Lecture on Chagas Disease

Overview

• Chagas Disease is caused by a protozoan parasite, a type of trypanosome.
• Predominantly affects 6-7 million people in Mexico, Central, and South America.
• Known as American trypanosomiasis, distinct from African trypanosomiasis (African sleeping sickness).

Transmission

• Caused by Trypanosoma cruzi.
• Transmitted by the kissing bug (triatomine bug), which bites typically around the eyes or mouth.
• Other transmission methods:
  • Mother to child
  • Blood and organ donations
  • Ingesting contaminated food
• Climate change is causing kissing bugs to move north, with ~300,000 cases in the U.S.

Life Cycle

• Triatomine Bug bites and defecates simultaneously, leading to infection when feces infects bite cells.
• Parasites enter blood, then muscle tissue (including heart and gut).
• Can perpetuate cycle by infecting a new bug and person.

Symptoms

• Acute Phase: (few weeks to months)
  • Fever
  • Swelling around bite
  • Possible to be asymptomatic
• Chronic Phase:
  • Asymptomatic for some, but possible severe symptoms for 20-30% of cases:
    • Heart rhythm issues
    • Enlarged heart
    • Dilated esophagus or colon

Treatment and Prevention

• Early treatment crucial to prevent permanent damage.
• Effective drugs:
  • Benznidazole
  • Nifurtimox
• Prevention strategies:
  • Improve housing to reduce bug presence
  • Use insecticides and bed nets
  • Screen blood and organ donations
  • Screen pregnant women to prevent mother-to-child transmission.

Next Topic

• Brief introduction to infections of the nervous system.