Infectious Diseases — MCQs

Infectious Diseases Indian Medical PG Practice Questions and MCQs

Question 431: According to WHO, the major clinical sign of HIV infection in children in stage 1 is the following.

A. Not gaining weight
B. Generalised lymphadenopathy (Correct Answer)
C. Oral candidiasis
D. None of the options

Explanation: ***Generalised lymphadenopathy*** - According to WHO staging for HIV infection in children, **persistent generalized lymphadenopathy (PGL)** is a major clinical sign in Stage 1. - This stage is characterized by asymptomatic or mild clinical manifestations, with PGL being one of the key visible indicators. - PGL is defined as enlarged lymph nodes (>1 cm) in two or more non-contiguous sites, excluding inguinal nodes. *Not gaining weight* - **Failure to thrive** or **unexplained moderate malnutrition** typically falls under WHO clinical Stage 2 or 3, not Stage 1. - While weight loss can occur in HIV, it usually signifies more advanced disease progression in children. *Oral candidiasis* - **Oral candidiasis** in children with HIV usually indicates more advanced disease and is classified under **WHO clinical Stage 2 or 3**, depending on its persistence and severity. - It suggests a compromised immune system beyond the earliest stages of HIV infection. *None of the options* - This option is incorrect because **generalized lymphadenopathy** is indeed a major clinical sign of HIV infection in children in Stage 1, according to WHO criteria. - The other options provided represent signs found in later stages of HIV disease in children.

Question 432: Which of the following is the most common congenital viral infection?

A. Herpes simplex
B. Cytomegalovirus (Correct Answer)
C. HIV
D. Rubella

Explanation: ***Cytomegalovirus*** - **Cytomegalovirus (CMV)** is the most prevalent congenital viral infection, with an incidence of 0.2-2% of all live births. - While many infected infants are asymptomatic at birth, up to **10-15% develop neurological sequelae**, such as sensorineural hearing loss, developmental delay, or microcephaly. *Herpes simplex* - **Congenital herpes simplex virus (HSV)** infection is rare, usually acquired during passage through an infected birth canal. - It typically presents with **skin lesions, encephalitis, or disseminated disease** rather than being the most common congenital infection overall. *HIV* - **Perinatal HIV transmission** has significantly decreased due to widespread screening and effective antiretroviral therapy during pregnancy. - While it was a major concern historically, its incidence is now lower than CMV, and it affects the **immune system** primarily. *Rubella* - **Congenital rubella syndrome (CRS)** can lead to severe birth defects, but its incidence has drastically reduced due to the widespread implementation of the **MMR vaccine**. - While devastating, it is no longer the most common congenital viral infection due to successful vaccination programs.

Question 433: 'Slapped cheeks' appearance is seen in:

A. Erythema multiforme
B. Erythema subitum
C. Erythema infectiosum (Correct Answer)
D. Roseola infantum

Explanation: ***Erythema infectiosum*** - This condition, also known as **Fifth Disease**, is caused by **Parvovirus B19** and classically presents with a distinctive erythematous rash on the cheeks, giving them a **"slapped cheeks" appearance**. - The facial rash is often followed by a **lacy, reticulate rash** on the trunk and extremities. *Erythema multiforme* - Characterized by **target lesions** with multiple rings of color, commonly found on the extremities and trunk. - It is typically a **hypersensitivity reaction** to infections (e.g., HSV) or medications, not a primary viral exanthem with a "slapped cheeks" presentation. *Erythema subitum* - This term is a synonym for **Roseola infantum**, a common childhood viral illness. - It does not primarily present with a "slapped cheeks" rash; rather, it's known for a **high fever followed by a truncal rash** once the fever breaks. *Roseola infantum* - Caused by **Human Herpesvirus 6 (HHV-6)** or sometimes HHV-7, it is characterized by **3-5 days of high fever** that resolves suddenly. - A **maculopapular rash** then appears on the trunk and neck, sparing the face, not the "slapped cheeks" rash.

Question 434: All of the following are complications of meningitis in a child EXCEPT:

A. Arachnoiditis
B. Intellectual disability
C. Status epilepticus
D. Thyroid dysfunction (Correct Answer)

Explanation: ***Thyroid dysfunction*** - **Thyroid dysfunction** is NOT a recognized complication of bacterial or viral meningitis in children. - Meningitis causes neurological complications due to inflammation of the meninges and brain parenchyma, but does not directly affect endocrine organs like the thyroid gland. - This is the correct answer as it is the exception. *Arachnoiditis* - **Arachnoiditis** is inflammation of the arachnoid membrane that can occur as a complication of meningitis. - It leads to scarring and adhesions within the subarachnoid space, potentially causing chronic pain, neurological deficits, and **hydrocephalus** due to impaired CSF circulation. - This is a recognized late complication. *Intellectual disability* - **Intellectual disability** can result from severe or prolonged meningitis causing significant brain damage. - Widespread inflammation, cerebral edema, ischemia, and direct neuronal injury can damage regions responsible for cognitive function. - This affects learning, memory, and developmental milestones in children. *Status epilepticus* - **Status epilepticus** is a life-threatening complication where prolonged or recurrent seizures occur without recovery of consciousness. - It results from direct cortical irritation by inflammation, cerebral edema, metabolic derangements, or hypoxia. - Requires emergency treatment to prevent permanent brain damage and systemic complications.

