Clinician Alert: Measles cases continue into summer 2019

August 9, 2019

Originally issued Aug. 5, 2019

This alert is a reminder that measles is currently present in the Portland Metro area; keep measles on your differential for acute, febrile, respiratory illness with or without rash. Please distribute widely to clinicians in your organization and networks

Update on Measles Cases

Six cases of measles cases have been identified by Clackamas and Multnomah counties since the beginning of July. All cases were unimmunized. There is no evidence of ongoing transmission in the community at this time, and all known exposed contacts are under monitoring by local health departments.

Possible public exposures

Providence Immediate Care Happy Valley, 16180 SE Sunnyside Rd Suite 102, Happy Valley

  • July 21, 2019, 1 p.m. to 4:30 p.m.
  • July 31, 2019, 10 a.m. to 2:15 p.m.

Legacy GoHealth Gresham, 2850 SE Powell Valley Rd., Ste. 100, Gresham

  • August 2, 2019, 5 p.m. to 8 p.m.

Measles is a highly contagious, severe, febrile viral respiratory illness that is preventable by vaccination. In addition to prominent fever, respiratory symptoms and malaise, measles is characterized by cough, conjunctivitis and an extensive rash that typically begins the day of illness. The fever tends to persist into the rash phase. Infants, susceptible pregnant women and immunocompromised hosts may be at greater risk for serious complications of measles. Measles spreads easily in healthcare settings; your diligence and awareness will help prevent additional cases.

Testing

Laboratory confirmation of measles is critical to track the course of the outbreak and to prioritize prevention efforts. Health department approval is required for this test. Traditional measles IgM has poor sensitivity until 72 or more hours after rash onset. The Oregon State Public Health Laboratory (OSPHL) offers a sensitive RT-PCR test for measles that is more reliable early in illness. This test can be requested by contacting the local health department of the patient if their evaluation shows:

  1. A compatible illness; AND

  2. Likely susceptibility to measles

Healthcare Infection Control

Measles primarily spreads to close and household contacts through large droplets but can also be transmitted through the airborne route. According to the CDC the virus can be transmitted through the latter route up to 2 hours after a contagious patient coughed or sneezed. Preventing healthcare exposures is critical to keep high-risk groups safe. When possible, use phone triage and assessment to determine if patients who might have measles need to be seen in-person. 

If patients or caregivers are concerned about measles, inquire whether they could have been exposed at the locations above. Up-to-date vaccination status makes measles much less likely. Please implement these interventions in your clinical settings to minimize exposure to others:

  • If a patient with possible measles arrives unexpectedly, place a mask on the patient and room promptly

  • Report any possible measles cases immediately to the health department of the county where the patient resides.

  • If possible and appropriate, schedule possible measles patients as the last patient of the day.

  • If feasible, appropriate, consider patient evaluation outdoors at least 30 feet away from others. Once patient is masked, escort patient into the building for immediate rooming.

  • If possible, suspected measles patients should be escorted into the building via an entrance that allows them to access an exam room without exposing others.

  • Minimize the number of health care workers interacting with the patient; caregivers should have documented immunity to measles and wear an N-95 mask or PAPR

  • If the patient is already in the clinic/waiting room, patient should be roomed immediately rather than waiting in the lobby.

  • Use a negative pressure room if available; regardless the exam room door should remain closed.

  • Perform all labs and clinical interventions in the exam room if possible.

  • The exam room should not be used for 2 hours until after the patient has left.

  • Local Health Departments can facilitate testing for suspected cases who have no rash or rash for less than 3 days

  • Patients who are under evaluation for measles should isolate at home until the diagnosis is clarified.

Prevention

Measles is best prevented by 2 doses of MMR or MMRV. In normal circumstances, the first dose is recommended between 12-15 months of age to avoid interference from maternal antibody. The definitive resource on the timing of the second dose is the CDC Pink Book which states:

The second dose of MMR may be administered as soon as 4 weeks (28 days) after the first dose. Children who have already received two doses of MMR vaccine at least 4 weeks apart, with the first dose administered no earlier than the first birthday, do not need an additional dose when they enter school.

Post-exposure prophylaxis with immunoglobulin within 6 days after exposure is recommended for certain susceptible individuals who have been exposed to measles. Oregon recommendations are available here. In general, immunoglobulin is prioritized for susceptible individuals at risk for severe disease including:

  • Infants under age 12 months (intramuscular IG 0.5 mL/kg, max 15 mL)

  • Pregnant women without evidence of immunity (400 mg/kg IVIG)

  • Severely immunocompromised persons regardless of vaccination history (400 mg/kg

  • IVIG)

Infants aged 6-12 months and other healthy contacts to measles cases should receive MMR vaccine as post-exposure prophylaxis if it can be given within 72 hours of exposure. MMR provides long term immunity and may prevent disease if given promptly. Even if the MMR vaccine is not given within 72 hours of exposure, the vaccine should be offered to provide protection from future exposures. MMR should not be used in pregnant women or severely immunocompromised patients.

Specimen Collection Guidance

https://www.oregon.gov/oha/PH/DISEASESCONDITIONS/DISEASESAZ/Measles1/2019-measles-lab-testing-at-osphl.pdf