KMU Past Paper Practice

Question:

A 58-year-old man develops fever and respiratory symptoms after attending a crowded indoor gathering. Several attendees subsequently become ill. Which combination best explains why this setting facilitated coronavirus transmission?

Options:

Correct Answer: Close contact with limited indoor ventilation

Explanation: Coronavirus spreads efficiently through virus-containing respiratory particles. Prolonged close contact in poorly ventilated indoor spaces increases the concentration and duration of respiratory exposure.

Question:

A patient with lower respiratory coronavirus disease has a negative rapid antigen test despite persistent symptoms. The physician requires a more sensitive method that identifies viral genetic material. Which investigation is most appropriate?

Options:

Correct Answer: Nucleic acid amplification testing

Explanation: Nucleic acid amplification methods detect coronavirus RNA directly and are appropriate when specific confirmation of active infection is required.

Question:

Region X reports twice as many coronavirus cases as Region Y. Region X has extensive community testing, while Region Y has limited laboratory access. Which epidemiological conclusion is most defensible?

Options:

Correct Answer: Case detection differences may distort comparison

Explanation: Recorded incidence depends partly on testing and surveillance intensity. Apparent geographical differences must therefore be interpreted alongside differences in case detection.

Question:

A researcher studies replication of an enveloped respiratory virus and finds that its genomic RNA can function directly in the infected cell as messenger RNA. Which viral property is being demonstrated?

Options:

Correct Answer: Positive-sense RNA genome

Explanation: Coronavirus contains positive-sense single-stranded RNA, allowing its genomic RNA to function in the direction required for viral protein synthesis after entry.

Question:

An unvaccinated 8-year-old develops fever followed by respiratory symptoms and a generalized rash. Several classmates develop similar illness. Which feature of the responsible virus most strongly supports the possibility of effective population prevention through vaccination?

Options:

Correct Answer: Humans serving as the principal reservoir

Explanation: Measles transmission is maintained primarily among humans. High population immunity can therefore markedly reduce circulation by removing susceptible hosts from the transmission chain.

Question:

A child with suspected measles is evaluated during a community outbreak. The physician explains that the skin eruption is not simply the result of direct viral destruction of epidermal cells. Which process contributes most importantly to development of the rash?

Options:

Correct Answer: Cellular response against infected tissues

Explanation: The measles exanthem largely reflects the host cell-mediated immune response directed against virus-infected cells after systemic viral spread.

Question:

A district surveillance team confirms several measles cases in neighboring schools. The affected communities have gaps in childhood immunization. Which population characteristic most strongly allows continued outbreaks?

Options:

Correct Answer: Large pool of susceptible individuals

Explanation: Inadequate population immunity leaves enough susceptible hosts for sustained person-to-person transmission, making outbreaks more likely after introduction of measles.

Question:

A 20-year-old man develops fever and bilateral painful swelling over the parotid regions. Four days later, he develops upper abdominal pain. Which feature of the infection best explains involvement of an organ distant from the salivary glands?

Options:

Correct Answer: Systemic dissemination during viremia

Explanation: Mumps begins in the respiratory tract and can disseminate through the bloodstream, allowing involvement of salivary glands, pancreas, CNS and gonads.

Question:

A young adult presents with painful parotid enlargement. Serum amylase is elevated, but the physician requests a more specific investigation because other disorders can also increase amylase. Which approach provides better etiological confirmation?

Options:

Correct Answer: Molecular detection of viral RNA

Explanation: Elevated amylase supports salivary-gland involvement but is nonspecific. Detection of mumps viral RNA provides direct evidence of the infecting virus.

Question:

A woman develops a mild febrile rash illness during early pregnancy. Her newborn later has ocular, auditory and cardiac abnormalities. Which sequence best explains development of these abnormalities?

Options:

Correct Answer: Maternal infection → viremia → placental spread → fetal injury

Explanation: Rubella can enter the maternal bloodstream, cross the placenta and infect developing fetal tissues, where interference with cellular growth produces congenital abnormalities.

Question:

During investigation of a rubella outbreak, public-health officials identify several women of reproductive age without documented immunity. Which preventive principle has the greatest long-term importance for reducing congenital disease?

