Infectious Diseases Practice Questions

Q: Koplik's spots occur in which phase of measles -

End of prodromal phase. ***End of prodromal phase*** - **Koplik's spots**, pathognomonic for measles, typically appear 1-2 days before the onset of the **maculopapular rash**, marking the very end of the **prodromal phase**. - These are small, white spots with a bluish-white center on an erythematous base, found on the **buccal mucosa** opposite the molars. *Post exanthematous phase* - This phase occurs *after* the rash has faded and is characterized by **desquamation** and **cough**, not the appearance of Koplik's spots. - Koplik's spots would have long disappeared by this stage. *Recrudescence phase* - This term usually refers to the **reappearance of symptoms** after a period of improvement, which is not characteristic of Koplik's spots in measles. - Koplik's spots represent an initial diagnostic sign rather than a recurrent symptom. *Exanthematous phase* - The **exanthematous phase** is when the characteristic **maculopapular rash** appears and spreads, typically starting a few days *after* Koplik's spots have already emerged and are beginning to fade. - While overlap can occur, Koplik's spots are *most prominent* and diagnostic *before* the rash fully develops.

Q: An asymptomatic infant with a history of TB exposure, is 3 months old and had taken 3 months of chemoprophylaxis, what is to be done next?

Tuberculin test, then decide. ***Tuberculin test, then decide*** - A **tuberculin skin test (TST)** or **IGRA** should be performed after completing the initial chemoprophylaxis period to determine if the infant has developed **latent TB infection (LTBI)**. - According to **IAP guidelines**, if TST is **negative**, complete a total of **6 months of prophylaxis** and then administer **BCG vaccine**. - If TST is **positive**, it indicates LTBI and the infant should complete the full course of treatment as per standard protocols. - The decision to continue, modify, or stop treatment depends on **TST results** and **clinical evaluation**. *Immunise with BCG and stop prophylaxis* - **BCG vaccination** should not be given during or immediately after stopping prophylaxis without first performing a **TST**. - In TB-endemic areas, BCG is ideally given at birth, but if delayed due to TB exposure, it should only be given after **ruling out infection** with a negative TST. - Stopping prophylaxis prematurely without assessment can increase the risk of developing **active TB**. *Continue prophylaxis for 3 months* - While the standard duration of prophylaxis is **6 months total**, blindly continuing for another 3 months without TST assessment is not the most appropriate next step. - The decision to continue should be based on **TST results** performed at this juncture, not arbitrary time extension. - Prolonged unnecessary prophylaxis can lead to **drug toxicity** and **poor compliance**. *Test sputum, then decide* - An **asymptomatic infant** is unlikely to produce sputum, making this test impractical and inappropriate. - Sputum testing is used for diagnosing **active pulmonary TB**, which is not suspected in this asymptomatic child. - Sputum testing is invasive and reserved for children with **clinical symptoms** suggestive of active disease such as persistent cough, fever, or weight loss.

Q: Pathognomonic clinical feature of measles is -

Koplik spots. ***Koplik spots*** - **Koplik spots** are small, white, or bluish-white spots surrounded by a red halo, typically found on the buccal mucosa opposite the molars [1]. - They are considered **pathognomonic** for measles and usually appear 1-2 days before the generalized rash [1]. *Bitot spots* - **Bitot spots** are foamy, triangular patches on the conjunctiva, characteristic of severe **vitamin A deficiency**. - They are unrelated to measles infection. *Brushfield spots* - **Brushfield spots** are white or grayish/brown spots on the periphery of the iris. - They are a clinical feature often seen in individuals with **Down syndrome** (Trisomy 21). *Erythematous macular rash* - An **erythematous macular rash** is a common feature of measles, but it is not pathognomonic as similar rashes can be seen in other viral exanthems [1]. - The rash typically starts on the face and spreads downwards, becoming confluent [1].

