Quiz: Cestode Infections: Pathology and Prevention — 12 domande

1. What is the role of plerocercoid larvae in the life cycle of Diphyllobothrium latum?

A. To penetrate the intestinal wall of freshwater fish and develop into procercoid larvae

B. To hatch from eggs in freshwater and develop into coracidium

C. To infect humans by attaching to the small intestinal wall and maturing into adult worms

D. To infect Cyclops and develop into procercoid larvae

Answer: (C)

Spiegazione

Plerocercoid larvae infect humans when ingested in uncooked fish, attach to the small intestine, and mature into adult worms, as stated in the source excerpt. Review: Diphyllobothriasis epidemiology, morphology, and life cycle. Course evidence: "Man and other animals are infected by eating uncooked fish that contains plerocercoid larvae (15 x 2 mm) which attach to the small intestinal wall and mature into adult worms in 3 to 5 weeks."

2. Which diagnostic methods are used to confirm diphyllobothriasis infection?

A. Microscopic stool examination for ova and parasites and complete blood count

B. Urinalysis and blood glucose measurement

C. Serological testing for specific antibodies and skin biopsy

D. Chest X-ray and sputum culture

Answer: (A)

Spiegazione

The source explicitly states that diagnosis is by microscopic stool examination for ova and parasites and complete blood count showing possible low hemoglobin and hematocrit levels, making these the correct diagnostic methods for diphyllobothriasis. Review: Clinical manifestations and diagnosis of diphyllobothriasis. Course evidence: "Diagnosis is by microscopic stool examination for ova and parasites and complete blood count showing possible low hemoglobin and hematocrit levels."

3. How long can adult Taenia tapeworms live in the human small intestine?

A. Several days

B. Up to 25 years

C. About 3 to 4 months

D. Up to 1 year

Answer: (B)

Spiegazione

The source states that adult tapeworms mature in 3 to 4 months and may live up to 25 years in the small intestine, making 'Up to 25 years' the correct answer. Review: Taenia solium and T. saginata life cycle and human infection. Course evidence: "Adult tapeworms mature in 3 to 4 months and may live up to 25 years, releasing gravid proglottids with eggs in feces."

4. What causes human cysticercosis to develop in tissues such as the brain and muscle?

A. Autoimmune reaction to Taenia solium eggs in the intestine

B. Development of T. solium oncospheres into cysticerci in tissues

C. Direct penetration of larvae through the skin into tissues

D. Ingestion of adult Taenia solium tapeworms in undercooked meat

Answer: (B)

Spiegazione

Human cysticercosis is caused by the development of T. solium oncospheres into cysticerci in tissues, as stated explicitly in the source. The other options describe incorrect or unrelated mechanisms. Review: Pathology, clinical features, and complications of taeniasis and cysticercosis. Course evidence: "Human cysticercosis results from T. solium oncospheres developing into cysticerci in tissues, especially brain, muscle, and subcutaneous tissue."

5. How do the larval and adult stages of Hymenolepis nana differ in their location and interaction within the human host?

A. Larvae penetrate the ileal villi to mature, while adults attach to the villus mucosa surface

B. Larvae attach to the colon mucosa, while adults inhabit the small intestine lumen

C. Larvae remain in the stomach lining, while adults invade the intestinal wall

D. Larvae circulate in the bloodstream, while adults reside in the liver

Answer: (A)

Spiegazione

The source states that eggs hatch in the ileum, larvae penetrate villi, mature into cysticercoid larvae, and adults attach to villus mucosa, showing larvae invade tissue while adults attach to mucosal surface. Review: Hymenolepis nana infection, life cycle, clinical symptoms, diagnosis, and treatment. Course evidence: "Humans acquire Hymenolepis nana infection mainly through ingestion of infective eggs via fecal-oral exposure. Eggs hatch in the ileum, larvae penetrate villi, mature into cysticercoid larvae, and adults attach to villus mucosa. Most infections are…"

6. How does a definitive host typically become infected with Echinococcus granulosus in the life cycle of cystic echinococcosis?

A. By inhaling eggs released in the environment

B. By ingesting cyst-containing organs of infected intermediate hosts

C. By direct contact with infected definitive hosts

D. By skin penetration of oncospheres from contaminated soil

Answer: (B)

Spiegazione

The definitive host becomes infected by ingesting the cyst-containing organs of the infected intermediate host, which completes the parasite's life cycle as stated in the source. Review: Echinococcus granulosus life cycle and epidemiology of cystic echinococcosis. Course evidence: "Definitive hosts become infected by ingesting cyst-containing organs of intermediate hosts, completing the cycle."

