Sexually Transmitted Infections — MCQs
Which of the following is a risk factor for cervical cancer?
What is the most likely cause of yellow-green watery discharge and pruritus in a female patient?
A sexually active female presenting with profuse frothy foul-smelling discharge with intense itching. Strawberry cervix revealed on examination. What will be the diagnosis?
A 25-year-old man presents with multiple painful genital ulcers with undermined edges and suppurative lymphadenopathy. Gram stain shows 'school of fish' arrangement. What is the most appropriate initial treatment?
Which of the following statements about screening for chlamydia and gonorrhea is MOST accurate?
What is the underlying pathophysiology of post-gonococcal urethritis?
A 22-year-old woman presents for STI screening. She reports multiple sexual partners and inconsistent condom use. What screening tests would be most appropriate?
A 16-year-old female comes to the physician because of an increased vaginal discharge. She developed this symptom 2 days ago. She also complains of dysuria. She is sexually active with one partner and uses condoms intermittently. Examination reveals some erythema of the cervix but is otherwise unremarkable. A urine culture is sent which comes back negative. Sexually transmitted disease testing is performed and the patient is found to have gonorrhea. While treating this patient's gonorrhea infection, treatment must also be given for which of the following?
Which one of the following statements best characterizes lympho-granuloma venereum (LGV)?
A female presents with dysuria and vaginal discharge. Wet mount examination shows pear-shaped organisms. What is the most likely diagnosis?
Sexually Transmitted Infections Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is a risk factor for cervical cancer?
- A. Persistent infection with high-risk HPV types. (Correct Answer)
- B. Chronic cigarette smoking.
- C. Delayed onset of menstruation (late menarche).
- D. Having no children (nulliparity).
Explanation: ***Persistent infection with high-risk HPV types.*** - **Persistent infection with high-risk human papillomavirus (HPV) types**, particularly HPV-16 and HPV-18, is the **primary and most significant risk factor** for cervical cancer. - HPV infection is the **necessary cause** of virtually all cervical cancers, leading to cellular changes that can progress from **dysplasia** to **invasive cervical carcinoma** over time. - This is the **most important risk factor** among all options. *Chronic cigarette smoking.* - Smoking **is an independent risk factor** for cervical cancer that approximately doubles the risk in women. - Tobacco by-products in cervical mucus damage cervical cell DNA and impair immune function. - In women with HPV infection, smoking acts as a **strong cofactor** that increases progression to cervical cancer by impairing the body's ability to clear HPV infections. - However, **HPV infection is the stronger and necessary risk factor**, making Option A the best answer. *Delayed onset of menstruation (late menarche).* - **Late menarche is NOT a risk factor** for cervical cancer. - Early menarche is weakly associated with increased risk of breast cancer due to prolonged estrogen exposure, but menarche timing has no established relationship with cervical cancer risk. - Cervical cancer risk is primarily related to **HPV exposure**, not hormonal factors like age at menarche. *Having no children (nulliparity).* - **Nulliparity is NOT a risk factor** for cervical cancer. - Conversely, **multiparity** (having 3 or more full-term pregnancies) is associated with increased cervical cancer risk, possibly due to hormonal changes, immunosuppression during pregnancy, or increased HPV exposure. - Among parous women, higher parity increases risk compared to lower parity.
Question 2: What is the most likely cause of yellow-green watery discharge and pruritus in a female patient?
- A. Candida
- B. Bacterial vaginosis
- C. Chlamydia trachomatis
- D. Trichomonas vaginalis (Correct Answer)
Explanation: ***Trichomonas vaginalis (Correct)*** - The characteristic presentation of **yellow-green, frothy, watery vaginal discharge** with associated **pruritus** is highly suggestive of **trichomoniasis**. - Other clinical findings may include **dyspareunia**, **dysuria**, and a **"strawberry cervix"** on speculum examination. - Trichomoniasis is a sexually transmitted infection caused by the protozoan *Trichomonas vaginalis*. *Candida (Incorrect)* - **Candidiasis** (yeast infection) typically presents with **thick, white, cottage cheese-like discharge** and severe pruritus, often described as a burning sensation. - The discharge is usually not watery or yellow-green, and the characteristic fishy odor is absent. - pH is typically normal (<4.5), unlike trichomoniasis where pH is elevated (>4.5). *Bacterial vaginosis (Incorrect)* - **Bacterial vaginosis** is characterized by a **thin, gray-white discharge** with a **fishy odor**, especially after intercourse or with alkalinization. - The discharge is not typically yellow-green or frothy. - Pruritus may be present but is usually less prominent than with candidiasis or trichomoniasis. *Chlamydia trachomatis (Incorrect)* - **Chlamydia** infection is often **asymptomatic** in women (up to 70% of cases), but when symptoms occur, they may include **mucopurulent cervical discharge**, intermenstrial bleeding, or lower abdominal pain. - It does not typically cause the **profuse, frothy, yellow-green discharge** with significant pruritus described in this clinical presentation. - Chlamydia primarily causes cervicitis rather than vaginitis.