Question 435: Exanthema subitum is caused by -

A. HIV
B. HCV
C. HPV
D. HHV (Correct Answer)

Explanation: ***HHV*** - **Exanthema subitum**, also known as **roseola infantum**, is most commonly caused by **Human Herpesvirus 6 (HHV-6)** and sometimes **Human Herpesvirus 7 (HHV-7)**. - It is characterized by high fever followed by a **maculopapular rash** once the fever subsides. *HIV* - **Human Immunodeficiency Virus (HIV)** causes **Acquired Immunodeficiency Syndrome (AIDS)**, leading to a weakened immune system. - While HIV can cause various skin manifestations, **exanthema subitum** is not one of its primary or characteristic presentations. *HCV* - **Hepatitis C Virus (HCV)** primarily causes **hepatitis**, infecting the liver and potentially leading to chronic liver disease. - HCV is not known to cause **exanthema subitum** or similar childhood exanthems. *HPV* - **Human Papillomavirus (HPV)** is responsible for **warts** and certain **cancers**, particularly cervical cancer. - HPV does not cause **exanthema subitum**; its manifestations are typically localized to skin and mucous membranes as proliferative lesions.

Question 436: What is the treatment of choice for an 11-year-old child with hepatitis C infection?

A. Direct-Acting Antivirals (DAAs) (Correct Answer)
B. Gamma-globulin
C. Corticosteroids
D. Vaccine

Explanation: ***Direct-Acting Antivirals (DAAs)*** - **Direct-acting antivirals** are the current **standard of care** for hepatitis C infection in children due to their high efficacy, good safety profile, and ability to achieve sustained virologic response (SVR). - Several DAAs are approved and recommended for use in children as young as 3 years, with treatment regimens tailored to the **genotype** of the hepatitis C virus (HCV). *Gamma-globulin* - **Gamma-globulin** (immunoglobulin) is primarily used for **passive immunization** against certain infections or in conditions involving antibody deficiencies; it has no direct antiviral activity against chronic hepatitis C. - It would not be effective in eradicating the hepatitis C virus from an infected individual. *Corticosteroids* - **Corticosteroids** are potent **anti-inflammatory** and immunosuppressive agents, but they do not possess direct antiviral properties against HCV. - Using corticosteroids could potentially worsen the infection by **suppressing the immune response** needed to clear the virus, and they are generally contraindicated in active viral hepatitis. *Vaccine* - While there are effective **vaccines** for hepatitis A and hepatitis B, there is currently **no vaccine available** to prevent hepatitis C infection. - Research is ongoing, but a preventive vaccine for HCV has yet to be developed.

Question 437: The most common manifestation of congenital toxoplasmosis is?

A. Hepatosplenomegaly
B. Thrombocytopenia
C. Chorioretinitis (Correct Answer)
D. Hydrocephalus

Explanation: ***Chorioretinitis*** - **Chorioretinitis** is the most common and often the primary manifestation of congenital toxoplasmosis, affecting the eyes. - It results from the parasitic infection of the retina and choroid, leading to inflammation, scarring, and potentially severe **vision loss**. *Hepatosplenomegaly* - While **hepatosplenomegaly** can be a feature of congenital toxoplasmosis, it is less common than chorioretinitis. - It indicates systemic involvement but is not considered the most defining or frequent symptom. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) can occur in severe cases of congenital toxoplasmosis but is not the most common manifestation. - It is more indicative of disseminated disease or bone marrow suppression. *Hydrocephalus* - **Hydrocephalus** is a significant but less common finding in congenital toxoplasmosis compared to chorioretinitis. - It arises from inflammation and blockage of CSF flow, often in conjunction with **intracranial calcifications**.

Question 438: What is the most common presentation of AIDS in infants?

