Microscopic examination of fresh anticoagulated blood, the buffy coat, or blood smears may reveal organisms in cases of acute Chagas disease. Serology has no major diagnostic role in acute disease, but PCR assays can be helpful. Chronic Chagas disease is diagnosed by detection of specific IgG antibodies. Given the frequency of false-positive results, a positive result should be confirmed by at least two additional assays.
Treatment: Chagas Disease - Only two drugs—nifurtimox and benznidazole—are available to treat Chagas disease; neither is entirely effective.
- - Nifurtimox (8-10 mg/kg qd in four divided oral doses for 90-120 days) reduces symptom duration, parasitemia level, and mortality rate but offers a parasitologic cure in only ~70% of cases.
- - Benznidazole (5 mg/kg qd in two or three divided doses for 60 days) is the drug of choice in Latin America and may provide parasitologic cure rates >90%.
- - Both drugs have a number of side effects.
- Treatment of chronic Chagas disease is controversial; no adequate studies demonstrate efficacy. However, a panel of experts convened by the CDC recommends that pts <50 years old with presumably long-standing T. cruzi infection be offered treatment.
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