infectious diseases
Chagas Disease
Introduction
Chagas disease is infection withTrypanosoma cruzi, transmitted by Triatominae bug bites or, less commonly, via ingestion of sugar cane juice or foods contaminated with infected Triatominae bugs or their feces, via blood transfusion or an organ transplant from an infected donor, or via maternal-fetal transmission. Symptoms after a Triatominae bite typically begin with a skin lesion or unilateral periorbital edema, then progress to fever, malaise, generalized lymphadenopathy, and hepatosplenomegaly; years later, 20 to 30% of infected patients develop arrhythmias, chronic cardiomyopathy, or, less commonly, megaesophagus or megacolon. In patients with AIDS, the skin or brain may be affected. Diagnosis is by detecting trypanosomes in peripheral blood or aspirates from infected organs. Antibody tests are sensitive and can be helpful. Treatment is withnifurtimoxorbenznidazole; however, antiparasitic drugs do not reverse the course of cardiac or intestinal disease that has developed. Chagas disease is caused byTrypanosoma cruzi.Infection is transmitted to humans when bitten by Triatominae (reduviid, kissing, or assassin) bugs in South and Central America, Mexico, and very rarely in the US. Less commonly,T. cruziis transmitted via ingestion of sugar cane juice or food contaminated with infected Triatominae bugs or their feces, transplacentally from an infected mother to her fetus, or via blood transfusion or an organ transplant from an infected donor. Nonhuman reservoirs include domestic dogs, opossums, armadillos, rats, raccoons, and many other animals. Worldwide, an estimated 8 million people are chronically infected withT. cruzi. Most reside in Latin America, but about 300,000 of those infected in Latin America now live in the US; others live in Europe or elsewhere (seeCenters for Disease Control and Prevention: Epidemiology & Risk Factors). The incidence ofT. cruziinfection has been decreasing in Latin America because of improved housing, screening of blood and organ donors, and other control measures. There are an estimated 40,000T. cruzi-infected women of childbearing age in the US. It is estimated that 1 to 5% of their children are born with congenital infection. 