchers share information, the Chagas Disease Foundation is currently prototyping a digital patient registry in the U.S. with hopes to expand it globally once the systems are in place. The foundation also organized and continues to help fund the Chagas Drug Discovery Consortium, which brings together the academic, industry, and public/private partnership groups to share information on better drug screening protocols for anti-T. cruzi compounds and providing screening services for individuals and companies.
“Chagas disease is a solvable problem,”said Dr. Tarleton. “We have T. cruzi and the triatomine insects in the U.S., but it’s not a public health problem here. With more screening, better education, improved housing, and vector control, we can solve the Chagas problem in Latin America.”
For more information about the Chagas Disease Foundation, visit www.chagasfound.org.
1 http://www.who.int/mediacentre/factsheets/fs340/en/
2 http://www.cdc.gov/parasites/chagas/epi.html