Tropical Terrors

Chagas Disease - American Trypanosomiasis

Like African trypanosomiasis, Chagas Disease is spread by a trypanosome parasite. But unlike sleeping sickness, it is spread not directly by the bite of a fly but indirectly - as the infected reduviid fly feeds on its victim's blood, it defecates on the skin. Later, when the victim rubs the bite - typically near the eye - the infected material is rubbed into the bite.

Reduviid bugs are generally found living in the roofs - especially thatched roofs - of poor housing.

They come out at night, so prevention is aimed at both spraying for the fly, improving housing, and sleeping in bed nets.  The reduviid bug:

 

 

Victims - especially children -  often develop as the first sign swelling at the site of the infected bite - called Romañas sign:

 

 

 

 

 

 

 

Later, an ulcer and swelling may develop. This may eventually heal, but the parasite is still present in the body. And just like the filaria of African trypanosomiasis is attracted to the brain, this one is attracted to the heart. In Latin America, this disease is a major cause of heart failure and heart arrhythmias (irregular rhythms). This disease can be spread through blood transfusions, so donated blood is tested in all countries at risk, and many donated units are now tested in the United States because of the number of immigrants from Latin America.

Map of at-risk countries: