KMU Past Paper Practice

Question:

A 46-year-old livestock worker has a slowly enlarging pulmonary cyst detected during evaluation of persistent cough and chest discomfort. A parasitic larval cyst is suspected. Which feature of the parasite best explains why the patient may remain symptom-free until the lesion becomes large?

Options:

Correct Answer: Slow expansion producing progressive local compression

Explanation: Hydatid cysts enlarge gradually and symptoms commonly appear when their increasing size compresses surrounding structures.

Question:

During pathological examination of a hydatid cyst, a thick fibrous layer is found surrounding the parasitic wall. Which interpretation of this layer is most accurate?

Options:

Correct Answer: It is produced by the host tissue reaction

Explanation: The pericyst is fibrous host tissue formed around the parasite; the laminated and germinal layers are components of the parasite itself.

Question:

A cyst aspirate obtained under specialist-controlled conditions contains fine sediment composed of numerous protoscolices and detached parasitic material. Which term best describes this finding?

Options:

Correct Answer: Hydatid sand

Explanation: Hydatid sand is the sediment of protoscolices and detached parasitic material within hydatid cyst fluid.

Question:

A patient has imaging strongly suggestive of an extrahepatic hydatid cyst, but serological testing is negative. Which interpretation is most appropriate?

Options:

Correct Answer: Serological sensitivity can vary with cyst location

Explanation: Hydatid serology is supportive rather than absolute; its sensitivity varies with the anatomical site and condition of the cyst.

Question:

A 27-year-old man develops progressive ulceration involving nasal mucosa months after living in a leishmaniasis-endemic area. Which disease pattern best accounts for the destructive mucosal lesion?

Options:

Correct Answer: Mucocutaneous disease

Explanation: Mucocutaneous leishmaniasis involves mucosal tissues and can produce progressive inflammatory destruction of the nose and oropharyngeal region.

Question:

A patient has a solitary chronic skin lesion suspected to be leishmaniasis. The clinician wants the specimen most likely to demonstrate organisms directly. Which sampling approach is most appropriate?

Options:

Correct Answer: Material obtained from the active lesion margin

Explanation: In cutaneous leishmaniasis, material from the active edge of the lesion offers an appropriate site for direct demonstration of tissue amastigotes.

Question:

Two patients are investigated for leishmaniasis. One has localized skin disease and the other has systemic visceral involvement. In which patient is antibody-based testing expected to be more useful?

Options:

Correct Answer: The patient with visceral disease

Explanation: Serological testing has greater diagnostic usefulness in visceral leishmaniasis than in localized cutaneous disease.

Question:

A sandfly feeds on a person infected with leishmaniasis and ingests parasitized host cells. Which subsequent event within the vector is essential before transmission to another person can occur?

Options:

Correct Answer: Development of transmissible promastigote forms

Explanation: Parasites ingested by the sandfly develop into promastigotes within the vector before being transmitted during a later blood meal.

Question:

A healthy 24-year-old woman is found to have evidence of previous Toxoplasma gondii exposure during investigation for another condition. She has no neurological or systemic symptoms. Which clinical course best fits infection in an immunocompetent adult?

Options:

Correct Answer: Asymptomatic or mild systemic illness

Explanation: Most immunocompetent individuals with toxoplasmosis have no symptoms or only a mild self-limited systemic illness.

Question:

A newborn is evaluated after maternal toxoplasmosis during pregnancy. Which pair of tissues is particularly important when assessing congenital injury caused by this infection?

Options:

Correct Answer: Central nervous system and eyes

Explanation: Congenital toxoplasmosis has important neurological and ocular consequences because the developing brain and eyes are major sites of fetal injury.

Question:

Two individuals acquire toxoplasmosis by different routes. One has frequent contact with contaminated soil and the other consumes inadequately cooked meat. Which infective forms best explain these exposures respectively?

Options:

Correct Answer: Oocyst and tissue cyst

Explanation: Environmental contamination can expose humans to oocysts, while inadequately cooked infected meat can transmit tissue cysts.

Question:

A tissue biopsy from a patient with previous toxoplasmosis demonstrates persistent intracellular cysts in neural tissue. Which biological change allows the parasite to remain in this relatively quiescent state after the acute phase?

Options:

Correct Answer: Transformation of tachyzoites into bradyzoites

Explanation: Host immunity limits active tachyzoite multiplication and promotes persistence of slowly replicating bradyzoites within tissue cysts.

Question:

A student examines an adult tapeworm removed from the intestine. The specimen consists of an anterior attachment organ followed by a narrow region and a long chain of reproductive segments. Which sequence correctly identifies these structures?

Options:

Correct Answer: Scolex → neck → proglottids

Explanation: Adult Taenia has an anterior scolex for attachment, a neck, and a chain of reproductive segments called proglottids.

Question:

A man with an adult intestinal Taenia infection reports intermittent abdominal discomfort and passage of segments but has no evidence of tissue invasion. Which mechanism best explains his relatively mild symptoms?

Options:

Correct Answer: Localized presence of the adult worm in intestine

Explanation: Intestinal taeniasis commonly causes limited local effects because the adult tapeworm remains within the bowel rather than widely invading tissues.

Question:

During discussion of the normal life cycles of T. saginata and T. solium, a student is asked to identify the role shared by humans in uncomplicated intestinal infection with either species. Which is the best answer?

Options:

Correct Answer: Definitive host carrying the adult tapeworm

Explanation: In intestinal taeniasis, humans are the definitive hosts because the sexually mature adult worms live in the human intestine.

Question:

A veterinary-public health investigation traces intestinal taeniasis in a community to a cycle involving human fecal contamination of grazing areas and infected livestock meat. Which event allows the parasite to pass from humans back into the animal intermediate host?

Options:

Correct Answer: Animals ingest eggs contaminating the environment

Explanation: Eggs passed in human feces contaminate the environment and are ingested by cattle or pigs, where the larval cysticercus stage develops.

Question:

A previously unaffected settlement begins reporting cutaneous leishmaniasis after rapid expansion of housing into an area favorable for sandfly breeding. Which epidemiological factor best explains the change in disease occurrence?

Options:

Correct Answer: Change in vector-human ecological contact

Explanation: Environmental and housing changes can alter human exposure to sandflies and thereby change the focal distribution of leishmaniasis.

Question:

Seasonal workers travel from a non-endemic area to a region with established leishmaniasis transmission. Several develop disease after prolonged outdoor exposure. Which determinant most directly increased their risk?

Options:

Correct Answer: Exposure to a competent vector in an endemic focus

Explanation: Movement of susceptible people into an endemic area increases risk when they are exposed to infected sandflies in an established transmission cycle.

Question:

A district has limited resources for leishmaniasis control. Health authorities use case reports to identify villages with increasing disease activity and then concentrate vector-control activities in those locations. Which public-health function is providing the information needed for this targeted response?

Options:

Correct Answer: Disease surveillance

Explanation: Surveillance identifies affected populations and changing case patterns, allowing public-health teams to direct control measures toward active transmission areas.

Question:

Four patients are being investigated for parasitic disease. One has a pulmonary space-occupying cyst, one has destructive nasal mucosal disease, one has mild lymph-node enlargement after protozoal exposure, and one has abdominal discomfort with passage of tapeworm segments. Which sequence best matches the likely conditions?

Options:

Correct Answer: Hydatid disease → mucocutaneous leishmaniasis → toxoplasmosis → taeniasis

Explanation: Hydatid disease produces organ cysts, mucocutaneous leishmaniasis causes destructive mucosal lesions, uncomplicated toxoplasmosis may cause mild lymphadenopathy, and taeniasis may present with passage of proglottids.