Miscellaneous Vector-Borne Diseases

Abstract

Chagas’ disease, or American trypanosomiasis, is one of the most important arthropod-borne diseases in the Western Hemisphere. It mostly occurs in Mexico and Central and South America (Fig. 1), but at least two indigenous cases have been reported in the United States (1). At present, some 16–18 million people are estimated to be infected, with 90–100 million people at risk (2) Often being a long, chronic, and debilitating disease, Chagas’ causes tremendous economic losses. The economic loss for South America alone owing to early mortality and disability in economically most productive young adults currently amounts to over 8 billion dollars (3). Chagas’ disease is caused by Trypanosoma cruzi, a protozoan that occurs in humans as a hemoflagellate and as an intracellular parasite without an external flagellum. Vectors of Chagas’ disease are hemipteran insects (the true bugs) in the family Reduviidae, subfamily Triatominae. They are commonly called “kissing bugs” because of the nasty habit of taking a bloodmeal from around the lips of a sleeping victim. (However, this is an overgeneralization; the bugs will bite on exposed skin just about anywhere on the body.) Chagas’ disease has both acute and chronic forms, but is perhaps best known for its chronic sequelae, including myocardial damage with cardiac dilatation, arrhythmias and major conduction abnormalities, and digestive tract involvement, such as megaesophagus and megacolon (4).