Infectious Diseases Practice Questions

Q: Which is not included in AIDS related complex?

Ectopic pregnancy. ***Ectopic pregnancy*** - **Ectopic pregnancy** is a gynecological condition related to reproductive health and is **not a direct manifestation** of HIV infection or one of the opportunistic infections/conditions characteristic of AIDS-related complex. - While HIV can affect overall health during pregnancy, an ectopic pregnancy itself is a different medical issue. *Recurrent genital candidiasis* - **Recurrent genital candidiasis** can be a sign of **diminished immune function** in HIV-positive women [1]. - It is often considered an AIDS-defining condition or a common opportunistic infection seen in the progression of HIV to AIDS-related complex [1]. *Generalised lymphadenopathy* - **Generalized lymphadenopathy**, specifically **persistent generalized lymphadenopathy (PGL)**, is a common early manifestation of HIV infection [1]. - It reflects ongoing immune activation and is part of the spectrum of conditions included in AIDS-related complex [1]. *Chronic diarrhea* - **Chronic diarrhea** (lasting more than one month) is a frequent and significant symptom in individuals with HIV infection, particularly as the disease progresses [1]. - It can be caused by various opportunistic infections or directly by HIV, and is a component of AIDS-related complex or AIDS-defining illness [1].

Q: Which condition is most commonly associated with cryoglobulinemia?

Hepatitis C. **Hepatitis C** - **Hepatitis C virus (HCV) infection** is the most common cause of mixed cryoglobulinemia, with cryoglobulins being detected in a high percentage of infected individuals. - The chronic immune stimulation caused by HCV leads to the production of **monoclonal or polyclonal immunoglobulins** (cryoglobulins) that precipitate in the cold. *Ovarian cancer* - While certain malignancies can be associated with paraneoplastic syndromes, **ovarian cancer** is not typically linked to cryoglobulinemia. - Cryoglobulinemia is more commonly associated with **lymphoproliferative disorders** or chronic infections rather than solid tumors like ovarian cancer. *Diabetes* - **Diabetes mellitus** is not directly associated with cryoglobulinemia; it is a metabolic disorder affecting glucose regulation. - Complications of diabetes include microvascular and macrovascular disease, but not primary cryoglobulin formation. *Leukemia* - Certain hematological malignancies, particularly **lymphoproliferative disorders like Waldenström macroglobulinemia or multiple myeloma**, can be associated with cryoglobulinemia. - However, **leukemia** (especially acute forms) is less commonly linked to cryoglobulinemia than chronic infections like hepatitis C or certain B-cell lymphomas.

Q: Most common organism associated with reactive arthritis is:

Chlamydia. ***Chlamydia*** - **Chlamydia trachomatis** is a commonly identified pathogen causing **genitourinary infections** that can trigger reactive arthritis [1]. - The organism itself is not present in the joint, but its antigens trigger an immune response leading to sterile arthritis [1]. *Staphylococcus* - **Staphylococcus aureus** is a common cause of septic arthritis, which involves direct bacterial invasion of the joint. - Reactive arthritis is a **sterile arthritis** triggered by an infection elsewhere, not directly caused by staphylococcal joint infection. *Shigella* - While **Shigella** is a known enteric pathogen that can trigger reactive arthritis, it is less commonly associated with the condition globally compared to Chlamydia [1]. - Reactive arthritis often follows episodes of **dysentery** caused by Shigella species [1]. *Yersinia* - **Yersinia enterocolitica** is another enteric bacterium that can induce reactive arthritis, typically after **gastrointestinal infections**. - Its prevalence as a trigger for reactive arthritis is generally lower than that of Chlamydia.

Q: What does the acronym I.R.I.S. stand for in the context of immunology?

Immune reconstitution inflammatory syndrome. ***Immune reconstitution inflammatory syndrome*** - **IRIS** refers to a paradoxical worsening, unmasking, or new manifestation of opportunistic infections or inflammatory disorders during **immune recovery**, typically following the initiation of **antiretroviral therapy (ART)** in HIV-infected individuals [1]. - It occurs when a weakened immune system, suddenly bolstered by treatment, mounts an excessive inflammatory response to pre-existing or newly recognized pathogens or antigens [1]. *Immune reconstitution idiopathic syndrome* - The term **"idiopathic"** implies an unknown cause, which is not accurate for IRIS, as its pathophysiology is linked to **immune recovery**. - While some cases might have less clear triggers, the overall syndrome is understood to be inflammation driven by specific **immune responses**. *Immune reconstitution immunological syndrome* - This option uses the redundant term **"immunological"** after "immune reconstitution," which does not form the correct acronym or accurately describe the syndrome's hallmark: **inflammation** [1]. - The key feature of IRIS is the **inflammatory response**, not merely an "immunological" event [1]. *Inflammatory reconstitution immune syndrome* - This arrangement of words reverses the correct order and meaning of the acronym **IRIS**, placing "inflammatory" before "reconstitution." - The syndrome describes **immune reconstitution** leading to **inflammatory** manifestations, not the other way around [1].

