Measles, rubella and congenital rubella — formative SAQs

SAQ 1 (10 marks)

A 4-year-old unvaccinated child is brought to the emergency department with four days of fever, coryza, cough and red, watery eyes. This morning a blotchy red rash appeared behind the ears and is now spreading down the trunk. On examination the child is febrile to 39.5 °C, miserable, with conjunctivitis and small white lesions on an erythematous buccal mucosa. There are scattered crackles at the right base. The family recently returned from a region with an ongoing measles outbreak. ^[5]

Question: Outline the immediate and stepwise management of this child, including diagnosis, treatment, supportive care, infection control and the public-health response. (10 marks) ^[1]

Model answer

Recognition and disposition (2 marks). This is classic measles — the 3 C's (cough, coryza, conjunctivitis), Koplik spots on the buccal mucosa, a cephalocaudal maculopapular rash in an unvaccinated child with an exposure history. Isolate immediately with airborne precautions. The basal crackles raise pneumonia — the commonest cause of measles death — so admit for monitoring, oxygen and supportive care, with a low threshold for escalation if work of breathing rises. ^[5]

Diagnosis (2 marks). Confirm with measles-specific IgM on a serum sample taken at first contact (positive from the first day of the rash) plus RT-PCR and genotyping on a throat or nasopharyngeal swab and urine within the first days of the rash. PCR is particularly useful early when IgM may still be negative, and genotyping supports outbreak linkage. Do not delay management while waiting. ^[1]

Treatment — vitamin A and supportive care (3 marks). Give vitamin A in two age-appropriate doses 24 hours apart — the randomised trial and the Cochrane review confirm it reduces measles mortality and morbidity. Provide supportive care: fluids, antipyretics and nutrition; treat secondary bacterial pneumonia with antibiotics if present; protect the eyes and watch for corneal ulceration. Give oxygen for hypoxia and escalate to intensive care if the respiratory status deteriorates. ^{[4] [9]}

Infection control and public health (3 marks). Maintain airborne precautions and exclude from school or childcare until four days after the rash onset. Notify public health on suspicion — do not wait for confirmation — which triggers contact tracing. Identify susceptible contacts (fewer than two documented MMR doses) and offer post-exposure MMR within 72 hours of exposure; give immunoglobulin to high-risk contacts such as pregnant non-immune women, immunocompromised children and infants under protocol. Document onset and rash dates, the infectious period (prodrome to four days after the rash), and exposures. Reinforce catch-up vaccination for the household and counsel the family that immunity to other infections may be impaired for months to years because of measles immune amnesia. ^{[1] [8] [3]}