Protozoa and Flagellates Quiz

Trypanosoma cruzi (Chagas’ disease)

• Causes myocarditis and Trypanosoma-induced heart disease.
• Acute infections exhibit tropism for cardiac myofibers, implicated in chronic heart disease.
• Myocardial fibers suffer from myocytolysis and myofibrillar degeneration.
• Approximately 10% of infected individuals develop megacolon.
• Chronic infection results in scarring of the myocardium, affecting 20-30% of cases.

Signs and Symptoms of Chagas’ Disease

• Initial chagomas (swelling from insect bites).
• Generalized stage includes fever, swollen lymph nodes, myocarditis, splenomegaly, and esophagus/colon enlargement.
• Chronic stage may be asymptomatic for years before symptomatic heart failure occurs.

Transmission

• Transmitted via bites of Triatoma bugs, known as kissing bugs.

Location of Parasite

• Primarily found in the circulatory system; trypanosomes transform within macrophages and heart cells.

Means of Diagnosis

• Microscopic identification of trypanosomes or antigens in blood, lymph, spinal fluid, or tissue biopsy.
• Xenodiagnosis involves allowing uninfected kissing bugs to feed on suspected individuals, with subsequent dissection revealing infections.

Trypanosoma brucei gambiense (African sleeping sickness)

• Pathology includes meningoencephalitis, hemolytic anemia, and impaired consciousness; can lead to death if untreated.

Signs and Symptoms of African Sleeping Sickness

• Lesions form at fly bite sites, leading to fever, lymph node swelling, and headaches.
• CNS invasion results in severe drowsiness, abnormal neurological function, and coma.

Transmission

• Spread via bites from the tsetse fly (Glossina); cattle and sheep serve as reservoirs.

Location of Parasite

• Trypanosomes circulate in blood and lymph, with some entering the CNS.

Means of Diagnosis

• Microscopic observation of long, thin trypanosomes in blood, lymph, spinal fluid, or tissue biopsy, identifiable by their structure.

Giardia intestinalis (Beaver fever)

• Causes enterocyte damage, loss of intestinal brush border, and altered epithelial barrier function.

Signs and Symptoms of Beaver Fever

• Frequently asymptomatic but can lead to severe gastrointestinal distress.
• Symptoms include greasy, frothy, fatty diarrhea, abdominal pain, flatulence, nausea, vomiting, and low-grade fever.
• Characteristic “rotten egg” smell in patient stools indicates infection.

Transmission

• Primarily through ingestion of contaminated water or food containing cysts from feces.

Location of Parasite

• Trophozoites attach to intestinal lining via a ventral adhesive disc or remain free in the intestine.

Test your knowledge on protozoa, particularly flagellates like Trypanosoma cruzi, the causative agent of Chagas' disease. The quiz covers the pathology associated with the infection, including its effects on the heart and potential complications such as megacolon. Explore the scientific and common names of relevant diseases.