Hello everyone and welcome back! As promised from last week’s blog, and keeping in the vein of microbial pathogenesis, I wanted to write a little about Chagas disease, and what exactly it is.
Most likely, if you reside in Latin America, you may have heard about this disease before. A protist by the name of Trypanosoma cruzi is the culprit. By definition, a protist is any eukaryotic organism, which is not a fungus, plant, or animal. T. cruzi is transported to vertebrates, such as humans, through a vector called the kissing bug (or Triatominae). Other members of this subfamily carry names such as vampire bugs and assassin bugs. This subfamily contains more than 130 species, with most feeding on blood from vertebrates (some feed on blood of invertebrates), and tend to be found in close proximity to their blood meals, and predominantly throughout the Americas. If you are a student, can you quickly research which Brazilian scientist this disease is named after?
How do you get this disease you ask? Well, this kissing bug comes out at night, tending to bite sleeping persons on their faces in order to get a blood meal. While doing so, they ‘take a crap’ on the person! (How rude!! And quite gross actually…). The T. cruzi is actually in the feces/faeces itself, left close to the bite spot. When the person starts to scratch the bite, this leads to broken skin and T. cruzi infection. This is very different from how Malaria is spread, for example, where the parasite is introduced to the blood stream, by the mosquito’s saliva, with the bite itself.
Infection with T. cruzi can also occur, however, accidentally in the lab, through blood transfusions, breast milk, or from woman to baby during pregnancy.
This disease can have acute and chronic stages, with no vaccine currently available. Acute symptoms include chagoma (a swelling where the T. cruzi entered the body), fever, nausea and body aches. Immunocompromised persons may suffer greater effects. A notable mark of this disease is called Romaña’s sign, where there’s swelling of the eyelids and face close to the bug bite, and where the feces/faeces was accidentally rubbed into the eye, or was deposited by the bug. Chronic effects include complications of the heart, digestive- and nervous systems.
The disease can be prevented by controlling the vector (the kissing bug) itself by use of insecticides. Medication such as benznidazole can also be used, and tend to work best if administered early.
This tropical disease is the gift of the kissing bug that everyone could definitely do without getting!
Take care until next time! 🙂
Follow these links to read more on Chagas disease, Protists, Triatominae, Chagoma, and Carlos Chagas disease. Credit is given for use of images to show Romaña’s sign, Triatomina, Carlos Chagas, and T. cruzi Giant Microbe.
jtbtrinbagomicrobiologist 