Infectious Diseases Practice Questions

Q: In a small child diagnosed with H. influenzae meningitis, what investigation must be done before discharging him from the hospital?

Hearing assessment. ***Hearing assessment*** - **Sensorineural hearing loss** is a significant and common complication of *H. influenzae* meningitis, occurring in up to 30% of children. - Early detection through a **hearing assessment** is crucial for intervention and to minimize long-term developmental impact. *CT scan* - A CT scan is typically performed during the acute phase of meningitis to rule out complications like **hydrocephalus** or **brain abscess**, not routinely before discharge for long-term sequelae. - While it can identify structural abnormalities, it does not directly assess **auditory function**. *X-ray skull* - An X-ray of the skull has very limited utility in the diagnosis or follow-up of meningitis. - It does not provide information about brain pathology or potential **hearing damage**. *MRI* - MRI is a more sensitive imaging modality than CT for detecting subtle brain parenchymal changes and is sometimes used in complicated cases of meningitis. - However, like CT, it is not the primary investigation required to assess for **hearing loss** as a post-meningitis sequela before discharge.

Q: Which of the following is NOT a feature of HIV infection in childhood -

Kaposi sarcoma. ***Kaposi sarcoma*** - While Kaposi's sarcoma is a common HIV-associated malignancy in adults, it is **very rare in HIV-infected children**. - Its presence in children with HIV usually suggests a **more aggressive and rapidly progressing disease course**, but it is not a typical or common feature. *Failure to thrive* - **Failure to thrive** is a very common manifestation of HIV infection in children, often due to **poor nutrient absorption**, increased metabolic demands, and chronic infections. - It leads to **poor weight gain and growth faltering**, negatively impacting overall development. *Hepatomegaly* - **Hepatomegaly**, or an enlarged liver, is a frequent finding in HIV-infected children due to various causes such as **opportunistic infections**, drug side effects, and direct HIV involvement of the liver. - It can be a clinical sign indicating **inflammation or dysfunction** of the liver. *Lymphoid interstitial pneumonitis* - **Lymphoid interstitial pneumonitis (LIP)** is a prevalent pulmonary complication specific to HIV infection in children, characterized by **lymphocytic infiltration of the alveolar septa and peribronchial spaces**. - It often leads to **chronic cough**, hypoxemia, and is considered an **AIDS-defining condition** in pediatric HIV.

Q: A 10-year-old girl presented with fever, convulsions, and neck rigidity. CSF findings are protein 150 mg/dL, sugar 40 mg/dL with lymphocytic pleocytosis –

Tuberculous meningitis. ***Tuberculous meningitis*** - The combination of **fever, convulsions, neck rigidity** (suggesting meningitis), elevated **CSF protein (150 mg/dL)**, **low CSF sugar (40 mg/dL)**, and **lymphocytic pleocytosis** is highly characteristic of tuberculous meningitis. - Tuberculous meningitis typically presents with a **subacute** or **chronic** course and CSF analysis reveals **elevated protein**, **low glucose**, and a **lymphocytic pleocytosis**. *Viral meningitis* - While viral meningitis presents with fever and meningeal signs, the **CSF protein** is usually mildly elevated ( 100 mg/dL)**, very low **CSF glucose (<40 mg/dL)**, and a predominant **neutrophilic pleocytosis**. - Symptoms are usually **acute and severe**, rapidly progressing over hours to days. *Cryptococcal meningitis* - This is more common in **immunocompromised individuals**, such as those with HIV/AIDS, and the clinical picture in a 10-year-old girl without immune compromise makes it less likely. - While it can cause elevated CSF protein and low glucose, the presence of **lymphocytic pleocytosis** is less specific for cryptococcal infection compared to tuberculous meningitis in this clinical context.

Q: Pathognomonic of measles?

Koplik spot. ***Koplik spot*** - **Koplik spots** are tiny, white spots with a bluish-white center found on the buccal mucosa opposite the molars; they are **pathognomonic** for measles [1]. - The appearance of Koplik spots often precedes the characteristic measles rash by 1-2 days and helps in early diagnosis [1]. *Rash* - While a **maculopapular rash** is a prominent feature of measles [1], it is not pathognomonic as similar rashes can be seen in other viral exanthems. - The measles rash typically starts on the face and behind the ears, spreading downwards, but its presence alone is insufficient for a definitive diagnosis. *Conjunctivitis* - **Conjunctivitis** is a common symptom in measles, contributing to the "3 C's" (cough, coryza, conjunctivitis), but it is a non-specific finding seen in many other viral illnesses. - It presents as red, watery eyes and is part of the prodromal phase but does not uniquely identify measles. *Fever* - **Fever** is a universal symptom of measles, usually high-grade, but it is a general sign of infection and not specific to measles. - Many viral and bacterial infections cause fever, making it a poor diagnostic indicator on its own.

