Sign up to receive posts from The Exchange
Posted By: Susan M. Tiso, DNP, APRN, FNP-BC
January 31, 2019
As of January 31, 2019, there were 42 confirmed cases of measles in the Pacific Northwest. This includes 41 cases in Clark County, the epicenter for the outbreak, and one in King County. Clark County has a lower-than-normal vaccination rate, according to Dr Alan Melnick, public health director for Clark County. The 41 confirmed cases include two cases that traveled to Hawaii and another one that traveled to Bend, Oregon. Of the confirmed cases, at least 37 were not immunized; 30 cases have been reported in children ages 1-10 years, and 10 cases have occurred in children ages 11-18 years.
A vaccination rate of 95% is required for herd immunity for a highly contagious virus such as measles, and the vaccination rate in Clark County is 78%. Washington is one of 18 states allowing parents to opt out of vaccines for nonreligious reasons. One dose of measles vaccine provides 93% lifelong immunity; a second dose between ages 4 to 6 years provides 97% to 99% immunity.
Measles vaccine has been a component of routine childhood immunizations for many years, and measles was declared eliminated in the United States in 2000. However, measles remains endemic in some areas of the world and travelers infected abroad can easily bring the virus back to the US, causing periodic outbreaks. Last year, there were 17 outbreaks in the US, with about 350 reported measles cases.
Before routine immunization, 400 to 500 people died from measles annually in the US, and another 50,000 people were hospitalized, with about 4000 developing encephalitis, some resulting in deafness. One to three cases out of every 1000 are fatal.
The attack rate for measles virus contacts is about 90%, and early symptoms such as rhinorrhea and cough may easily be mistaken for many other respiratory viruses, especially problematic during flu season. Measles may be transmitted 4 days prior to onset of the rash and remain contagious for 4 days after the rash appears.
Media coverage of this outbreak has already spurred some parents to seek vaccination for their children now, and NPs and PAs can revisit the vaccination issue in those who have declined in the past.
- Washington State Department of Health. Measles outbreak 2019. www.doh.wa.gov/YouandYourFamily/IllnessandDisease/Measles/MeaslesOutbreak. Accessed February 1, 2019.
- Centers for Disease Control and Prevention. Immunization. www.cdc.gov/nchs/fastats/immunize.htm. Accessed February 1, 2019.
- Centers for Disease Control and Prevention. Measles cases and outbreaks. www.cdc.gov/measles/cases-outbreaks.html. Accessed February 1, 2019.