Infectious Diseases Practice Questions

Q: Which one of the following is the recommended site for immunization with hepatitis B vaccine in young children for ensuring reliable absorption?

Anterolateral aspect of thigh. ***Anterolateral aspect of thigh*** - The **anterolateral aspect of the thigh** is the recommended site for intramuscular injections in infants and young children due to the sufficient muscle mass and lower risk of damaging nerves or blood vessels. - This site ensures reliable absorption of the vaccine due to its **large quadriceps femoris muscle**. *Gluteal region* - The **gluteal region** is generally avoided for intramuscular injections in young children due to the risk of injury to the **sciatic nerve**. - While it has significant muscle mass, the proximity of major nerves makes it less safe for routine vaccinations in this age group. *Anterior aspect of thigh* - The **anterior aspect of the thigh** is not specifically recommended; rather, the **anterolateral aspect** is preferred for its greater muscle mass and safety. - While muscles are present, using the exact anterior aspect might be less reliable for consistent absorption compared to the designated anterolateral site. *Deltoid region* - The **deltoid muscle** is generally too small and underdeveloped in young children and infants to safely administer intramuscular injections. - Using the deltoid in this age group increases the risk of injecting into subcutaneous tissue or hitting underlying nerves/blood vessels, leading to poorer absorption and potential injury.

Q: A 10 week old child comes for vaccination, with previous history of inconsolable cry & fever after getting vaccinated at 6 weeks. What should be done next?

Give DT. ***Correct Option: Give DT*** - **Inconsolable crying** (typically defined as crying ≥3 hours) following pertussis-containing vaccine is classified as a **precaution** for subsequent doses per IAP, CDC, and WHO guidelines - When a **precaution** exists, the pertussis component should be **withheld** from future doses - **DT vaccine** (diphtheria-tetanus without pertussis) ensures continued protection against diphtheria and tetanus while avoiding repeat exposure to the pertussis antigen that likely caused the reaction - This represents appropriate **risk-benefit assessment** in immunization practice *Incorrect: Give DPT vaccination* - Continuing DPT after inconsolable crying ignores established AEFI (Adverse Events Following Immunization) guidelines - While fever alone is not a contraindication, **inconsolable crying is a recognized precaution** that warrants modification of the vaccination schedule - Repeating the same vaccine risks recurrence of the adverse event *Incorrect: Defer for 1 month* - Simply deferring without changing the vaccine type doesn't address the underlying issue - The child would still receive the pertussis component later, risking another adverse reaction - Unnecessary delay in protection against diphtheria and tetanus when DT is available *Incorrect: Administer antibiotics* - **Post-vaccination fever and crying** are inflammatory responses to vaccine antigens, not bacterial infections - Antibiotics have no role in managing vaccine-related reactions - This approach doesn't address the need for continued immunization protection

Q: A 10-week-old baby came for vaccination. The baby had a previous history of inconsolable crying and fever (40°C) after vaccination at 6 weeks. What should be given now?

Give DT only. ***Give DT only*** - The previous severe adverse reaction (**inconsolable crying** and **fever of 40°C**) is a specific contraindication to the **pertussis component** of the DPT vaccine. - According to **pediatric vaccination guidelines**, severe reactions (fever ≥40°C, inconsolable crying >3 hours) are absolute contraindications to further pertussis-containing vaccines. - The **diphtheria and tetanus toxoids** were not associated with the adverse reaction and should be safely continued. - **DT vaccine (without pertussis)** provides essential protection against diphtheria and tetanus while avoiding the problematic pertussis component. *Don't give DPT* - This option is imprecise because it doesn't specify what should be given instead. - While it correctly identifies that full DPT should be avoided, it fails to address the need for continued protection against diphtheria and tetanus. - The medically appropriate approach is to give **DT vaccine**, not to simply withhold vaccination. *Defer for 1 month* - Deferring vaccination does not address the core issue that the **pertussis component specifically** caused the severe reaction. - This approach would unnecessarily **delay protection** against diphtheria and tetanus, which the baby can safely receive immediately as DT vaccine. - The problem is not timing but the vaccine component itself. *Give DPT* - Administration of the full DPT vaccine is **absolutely contraindicated** given the history of severe adverse reactions (fever ≥40°C and inconsolable crying). - Repeating DPT risks another severe reaction and potential permanent neurological complications. - This would be a dangerous and inappropriate management decision.