Question 3: A sexually active female presenting with profuse frothy foul-smelling discharge with intense itching. Strawberry cervix revealed on examination. What will be the diagnosis?
- A. Trichomonas vaginalis (Correct Answer)
- B. Bacterial vaginosis
- C. Candidiasis
- D. None of the options
Explanation: **Trichomonas vaginalis** - The classic presentation of **profuse, frothy, foul-smelling vaginal discharge** with **intense itching** and the presence of a **strawberry cervix** are highly characteristic of a *Trichomonas vaginalis* infection. - *Trichomonas vaginalis* is a **motile protozoan** and a common sexually transmitted infection. *Bacterial vaginosis* - While bacterial vaginosis (BV) causes a **foul-smelling discharge** (often described as "fishy"), it is typically **thin and grayish-white**, not frothy, and does not cause a strawberry cervix. - BV is caused by an **overgrowth of anaerobic bacteria** and a decrease in lactobacilli, leading to an elevated vaginal pH. *Candidiasis* - Candidiasis (yeast infection) presents with a **thick, white, "cottage cheese-like" discharge** and intense itching, but the discharge is usually odorless and it does not cause a frothy discharge or strawberry cervix. - It is caused by an **overgrowth of *Candida* species**, primarily *Candida albicans*, and is not typically sexually transmitted. *None of the options* - Given the classic constellation of symptoms and definitive signs, a specific diagnosis can be made, making this option incorrect.
Question 4: A 25-year-old man presents with multiple painful genital ulcers with undermined edges and suppurative lymphadenopathy. Gram stain shows 'school of fish' arrangement. What is the most appropriate initial treatment?
- A. Erythromycin 500mg QID for 7 days
- B. Azithromycin 1g single dose (Correct Answer)
- C. Ceftriaxone 250mg IM single dose
- D. Doxycycline 100mg BD for 7 days
Explanation: ***Azithromycin 1g single dose*** - This presentation is highly suggestive of **chancroid**, caused by *Haemophilus ducreyi*. **Azithromycin 1g single dose** is a highly effective and convenient treatment as recommended by CDC guidelines. - The **"school of fish"** gram stain appearance and **painful genital ulcers with undermined edges** are classic features of chancroid [1], making azithromycin the most appropriate initial therapy. *Erythromycin 500mg QID for 7 days* - While **erythromycin** is an effective treatment for chancroid, the **multi-day regimen** makes it less convenient and potentially lowers adherence compared to a single-dose option. - This regimen is less preferred as a first-line initial treatment given the availability of single-dose options for chancroid. *Ceftriaxone 250mg IM single dose* - **Ceftriaxone IM** is the preferred treatment for uncomplicated **gonorrhea** and is also used for **syphilis**, but it is **not the primary treatment for chancroid**. - While it has some activity against *Haemophilus ducreyi*, azithromycin or ciprofloxacin are generally more effective and recommended for chancroid. *Doxycycline 100mg BD for 7 days* - **Doxycycline** is the treatment of choice for **chlamydia** and **syphilis**, but it is **not the recommended first-line treatment for chancroid**. - Its efficacy against *Haemophilus ducreyi* is not as reliable as macrolides or fluoroquinolones for chancroid.
Question 5: Which of the following statements about screening for chlamydia and gonorrhea is MOST accurate?
