HIV and STIs — MCQs
Perivascular lymphocytes & microglial nodules are seen in -
Genital ulcers are seen in all except:
In diagnosis of AIDS, criteria include the following except -
What is the initial clinical manifestation of Treponema pallidum infection in primary syphilis?
A man presents with a history of dysuria and urethral discharge after having unprotected sexual intercourse. What is the treatment of choice for this infection?
An adult man presents with the clinical condition shown in the image, and a Gram stain reveals Gram-negative diplococci. What is the most appropriate treatment?
A male patient presents with white discharge from the urethra, as shown in the image. What is the most probable causative organism?
WHO stage IV HIV includes all, except:
Which of the following statements about lymphogranuloma venereum (LGV) is NOT true?
A male presents with urethral discharge as shown in the figure. What is the most likely cause?
HIV and STIs Indian Medical PG Practice Questions and MCQs
Question 1: Perivascular lymphocytes & microglial nodules are seen in -
- A. HIV encephalitis (Correct Answer)
- B. CMV meningitis
- C. Bacterial meningitis
- D. Multiple sclerosis
Explanation: ***HIV encephalitis*** - **Perivascular lymphocytes** and **microglial nodules** are the characteristic histopathological hallmarks of **HIV encephalitis (HIV-associated dementia complex)** [1][2]. - Microglial nodules are formed by activated microglia and macrophages, often accompanied by **multinucleated giant cells** (the classic triad) [2]. - These features reflect chronic CNS inflammation and neuronal damage caused by HIV infection. *CMV meningitis* - Cytomegalovirus (CMV) infection in immunocompromised patients causes meningoencephalitis with characteristic **intranuclear ("owl's eye") inclusion bodies** and necrotizing inflammation. - The histological pattern differs from the microglial nodules and perivascular lymphocytes seen in HIV encephalitis. *Bacterial meningitis* - Characterized by prominent **neutrophilic infiltrate** in the subarachnoid space, fibrinopurulent exudate, and potential vasculitis. - Acute bacterial meningitis does not show the lymphocytic and microglial nodular pattern characteristic of viral encephalitis. *Multiple sclerosis* - An autoimmune demyelinating disease with **perivenular demyelinating plaques** containing lymphocytes and macrophages. - While perivascular inflammation occurs, **microglial nodules** are not a characteristic feature; instead, MS shows demyelination with reactive gliosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, p. 1278. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 711-712.
Question 2: Genital ulcers are seen in all except:
- A. H. ducreyi
- B. HSV
- C. Chlamydia
- D. H. aegyptius (Correct Answer)
Explanation: ***H. aegyptius*** - *Haemophilus aegyptius* is primarily known to cause **conjunctivitis (pinkeye)**, especially in children, and **Brazilian purpuric fever**, which is a severe systemic illness. - It does **not typically cause genital ulcers**, differentiating it from other listed pathogens. *H. ducreyi* - *Haemophilus ducreyi* is the causative agent of **chancroid**, which typically presents as painful **genital ulcers** with soft, friable bases. - These ulcers are often accompanied by **inguinal lymphadenopathy (buboes)**. *HSV* - **Herpes Simplex Virus (HSV)**, particularly HSV-2, is a common cause of **genital herpes**, characterized by painful, vesicular eruptions that progress to **ulcers** on the genitals. - These lesions often recur and are associated with **neuropathic pain and tenderness**. *Chlamydia* - While *Chlamydia trachomatis* is known for causing **genital infections** like urethritis and cervicitis, specific serovars (L1, L2, L3) are responsible for **lymphogranuloma venereum (LGV)**. - LGV typically begins with a **transient, often unnoticed, small genital ulcer** or papule, followed by marked **inguinal lymphadenopathy** and systemic symptoms.
Question 3: In diagnosis of AIDS, criteria include the following except -
- A. CD8<500 (Correct Answer)
- B. CD4<200
- C. Presence of any of the opportunistic infections tuberculosis, pneumocystis carinii, cytomegalovirus
- D. CD4 : CD 8 =1
Explanation: ***CD8<500*** - While **CD8+ T cells** are involved in the immune response to HIV, their absolute count is not a primary criterion for diagnosing or staging **AIDS**. - **AIDS** diagnosis is primarily based on **CD4+ T cell counts** and the presence of **AIDS-defining opportunistic infections** [1]. *CD4<200* - A **CD4+ T cell count** below **200 cells/µL** is a key diagnostic criterion for **AIDS**, indicating severe immunosuppression [1]. - This threshold signifies a significantly compromised immune system, making the individual highly susceptible to opportunistic infections. *Presence of any of the opportunistic infections tuberculosis, pneumocystis carinii, cytomegalovirus* - The occurrence of **AIDS-defining opportunistic infections** like **tuberculosis**, **Pneumocystis jirovecii pneumonia**, or **cytomegalovirus retinitis** in an HIV-positive individual confirms an **AIDS diagnosis**, regardless of the CD4 count [1]. - These infections typically manifest when the immune system is severely weakened. *CD4 : CD 8 =1* - A **CD4:CD8 ratio of 1** (or any specific ratio) is not a direct criterion for diagnosing **AIDS**. - In HIV infection, the **CD4:CD8 ratio typically inverts** (becomes less than 1) as CD4 cells decline, but this ratio alone is not a defining characteristic for AIDS.
