Possible measles outbreak highlights risks of vaccination exemptions

On Tuesday August 21st, the OHA confirmed the second case of measles in the Portland area. This case apparently sprung from a case confirmed August 10, 2018, in a person who had traveled downtown on the MAX and in the Beaverton area July 30th to August 2nd potentially exposing many Portlanders to the particularly contagious virus.

These exposures come in the wake of  the exposure of upward of 500 adults and children earlier this June and July. At that time, officials discovered a patient diagnosed in an emergency room had visited a child care facility in Gresham exposing approximately 40 unvaccinated youngsters and others. OHA, however, notes that there is no connection between this case and the previous case.

Before the measles vaccine was developed, three to four million people a year used to contract the disease in the United States with 400 to 500 dying, according to the Centers for Disease Control and Prevention (CDC). After the vaccine became available in the 1960s, measles rates dramatically dropped leading the CDC to declare the disease eradicated in 2000. It has made a comeback in recent years after false reports linking vaccines to autism lead some parents to fear vaccines more that the deadly diseases they were developed to prevent.

Approximately one in four people who contract measles will be hospitalized with high fevers or brain swelling. Measles are particularly contagious and pose the highest risk to people who have not been vaccinated, to pregnant women, infants under 12 months and people with weakened immune systems. The illness usually develops around two weeks after exposure but sometimes can take longer.

The recent exposures in Oregon are particularly troubling given an OHA analysis released in May that showed a sharp increase in the rate of parents choosing nonmedical exemptions to vaccines for their kindergarten-age children. The rate of exemptions in Oregon fell in 2015 to just 5.2 percent after a law took effect requiring a parent to receive education about the benefits and risks of immunization from a health care practitioner or by  watching the online class. However, since that initial decrease, the rates have increased each year, to 7.5 percent in 2018.



Because of the risk of contagion, OHA and public health agencies advise anyone who experiences symptoms of measles to call their health care provider or urgent care by telephone first to create an entry plan to avoid exposing others in waiting rooms. Explains, Rebecca Pierce, RN, PhD, of OHA’s Acute and Communicable Disease Prevention section,

“Measles is one of the most contagious diseases we know. It takes very high levels of vaccination in the population to stop its spread.”