1Disease Classification
American Trypanosomiasis, Chagas’ Disease (acute or chronic protozoan disease)
2Causative Organism
Trypanosoma cruzi
3Get to Know your CA
Eukaryote Protozoa; Intracellular parasite, motile- single flagellum attached to an undulating membrane, complex multi host life cycle
4Epidemiology: Reservoir
Wild and domesticated animals, humans, and reduviid bugs
5Epidemiology: POE
Mucose or compromised skin
6Epidemiology: MOT
Zoonotic, arthropod vector= Reduviid “kissing” bug bites and defecates; scratching infects bite wound, vertical transmission, contaminate food, latent infections
7Incubation Period
1 week for acute; months-years for chronic
8Pathogenesis
Protozoan replicates in cells at site of infection. Cellular damage and release of new protozoa results in inflammation and spread of infection to the ciculatory system and other organs. persistence of protozoa as intracellular parasites inhibits normal organ function resulting in various chronic disease states and reduced host life spans
9Symptoms of Acute Phase (weeks- months)
Possible swelling at site of infection, fever, fatigue or malaise, headache, diarrhea, vomiting, Romana’s sign, mild organ enlargment
10What is Romana’s sign?
Unilateral periocular edema with conjunctivitis
11Symptoms of Chronic Phase (decades)
Constipation, digestive problems, abdominal pain
12Complications of Acute Phase
Severe inflammation, myocarditis, meningoencephalitis, mortality in young children <5%
13Complications of Chronic Phase (life time risk = 30-40%)
Megacolon and megaesophagus (5-10% of chronic patients), cardiomyopathy, heart failure, Mortality- ARP =42.5%
14ARP
Attributable Risk Percent
15Prevention
Contol reduviid bug population- reduce hiding areas around home, insectcides, use bed nets; testing/treatment, screen blood and organ supply
16Treatment
Antiparasitics- Nifurtimox, Benznidazole (Acute phase efficacy)