Question 4: What is the initial clinical manifestation of Treponema pallidum infection in primary syphilis?
- A. Primary chancre (Correct Answer)
- B. Secondary rash
- C. Neurosyphilis
- D. Dark-field microscopy
Explanation: ***Primary chancre*** - *Treponema pallidum* is the causative agent of syphilis, and the **primary chancre** is the initial clinical manifestation at the site of inoculation. - A **chancre** is a painless, indurated ulcer with a clean base that develops 10-90 days after infection, typically on the genitals, rectum, or mouth. - This represents the hallmark of **primary syphilis** and is the first clinical sign of *T. pallidum* infection. *Secondary rash* - A **secondary rash** is a manifestation of **secondary syphilis**, occurring several weeks to months after the primary chancre heals. - This disseminated stage occurs as spirochetes spread throughout the body, but it is not the initial clinical manifestation. *Neurosyphilis* - **Neurosyphilis** refers to infection of the central nervous system by *Treponema pallidum*, which can occur at any stage but typically represents **tertiary syphilis**. - This is a severe complication but not the initial clinical manifestation of the infection. *Dark-field microscopy* - **Dark-field microscopy** is a diagnostic laboratory technique used to visualize motile *Treponema pallidum* directly from chancre exudate. - This is a diagnostic method, not a clinical manifestation of the infection.
Question 5: A man presents with a history of dysuria and urethral discharge after having unprotected sexual intercourse. What is the treatment of choice for this infection?
- A. Erythromycin
- B. Azithromycin
- C. Ceftriaxone (Correct Answer)
- D. Penicillin G
Explanation: ***Ceftriaxone*** - The combination of **dysuria** and **urethral discharge** following unprotected sexual intercourse is highly suggestive of **gonorrhea**. - **Ceftriaxone** is the recommended first-line treatment for uncomplicated gonococcal infections due to increasing antibiotic resistance. *Erythromycin* - Erythromycin is primarily used for atypical bacterial infections, such as those caused by *Mycoplasma pneumoniae* or *Chlamydia trachomatis*. - While it can be used for chlamydia, it is not the preferred treatment for suspected gonorrhea. *Azithromycin* - Azithromycin is often used in combination with ceftriaxone for gonorrhea to cover potential co-infection with **Chlamydia trachomatis**. - However, **monotherapy with azithromycin is not recommended for gonorrhea** due to concerns about emerging resistance and suboptimal efficacy. *Penicillin G* - Penicillin G was historically used to treat gonorrhea, but this is no longer the case due to widespread **resistance** of *Neisseria gonorrhoeae* strains. - Its primary use now is for susceptible bacterial infections, such as syphilis and certain streptococcal infections.
Question 6: An adult man presents with the clinical condition shown in the image, and a Gram stain reveals Gram-negative diplococci. What is the most appropriate treatment?
- A. Ceftriaxone (Correct Answer)
- B. Azithromycin
- C. Doxycycline
- D. Acyclovir
Explanation: ***Ceftriaxone*** - The image shows **urethritis** (discharge from the urethra), and the Gram stain revealing **Gram-negative diplococci** is characteristic of **Neisseria gonorrhoeae**. - **Ceftriaxone** is the recommended first-line treatment for **gonorrhea**, often administered as a single intramuscular dose. *Azithromycin* - While often co-administered with ceftriaxone to cover potential **Chlamydia coinfection**, it is not the primary treatment for gonorrhea alone. - Azithromycin is the main treatment for uncomplicated **Chlamydia trachomatis** infections. *Doxycycline* - **Doxycycline** is a highly effective antibiotic for treating **Chlamydia trachomatis** infections and certain other bacterial STIs. - It is not the primary treatment for **gonorrhea** due to resistance concerns and preferred efficacy of cephalosporins. *Acyclovir* - **Acyclovir** is an antiviral medication used to treat infections caused by the **herpes simplex virus (HSV)**. - It has no activity against **bacterial infections** like gonorrhea, making it inappropriate for this presentation.
Question 7: A male patient presents with white discharge from the urethra, as shown in the image. What is the most probable causative organism?
