Measles Exposure in the Emergency Department
A 32-year-old man presents to a 250-bed community hospital ED with fever, cough, coryza, and a maculopapular rash that began today. He waited in the general waiting area for 3 hours before triage because the ED was busy; he was masked only after triage. He is later confirmed to have measles by PCR. The ED has no airborne infection isolation room (AIIR); the only negative-pressure room is occupied. During the exposure period, 42 patients, 12 staff, and 6 visitors were in the waiting area. The hospital’s employee health records show that 3 nurses have no documented measles immunity; one is pregnant. The patient’s infectious period is estimated from 4 days before rash onset through 4 days after. The ED uses a shared triage bathroom. The hospital has a policy to notify public health within 24 hours.
1. What immediate isolation and notification actions should be taken when measles is suspected, given no AIIR is available?
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Measles is airborne, so do not wait for lab confirmation. Place a surgical mask on the patient immediately and move him to a private room with the door closed; if an AIIR is unavailable, use a room with a dedicated bathroom and, if possible, a portable HEPA filter. Limit entry to immune staff wearing N95 respirators. Notify infection prevention, employee health, and public health promptly. After the patient leaves, avoid using the space for at least two hours if air exchange is inadequate, because measles virus can remain airborne. Standard cleaning of surfaces is sufficient; measles is not primarily fomite-borne. Identify the exposure window from 4 days before rash onset to 4 days after and begin a contact list. The shared bathroom is lower risk than the waiting area but should be cleaned.
2. Who among the exposed should receive post-exposure prophylaxis, and what timing applies?
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Assess immunity first: documented two doses of MMR, positive IgG, or birth before 1957. For susceptible contacts, MMR is preferred within 72 hours of exposure. If MMR is contraindicated-pregnancy, severe immunocompromise, or age under 12 months-give immune globulin within 6 days. The pregnant nurse without documented immunity should receive IG, not MMR. Immunocompromised patients and infants also need IG. Exposed staff without immunity should be excluded from work from day 5 through day 21 after exposure. The 42 patients and 6 visitors need risk assessment and notification; prioritize those at high risk. Do not give MMR to the pregnant nurse. Document immunity and prophylaxis decisions.
3. How would you manage the shared triage bathroom and the ED waiting area?
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The waiting area is the main airborne exposure site. After the infectious patient leaves, close it only as long as needed to complete air changes-often about two hours if ventilation is unknown-then clean routinely. Measles is not a major fomite threat, so extensive terminal cleaning is not the priority. The shared bathroom should be cleaned with a standard disinfectant, but it is unlikely to be a primary transmission route. Notify all exposed patients and visitors by phone or letter, advise them to watch for symptoms for 21 days, and tell them to call ahead before seeking care. Keep a log. Coordinate messaging with public health. Do not disclose the patient’s identity.