Infectious Diseases Practice Questions

Q: A 4-year-old with fever, neck stiffness, and petechial rash presents with a positive Kernig sign, positive Brudzinski sign, heart rate of 140, respiratory rate of 30, and blood pressure of 90/50. CSF analysis shows increased white blood cells, decreased glucose, and increased protein. Analyze the situation and initiate the most appropriate treatment.

IV antibiotics + IV dexamethasone. ***IV antibiotics + IV dexamethasone*** - The clinical picture of **fever**, **neck stiffness**, **petechial rash**, and positive **Kernig** and **Brudzinski** signs strongly indicates **bacterial meningitis**, which is a medical emergency. The CSF analysis with **increased WBCs**, **decreased glucose**, and **increased protein** further confirms bacterial meningitis. - **IV antibiotics** are crucial for killing the bacteria, while **IV dexamethasone** reduces inflammation in the brain, helping to prevent neurological complications such as hearing loss. *IV antivirals + fluid resuscitation* - While fluid resuscitation might be necessary for hemodynamic stability, **IV antivirals** are not the primary treatment for **bacterial meningitis**. - **Antivirals** are used for **viral meningitis** or encephalitis, but the CSF profile (especially **low glucose**) is more consistent with a bacterial infection. *Lumbar puncture + observation without antibiotics* - Performing a **lumbar puncture** is appropriate for diagnosis, but **observation without immediate antibiotics** in a case of suspected bacterial meningitis is extremely dangerous and can lead to rapid deterioration and death. - The patient's critical condition warrants urgent treatment, not just observation after diagnosis. *Supportive care and observation only* - **Supportive care** (e.g., fever reduction, fluid management) is necessary but not sufficient for **bacterial meningitis**. - **Observation only** without specific antimicrobial therapy would result in severe morbidity or mortality in a patient with confirmed bacterial meningitis.

Q: A 1-year-old child is brought in for routine vaccination. Which of the following vaccines is typically administered at this age to provide immunity against multiple diseases?

MMR vaccine. ***MMR vaccine*** - The **Measles, Mumps, and Rubella (MMR) vaccine** is typically recommended for administration at **9-12 months of age** (first dose at 9 months as per IAP schedule, or 12-15 months as per WHO/CDC) as part of routine childhood immunizations. - It provides protection against **three common childhood diseases** (measles, mumps, and rubella) with a single shot. - This is the **primary multi-disease vaccine** given at this age. *BCG vaccine* - The **Bacillus Calmette-Guérin (BCG) vaccine** primarily protects against **tuberculosis** and is typically given **at birth** as per the Indian immunization schedule. - It is not a multi-disease vaccine and is not administered at 1 year of age. *Hepatitis B vaccine* - The **Hepatitis B vaccine** is administered in a **series**, with the first dose given at **birth**, followed by doses at 6, 10, and 14 weeks of age. - It specifically targets the **Hepatitis B virus** only and is not a multi-disease vaccine given at 1 year. *Influenza vaccine* - The **influenza vaccine** is recommended **annually** starting at **6 months of age**, but it targets **seasonal influenza strains** only. - It is not considered a routine multi-disease vaccine like MMR for childhood immunization.

Q: A 5-year-old boy presents with a rash that began on his face and has spread to his trunk and limbs. The rash consists of red patches that give a 'slapped cheek' appearance on the face, followed by a lacy, net-like rash on the trunk and limbs, and he also has a low-grade fever. What is the most likely diagnosis?

Erythema Infectiosum. ***Erythema Infectiosum*** - The distinctive **'slapped cheek' rash** on the face, followed by a **lacy, reticular (net-like) rash** spreading to the trunk and limbs, is characteristic of Erythema Infectiosum, also known as Fifth Disease, caused by **Parvovirus B19**. - It often presents with a **low-grade fever** and is more common in school-aged children. *Scarlet Fever* - Characterized by a **fine, sandpaper-like rash** that blanches with pressure and often starts on the neck and chest before spreading. - Typically accompanied by a **high fever**, sore throat, and swollen lymph nodes, due to a **Group A Streptococcus** infection. *Measles* - Measles rash typically presents as **maculopapular, erythematous lesions** that start behind the ears and on the face, spreading downwards. - It is preceded by **Koplik spots** (small white spots on the buccal mucosa) and a prodrome of high fever, cough, conjunctivitis, and coryza. *Roseola* - Roseola is characterized by a **high fever** (often >103°F) that lasts for 3-5 days, followed by the sudden appearance of a **rose-pink maculopapular rash** once the fever breaks. - The rash usually starts on the trunk and spreads to the neck and extremities, but does not present with a "slapped cheek" or lacy appearance.

