Infectious Diseases Practice Questions

Q: Which viral infection is primarily associated with hemolysis?

Epstein-Barr virus. **Epstein-Barr virus** - **Epstein-Barr virus (EBV)** is strongly associated with **cold agglutinin disease**, an **autoimmune hemolytic anemia** where cold-reacting antibodies agglutinate and lyse red blood cells. [4] - Hemolysis in EBV infection can also occur due to direct viral effects on red blood cells or immune-mediated mechanisms beyond cold agglutinins. [1] *Hepatitis B virus* - Hepatitis B virus is primarily known for causing **liver inflammation** and **hepatocellular damage**, rather than direct or immune-mediated hemolysis. [2] - While chronic HBV infection can lead to complications such as cirrhosis or liver cancer, it is not a common cause of hemolytic anemia. *Hepatitis-C* - Hepatitis C virus is a common cause of **chronic liver disease**, leading to **fibrosis**, **cirrhosis**, and **hepatocellular carcinoma**. [3] - Although HCV is sometimes associated with mixed cryoglobulinemia, which can cause vasculitis and organ damage, it does not typically cause significant hemolysis. *Hepatitis A virus* - Hepatitis A virus causes **acute, self-limiting liver inflammation** and is primarily transmitted through the **fecal-oral route**. [2] - It does not typically cause sustained or severe hemolysis; any hemolytic events are rare and usually mild.

Q: Commonest fungal infection of the female genitalia in diabetes is?

Candidal. ***Candidal*** - **Candida albicans** is the most common cause of fungal infections, particularly **vulvovaginal candidiasis**, in diabetic women due to high glucose levels providing a favorable environment for fungal growth. - Diabetes leads to **immunosuppression** and elevated vaginal glycogen, both of which promote Candida proliferation. *Cryptococcal* [1] - **Cryptococcus neoformans** primarily causes infections in immunocompromised individuals, typically affecting the **lungs** and **central nervous system**, not the genitalia. - Genital cryptococcosis is exceedingly rare and usually a manifestation of disseminated disease, not a common primary infection. *Madura mycosis* - **Madura mycosis** (also known as mycetoma) is a chronic, localized infection of the **skin and subcutaneous tissue**, usually affecting the feet, and is caused by certain fungi or bacteria. - It is not a common cause of genital infection, even in diabetic patients, and is typically associated with **traumatic inoculation in tropical regions**. *Aspergellosis* - **Aspergillus** species typically cause respiratory infections (e.g., **aspergilloma**, **invasive aspergillosis**) mainly in immunocompromised patients. - Genital involvement is extremely rare and usually occurs as part of **disseminated disease**, not as a common primary infection in diabetic women.

Q: Commonest cause for acute sinusitis is:

Acute rhinitis. **Acute rhinitis** - **Acute rhinitis**, commonly known as the common cold, is the most frequent precursor to acute sinusitis due to inflammation and obstruction of the ostia. - The **inflammation** and **edema** of the nasal passages in rhinitis can block the sinus drainage pathways, leading to fluid accumulation and secondary bacterial infection within the sinuses. *Swimming/Diving* - While **swimming** and **diving** can introduce water and pathogens into the sinuses, leading to sinusitis, they are not the most common cause overall. - **Pressure changes** and chemical irritants like chlorine can also contribute, but usually as an exacerbating factor rather than the primary etiology. *Nasal tumours* - **Nasal tumors** can cause chronic sinusitis by physically obstructing sinus drainage, but they are relatively rare and not the most common cause of acute sinusitis. - Symptoms typically develop **gradually** and may include unilateral nasal obstruction, epistaxis, or facial pain, which are distinct from acute inflammatory onset. *Deviated nasal septum* - A **deviated nasal septum** can predispose individuals to sinusitis by impairing mucociliary clearance and ventilation of the sinuses, but it is a predisposing factor rather than the direct cause of acute sinusitis itself. - Often contributes to **recurrent** or **chronic sinusitis** by creating anatomical blockages, but an acute infectious trigger is usually necessary for an acute episode.

Q: Exanthems are caused by all except which of the following?

Malaria. ***Malaria*** - **Malaria** is a parasitic disease that affects red blood cells and typically causes symptoms like **fever, chills, and headache**, but does not present with a characteristic skin rash or exanthem [3]. - While skin manifestations like **petechiae or jaundice** can occur in severe cases, a widespread rash defining an exanthem is not typical [3]. *Typhoid* - **Typhoid fever**, caused by *Salmonella Typhi*, can present with a characteristic exanthem known as **"rose spots"** on the trunk and abdomen [3]. - These are small, erythematous macules that blanch on pressure and are an important diagnostic clue. *Measles* - **Measles**, caused by the measles virus, is well-known for its characteristic **maculopapular rash** (exanthem) that typically starts on the face and spreads downwards [1]. - This rash is often preceded by **Koplik spots** in the mouth [1]. *Rubella* - **Rubella** (German measles), caused by the rubella virus, also presents with a classic exanthem, which is a **fine, pinkish-red maculopapular rash** that begins on the face and neck and spreads to the trunk and extremities [2]. - The rash is typically milder and resolves more quickly than measles.

