Three were confirmed in Harris County and one each in Galveston, Montgomery and Bell counties.
The Centers for Disease Control and Prevention recommends children get two doses of the measles, mumps and rubella vaccine - one between 12 and 15 months and the second between ages 4 and 6 - to be fully protected against measles.
These new Multnomah County cases are linked to the Clark County outbreak.
The Oregon cases are a part of the larger Vancouver-area outbreak that stands at 50 confirmed cases of measles and 11 suspected cases as of Wednesday, according to Clark County Public Health.
The best way to prevent measles infection is with 2 doses of the MMR vaccine. Anyone born since 1978 who is unsure if they have received two doses of a measles containing vaccine, such as MMR, should speak with their GP. Three times as many people have gotten vaccinated in January - from 200 per day in 2018 to 600 per day in 2019. The CDC says measles are more likely to spread in areas with "pockets of unvaccinated people". "It has also raised an awareness that measles could easily make a comeback, and the only way to prevent that is to get as many people vaccinated as possible".
If you are unsure of your family's immunization status, you can view, download and print your family's immunization information online at wa.MyIR.net or request a copy of your immunization record from the Washington State Department of Health.More news: West Indies slam 'crippling' Jason Holder ban ahead of third England Test
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Public Health has established a call center for questions related to the investigation.
The case is the seventh in Texas in recent days.
For a complete list of exposure sites, visit the Public Health measles investigation webpage at www.doh.wa.gov/YouandYourFamily/IllnessandDisease/Measles/MeaslesOutbreak.
Measles symptoms include a fever, a dry cough, a runny nose, a sore throat and inflamed eyes.
Anyone experiencing symptoms of the virus should call their physician. After someone is exposed to measles, illness develops in about one to three weeks.