Q: A 7-year-old girl presents with a sore throat, fever, and a strawberry tongue. Which of the following conditions is most likely?

Scarlet fever. ***Scarlet fever*** - The classic triad of **sore throat**, **fever**, and **strawberry tongue** is highly characteristic of scarlet fever, a systemic illness caused by toxigenic strains of **Group A Streptococcus**. - Other common findings include a **scarlatiniform rash** (sandpaper-like texture) and **circumoral pallor**. *Kawasaki disease* - While it can present with fever and strawberry tongue, Kawasaki disease typically involves **bilateral conjunctival injection**, **polymorphous rash**, **cervical lymphadenopathy**, and changes in **extremities** (e.g., desquamation). - It usually occurs in children younger than 5 years and lacks the prominent pharyngitis associated with scarlet fever. *Infectious mononucleosis* - Caused by the **Epstein-Barr virus**, it is characterized by **fever**, **pharyngitis**, **lymphadenopathy**, and sometimes **splenomegaly**. - A strawberry tongue is not a typical feature, and the pharyngitis is often exudative. *Hand-foot-and-mouth disease* - This viral illness, often caused by **Coxsackievirus**, presents with **fever**, **oral lesions** (herpangina-like), and a characteristic rash on the **hands and feet** (vesicular or papular). - A strawberry tongue is not a typical or distinguishing feature of hand-foot-and-mouth disease.

Q: A 7-year-old boy presents with fever, sore throat, and painful swelling of the parotid glands. What is the most likely diagnosis?

Mumps. ***Correct Answer: Mumps*** - **Fever**, **sore throat**, and **painful swelling of the parotid glands** are classic symptoms of mumps, a viral infection caused by the mumps virus (paramyxovirus). - Mumps primarily targets the **salivary glands**, especially the parotid glands, leading to characteristic bilateral facial swelling. - The combination of constitutional symptoms with parotid involvement is pathognomonic for mumps. *Incorrect: Tonsillitis* - Characterized by **inflamed and swollen tonsils**, often with exudate, leading to severe sore throat and difficulty swallowing. - **Parotid gland swelling** is not a typical feature of tonsillitis. - Lymph node enlargement may occur but differs from parotid enlargement. *Incorrect: Epiglottitis* - A serious bacterial infection causing inflammation and swelling of the **epiglottis**, which can rapidly obstruct the airway. - Symptoms include **stridor**, **drooling**, **tripod positioning**, and **difficulty breathing**, not parotid swelling. - This is a medical emergency requiring immediate airway management. *Incorrect: Lymphadenitis* - Refers to inflammation of the **lymph nodes**, which can cause localized swelling and tenderness. - While cervical lymph nodes might be swollen with a sore throat, this presents as distinct nodular swelling along lymph node chains. - Does not involve the specific, bilateral swelling of the **parotid glands** as seen with mumps.

Q: Which of the following is a criterion for clinical Stage II of AIDS in children?

Hepatosplenomegaly. ***Hepatosplenomegaly*** - **Unexplained persistent hepatosplenomegaly** is a defining criterion for WHO clinical **Stage II** of pediatric HIV/AIDS - This stage reflects moderate immune deterioration with clinical manifestations beyond the asymptomatic or mild Stage I findings - Other Stage II criteria include herpes zoster, recurrent upper respiratory tract infections, and fungal nail infections *Oesophageal candidiasis* - **Oesophageal candidiasis** is a severe opportunistic infection classified under **Stage IV** (severe HIV disease) - This indicates advanced immunosuppression with severe AIDS-defining conditions - Stage IV includes other severe infections like cryptococcal meningitis, toxoplasmosis of the brain, and extrapulmonary tuberculosis *Oral candidiasis* - **Oral candidiasis** (persistent or recurrent beyond 2 months of age) is classified under **Stage II** when it meets specific WHO criteria - However, in this context, **hepatosplenomegaly** is the more definitive and commonly emphasized Stage II criterion being tested - Oral thrush in young infants (<2 months) may be physiological and doesn't indicate HIV staging *Lymphadenopathy* - **Persistent generalized lymphadenopathy (PGL)** is a characteristic finding in **Stage I** (asymptomatic or mild HIV disease) - PGL alone represents minimal immune dysfunction and is one of the earliest clinical manifestations - Stage II requires more specific symptoms indicating moderate immunosuppression beyond lymphadenopathy alone

Q: At what age should the rotavirus vaccine not be initiated to prevent complications?