Q: Which condition is associated with Streptococcus bovis infection?

Colorectal cancer. ***Colorectal cancer*** - *Streptococcus gallolyticus* (formerly known as *Streptococcus bovis* biotype I) infection, particularly **bacteremia** or **endocarditis**, has a strong association with underlying **colorectal cancer**. - It is hypothesized that the bacteria may play a role in **tumorigenesis** or that the cancerous lesions provide an entry point for the bacteria into the bloodstream. *Chronic lymphocytic leukemia (CLL)* - While patients with CLL are **immunocompromised** and prone to infections, there is no specific association between *Streptococcus bovis* and CLL. - Infections in CLL patients are typically due to encapsulated bacteria, such as *Streptococcus pneumoniae* or *Haemophilus influenzae*. *Hairy cell leukemia (HCL)* - Patients with HCL often experience **immunosuppression** due to neutropenia and monocytopenia, leading to increased susceptibility to infections. - However, there is no direct or specific link between *Streptococcus bovis* infection and HCL itself. *Multiple myeloma (MM)* - Patients with multiple myeloma have **impaired humoral immunity** and are at risk for infections, especially from encapsulated bacteria. - There is no established specific association between *Streptococcus bovis* infection and multiple myeloma.

Q: ABO non- secretors are more prone to ?

Increased risk of infections. Increased risk of infections - Non-secretors of ABO antigens exhibit an increased susceptibility to a variety of infections, particularly bacterial and viral pathogens. - This is thought to be due to the absence of ABO antigens in secretions, which typically act as decoy receptors to prevent pathogen adhesion to host cells. Autoimmune diseases - While some associations between ABO blood groups and autoimmune diseases exist, non-secretor status is not consistently linked to a higher overall risk of autoimmune conditions. Cardiovascular diseases - ABO blood groups have been associated with cardiovascular risk, with non-O blood types generally having a slightly higher risk of certain cardiovascular events. - However, secretor status (the ability to secrete ABO antigens into bodily fluids) itself is not a prominent independent risk factor for cardiovascular diseases. Cancer - There are some documented associations between specific ABO blood types and certain types of cancer (e.g., non-O blood types with pancreatic cancer), but this is distinct from secretor status. - Being an ABO non-secretor is not a primary, broadly recognized risk factor for developing cancer.

Q: Most common complication of diphtheria is -

Myocarditis. ***Myocarditis*** - Diphtheria toxin can directly damage myocardial cells, leading to inflammation and dysfunction of the heart muscle, making **myocarditis** the most common and serious complication. - This can result in **heart failure**, arrhythmias, and even death, highlighting its significance in diphtheria. *Pneumonia* - While respiratory complications can occur in diphtheria, **pneumonia** is not the most common or life-threatening complication associated with the diphtheria toxin itself. - Secondary bacterial infections might lead to pneumonia, but it is not a direct toxic effect like myocarditis. *Meningitis* - **Meningitis**, an inflammation of the membranes surrounding the brain and spinal cord, is an extremely rare complication of diphtheria. - Diphtheria primarily affects the upper respiratory tract and heart [1], with neurological complications typically manifesting as neuropathies rather than meningitis. *Endocarditis* - Although diphtheria can cause cardiac complications, **endocarditis** (inflammation of the heart's inner lining, including the valves) is not a common complication. - Myocarditis, due to the direct toxic effect on heart muscle, is far more prevalent than endocarditis in diphtheria.

Q: Eschar is seen in all the Rickettsial diseases except:

Endemic typhus. ***Endemic typhus*** - **Endemic typhus**, caused by *Rickettsia typhi*, is transmitted by **fleas** and typically presents without an eschar. - The disease is characterized by fever, headache, and a maculopapular rash, but the **inoculation site lesion (eschar) is rare or absent**. *Scrub typhus* - **Scrub typhus**, caused by *Orientia tsutsugamushi*, is known for causing a prominent **eschar** [1] at the site of the **chigger mite bite**. - This **painless black scab** is a classic diagnostic feature of the disease [1]. *Rickettsial pox* - **Rickettsial pox**, caused by *Rickettsia akari*, almost invariably presents with an **eschar**, often referred to as an **inoculation lesion**. - This lesion appears as a papule that vesiculates and then forms a scab, indicating the site of the **mite bite**. *Indian tick typhus* - **Indian tick typhus** (part of the **spotted fever group rickettsioses**), caused by *Rickettsia conorii*, frequently presents with a characteristic **eschar** at the site of the **tick bite**. - This eschar, known as a **tache noire**, is a valuable diagnostic clue in affected patients.