Options:

Correct Answer: Maintaining adequate population vaccination

Explanation: Sustained vaccination reduces rubella circulation and therefore reduces the chance that susceptible pregnant women will encounter the virus and transmit it to the fetus.

Question:

A cervical biopsy from a woman with persistent high-risk HPV infection shows increasing epithelial dysplasia. Viral protein analysis demonstrates interference with two major tumor-suppressor pathways. Which pair of host proteins is principally affected?

Options:

Correct Answer: p53 and RB

Explanation: High-risk HPV E6 promotes loss of p53 activity, while E7 disrupts RB-mediated cell-cycle control, allowing abnormal epithelial cells to continue proliferating.

Question:

A patient with a lymphoid malignancy is found to have evidence of Epstein-Barr virus within the tumor. Which characteristic of this virus is most relevant to its long-term oncogenic potential?

Options:

Correct Answer: Establishment of persistent latent infection

Explanation: EBV can persist lifelong in a latent state. Viral proteins expressed during persistence can influence cellular survival and proliferation, contributing to oncogenesis.

Question:

A man with long-standing chronic viral hepatitis develops a hepatic mass diagnosed as hepatocellular carcinoma. His virus is an enveloped positive-sense RNA virus. Which infection most closely fits this description?

Options:

Correct Answer: Hepatitis C virus

Explanation: HCV is an enveloped positive-sense RNA virus. Persistent hepatic inflammation and repeated regeneration during chronic infection increase the risk of hepatocellular carcinoma.

Question:

Two patients with chronic viral hepatitis develop hepatocellular carcinoma. In one patient, viral DNA has become incorporated into hepatocyte DNA and may directly contribute to genomic instability. Which virus is responsible?

Options:

Correct Answer: Hepatitis B virus

Explanation: HBV can contribute to hepatocarcinogenesis through chronic inflammation and additional effects related to integration of viral DNA and viral proteins.

Question:

A 52-year-old patient is diagnosed with adult T-cell leukemia/lymphoma. Viral studies identify a retrovirus whose genetic material becomes incorporated into the host genome and promotes prolonged lymphocyte proliferation. Which virus is most likely involved?

Options:

Correct Answer: HTLV-1

Explanation: HTLV-1 is an oncogenic retrovirus associated with adult T-cell leukemia/lymphoma; integration and viral regulatory effects promote T-cell proliferation and survival.

Question:

A patient with impaired immune control develops a vascular neoplasm involving the skin. Histological tissue testing demonstrates an oncogenic herpesvirus. Which viral association best explains the lesion?

Options:

Correct Answer: HHV-8 with Kaposi sarcoma

Explanation: HHV-8 is Kaposi sarcoma-associated herpesvirus. Impaired immune control facilitates persistent viral effects that contribute to the characteristic vascular neoplasm.

Question:

A patient tests positive for a high-risk oncogenic virus but has no evidence of dysplasia or malignancy. The patient is concerned that cancer is inevitable. Which principle of viral oncogenesis best addresses this concern?

Options:

Correct Answer: Additional cellular abnormalities influence progression

Explanation: Oncogenic viral infection increases cancer risk but is generally not sufficient by itself; persistent infection interacts with host factors and accumulated cellular abnormalities.

Question:

Following an increase in coronavirus admissions across several Pakistani districts, health authorities strengthen case reporting, expand diagnostic capacity and provide coordinated public-health communication. Which governmental function is primarily illustrated?

Options:

Correct Answer: Population surveillance and coordinated outbreak response

Explanation: Government control programs combine surveillance, laboratory support, communication and coordinated public-health action rather than relying only on treatment of individual cases.

Question:

A public-health team is planning measures for a community experiencing simultaneous respiratory viral outbreaks. The team wants an intervention that acts before infection occurs and also reduces the number of susceptible individuals available for transmission of measles, mumps and rubella. Which approach best meets both objectives?

Options:

Correct Answer: Maintaining high vaccination coverage

Explanation: Vaccination is primary prevention and reduces the susceptible population, thereby protecting individuals while limiting sustained MMR transmission within the community.