KMU Past Paper Practice
Topic 11 — Sexually Transmitted Infections
4th Year MBBS • 20 A-type Single Best Answer MCQs
MCQ 1
Question:
A 27-year-old man has repeated sexual exposure to a partner living with HIV. He is HIV-negative and anticipates continued exposure despite counseling. Which preventive intervention is most appropriate to reduce his risk of acquiring HIV?
Options:
Pre-exposure antiretroviral prophylaxis
Pre-exposure prophylaxis is used in HIV-negative people with substantial ongoing exposure risk to reduce the probability of acquiring HIV.
MCQ 2
Question:
A regional blood service is strengthening prevention of transfusion-associated HIV infection. Which intervention most directly reduces transmission through donated blood?
Options:
Screen donated blood for HIV infection
HIV can be transmitted through infected blood, so effective donor screening is a key health-system measure for prevention.
MCQ 3
Question:
A patient with HIV asks why several antiretroviral drugs are combined instead of relying on a single active drug. Which therapeutic principle best explains this approach?
Options:
Reduce emergence of resistant viral variants
Using drugs that act at different stages of HIV replication produces durable suppression and decreases the chance that resistant virus will dominate.
MCQ 4
Question:
An antiretroviral drug prevents HIV from converting its viral RNA into a DNA copy after entering a susceptible cell. Which viral process has been inhibited?
Options:
Reverse transcription
HIV uses reverse transcriptase to make DNA from its RNA genome; inhibition of this step interrupts viral replication.
MCQ 5
Question:
A newly developed antiretroviral drug allows HIV DNA to form but prevents it from becoming incorporated into the host-cell genome. Which viral step is being blocked?
Options:
Viral integration
After reverse transcription, HIV DNA must integrate into host-cell DNA; integrase inhibitors prevent this essential step.
MCQ 6
Question:
A 35-year-old patient has newly confirmed HIV infection. The clinician now wants a laboratory measure that primarily reflects the patient’s current degree of immune impairment. Which investigation is most appropriate?
Options:
CD4-cell count
CD4-cell assessment reflects the degree of HIV-related cellular immunodeficiency and helps evaluate the patient’s immune status after diagnosis.
MCQ 7
Question:
A man reports sexual contact with a partner who had an untreated genital lesion later diagnosed as infectious syphilis. Which mechanism most directly explains his risk of acquiring the infection?
Options:
Direct contact with an infectious lesion
Sexual transmission of syphilis occurs through direct contact with infectious lesions containing Treponema pallidum.
MCQ 8
Question:
A pregnant woman is diagnosed with untreated syphilis during antenatal assessment. Which route is responsible for the major fetal risk associated with this infection?
Options:
Transplacental passage of the organism
T. pallidum can cross the placenta and infect the fetus, which is why antenatal detection and treatment are important.
MCQ 9
Question:
A man develops a genital lesion compatible with primary syphilis but does not seek treatment. Several weeks later the lesion disappears completely. Which interpretation is most appropriate?
Options:
The infection may persist and progress despite healing
A syphilitic chancre can heal spontaneously, but untreated T. pallidum remains in the body and may progress to later stages.
MCQ 10
Question:
A patient with a remote history of untreated syphilis develops destructive granulomatous lesions and cardiovascular involvement years later. Which phase of infection best explains these findings?
Options:
Late tertiary syphilis
Untreated late syphilis may produce gummatous lesions and cardiovascular disease after a prolonged period of infection.
MCQ 11
Question:
A 24-year-old man develops a persistent sore throat after unprotected oral sexual exposure. His genital examination is normal, but the clinician suspects gonococcal infection at the exposed site. Which diagnostic approach is most appropriate?
Options:
NAAT from the pharyngeal site
Gonorrhea can infect the pharynx after oral exposure, so testing should sample the relevant anatomical site.
MCQ 12
Question:
A clinic updates its gonorrhea treatment protocol after local surveillance shows changing antimicrobial susceptibility. Why is adherence to current local treatment guidance particularly important in this infection?
Options:
Antimicrobial susceptibility patterns can change
Changing gonococcal resistance patterns mean that effective therapy should follow current local or national treatment recommendations.
MCQ 13
Question:
A 22-year-old man has dysuria and a mild urethral discharge. Testing does not support gonorrhea, and the clinician considers a common cause of nongonococcal urethritis. Which organism is most likely?
Options:
Chlamydia trachomatis
C. trachomatis is an important cause of nongonococcal urethritis and may produce dysuria with relatively modest urethral discharge.
MCQ 14
Question:
A young man with untreated genital chlamydial infection develops unilateral scrotal discomfort and tenderness. Which complication of the infection best explains this development?
Options:
Epididymal involvement
Genital chlamydial infection in men may extend beyond the urethra and involve the epididymis, producing pain and tenderness.
MCQ 15
Question:
An infant born to a mother with untreated genital chlamydial infection later develops respiratory symptoms. Which explanation best links the maternal infection to the infant’s illness?
Options:
Perinatal exposure can produce chlamydial respiratory infection
Infants exposed to maternal genital chlamydial infection during delivery may subsequently develop respiratory disease.
MCQ 16
Question:
A 26-year-old patient has several symptomatic external genital warts and asks for treatment of the visible lesions. Which management option directly removes or destroys established warts?
Options:
Cryotherapy of visible lesions
Cryotherapy is one accepted method for destroying visible genital warts; treatment targets the lesion rather than guaranteeing elimination of HPV infection.
MCQ 17
Question:
A woman who has received HPV vaccination asks whether she can permanently stop participating in cervical screening. Which advice best reflects the preventive principles of the topic?
Options:
Continue screening according to the relevant programme
HPV vaccination reduces risk from important viral types but does not remove the need for cervical screening according to the applicable programme.
MCQ 18
Question:
A cervical screening service wants a test that directly identifies infection with oncogenic HPV types rather than examining cell morphology alone. Which test best meets this objective?
Options:
High-risk HPV testing
High-risk HPV testing directly detects oncogenic HPV infection, whereas cervical cytology identifies abnormal epithelial cellular changes.
MCQ 19
Question:
A public-health programme identifies precancerous cervical epithelial changes in women who have no symptoms and arranges early management. At which level of prevention is this activity primarily operating?
Options:
Secondary prevention
Screening detects disease or precancerous change before symptoms or invasive disease develop, making it a form of secondary prevention.
MCQ 20
Question:
A community STI review finds that transmission is concentrated within networks in which people frequently have overlapping sexual partnerships. Which epidemiological factor should the prevention team recognize as contributing most directly to continued spread?
Options:
Multiple or concurrent sexual partners
Overlapping sexual partnerships increase opportunities for an infection to move rapidly between connected susceptible individuals.