A. GI infection (Correct Answer)
B. Rashes
C. Lymphadenopathy
D. Persistent cough

Explanation: ***GI infection*** - **Chronic diarrhea** and gastrointestinal infections are among the most common presentations of AIDS in infants, often leading to **failure to thrive** and malabsorption. - Infants frequently present with **persistent diarrhea** lasting more than 2 weeks, which is a common AIDS-defining illness in pediatric populations. - **Malnutrition** and poor weight gain secondary to GI manifestations are hallmark features of pediatric AIDS presentation. - Common pathogens include **Cryptosporidium**, **Salmonella**, **Cytomegalovirus**, and other opportunistic organisms. *Lymphadenopathy* - While **generalized lymphadenopathy** can occur in HIV-infected children, it is more commonly seen in older children and adults rather than as the primary presentation in infants. - It indicates immune system activation but is not the most frequent initial manifestation in the infant population. *Rashes* - Various **dermatological manifestations** such as seborrheic dermatitis, persistent candidiasis, and recurrent skin infections can occur in pediatric AIDS. - However, these are less common than gastrointestinal manifestations as the initial presentation in infants. *Persistent cough* - **Respiratory infections** including *Pneumocystis jirovecii* pneumonia (**PCP**) are serious and common opportunistic infections in infants with AIDS. - PCP is the most common serious opportunistic infection in pediatric AIDS, but chronic diarrhea and GI problems present more frequently overall as initial manifestations. - Other respiratory infections like recurrent pneumonia and lymphoid interstitial pneumonitis are also seen.

Question 439: All of the following statements about congenital rubella are true except:

A. Most common anomalies are hearing and heart defects
B. IgM antibody is present at birth
C. IgG persists for more than 6 months
D. Increased risk of congenital malformation if infection occurs after 16 weeks (Correct Answer)

Explanation: ***Increased risk of congenital malformation if infection occurs after 16 weeks*** - The risk and severity of **congenital rubella syndrome (CRS)** are significantly higher when infection occurs in the **first trimester** (especially weeks 1-12). - After **16 weeks gestation**, the risk of severe congenital malformations due to rubella infection is **very low**, making this statement false. *Most common anomalies are hearing and heart defects* - **Hearing impairment** (sensorineural deafness) and **cardiac defects** (e.g., patent ductus arteriosus, pulmonary artery stenosis) are indeed among the most frequent and serious manifestations of congenital rubella syndrome. - Other common anomalies include **ocular defects** (e.g., cataracts, microphthalmia) and **intracranial calcifications**. *IgM antibody is present at birth* - In a neonate with congenital rubella, the presence of **rubella-specific IgM antibodies** at birth indicates ongoing active infection in utero, as maternal IgM does not cross the placenta. - **IgM antibodies** are a key diagnostic marker for congenital infections. *IgG persists for more than 6 months* - **Rubella-specific IgG antibodies** in a neonate persisting beyond 6-12 months of age, in the absence of postnatal exposure or vaccination, are indicative of congenital infection, distinguishing it from maternally transferred IgG. - **Maternally acquired IgG** typically wanes within the first 6-12 months of life.

Question 440: The commonest cause of Bacterial Pneumonia in children is -

A. Staphylococcus aureus
B. Streptococcus pneumoniae (Correct Answer)
C. Haemophilus influenzae
D. Streptococcus pyogenes

Explanation: ***Streptococcus pneumoniae*** * **Streptococcus pneumoniae**, also known as pneumococcus, is globally the **most common bacterial cause of pneumonia in children**, particularly in unvaccinated populations. * It is a **gram-positive bacterium** that can cause a range of invasive and non-invasive diseases, with pneumonia being the most significant. * *Staphylococcus aureus* * While **Staphylococcus aureus** can cause pneumonia in children, especially in cases following a viral illness or in hospitalized patients, it is **less common overall** than *S. pneumoniae*. * *S. aureus* pneumonia often presents with more severe features, such as **abscess formation** and **empyema**. * *Hemophilus influenzae* * **Haemophilus influenzae type b (Hib)** used to be a major cause of bacterial pneumonia in children, but its incidence has **significantly decreased** due to widespread vaccination. * Non-typeable Haemophilus influenzae (NTHi) can still cause pneumonia, particularly in infants and children with underlying conditions, but it is not the leading cause. * *Streptococcus pyogenes* * **Streptococcus pyogenes** (Group A Strep) is primarily known for causing **pharyngitis** (strep throat), **scarlet fever**, and **skin infections**. * While it can cause pneumonia, this is a **relatively rare** presentation compared to *S. pneumoniae*.

Practice by Chapter

Vaccine-Preventable Diseases

Practice Questions

Immunization Schedule

Practice Questions

Common Childhood Infections

Practice Questions

Pediatric HIV

Practice Questions

Congenital Infections

Practice Questions

Fever in Infants and Children

Practice Questions

Meningitis and Encephalitis

Practice Questions

Respiratory Tract Infections

Practice Questions

Gastrointestinal Infections

Practice Questions

Parasitic Infections

Practice Questions

Tuberculosis in Children

Practice Questions

Opportunistic Infections

Practice Questions

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