With the measles outbreak in the Clark County area of Washington state growing, now up to 30 confirmed cases and several suspected, Gov. Jay Inslee declared a state of emergency on Friday.

Image/ National Atlas of the United States
Image/ National Atlas of the United States

In his proclamation, Inslee notes that a State of Emergency exists in all counties in the state of Washington, and direct the plans and procedures of the Washington State Comprehensive Emergency Management Plan be implemented. State agencies and departments are directed to utilize state resources and to do everything reasonably possible to assist affected political subdivisions in an effort to respond to and recover from the incidents.

On January 18, Clark County Council Chair Eileen Quiring declared a public health emergency in response to the measles outbreak.

Measles is a highly contagious and potentially serious illness caused by a virus. Measles is spread through the air after a person with measles coughs or sneezes. The virus can linger in the air for up to two hours after someone who is infectious has left.

Measles symptoms begin with a high fever, cough, runny nose and red eyes, followed by a rash that usually begins at the head and spreads to the rest of the body. A person can spread the virus before they show symptoms. People are contagious with measles for up to four days before and up to four days after the rash appears.

After someone is exposed to measles, illness develops in about one to three weeks.

How contagious is measles? Answer: Very

Measles can be serious in all age groups. However, children younger than 5 years and adults older than 20 years are more likely to suffer from measles complications. Common complications of measles include ear infection, pneumonia and diarrhea.

Measles/CDC
Measles/CDC

As many as one out of every 20 children with measles gets pneumonia, the most common cause of death from measles in young children. About one child out of every 1,000 who get measles will develop encephalitis (swelling of the brain) that can lead to convulsions and can leave the child deaf or with intellectual disability. Measles may cause pregnant women to give birth prematurely or to have a low-birth-weight baby.

In 2017, there were 110,000 measles deaths worldwide, mostly among children younger than 5, according to the World Health Organization.

Immunization is the best prevention for measles. The measles vaccine is very effective. One dose of the measles vaccine is about 93 percent effective at preventing measles. Two doses are about 97 percent effective, according to the Centers for Disease Control and Prevention.