Within the past three years there have been at least three outbreaks of South American trypanosomiasis, or Chagas’ disease, in metropolitan Caracas, the most recent being reported by Merco Press on May 14, 2010.
What is Chagas’ Disease?
Chagas’ disease, spread by a biting bug, is caused by a microscopic protozoan parasite that spreads through the bloodstream and invades internal organs. In its early stages, Chagas’ causes inflammation at the bite site, enlarged lymph nodes, fever, rash and other symptoms. This stage of the infection tends to affect small children the worst, and in the current outbreak four children are hospitalized.
Fifteen cases are confirmed, but there may be more: in older people the onset of infection may go unnoticed and Chagas’ progresses to a chronic parasitic disease that can destroy internal tissues including the heart, and organs of the digestive system. Chronic Chagas’ claims thousands of lives in South America each year and accounts for significant economic loss due to disability and early death.
How People Catch Chagas' Disease
Most cases of Chagas’ are acquired when the insect vector, the kissing bug, bites and takes a blood meal. In Venezuela, the kissing bug most often involved is Rhodnius prolixus, also known as the chipo. It’s not the bite that transmits the parasite however – Trypanosoma cruzi is found in the bug’s droppings, frequently deposited at the bite site while the bug feeds. Introduced into the bite lesion by rubbing or scratching, the trypanosomes gain entry to the body.
In Caracas, however, T. cruzi seems to find another way to infect people in some outbreaks. Accidental ingestion of bug feces that contain the parasites, or ingestion of infected bugs themselves can also result in infection. Giuliana Chiappe reports that contaminated fruit juice has been identified as the common source in two recent outbreaks, and this may turn out to be the source in the current outbreak as well.
The Southern Cone Initiative, an effort to wipe out Triatoma infestans, the common Chagas’ vector in countries to the south, has seen considerable success, but a different approach is needed in Venezuela. Triatoma infestans inhabits only human dwellings in much of its range, while Rhodnius prolixus is widespread in the Venezuelan environment.
References:
Chiappe, Giuliana. May 11, 2010, “Chagas disease threatens 6 million people in Venezuela .” El Universal.
“Outbreak of Tropical Parasite Disease Threatens Metropolitan Caracas” Merco Press, South Atlantic News Agency. May 14, 2010
Roberts, Larry S. and John Janovy Jr. Foundations of Parasitology 6th Ed. Boston: McGraw Hill, 2000.
Rosemary Drisdelle - Rosemary Drisdelle has been published many times as a nonfiction writer and several times as a poet. Her first book, Parasites: Tales of ...
Join the Conversation