Q: A 5 year old child with unprovoked dog bite, appropriate management is

Anti Rabies vaccine and Rabies Immunoglobulin. ***Anti Rabies vaccine and Rabies Immunoglobulin*** - For an **unprovoked dog bite**, especially in a child, presumptive exposure to **rabies** should be assumed, necessitating **both active immunization (vaccine)** and **passive immunization (immunoglobulin)**. - The **Rabies Immunoglobulin (RIG)** provides immediate, short-term protection, while the **rabies vaccine** stimulates the child's immune system for long-term protection. *Only Rabies Immunoglobulin at the site of bite* - While RIG provides immediate protection, it does not induce **long-term immunity**. - **Vaccination is essential** alongside RIG for sustained protection against rabies. *Kill the dog and send brain for Biopsy* - Killing the dog and performing a brain biopsy is a method to **confirm rabies in the animal**, but it does not provide immediate or preventative treatment for the exposed individual. - **Post-exposure prophylaxis (PEP)** should be initiated promptly without waiting for animal test results, especially if the animal's rabid status is unknown or suspected. *Observe the dog* - Observing the dog for **10 days** is appropriate if the bite was provoked, or if the animal is known and healthy, and **rabies risk is low**. - However, for an **unprovoked bite**, particularly from an unknown or stray dog, the risk of rabies is higher, and **post-exposure prophylaxis (PEP)** should not be delayed by observation.

Q: A 3-year-old boy was admitted to the hospital for high fever and difficulty in breathing. He had been well until 4 days before admission, when he developed sneezing and a runny and stuffy nose followed by a non-productive cough the next day. This was followed by appearance of characteristic rash on face, trunk, extremities and back along with fever. On examination: Shotty anterior cervical and supraclavicular lymph nodes, hyperemic conjunctiva, and Koplik spots on buccal mucosa. The white blood cell count was 3,100/ml, with a differential of 70% polymorphonuclear leukocytes. All of the following are complications of the above disease EXCEPT?

Orchitis. ***Orchitis*** - **Orchitis** is a common complication of **mumps**, an unrelated viral infection, and is not typically associated with **measles (rubeola)**. - The presenting symptoms (rash, Koplik spots, lymphadenopathy, fever) are classic for **measles**, which does not cause orchitis. *Otitis media* - **Acute otitis media** is a frequent bacterial superinfection following measles, often caused by streptococcal species, and is one of the most common complications. - The **immunosuppression** caused by measles makes children highly susceptible to secondary bacterial infections, including ear infections. *SSPE* - **Subacute sclerosing panencephalitis (SSPE)** is a rare, but fatal, chronic progressive encephalitis caused by persistent measles virus infection in the brain, developing years after the initial infection. - The measles virus can remain latent and reactivate, leading to severe neurological degeneration. *Encephalitis* - **Acute post-infectious encephalitis** is a serious neurological complication of measles, occurring in approximately 1 in 1000 cases, usually 5-7 days after the onset of the rash. - It is typically an **autoimmune demyelinating process**, rather than direct viral invasion of the brain.

Q: A child suffering from Rubella presented with small red spots (petechiae) on the soft palate. These are known as __________.

Forchheimer spots. **Forchheimer spots** - These are **petechiae** that appear on the **soft palate** and **uvula** during the **prodromal phase** of **Rubella** (German measles). - They are a classic, though not always present, clinical sign that helps in the diagnosis of Rubella. *Nagayama spots* - These are **erythematous papules** on the **uvula and soft palate** that are seen in **Roseola infantum** (Exanthem subitum), caused by HHV-6 and HHV-7. - While similar in location to Forchheimer spots, their viral etiology and morphology differ significantly. *Koplik spots* - These are **pathognomonic enanthem** of **measles** (rubeola), characterized by **tiny white spots** on an erythematous base on the **buccal mucosa** opposite the molars. - They are an early sign of measles and are distinctly different in appearance and location from Forchheimer spots. *None of the options* - This option is incorrect as **Forchheimer spots** specifically describe the petechiae on the soft palate seen in Rubella. - The other options refer to different clinical signs associated with other viral exanthems.

Q: Prior to discharge of a patient with H. influenzae meningitis, the essential investigation to be done is?

ABER. ***Correct: ABER*** - **Hearing loss** is a well-known and common complication following **H. influenzae meningitis**, making audiological assessment crucial before discharge. - An **Auditory Brainstem Response (ABR) test**, or ABER, is an **objective measure of hearing** that can detect sensorineural hearing loss, which might otherwise be missed in young children. - **Standard of care** recommends hearing assessment in all cases of bacterial meningitis prior to discharge as per IAP and AAP guidelines. *Incorrect: Developmental screening test* - While significant neurological insult from meningitis can affect development, a **developmental screening test** is not the *most essential* immediate post-meningitis investigation prior to discharge. - Neurological and developmental sequelae are typically assessed over time during follow-up rather than as a primary discharge screen. *Incorrect: ECG* - An **ECG (electrocardiogram)** assesses cardiac function and is generally not indicated for routine discharge after uncomplicated bacterial meningitis unless there are specific cardiac concerns. - **H. influenzae meningitis** primarily affects the central nervous system, not directly the heart. *Incorrect: EEG* - An **EEG (electroencephalogram)** measures brain electrical activity and is used to diagnose seizure disorders or assess for encephalopathy. - While seizures can be a complication, an EEG is typically performed if there are clinical signs of **seizure activity** or altered mental status, rather than as an essential routine discharge investigation for all patients.