Q: Which of the following statements about post-exposure prophylaxis (PEP) for HIV is correct?

Should be started within 72 hours of exposure. ***Should be started within 72 hours of exposure*** - PEP is most effective when initiated as soon as possible after a potential HIV exposure, with the **maximum benefit observed within 72 hours**. - Delaying initiation beyond this window significantly **reduces its efficacy** in preventing HIV seroconversion. *Should be continued for 4 weeks* - PEP is typically continued for 28 days, which is approximately **four weeks**. While this statement is generally true, it is not the most crucial initial action. - The duration of 28 days is crucial for ensuring the antiretroviral drugs effectively interrupt the **HIV replication cycle** before it can establish a permanent infection. *Standard protocol includes three antiretroviral drugs* - The standard PEP regimen typically involves a **combination of three antiretroviral drugs**. However, this option alone does not capture the critical timing aspect of PEP. - The combination of three drugs aims to target different stages of the **HIV life cycle** to maximize the chances of preventing infection. *Involves a combination of antiretroviral drugs for 28 days* - This statement accurately describes the components and duration of PEP but does not emphasize the **critical time window** for initiation, which is the most important factor for its effectiveness. - The **28-day duration** with a combination of drugs is designed to cover the period during which initial HIV replication could occur, allowing the drugs to suppress viral activity.

Q: Buboes form is which stage of LGV?

Secondary. ***Secondary*** - Buboes, which are swollen, painful lymph nodes, are a hallmark of the **secondary stage** of **Lymphogranuloma Venereum (LGV)** [1]. - This stage typically develops weeks after the initial infection, following the unnoticed or transient primary lesion. *Primary* - The primary stage of LGV is characterized by a **small, painless papule or ulcer** at the site of inoculation, which often goes unnoticed. - **Buboes are not formed** during this initial, often asymptomatic, phase. *Tertiary* - The tertiary stage of LGV involves **chronic inflammation** and **tissue destruction**, leading to complications like **genital elephantiasis**, rectal strictures, and fistulas. - While there is chronic lymphedema, the acute, painful buboes are characteristic of the secondary stage, not this late, destructive phase. *Latent* - The concept of a latent stage is not typically used to describe the progression of LGV in the same way as other infections like syphilis. - LGV progresses through distinct symptomatic primary, secondary, and potentially tertiary stages without a prolonged asymptomatic latency period between symptom presentations.

Question 1

Which is not included in AIDS related complex?

Accepted Answer

Ectopic pregnancy

Answer

Recurrent genital candidiasis

Answer

Generalised lymphadenopathy

Answer

Chronic diarrhea

Question 2

Which condition is most commonly associated with cryoglobulinemia?

Accepted Answer

Hepatitis C

Answer

Ovarian cancer

Answer

Diabetes

Answer

Leukemia

Question 3

Most common organism associated with reactive arthritis is:

Accepted Answer

Chlamydia

Answer

Staphylococcus

Answer

Shigella

Answer

Yersinia

Question 4

What does the acronym I.R.I.S. stand for in the context of immunology?

Accepted Answer

Immune reconstitution inflammatory syndrome

Answer

Immune reconstitution idiopathic syndrome

Answer

Immune reconstitution immunological syndrome

Answer

Inflammatory reconstitution immune syndrome

Question 5

Which condition is associated with Streptococcus bovis infection?

Accepted Answer

Colorectal cancer

Answer

Chronic lymphocytic leukemia (CLL)

Answer

Hairy cell leukemia (HCL)

Answer

Multiple myeloma (MM)

Question 6

ABO non- secretors are more prone to ?

Accepted Answer

Increased risk of infections

Answer

Autoimmune diseases

Answer

Cardiovascular diseases

Answer

Cancer

Question 7

Most common complication of diphtheria is -

Accepted Answer

Myocarditis

Answer

Pneumonia

Answer

Meningitis

Answer

Endocarditis

Question 8

Eschar is seen in all the Rickettsial diseases except:

Accepted Answer

Endemic typhus

Answer

Scrub typhus

Answer

Rickettsial pox

Answer

Indian tick typhus

Question 9

Which of the following statements about post-exposure prophylaxis (PEP) for HIV is correct?

Accepted Answer

Should be started within 72 hours of exposure

Answer

Should be continued for 4 weeks

Answer

Standard protocol includes three antiretroviral drugs

Answer

Involves a combination of antiretroviral drugs for 28 days

Question 10

Buboes form is which stage of LGV?

Accepted Answer

Secondary

Answer

Tertiary

Answer

Latent

Answer

Primary

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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