Q: A child presenting with the following appearance is at risk of developing?

Pure red cell aplasia. ***Pure red cell aplasia*** - The image shows a "slapped cheek" rash, which is characteristic of **erythema infectiosum** (fifth disease) caused by **Parvovirus B19**. - Parvovirus B19 has a tropism for **erythroid progenitor cells** in the bone marrow, leading to a temporary cessation of red blood cell production, especially critical in individuals with underlying hemolytic anemias. *Immunodeficiency* - While viral infections can be more severe in immunodeficient individuals, the presented rash is specifically characteristic of **Parvovirus B19 infection**, not a general sign of immunodeficiency. - Immunodeficiency would typically involve recurrent, severe, or unusual infections, which are not directly indicated by the rash alone. *Lymphoproliferative disorder* - Lymphoproliferative disorders involve abnormal proliferation of lymphocytes and typically do not present with a "slapped cheek" rash. - Clinical signs would more likely include **lymphadenopathy**, hepatosplenomegaly, and cytopenias, not the classic facial rash seen here. *Gingivostomatitis* - **Gingivostomatitis** is an inflammation of the gums and oral mucosa, often caused by herpes simplex virus, presenting with **sores and ulcers in the mouth**. - The rash seen in the image is on the **cheeks and body**, not primarily oral, and is a classic presentation of erythema infectiosum.

Q: A child presents with fever and vesicular lesions on the upper limb and the lower limb. Neck stiffness was present. Similar lesions were present on the palms, soles, and oral cavity. CSF analysis revealed normal glucose levels and elevated lymphocytes and protein. What is the most likely diagnosis?

Coxsackie viral meningitis and Hand Foot Mouth disease. Coxsackie viral meningitis and Hand Foot Mouth disease - The presence of **vesicular lesions** on the palms, soles, and oral cavity, along with fever, is highly characteristic of **Hand Foot Mouth Disease (HFMD)** caused by Coxsackievirus. - The CSF findings of **normal glucose**, **elevated lymphocytes** (pleocytosis), and **elevated protein** are typical for **aseptic meningitis**, which is often caused by enteroviruses like Coxsackievirus [2]. *Bacterial meningitis with sepsis* - **Bacterial meningitis** would typically present with **low CSF glucose**, **high protein**, and a predominance of **neutrophils**, not lymphocytes [2]. - The characteristic vesicular rash of HFMD is not seen in bacterial meningitis. *Tuberculous meningitis* - **Tuberculous meningitis** typically has **very low CSF glucose**, **markedly elevated protein**, and a pleocytosis with a high percentage of lymphocytes. - The vesicular lesions on the palms, soles, and oral cavity are not a feature of tuberculous meningitis. *Herpes simplex gingivostomatitis and meningoencephalitis* - While **Herpes simplex** can cause **vesicular lesions** (gingivostomatitis) and **meningoencephalitis** with similar CSF findings (lymphocytic pleocytosis, elevated protein), the widespread nature of the lesions on the palms and soles is **not characteristic of HSV** [1]. - HSV lesions are typically clustered and localized to specific dermatomes or mucosal surfaces.

Q: Which of the following is given as a part of the therapy for a child with severe COVID?