15 weeks. ***15 weeks*** - The first dose of the **rotavirus vaccine** should be administered **before 15 weeks of age** (specifically, no later than 14 weeks and 6 days). - Initiating the vaccine **at or after 15 weeks of age** is **not recommended** due to an increased risk of **intussusception**, a serious complication involving telescoping of the intestine. - The risk of intussusception increases with age, particularly when the first dose is given after the recommended window. *14 weeks* - This age is **within the acceptable window** for initiating the rotavirus vaccine series. - The first dose can be given up to **14 weeks and 6 days of age**, so 14 weeks is still appropriate for vaccine initiation. *6 weeks* - This is the **earliest recommended age** for the first dose of the rotavirus vaccine. - The vaccine is typically given at **6, 10, and 14 weeks** (or 2, 4, and 6 months) depending on the national immunization schedule and vaccine brand. *10 weeks* - This age is well within the **recommended window** for rotavirus vaccine administration. - This is often the timing for the second dose in many vaccination schedules, but the first dose can also be safely given at this age.

Question 1

A 6-month-old infant presents with a high fever, irritability, and a bulging fontanelle. Which immediate intervention is the most appropriate?

Accepted Answer

Administer intravenous antibiotics immediately and perform lumbar puncture after stabilization

Answer

Lumbar puncture to evaluate for meningitis

Answer

Oral antipyretics and outpatient follow-up

Answer

CT scan of the head to evaluate for intracranial pressure

Question 2

A 4-year-old with fever, neck stiffness, and petechial rash presents with a positive Kernig sign, positive Brudzinski sign, heart rate of 140, respiratory rate of 30, and blood pressure of 90/50. CSF analysis shows increased white blood cells, decreased glucose, and increased protein. Analyze the situation and initiate the most appropriate treatment.

Accepted Answer

IV antibiotics + IV dexamethasone

Answer

IV antivirals + fluid resuscitation

Answer

Lumbar puncture + observation without antibiotics

Answer

Supportive care and observation only

Question 3

A 1-year-old child is brought in for routine vaccination. Which of the following vaccines is typically administered at this age to provide immunity against multiple diseases?

Accepted Answer

MMR vaccine

Answer

BCG vaccine

Answer

Hepatitis B vaccine

Answer

Influenza vaccine

Question 4

A 5-year-old boy presents with a rash that began on his face and has spread to his trunk and limbs. The rash consists of red patches that give a 'slapped cheek' appearance on the face, followed by a lacy, net-like rash on the trunk and limbs, and he also has a low-grade fever. What is the most likely diagnosis?

Accepted Answer

Erythema Infectiosum

Answer

Scarlet Fever

Answer

Measles

Answer

Roseola

Question 5

A 7-year-old girl presents with a sore throat, fever, and a strawberry tongue. Which of the following conditions is most likely?

Accepted Answer

Scarlet fever

Answer

Kawasaki disease

Answer

Infectious mononucleosis

Answer

Hand-foot-and-mouth disease

Question 6

A 2-month-old infant presents with poor feeding, irritability, and a bulging anterior fontanelle. What is the most likely diagnosis?

Accepted Answer

Meningitis

Answer

Hydrocephalus

Answer

Intraventricular Hemorrhage

Answer

Cerebral Palsy

Question 7

A 7-year-old boy presents with fever, sore throat, and painful swelling of the parotid glands. What is the most likely diagnosis?

Accepted Answer

Mumps

Answer

Tonsillitis

Answer

Epiglottitis

Answer

Lymphadenitis

Question 8

Which of the following is a criterion for clinical Stage II of AIDS in children?

Accepted Answer

Hepatosplenomegaly

Answer

Oesophageal candidiasis

Answer

Lymphadenopathy

Answer

Oral candidiasis

Question 9

At what age should the rotavirus vaccine not be initiated to prevent complications?

Accepted Answer

15 weeks

Answer

14 weeks

Answer

6 weeks

Answer

10 weeks

Question 10

Which statement regarding the administration of vaccines is correct?

Accepted Answer

Live vaccines should not be administered for 12 weeks if immunoglobulin has been given.

Answer

Live and killed vaccines can be administered together.

Answer

Immunoglobulin should not be given for at least 6 weeks when a live vaccine is administered.

Answer

Two live vaccines can be given together if they are compatible.

Infectious Diseases — MCQs

Infectious Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?