- A. Screening is not cost-effective and should be avoided in low-risk populations
- B. Screening is recommended for sexually active women under 25, men who have sex with men, and pregnant women (Correct Answer)
- C. Screening is only recommended for patients with symptoms
- D. Annual screening is recommended for all sexually active adults regardless of age or risk factors
Explanation: ***Screening is recommended for sexually active women under 25, men who have sex with men, and pregnant women*** - This statement aligns with current **CDC guidelines** which prioritize screening in populations with a higher prevalence or increased risk of complications from chlamydia and gonorrhea. - Early detection and treatment in these groups can prevent serious long-term health consequences like **pelvic inflammatory disease (PID)**, **infertility**, and **adverse pregnancy outcomes**. *Screening is not cost-effective and should be avoided in low-risk populations* - While screening in genuinely low-risk populations might be less cost-effective, chlamydia and gonorrhea often have **asymptomatic presentations**, making targeted screening essential for disease control. - The long-term costs associated with untreated infections (e.g., infertility treatment, chronic pain) often outweigh the costs of screening, even in lower-prevalence settings, when focused on at-risk groups. *Screening is only recommended for patients with symptoms* - This statement is incorrect because a significant proportion of chlamydia and gonorrhea infections are **asymptomatic**, meaning individuals can be infected and transmit the infection without showing any symptoms. - Relying only on symptoms would lead to widespread **undetected infections** and continued transmission within communities. *Annual screening is recommended for all sexually active adults regardless of age or risk factors* - While broad screening might seem comprehensive, current guidelines emphasize **targeted screening** based on age, sexual history, and risk factors to optimize resource allocation and maximize public health impact. - Overly broad screening in genuinely low-risk older populations may not be the most **cost-effective strategy**.
Question 6: What is the underlying pathophysiology of post-gonococcal urethritis?
- A. Development of antibiotic resistance
- B. Immunological reaction to gonococcal antigens
- C. Concurrent chlamydial infection unaffected by gonococcal treatment (Correct Answer)
- D. Incomplete treatment of gonorrhea
Explanation: ***Concurrent chlamydial infection unaffected by gonococcal treatment*** - Post-gonococcal urethritis often occurs because many individuals co-infected with **gonorrhea** also have a **chlamydial infection** [1]. - Standard **gonorrhea treatment** (e.g., ceftriaxone) does not effectively treat chlamydia, leading to persistent urethritis symptoms caused by the untreated *Chlamydia trachomatis* [1]. *Development of antibiotic resistance* - While **antibiotic resistance** in *Neisseria gonorrhoeae* is a concern, post-gonococcal urethritis typically refers to persistent symptoms after *successful* treatment of gonorrhea [1]. - If initial treatment fails due to resistance, it would be considered **unresolved gonorrhea**, not post-gonococcal urethritis in the context of co-infection. *Immunological reaction to gonococcal antigens* - An **immunological reaction** to gonococcal antigens can occur, but it is not the primary cause of persistent urethritis after *successful* gonococcal eradication. - Such reactions are more characteristic of conditions like **reactive arthritis** following certain infections, which is distinct from persistent urethral inflammation. *Incomplete treatment of gonorrhea* - **Incomplete treatment** implies that the initial *Neisseria gonorrhoeae* infection was not fully eradicated, which would result in persistent gonococcal urethritis [1]. - Post-gonococcal urethritis, by definition, suggests the *gonorrhea* has been effectively treated, and the persistent symptoms are due to another cause, most commonly **co-infection** [1].
Question 7: A 22-year-old woman presents for STI screening. She reports multiple sexual partners and inconsistent condom use. What screening tests would be most appropriate?
- A. HPV DNA testing only
- B. Complete blood count and urinalysis
- C. HIV and syphilis testing only
- D. HIV, syphilis, gonorrhea, and chlamydia testing (Correct Answer)
Explanation: ***HIV, syphilis, gonorrhea, and chlamydia testing*** - This comprehensive panel screens for the most common bacterial and viral STIs in sexually active individuals with **multiple partners** and **inconsistent condom use**, as recommended by **NACO and WHO guidelines**. - **Gonorrhea and chlamydia** often present asymptomatically but can lead to serious reproductive health complications including pelvic inflammatory disease (PID) and infertility if untreated. - In high-risk populations, comprehensive screening is essential for early detection and prevention of transmission. *HPV DNA testing only* - **HPV DNA testing** is primarily for cervical cancer screening in women over 30 years or as a co-test with cytology; it doesn't cover other STIs. - While HPV is common, testing for other prevalent STIs like chlamydia, gonorrhea, syphilis, and HIV is crucial given her risk factors. *Complete blood count and urinalysis* - A **complete blood count (CBC)** assesses overall health and detects conditions like anemia or infection but is not a specific STI screening test. - **Urinalysis** checks for urinary tract infections or kidney issues and does not directly screen for STIs. - These are general screening tests and miss the targeted STI screening needed. *HIV and syphilis testing only* - Although **HIV and syphilis testing** are essential components of STI screening, this option misses other common and treatable bacterial STIs like gonorrhea and chlamydia. - Given the patient's risk factors (multiple partners, inconsistent condom use), a more comprehensive screening panel is warranted to prevent long-term reproductive complications.