Corticosteroids. ***Correct: Corticosteroids*** - **Corticosteroids** (specifically **dexamethasone**) are the **most established evidence-based therapy** for severe COVID-19 in children requiring oxygen support or mechanical ventilation - They reduce **mortality** by suppressing the hyperinflammatory response and cytokine storm associated with severe COVID-19 - Recommended by **WHO, NIH, and Indian Academy of Pediatrics (IAP)** for hospitalized children with severe COVID-19 requiring supplemental oxygen - The **RECOVERY trial** demonstrated significant mortality reduction in patients receiving oxygen therapy *Incorrect: Ivermectin* - **Ivermectin** is **NOT recommended** for COVID-19 treatment by WHO, FDA, NIH, or IAP - Multiple large randomized controlled trials (including TOGETHER trial) showed **no significant benefit** in preventing severe disease, hospitalization, or mortality - Initial in-vitro activity did not translate to clinical efficacy - Not part of standard therapy for severe COVID-19 in children *Incorrect: Remdesivir* - **Remdesivir** is an antiviral that may shorten recovery time in hospitalized adults - Evidence in **pediatric patients** is limited compared to adults - While used in some hospitalized patients, it is **not as universally recommended** as corticosteroids for severe disease - The **primary established therapy** for severe COVID-19 remains corticosteroids *Incorrect: All of the options* - Only **corticosteroids** represent standard, evidence-based therapy for severe pediatric COVID-19 - Ivermectin lacks efficacy evidence and is not recommended - The question asks what "is given as part of therapy" - corticosteroids are the definitive answer

Q: A 10-year-old boy is brought to the physician with painful and enlarged lymph nodes in his right axilla that was noticed 5 days ago and has slowly grown bigger. He has had weakness, sweating, and poor appetite during this time. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not take any medication. There are no similar cases in the family. On physical exam, his temperature is 38.2°C (100.8°F), the pulse is 89/min, the respiratory rate is 13/min, and the blood pressure is 110/60 mm Hg. In his right axilla, there are multiple tender, fluctuant, and enlarged lymph nodes with overlying erythematous skin. There is a separate lesion on the child's forearm (see image). The lesion is painless to palpation and appears inflamed. Additional history should be obtained regarding which of the following?

Contact with pets. ***Contact with pets*** - The presentation of **painful, enlarged, fluctuant lymph nodes** in the axilla, accompanied by **fever and constitutional symptoms** (weakness, sweating, poor appetite), along with a **painless, inflamed lesion** (possibly a primary inoculation site, like a papule or scratch) on the forearm, is highly suggestive of **cat scratch disease**. - **Cat scratch disease** is caused by *Bartonella henselae* and is transmitted through a **scratch, bite, or lick** from an infected cat or kitten, making contact with pets a crucial piece of history. *Swimming* - While *atypical mycobacterial infections* can cause localized lymphadenitis and skin lesions, they are more commonly associated with **exposure to water** (e.g., swimming pools, fish tanks) or soil. - This option does not directly explain the specific constellation of symptoms, especially the presence of a primary **inoculation lesion** followed by regional lymphadenopathy. *Frequent infections* - While a **history of frequent infections** could raise concerns about immunodeficiency, it does not specifically point to the particular infectious etiology suggested by the patient's symptoms. - The isolated, regional nature of the lymphadenopathy following a skin lesion is more indicative of a **localized infection** like cat scratch disease rather than a systemic immune deficit. *Tick bites* - **Tick-borne illnesses** can cause fever and constitutional symptoms, but the **axillary lymphadenopathy** and the *specific appearance of the skin lesion* are not typical for most common tick-borne diseases. - For example, **Lyme disease** presents with an *erythema migrans rash* (bull's-eye pattern) and often diffuse arthralgias, not usually isolated axillary lymphadenopathy with a preceding painless papule.

Q: For a child 3-5 months of age with H1N1, treatment Oseltamivir dose is

20 mg BD X 5 days. ***20 mg BD X 5 days*** - For infants aged **3-5 months** with H1N1 influenza, the recommended dose of **Oseltamivir** is **20 mg twice daily** (BD) for **5 days**. This dosage is based on weight-based recommendations to ensure appropriate antiviral activity. - This treatment regimen is crucial for reducing the severity and duration of influenza symptoms in this vulnerable age group and should be initiated as early as possible. *12 mg BD X 5 days* - This dosage is typically recommended for younger infants, specifically those aged **less than 1 month up to 2 months** (up to 3 kg body weight). - It is **underdosing** for a child in the 3-5 months age range, which could lead to suboptimal antiviral effect. *25 mg BD X 5 days* - This dosage is generally used for children weighing **between 15 kg and 23 kg**, which is significantly higher than the average weight for an infant aged 3-5 months. - Administering this dose to a 3-5 month old would constitute an **overdose**, potentially leading to increased side effects such as nausea, vomiting, or other adverse reactions. *20 mg OD X 5 days* - While 20 mg is the correct single dose, giving it **once daily (OD)** is incorrect for treating H1N1 influenza in infants. - Oseltamivir requires a **twice-daily (BD)** regimen to maintain therapeutic drug levels and effectively inhibit viral replication over the 24-hour period.