Q: A child who was treated for H. influenzae meningitis is being discharged. Most important investigation to be done before discharge is:

Brainstem evoked auditory response. ***Brainstem evoked auditory response*** - **Sensorineural hearing loss** is a common and severe complication of *H. influenzae* meningitis, occurring in about 5-30% of cases due to damage to the auditory nerve or cochlea. - **Brainstem Evoked Auditory Response (BAER)** is an objective test that measures the electrical activity in the auditory pathway from the cochlea to the brainstem, making it the most reliable method for detecting hearing impairment in infants and children. *Growth screening test* - While chronic illness can affect growth, **growth faltering** is not specific to *H. influenzae* meningitis or its sequelae in the acute or subacute phase. - Growth checks are part of routine pediatric care and would be performed but are not the *most important* specific investigation for meningitis complications before discharge. *Psychotherapy* - **Psychotherapy** is a treatment modality for psychological and behavioral issues, not a diagnostic test. - It would only be considered if the child developed significant emotional or behavioral problems after meningitis, and these are typically assessed through clinical observation and neurodevelopmental screening, not a direct "psychotherapy" investigation. *MRI* - **MRI** is primarily used to detect structural brain abnormalities such as **hydrocephalus**, **subdural effusions**, **cerebral edema**, or **infarcts** that may result from meningitis. - While important for assessing neurological damage, **hearing loss** is a distinct and prevalent complication that requires a specific functional assessment (BAER), which MRI does not provide.

Q: Most serious characteristic finding of HIV in children is?

Recurrent chest infection. ***Recurrent chest infection*** - **Recurrent chest infections**, particularly with common bacterial pathogens, are a hallmark of HIV in children due to their underdeveloped immune systems being further compromised. - Children with HIV are highly susceptible to respiratory infections such as **pneumonia** and **bronchiolitis**, leading to frequent hospitalizations and poor outcomes. *Kaposi sarcoma is common* - **Kaposi sarcoma** is a well-known HIV-associated malignancy, but it is much more prevalent in **HIV-positive adults**, especially men who have sex with men, rather than in children. - While it can occur in children, it is not considered a *characteristic* or common presenting feature, as other opportunistic infections and non-specific symptoms are far more frequent. *Cryptococcal diarrhoea is common* - **Cryptococcal infection** primarily manifests as **meningitis** or disseminated disease, particularly in adults with advanced HIV. - While gastrointestinal symptoms can occur, **Cryptococcal diarrhea** is not a common or characteristic presentation of HIV in children. *Recurrent candidiasis* - While **recurrent oral candidiasis** (thrush) is common in HIV-infected children, it is often one of the **earliest indicators** and can be present even in less advanced disease. - However, **recurrent chest infections** generally represent a more significant and debilitating manifestation of immune compromise in pediatric HIV.

Q: All of the following statements regarding measles are true, except:

Koplik spot are seen on retina. ***Koplik spot are seen on retina*** - **Koplik spots** are pathognomonic for measles and are typically found on the **buccal mucosa** (inside the cheeks), not on the retina [1]. - These are small, white, or bluish-white lesions with a red halo, appearing before the characteristic rash. *I-P is 10-14 days* - The **incubation period (I-P)** for measles, from exposure to the onset of symptoms, typically ranges from **10 to 14 days**. - This period includes the initial prodromal symptoms before the rash appears. *Long term complication may be seen in form of SSPE* - **Subacute sclerosing panencephalitis (SSPE)** is a rare, but fatal, **late complication** of measles infection [1]. - It results from persistent measles virus infection in the central nervous system, often developing years after the initial infection [1]. *Caused by RNA virus* - Measles is caused by the **measles virus**, which is a **single-stranded RNA virus** belonging to the *Paramyxoviridae* family. - It is an enveloped virus that primarily infects respiratory epithelial cells and replicates in lymphoid tissues. *Rash appears first on face* - The characteristic **maculopapular rash** of measles typically begins on the **face and behind the ears**. - It then spreads downwards to the trunk and extremities, fading in the same order [1].

Q: Which of the following has no role in the diagnosis of childhood TB?

ELISA. ***ELISA*** - ELISA (Enzyme-linked immunosorbent assay) is primarily used for detecting **antibodies** or **antigens** in various infections but has limited utility for diagnosing active childhood TB. - Due to the **variable immune response** in children and the difficulty in distinguishing latent from active TB, ELISA is not a recommended diagnostic tool for routine childhood TB diagnosis by most health organizations. *FNAC* - **Fine needle aspiration cytology (FNAC)** is a crucial tool for diagnosing childhood TB, especially in cases of lymphadenitis, by obtaining tissue for **cytological examination** and **microbiological culture**. - It allows for the detection of **acid-fast bacilli** and characteristic **granulomatous inflammation**. *Mantoux* - The **Mantoux test** (tuberculin skin test) is a valuable diagnostic aid in childhood TB, indicating past or present infection with *Mycobacterium tuberculosis*. - A positive result suggests **TB exposure** and helps in evaluating children with suspected TB, though it doesn't differentiate between latent and active disease. *CXR* - **Chest X-ray (CXR)** is an essential initial diagnostic tool for childhood TB, especially in pulmonary forms. - It can reveal characteristic findings like **hilar lymphadenopathy**, **lung infiltrates**, or **miliary patterns**, which are highly suggestive of TB in children.