- A. Haemophilus ducreyi
- B. Klebsiella granulomatis
- C. Neisseria gonorrhoeae (Correct Answer)
- D. Treponema pallidum
Explanation: ***Neisseria gonorrhoeae*** - Among the given options, *Neisseria gonorrhoeae* is the **most probable causative organism** for **urethral discharge** in males. - Gonorrhea is a common sexually transmitted infection (STI) presenting with **purulent urethritis**, typically with thick, yellow-green discharge, though appearance can vary. - **Clinical note:** While classic gonococcal discharge is purulent and yellow-green, the clinical presentation can vary. None of the other organisms listed cause urethritis with discharge. *Haemophilus ducreyi* - This bacterium causes **chancroid**, a sexually transmitted infection characterized by **painful genital ulcers (chancres)** and **inguinal lymphadenopathy**, not urethral discharge. - Presents with ulcerative lesions, not discharge. *Klebsiella granulomatis* - This organism is responsible for **donovanosis** (granuloma inguinale), which manifests as **painless, progressive ulcerative lesions** on the genitals. - It does not cause urethral discharge; presents with beefy red granulomatous lesions. *Treponema pallidum* - This spirochete causes **syphilis**, which presents with **painless chancres** in the primary stage, **maculopapular rash** in the secondary stage, and gummas or neurological symptoms in later stages. - Urethral discharge is not a typical symptom of syphilis; primary lesions are ulcerative.
Question 8: WHO stage IV HIV includes all, except:
- A. HIV wasting syndrome
- B. Pneumocystis jirovecii
- C. Toxoplasmosis
- D. Oral thrush (Correct Answer)
Explanation: ***Oral thrush*** - While common in HIV, **oral candidiasis (thrush)** is typically classified as a **WHO clinical stage I or II** condition, indicating less severe immunosuppression. - It does not signify the profound immune compromise characteristic of stage IV disease. *HIV wasting syndrome* - **HIV wasting syndrome** is explicitly listed as a **major clinical condition** in WHO clinical stage IV HIV infection. - It is defined by **involuntary weight loss** of more than 10% of baseline body weight, accompanied by fever or diarrhea for at least 30 days, or unexplained chronic weakness. *Pneumocystis jirovecii* - **Pneumocystis jirovecii pneumonia (PCP)** is a classic **opportunistic infection (OI)** that classifies HIV infection as **WHO clinical stage IV**. - Its presence indicates severe immune suppression and often signifies advanced disease. *Toxoplasmosis* - **Toxoplasmosis of the central nervous system (CNS)**, particularly cerebral toxoplasmosis, is a defining **WHO clinical stage IV** opportunistic infection in HIV. - It reflects severe immune compromise, making the patient susceptible to reactivation of latent *Toxoplasma gondii* infection.
Question 9: Which of the following statements about lymphogranuloma venereum (LGV) is NOT true?
- A. Groove sign is characteristic
- B. Caused by C. trachomatis serovars L1, L2, L3
- C. Can lead to proctocolitis
- D. Primary genital ulcer is painful (Correct Answer)
Explanation: ***Primary genital ulcer is painful*** - The primary genital lesion of LGV, known as a **papule or shallow ulcer**, is typically **painless** and often resolves spontaneously without being noticed [1]. - Painful ulcers are more characteristic of other sexually transmitted infections like **herpes simplex virus (HSV)** or **chancroid** [1]. *Groove sign is characteristic* - The **groove sign**, characterized by enlarged inguinal and femoral lymph nodes separated by the inguinal ligament, is a **pathognomonic clinical feature** of LGV, particularly in later stages [1]. - This sign indicates extensive involvement of regional lymphatics. *Caused by C. trachomatis serovars L1, L2, L3* - LGV is indeed caused by specific **invasive serovars** of *Chlamydia trachomatis*, namely **L1, L2, and L3** [1]. - These serovars have a greater capacity for systemic dissemination and lymphatic tissue invasion compared to the serovars causing ocular or urogenital chlamydial infections. *Can lead to proctocolitis* - **Proctocolitis** (inflammation of the rectum and colon) can occur, especially in individuals engaging in **anal-receptive intercourse**, as the infection can directly involve the rectal mucosa [1]. - This can lead to symptoms such as **rectal pain, discharge, tenesmus, and bleeding** [1].
Question 10: A male presents with urethral discharge as shown in the figure. What is the most likely cause?
- A. HIV
- B. Haemophilus ducreyi
- C. Gonorrhea (Correct Answer)
- D. Syphilis
Explanation: ***Gonorrhea*** - The image depicts **purulent urethral discharge**, a classic symptom frequently seen in **gonococcal urethritis**. - **Neisseria gonorrhoeae** commonly causes urethritis with a thick, yellowish, or greenish discharge. *HIV* - HIV primarily affects the immune system and does not typically present with **gonorrhea-like urethral discharge** as a direct symptom. - While HIV can increase susceptibility to other STIs, the discharge itself is not a direct manifestation of HIV infection. *Haemophilus ducreyi* - This bacterium is the causative agent of **chancroid**, which presents as painful genital ulcers, not urethral discharge. - **Chancroid ulcers** are typically soft, ragged, and associated with tender inguinal lymphadenopathy. *Syphilis* - Syphilis, caused by **Treponema pallidum**, presents with a **painless chancre** in its primary stage, not urethral discharge. - Later stages of syphilis involve rashes, neurological symptoms, or gummas, which are distinct from the penile discharge shown.
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