Question 1

Which one of the following is the recommended site for immunization with hepatitis B vaccine in young children for ensuring reliable absorption?

Accepted Answer

Anterolateral aspect of thigh

Answer

Gluteal region

Answer

Anterior aspect of thigh

Answer

Deltoid region

Question 2

Which statement about congenital syphilis is FALSE?

Accepted Answer

Long bone radiographs are unnecessary in asymptomatic infants born to adequately treated mothers

Answer

Hutchinson's triad includes interstitial keratitis, Hutchinson's teeth, and eighth nerve deafness

Answer

Most infants are asymptomatic at birth

Answer

Treatment of maternal syphilis before 32 weeks gestation prevents most cases

Question 3

A child presents with complaints of fever, rash, body ache, and throat ache. He had a history of thorn prick injury a week back. What antibiotics would you give empirically to this child?

Accepted Answer

Amoxicillin+ clavulanate

Answer

Ceftriaxone

Answer

Vancomycin

Answer

Meropenem

Question 4

A 10 week old child comes for vaccination, with previous history of inconsolable cry & fever after getting vaccinated at 6 weeks. What should be done next?

Accepted Answer

Give DT

Answer

Defer for 1 month

Answer

Administer antibiotics

Answer

Give DPT vaccination

Question 5

A 10-week-old baby came for vaccination. The baby had a previous history of inconsolable crying and fever (40°C) after vaccination at 6 weeks. What should be given now?

Accepted Answer

Give DT only

Answer

Don't give DPT

Answer

Defer for 1 month

Answer

Give DPT

Question 6

A child presenting with the following appearance is at risk of developing?

Accepted Answer

Pure red cell aplasia

Answer

Immunodeficiency

Answer

Lymphoproliferative disorder

Answer

Gingivostomatitis

Question 7

A child presents with fever and vesicular lesions on the upper limb and the lower limb. Neck stiffness was present. Similar lesions were present on the palms, soles, and oral cavity. CSF analysis revealed normal glucose levels and elevated lymphocytes and protein. What is the most likely diagnosis?

Accepted Answer

Coxsackie viral meningitis and Hand Foot Mouth disease

Answer

Bacterial meningitis with sepsis

Answer

Tuberculous meningitis

Answer

Herpes simplex gingivostomatitis and meningoencephalitis

Question 8

Which of the following is given as a part of the therapy for a child with severe COVID?

Accepted Answer

Corticosteroids

Answer

Ivermectin

Answer

Remdesivir

Answer

All of the options

Question 9

A 10-year-old boy is brought to the physician with painful and enlarged lymph nodes in his right axilla that was noticed 5 days ago and has slowly grown bigger. He has had weakness, sweating, and poor appetite during this time. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not take any medication. There are no similar cases in the family. On physical exam, his temperature is 38.2°C (100.8°F), the pulse is 89/min, the respiratory rate is 13/min, and the blood pressure is 110/60 mm Hg. In his right axilla, there are multiple tender, fluctuant, and enlarged lymph nodes with overlying erythematous skin. There is a separate lesion on the child's forearm (see image). The lesion is painless to palpation and appears inflamed. Additional history should be obtained regarding which of the following?

Accepted Answer

Contact with pets

Answer

Swimming

Answer

Frequent infections

Answer

Tick bites

Question 10

For a child 3-5 months of age with H1N1, treatment Oseltamivir dose is

Accepted Answer

20 mg BD X 5 days

Answer

12 mg BD X 5 days

Answer

25 mg BD X 5 days

Answer

20 mg OD X 5 days

Infectious Diseases — MCQs

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