Q: To prevent acute rheumatic fever, acute pharyngitis due to group A streptococci should be treated with antibiotics before:

9 days of illness. ***9 days of illness*** - Treatment of **Group A Streptococcus (GAS)** pharyngitis with appropriate antibiotics within **9 days** of symptom onset effectively prevents subsequent acute rheumatic fever. - This timeframe is crucial because it allows for clearance of the bacteria before the immune response that triggers **rheumatic fever** becomes fully established. *10 days of illness* - This duration is **beyond** the optimal window for preventing acute rheumatic fever, as the immune response may already be sufficient to initiate the disease process. - While still beneficial for symptom resolution, antibiotic treatment initiated at this point is **less effective** in preventing the sequelae of rheumatic fever. *7 days of illness* - Administering antibiotics within **7 days** of illness is highly effective and falls within the appropriate treatment window for preventing acute rheumatic fever [2]. - However, **9 days provides a slightly longer, yet still effective, cutoff**, making prevention of rheumatic fever still possible within this slightly extended period. *8 days of illness* - Antibiotic treatment at **8 days of illness** is still considered within the therapeutic window for preventing acute rheumatic fever [2]. - The goal is to clear the infection and prevent the immune system from mounting the **autoimmune response** that leads to cardiac damage [1].

Q: Koplik spots are a feature of -

Measles. ***Measles*** - **Koplik spots** are pathognomonic enanthem for measles, appearing as tiny, white spots on a reddened background, typically found on the **buccal mucosa** opposite the molars. - They usually appear 2-3 days before the characteristic **maculopapular rash** and are highly diagnostic of the disease. *Mumps* - Mumps is characterized by **parotitis** (swelling of the salivary glands), often accompanied by fever, headache, and malaise. - It does not involve Koplik spots or a generalized rash of the kind seen in measles. *Tetanus* - Tetanus is a serious bacterial infection affecting the **nervous system**, leading to muscle spasms and lockjaw. - It is caused by *Clostridium tetani* and does not present with any skin lesions or oral spots like Koplik spots. *Rubella* - Rubella, or German measles, presents with a milder rash than measles, often starting on the face and spreading to the trunk. - While it causes a rash and lymphadenopathy, **Koplik spots are not a feature** of rubella infection.

Question 1

In a small child diagnosed with H. influenzae meningitis, what investigation must be done before discharging him from the hospital?

Accepted Answer

Hearing assessment

Answer

CT scan

Answer

X-ray skull

Answer

MRI

Question 2

Which of the following is NOT a feature of HIV infection in childhood -

Accepted Answer

Kaposi sarcoma

Answer

Failure to thrive

Answer

Hepatomegaly

Answer

Lymphoid interstitial pneumonitis

Question 3

A 10-year-old girl presented with fever, convulsions, and neck rigidity. CSF findings are protein 150 mg/dL, sugar 40 mg/dL with lymphocytic pleocytosis –

Accepted Answer

Tuberculous meningitis

Answer

Viral meningitis

Answer

Pyogenic meningitis

Answer

Cryptococcal meningitis

Question 4

Pathognomonic of measles?

Accepted Answer

Koplik spot

Answer

Rash

Answer

Conjunctivitis

Answer

Fever

Question 5

A child who was treated for H. influenzae meningitis is being discharged. Most important investigation to be done before discharge is:

Accepted Answer

Brainstem evoked auditory response

Answer

Growth screening test

Answer

Psychotherapy

Answer

MRI

Question 6

Most serious characteristic finding of HIV in children is?

Accepted Answer

Recurrent chest infection

Answer

Kaposi sarcoma is common

Answer

Cryptococcal diarrhoea is common

Answer

Recurrent candidiasis

Question 7

All of the following statements regarding measles are true, except:

Accepted Answer

Koplik spot are seen on retina

Answer

I-P is 10-14 days

Answer

Long term complication may be seen in form of SSPE

Answer

Caused by RNA virus

Answer

Rash appears first on face

Question 8

Which of the following has no role in the diagnosis of childhood TB?

Accepted Answer

ELISA

Answer

FNAC

Answer

Mantoux

Answer

CXR

Question 9

To prevent acute rheumatic fever, acute pharyngitis due to group A streptococci should be treated with antibiotics before:

Accepted Answer

9 days of illness

Answer

10 days of illness

Answer

7 days of illness

Answer

8 days of illness

Question 10

Koplik spots are a feature of -

Accepted Answer

Measles

Answer

Mumps

Answer

Tetanus

Answer

Rubella

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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