What is Chagas disease (American trypanosomiasis)?

From the Guidelines

Chagas disease treatment should prioritize antiparasitic medications, such as benznidazole, during the acute phase, and consider treatment in the chronic phase for patients under 50 without advanced cardiac disease. The disease, caused by Trypanosoma cruzi, has acute and chronic phases, with many infected individuals remaining asymptomatic for decades before developing serious cardiac or digestive complications 1. Treatment is most effective during the acute phase, and even in the chronic phase, treatment is recommended for most patients under age 50 without advanced cardiac disease to prevent progression 1.

Key Considerations

• Diagnosis involves blood tests including serology and PCR 1
• Prevention focuses on vector control through improved housing, insecticide use, and blood screening 1
• The parasite invades human cells where it multiplies as amastigotes before transforming back to trypomastigotes that rupture cells and spread through the bloodstream, eventually causing inflammation and fibrosis in affected tissues, particularly the heart, esophagus, and colon 1

Treatment Options

• Benznidazole (5-7 mg/kg/day divided into two doses for 60 days) or nifurtimox (8-10 mg/kg/day divided into three doses for 60-90 days) are recommended for treatment during the acute phase 1
• Alternative regimens based on different doses and durations of treatment with benznidazole are being developed to improve tolerability while maintaining treatment efficacy 1

Patient Management

• Immunosuppressed patients are at risk of reactivation of disease and progressing to a more severe clinical state, and should be closely monitored 1
• Blood or organ donation is a situation where identification of people with infection could be particularly relevant for preventing transmission and providing appropriate treatment for positive cases 1

From the Research

Chagas Disease Overview

• Chagas disease is a significant public health problem, affecting 6-7 million people, mainly in the Americas 2.
• The disease is caused by the parasite Trypanosoma cruzi and can lead to serious cardiac and digestive complications if left untreated 2, 3.

Treatment Options

• Benznidazole is one of the two therapeutic options available for the treatment of Chagas disease, along with nifurtimox 2, 3.
• Benznidazole has been shown to be effective in eliminating the parasite from the body, preventing the establishment or progression of visceral damage, and interrupting vertical transmission when administered to women of childbearing age 2.

Benznidazole Efficacy and Dosage

• The recommended dosage of benznidazole is 5-8 mg/kg/day for 30-60 days for children and 5-10 mg/kg/day for 30-60 days for adults 4.
• The efficacy of benznidazole is closely correlated with the phase of infection, with greater therapeutic efficacy obtained in acute infections and gradually worsening as the infection becomes chronic 4.
• A study comparing benznidazole, nifurtimox, and placebo in patients with chronic Chagas disease found that benznidazole showed only 1.8% of positive xenodiagnoses post-treatment, compared to 9.6% for nifurtimox and 34.3% for placebo 5.

Challenges and Future Directions

• Despite its efficacy, benznidazole has a limited safety profile, and alternative strategies such as shorter regimens, lower doses, and fixed doses are being evaluated to improve access and safety 2.
• Ongoing investigations aim to optimize benznidazole therapy by adjusting the current standard regimen or by combining benznidazole with new chemical entities 3.
• Novel approaches to benznidazole delivery systems are being developed to improve treatment outcomes and reduce the burden of morbidity and mortality caused by Chagas disease 6.