What to know about the measles outbreak, affecting over 70 in Washington anti-vaccination hot spot

A measles outbreak is rapidly spreading across a Washington county known for choosing not to vaccinate its children, and health officials have declared a public health emergency.

Clark County, Washington, which is about nine miles away from Portland, Oregon, identified 71 confirmed cases and three suspected cases since the beginning of the year. Most cases are affecting children younger than 10.

The county has one of the lowest vaccination rates in the state: Nearly one in four Clark County kindergarten students during the 2017-18 school year did not get all their immunizations, according to data from the Washington Department of Health. At three schools in the county, more than 40 percent of kindergartners did not receive all recommended shots before starting school.

Here's what you should know about the measles and this outbreak:

What is measles? What are the symptoms?

Measles is an extremely contagious illness caused by a virus that is spread through the air.

People infected develop a red spotted rash that starts inside the mouth and spreads all over the body. Symptoms include fevers as high as 104 degrees, cough, runny nose and red, watery eyes.

How serious is it?

In 2017, about 110,000 died from measles, mostly among children younger than five, around the world, according to the World Health Organization. Young children and adults older than 20 are more likely to suffer measles complications that can be deadly.

As many as one out of every 20 children infected with measles gets pneumonia, the most common cause of death from measles in young children, according to health officials. One in every 1,000 children with measles develops swelling of the brain that can cause deafness or an intellectual disability. Pregnant women with measles might give birth early or have a low-weight baby.

More: I’m an adult worried about measles. What do I need to know?

Is there a cure?

There is no specific treatment available for measles.

How contagious is it?

Measles is so contagious that 90 percent of unvaccinated people who come in contact with an infected person will get the virus, according to the Centers for Disease Control and Prevention. The virus can linger in the air for up to two hours after an infected person coughs or sneezes. The virus can spread four days before and after symptoms appear.

How effective is the vaccine?

The measles two-dose vaccine is 97 percent effective against the virus, according to the CDC.

More: Son defies mom, chooses to get vaccinated at 18: 'God knows how I'm still alive'

How many people have been affected?

Clark County Public Health officials have identified 71 confirmed cases and three suspected cases.

So far, 52 children ages 1 to 10 have been infected; 15 children ages 11 to 18; one person between the age of 19 and 29; and three people between the age of 30 to 39. Sixty-two cases have been in unvaccinated people. Two infected people did receive a MMR vaccine. Vaccine records for the seven others were not immediately known.

Cases include two people who traveled to Hawaii and one case of a person who traveled to Bend, Oregon.

Where are people being infected?

Dozens of locations have been identified as possible exposure locations, including malls, grocery stores, daycares and churches.

Portland International Airport was previously identified by officials as an exposure location, but was later removed because the incubation period has passed.

Why aren't people vaccinating?

People choosing not to vaccinate have become a global health threat in 2019, the World Health Organization reported. The CDC recognized that the number of children who aren't being vaccinated by 24 months old has been gradually increasing.

Some parents opt not to vaccinate because of the discredited belief vaccines are linked to autism. The CDC said that there is no link and that there are no ingredients in vaccines that could cause autism.

More: A quarter of all kindergartners in this county in Washington aren’t immunized. Now there’s a measles crisis

More: These 15 U.S. cities are hotspots for kids not getting vaccines

Contributing: Ken Alltucker, Brett Molina and Joel Shannon. Follow Ashley May on Twitter: @AshleyMayTweets

This article originally appeared on USA TODAY: What to know about the measles outbreak, affecting over 70 in Washington anti-vaccination hot spot