Q: What should you do next for a 35-year-old man who is positive for HBsAg and HBeAg, discovered incidentally during blood donation screening, with normal SGOT and SGPT laboratory values?

HBV-DNA estimation. ***HBV-DNA estimation*** - The presence of **HBsAg** and **HBeAg** indicates **active viral replication**, necessitating quantification of HBV-DNA to assess viral load [1]. - Normal SGOT and SGPT suggest compensated liver function, but **viral load** is crucial for staging the disease and guiding future management [1]. *Observation* - While liver enzymes are normal, the presence of **HBsAg** and **HBeAg** indicates active hepatitis B infection, which warrants further investigation, not just observation [1]. - Undiagnosed and untreated chronic hepatitis B can lead to serious complications such as **cirrhosis** and **hepatocellular carcinoma** [1]. *Liver biopsy* - **Liver biopsy** is an invasive procedure typically reserved for cases where histological assessment is required to confirm **fibrosis** or **inflammation severity**, or when there's discordance between viral markers and clinical presentation. - It's not the initial step for a patient with normal transaminases and clear serological markers of active infection; **HBV-DNA estimation** is generally performed first [1]. *Interferon therapy* - **Interferon therapy** is a treatment for chronic hepatitis B, but initiating treatment requires a comprehensive assessment including **HBV-DNA levels**, in addition to liver enzyme levels and evaluation of liver damage [2]. - It would be premature to consider treatment without a **viral load** measurement and a full workup to determine the phase of infection and the need for therapy [2].

Q: Which live vaccine is contraindicated in AIDS patients?

BCG. **BCG** - The **BCG vaccine** is a live attenuated vaccine, and due to the immunocompromised state of AIDS patients, there is a significant risk of developing disseminated BCG infection. - This risk is particularly high in individuals with **severe immunodeficiency** (low CD4 count), making it a strong contraindication. *Oral Polio Vaccine (OPV)* - While OPV is a live vaccine, it is generally considered safe in asymptomatic HIV-infected individuals, but contraindicated in **symptomatic AIDS patients** due to the risk of vaccine-associated paralytic poliomyelitis [1]. - However, in many regions, the inactivated polio vaccine (IPV) is preferred for all HIV-infected individuals to completely eliminate this risk. *Varicella (Chickenpox)* - The **varicella vaccine** is a live attenuated vaccine; however, it is generally recommended for HIV-infected children and adults who are not severely immunocompromised (CD4 count >200 cells/µL). - The benefits of preventing severe chickenpox often outweigh the risks of vaccination in these individuals. *Measles* - The **measles vaccine (MMR)** is a live attenuated vaccine and is generally recommended for HIV-infected individuals who are not severely immunocompromised (CD4 count >200 cells/µL). - The severe morbidity and mortality associated with measles in immunocompromised individuals prioritize vaccination when appropriate.

Q: The most common ophthalmic affection of diphtheria is –

Isolated ocular palsies. ***Isolated ocular palsies*** - Diphtheria exotoxin can lead to localized neuropathies, and **ocular muscle palsies** are common, often affecting individual extraocular muscles rather than generalized paralysis. - Involvement typically presents as problems with **accommodation** or specific ocular movements due to cranial nerve involvement. *Ptosis* - While ptosis can occur due to **oculomotor nerve dysfunction**, it is less common as an isolated, primary ophthalmic manifestation of diphtheria compared to other ocular palsies. - It usually indicates more widespread **Cranial Nerve III involvement**, which is not the most frequent initial or isolated ocular finding. *Total ophthalmoplegia* - This involves paralysis of **all extraocular muscles**, which is a severe and less common manifestation of diphtheria. - Diphtheria typically causes more **localized and incomplete palsies** rather than affecting all eye movements universally. *Ophthalmoplegia externa* - This involves paralysis of the **extraocular muscles** but spares the **intrinsic eye muscles** (pupil and accommodation). - While diphtheria *can* cause external ophthalmoplegia, **isolated ocular palsies** (which include external ophthalmoplegia) more accurately describe the common presentation of affecting specific muscles or nerves.

Q: Which of the following statements is true regarding acute epididymitis?

Typically presents with pain. ***Typically presents with pain*** - **Acute epididymitis** characteristically causes sudden onset of **unilateral scrotal pain**, which can range from mild to severe. - The pain often radiates to the **inguinal area** or lower abdomen and is accompanied by tenderness of the epididymis. *Commonly associated with urinary tract infections* - While acute epididymitis can occur secondary to **UTIs**, especially in older men or those with obstructive uropathy, it is more commonly associated with **sexually transmitted infections (STIs)** in younger, sexually active men [1]. - In children and prepubertal boys, non-bacterial causes or congenital anomalies are more prevalent. *Scrotum size is usually enlarged* - While the **epididymis** itself becomes **swollen** and tender, leading to a palpable mass, the scrotum itself is not typically described as generally enlarged in its overall size. - The swelling is localized to the affected epididymis and sometimes the testicle (epididymo-orchitis). *Can mimic testicular torsion* - Although both conditions present with acute scrotal pain, **epididymitis pain** usually has a more gradual onset, and fever or urinary symptoms may be present. - **Testicular torsion** typically causes sudden, severe pain with an absent or high-riding cremasteric reflex and requires urgent surgical intervention.

