Measles Exposure in a Community Emergency Department Waiting Room
A 6-year-old child is brought to a 12-bed community emergency department at 19:40 with a 3-day history of fever to 39.2°C, cough, coryza, and conjunctivitis. On arrival the child has a maculopapular rash beginning at the hairline and face. Triage notes the family declined MMR vaccination. The child is placed in the general waiting room and remains there for 65 minutes before being moved to a private room. During that period 22 people are in the waiting area, including three pregnant women, two infants under 12 months, and a stem-cell transplant recipient. The ED has two negative-pressure rooms; one is occupied by a patient with suspected pulmonary tuberculosis. Two ED nurses have no documented MMR immunity. The child is now masked in a private room. The charge nurse asks the infection preventionist for immediate direction.
1. What immediate isolation, staffing, and notification actions should the infection preventionist direct, and how should the negative-pressure room conflict be resolved?
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The diagnosis is suspected measles, so the immediate priority is airborne infection isolation, not a standard room with a mask. The child should be placed in a negative-pressure room with the door closed; if both negative-pressure rooms are occupied, the tuberculosis patient must not be moved into a shared space with a measles case, because that would create a second airborne exposure. Practical options, in order, are to transfer the measles patient to another facility with an available airborne room, discharge the patient home if medically appropriate with public health follow-up, or use a portable HEPA unit in a single room while documenting that the room meets the facility's airborne precautions policy. Only staff with documented immunity should enter. The two nurses without documented MMR immunity should be excluded from the room and referred for immunity assessment. Notify public health immediately, because measles is reportable and the waiting-room exposure requires contact tracing. Notify the laboratory before specimens arrive so staff can use appropriate precautions. Begin an exposure log now, because the waiting-room period and the air clearance time after the child leaves define who is at risk.
2. Which individuals should be considered exposed, and how should post-exposure prophylaxis be decided for the pregnant women, infants, and transplant recipient?
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The exposed cohort includes everyone who was in the waiting area during the child's 65-minute stay and for up to 2 hours after the child left, because measles virus can remain suspended in air and infectious for that period. Use registration logs, triage records, and video to identify them rather than relying on staff memory. For each exposed person, document age, pregnancy status, immune status, and contraindications. MMR vaccine can be given within 72 hours to non-immune people aged 12 months or older who have no contraindication. Measles immunoglobulin can be given within 6 days to people who cannot receive MMR or in whom vaccine is unlikely to be effective: pregnant women without evidence of immunity, infants under 12 months, and severely immunocompromised patients such as the stem-cell transplant recipient. The transplant recipient should also be assessed by the transplant team because immunoglobulin dosing and timing may need to be coordinated. The two nurses without documented immunity should be offered MMR within 72 hours or excluded from work from day 5 through day 21 after exposure. Do not wait for the child's laboratory result to begin prophylaxis decisions when the clinical picture is compatible and the exposure is real.
3. What diagnostic specimens and documentation are needed, and what would you tell the families while results are pending?
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Collect a throat or nasopharyngeal swab for measles RT-PCR, urine for RT-PCR, and serum for measles IgM as soon as possible; RT-PCR is most useful early, while IgM may be negative in the first few days. Notify the laboratory in advance so specimens are handled safely, and notify public health so testing and genotyping can be coordinated. Document the exposure timeline, room locations, ventilation, staff and patient contacts, and all advice given. While results are pending, tell the families that measles is suspected and that the actions being taken are precautionary but time-sensitive. Explain the exposure window and why prophylaxis must be arranged quickly, especially for pregnant women, infants, and immunocompromised people. Avoid saying the child definitely has measles before confirmation, but do not delay isolation or contact tracing while waiting. Provide written instructions for symptoms, after-hours contacts, and public health follow-up.