Question 1

Koplik's spots occur in which phase of measles -

Accepted Answer

End of prodromal phase

Answer

Post exanthematous phase

Answer

Recrudescence phase

Answer

Exanthematous phase

Question 2

A 12-year-old boy comes to the physician because of headache, fever, nausea and vomiting. His mother reports that he has been unwell for a couple of days but seems to have become worse. In addition to his headache, he has a very stiff neck. He has no other past medical history except for well-controlled asthma. His pulse is 114/min and he has a fever of 38.5°C (101.3°F). His examination is notable for meningismus, as evidenced by discomfort elicited by movement of his neck. He also becomes visibly uncomfortable when you check his pupillary responses with a flashlight.

Which of the following patterns of cerebrospinal fluid would you expect to see if this boy turns out to have viral meningitis?

Accepted Answer

Normal opening pressure; Elevated cell count; Elevated protein; Normal glucose

Answer

Normal opening pressure; Elevated cell count; Elevated protein; Low glucose

Answer

Elevated opening pressure; Normal cell count; Normal protein; Normal glucose

Answer

Elevated opening pressure; Elevated cell count; Elevated protein; Low glucose

Question 3

An asymptomatic infant with a history of TB exposure, is 3 months old and had taken 3 months of chemoprophylaxis, what is to be done next?

Accepted Answer

Tuberculin test, then decide

Answer

Immunise with BCG and stop prophylaxis

Answer

Continue prophylaxis for 3 months

Answer

Test sputum, then decide

Question 4

An 18-month-old child presents with cellulitis of the leg and SpO2 of 88%. There is no prior history of hospitalization or illness. What is the most probable organism?

Accepted Answer

Streptococcus pneumoniae

Answer

MRSA

Answer

Streptococcus pyogenes

Answer

All of the options

Question 5

Pathognomonic clinical feature of measles is -

Accepted Answer

Koplik spots

Answer

Bitot spots

Answer

Brushfield spots

Answer

Erythematous macular rash

Question 6

A 5 year old child with unprovoked dog bite, appropriate management is

Accepted Answer

Anti Rabies vaccine and Rabies Immunoglobulin

Answer

Only Rabies Immunoglobulin at the site of bite

Answer

Kill the dog and send brain for Biopsy

Answer

Observe the dog

Question 7

A 3-year-old child is brought to the outpatient department with an upper respiratory tract infection. On asking about their previous immunization history, it is found that they have had no primary immunizations from birth. What is the most appropriate step in the management of this patient?

Accepted Answer

Give BCG, OPV, DPT, measles vaccines and vitamin A

Answer

Give BCG, OPV, DPT and advise to come after 4 weeks for the next doses of OPV and DPT

Answer

Advise to come on the fixed immunization day of the week

Answer

Give BCG, OPV, DPT, measles vaccines

Question 8

A 3-year-old boy was admitted to the hospital for high fever and difficulty in breathing. He had been well until 4 days before admission, when he developed sneezing and a runny and stuffy nose followed by a non-productive cough the next day. This was followed by appearance of characteristic rash on face, trunk, extremities and back along with fever. On examination: Shotty anterior cervical and supraclavicular lymph nodes, hyperemic conjunctiva, and Koplik spots on buccal mucosa. The white blood cell count was 3,100/ml, with a differential of 70% polymorphonuclear leukocytes. All of the following are complications of the above disease EXCEPT?

Accepted Answer

Orchitis

Answer

Otitis media

Answer

SSPE

Answer

Encephalitis

Question 9

A child suffering from Rubella presented with small red spots (petechiae) on the soft palate. These are known as __________.

Accepted Answer

Forchheimer spots

Answer

Nagayama spots

Answer

Koplik spots

Answer

None of the options

Question 10

Prior to discharge of a patient with H. influenzae meningitis, the essential investigation to be done is?

Accepted Answer

ABER

Answer

Developmental screening test

Answer

ECG

Answer

EEG

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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