Q: In which of the following conditions is glucocorticoid used?

Severe typhoid. ***Severe typhoid*** * **Glucocorticoids** (e.g., **dexamethasone**) are indicated in **severe typhoid fever** with altered mental status, delirium, stupor, coma, or shock, as they can reduce inflammation and improve neurological outcomes. * Their use in severe typhoid can decrease mortality by attenuating the systemic inflammatory response induced by *Salmonella Typhi*. *E. coli septicemia* * The use of **glucocorticoids** in **bacterial sepsis**, including *E. coli* septicemia, is generally controversial and not recommended unless there is confirmed or suspected **adrenal insufficiency**. * Routine use can increase the risk of secondary infections and other adverse effects without clear mortality benefit in immunocompetent patients. *Cerebral malaria* * **Glucocorticoids** are **contraindicated** in **cerebral malaria** because studies have shown they increase the risk of complications (e.g., gastrointestinal bleeding, seizures, hyperglycemia, infections) without improving neurological outcomes or survival. * Their use can worsen immune suppression in a disease already characterized by significant immune dysregulation. *Leishmaniasis* * **Glucocorticoids** are **not a primary treatment** for **leishmaniasis**, which is caused by a protozoan parasite and requires specific antileishmanial drugs. * While they might be used to manage severe inflammatory reactions in specific forms (e.g., post-kala-azar dermal leishmaniasis), they are not a standard therapeutic intervention and can even exacerbate the infection by suppressing the immune response.

Q: What is a condition directly associated with HIV/AIDS?

Enteropathy. ***Enteropathy*** - **HIV enteropathy** is a condition characterized by chronic diarrhea, malabsorption, and weight loss, frequently seen in HIV/AIDS patients [1]. - It results from the direct effects of HIV on the **gastrointestinal tract**, leading to mucosal damage and immune dysfunction [1]. *Hypertrophic cardiomyopathy* - While cardiac complications can occur in HIV/AIDS, **hypertrophic cardiomyopathy** is not a direct or defining association. - HIV-associated cardiac disease typically manifests as **dilated cardiomyopathy** or myocarditis, rather than hypertrophy. *Bronchial asthma* - **Bronchial asthma** is a chronic inflammatory airway disease that is not directly increased or caused by HIV infection. - Its prevalence in HIV-positive individuals is similar to the general population, without a causal link. *Peptic ulcer disease* - **Peptic ulcer disease** is primarily caused by *Helicobacter pylori* infection or NSAID use and is not a direct consequence of HIV/AIDS [1]. - Although immunosuppression might alter its presentation, HIV does not directly lead to ulcer formation.

Question 1

Which viral infection is primarily associated with hemolysis?

Accepted Answer

Epstein-Barr virus

Answer

Hepatitis-C

Answer

Hepatitis A virus

Answer

Hepatitis B virus

Question 2

Commonest fungal infection of the female genitalia in diabetes is?

Accepted Answer

Candidal

Answer

Cryptococcal

Answer

Madura mycosis

Answer

Aspergellosis

Question 3

Commonest cause for acute sinusitis is:

Accepted Answer

Acute rhinitis

Answer

Swimming/Diving

Answer

Nasal tumours

Answer

Deviated nasal septum

Question 4

Exanthems are caused by all except which of the following?

Accepted Answer

Malaria

Answer

Typhoid

Answer

Rubella

Answer

Measles

Question 5

What should you do next for a 35-year-old man who is positive for HBsAg and HBeAg, discovered incidentally during blood donation screening, with normal SGOT and SGPT laboratory values?

Accepted Answer

HBV-DNA estimation

Answer

Observation

Answer

Liver biopsy

Answer

Interferon therapy

Question 6

Which live vaccine is contraindicated in AIDS patients?

Accepted Answer

BCG

Answer

Measles

Answer

Varicella (Chickenpox)

Answer

Oral Polio Vaccine (OPV)

Question 7

The most common ophthalmic affection of diphtheria is –

Accepted Answer

Isolated ocular palsies

Answer

Ptosis

Answer

Total ophthalmoplegia

Answer

Ophthalmoplegia externa

Question 8

Which of the following statements is true regarding acute epididymitis?

Accepted Answer

Typically presents with pain

Answer

Commonly associated with urinary tract infections

Answer

Scrotum size is usually enlarged

Answer

Can mimic testicular torsion

Question 9

In which of the following conditions is glucocorticoid used?

Accepted Answer

Severe typhoid

Answer

E. coli septicemia

Answer

Cerebral malaria

Answer

Leishmaniasis

Question 10

What is a condition directly associated with HIV/AIDS?

Accepted Answer

Enteropathy

Answer

Hypertrophic cardiomyopathy

Answer

Bronchial asthma

Answer

Peptic ulcer disease

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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