Question 8: A 16-year-old female comes to the physician because of an increased vaginal discharge. She developed this symptom 2 days ago. She also complains of dysuria. She is sexually active with one partner and uses condoms intermittently. Examination reveals some erythema of the cervix but is otherwise unremarkable. A urine culture is sent which comes back negative. Sexually transmitted disease testing is performed and the patient is found to have gonorrhea. While treating this patient's gonorrhea infection, treatment must also be given for which of the following?
- A. Chlamydia (Correct Answer)
- B. Herpes
- C. Bacterial vaginosis
- D. Syphilis
Explanation: **Chlamydia** - Due to the high rate of **co-infection** between *Neisseria gonorrhoeae* and *Chlamydia trachomatis*, it is standard practice to empirically treat for chlamydia when gonorrhea is diagnosed. - The patient's symptoms (vaginal discharge, dysuria, cervical erythema) are consistent with both infections, and co-treatment ensures all likely pathogens are addressed. *Herpes* - Genital herpes typically presents with **painful vesicular or ulcerative lesions**, which are not described in this patient. - While sexually transmitted, there is no high co-infection rate with gonorrhea that mandates empirical treatment. *Bacterial vaginosis* - This is an imbalance of vaginal flora, often characterized by a **fishy odor** and a thin, gray discharge, which are not mentioned here. - It is not routinely co-treated with gonorrhea unless specifically diagnosed, and its symptoms do not mimic gonorrhea as closely as chlamydia. *Syphilis* - Syphilis presents with distinct stages, such as a **painless chancre** in primary syphilis or a rash in secondary syphilis, none of which are described. - While also sexually transmitted, there is no automatic co-treatment recommendation for syphilis with gonorrhea due to a low rate of co-infection and different testing/treatment protocols.
Question 9: Which one of the following statements best characterizes lympho-granuloma venereum (LGV)?
- A. It is most common in temperate regions
- B. The causative agent is C. trachomatis (Correct Answer)
- C. In the United States, it is more common among women
- D. Penicillin is effective in early treatment
Explanation: **The causative agent is *C. trachomatis*** - **Lymphogranuloma venereum (LGV)** is a sexually transmitted infection caused by specific serovars (**L1, L2, L2a, L2b, L3**) of *Chlamydia trachomatis*. [1] - These serovars are **invasive** and replicate in **mononuclear phagocytes** of lymphatic tissue, leading to the characteristic lymphadenopathy. [1] *It is most common in temperate regions* - LGV is **most common in tropical and subtropical regions**, particularly in parts of Africa, Southeast Asia, South America, and the Caribbean. - Its prevalence is much lower in temperate regions, though outbreaks can occur, especially in specific *high-risk populations*. *In the United States, it is more common among women* - In developed countries like the United States, LGV primarily affects **men who have sex with men (MSM)**, particularly those who are HIV-positive. [1] - While it can occur in women, its incidence is **significantly lower** in this population. *Penicillin is effective in early treatment* - LGV is caused by *Chlamydia trachomatis*, which is a **bacterium that lacks a peptidoglycan cell wall**, making it inherently resistant to penicillin. - The recommended treatments for LGV are **doxycycline** or **erythromycin**, not penicillin.
Question 10: A female presents with dysuria and vaginal discharge. Wet mount examination shows pear-shaped organisms. What is the most likely diagnosis?
- A. Candida
- B. Chlamydia
- C. Trichomonas (Correct Answer)
- D. Bacterial vaginosis
Explanation: ***Trichomonas*** - The presence of **dysuria**, **vaginal discharge**, and **pear-shaped organisms** on wet mount examination is classic for **Trichomonas vaginalis** infection. - **Microscopic identification of motile trichomonads** confirms the diagnosis. *Candida* - **Candida** infections typically present with **thick, white, curd-like vaginal discharge**, and a wet mount would show **yeast buds or pseudohyphae**, not pear-shaped organisms. - While it can cause dysuria, the discharge characteristics and microscopy findings differentiate it. *Chlamydia* - **Chlamydia trachomatis** causes **mucopurulent cervicitis** with dysuria and vaginal discharge, but requires **specific diagnostic tests** such as **NAAT (nucleic acid amplification test)** or cell culture for diagnosis. - Wet mount examination would **not show pear-shaped organisms**; instead, it may show increased white blood cells but no specific pathogen visualization. *Bacterial vaginosis* - **Bacterial vaginosis** is characterized by a **thin, gray discharge** and a **"fishy" odor**, which is especially noticeable after intercourse. - Wet mount shows **clue cells** (vaginal epithelial cells studded with bacteria), not pear-shaped organisms, and **absent or few white blood cells**.
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