7. What is the primary role of the contents inside a hydatid cyst when the cyst ruptures?

A. To trigger anaphylactic reactions

B. To induce loss of appetite and weight loss

C. To cause intracranial pressure in brain cysts

D. To produce protoscolices and daughter cysts

Answer: (A)

Spiegazione

The source states that cyst contents may trigger anaphylactic reactions if ruptured, indicating their role in provoking severe allergic responses upon rupture. Producing protoscolices and daughter cysts is a function of the cyst itself, not specifically the contents upon rupture. Intracranial pressure and systemic symptoms are consequences of cyst location or presence, not directly the function of the cyst contents when ruptured. Review: Hydatid cyst development, pathology, and host interactions. Course evidence: "Cyst contents may trigger anaphylactic reactions if ruptured."

8. How do the definitive and intermediate hosts differ between Echinococcus multilocularis and Echinococcus vogeli?

A. E. multilocularis uses wild felids as definitive hosts, whereas E. vogeli uses foxes and coyotes.

B. E. multilocularis has mainly foxes as definitive hosts and no specified intermediate hosts, while E. vogeli has bush dogs and dogs as definitive hosts and rodents as intermediate hosts.

C. E. multilocularis and E. vogeli both use rodents as definitive hosts but differ in intermediate hosts.

D. Both species share the same definitive hosts but differ in larval development patterns in intermediate hosts.

Answer: (B)

Spiegazione

According to the source, E. multilocularis's definitive hosts are mainly foxes with secondary hosts, and no intermediate hosts are specified here, while E. vogeli's definitive hosts are bush dogs and dogs, and its intermediate hosts are rodents. This distinguishes their host relationships clearly. Review: Differences in life cycles and hosts of Echinococcus multilocularis, E. vogeli, and E. oligarthrus. Course evidence: "- E. multilocularis's definitive hosts are mainly foxes, with secondary hosts like dogs, cats, coyotes, and wolves. - E. vogeli's definitive hosts are bush dogs and dogs; its intermediate hosts are rodents, with larval development forming multiple vesicles.…"

9. What is the most common primary site of infection in alveolar echinococcosis?

A. Liver, usually the right lobe

B. Lungs

C. Spleen

D. Brain

Answer: (A)

Spiegazione

The source states that the primary infection of alveolar echinococcosis is in the liver (60%), usually the right lobe, making it the most common site. The lungs and brain are affected less frequently by hematogenous spread, and the spleen is not mentioned as a primary site. Review: Clinical manifestations and organ involvement in cystic and alveolar echinococcosis. Course evidence: "The primary infection of alveolar echinococcosis is in the liver (60%), usually the right lobe, but direct extension to contiguous organs, as well as hematogenous metastases to the lungs (20%) and brain (<2%) is not uncommon."

10. What is the primary role of diagnostics in cystic echinococcosis?

A. To identify cysts and complications through clinical suspicion, imaging, and serological tests

B. To treat allergic reactions caused by cyst rupture

C. To relieve symptoms such as hepatic enlargement and pain

D. To prevent secondary echinococcosis by avoiding cyst rupture

Answer: (A)

Spiegazione

Diagnostics in cystic echinococcosis is defined as a process based on clinical suspicion, imaging techniques, and serological tests to identify cysts and complications, making option 0 the correct function. Review: Diagnosis and clinical signs of cystic echinococcosis including secondary infection. Course evidence: "Diagnostics : A process based on clinical suspicion, imaging techniques such as ultrasound, CT, or MRI, and serological tests detecting Echinococcus antibodies to identify cysts and complications."

11. What is the primary role of surgery in the treatment of hepatic hydatid cysts?

A. To primarily manage inoperable cases where patient condition is poor

B. To provide the main curative approach with cystectomy or pericystectomy offering good cure rates

C. To reduce symptoms temporarily without removing the cysts

D. To serve as a last resort when chemotherapy and PAIR fail

Answer: (B)

Spiegazione

The source states that surgery is the primary treatment for hepatic hydatid cysts, with cystectomy and pericystectomy offering good cure rates. Chemotherapy is used when surgery is contraindicated, and surgery is not described as a last resort or only for symptom reduction. Review: Treatment options for hydatid cysts including surgery, chemotherapy, and PAIR technique. Course evidence: "Surgery is the primary treatment for hepatic hydatid cysts, with cystectomy and pericystectomy offering good cure rates."

12. What is the primary role of maintaining good personal hygiene and proper sewage disposal in preventing cestode infections?

A. To increase the effectiveness of antiparasitic drugs

B. To enhance the immune response against cestodes

C. To directly kill infective larvae in contaminated food

D. To interrupt transmission of cestode infections

Answer: (D)

Spiegazione

The source states that preventing cestode infections requires good personal hygiene and proper disposal of sewage to interrupt transmission, highlighting their role in breaking the parasite's transmission cycle rather than directly killing larvae or enhancing immunity. Review: Prevention and control measures for cestode infections. Course evidence: "- Preventing cestode infections requires good personal hygiene and proper disposal of sewage to interrupt transmission. - Proper cooking or freezing of fish and meat kills infective larvae and prevents human infection. - Handwashing after handling pets…"