According to a Tuesday statement from the Clark County Health Department, there have been 23 confirmed cases and two suspected cases of measles in the county since January 1.
Out of the 23 patients, 20 had not been vaccinated against measles. The immunization status of three people who contracted the virus has not been determined yet, and at least one person has been hospitalized so far, the health department reported.
According to the Centers for Disease Control and Prevention (CDC), measles is a very contagious virus that lives in the nose and throat mucus of infected individuals. It can be transmitted to others through coughing and sneezing. The virus can be prevented with the MMR vaccine, which also protests against mumps (a viral infection that affects the salivary glands) and rubella (also a viral infection that is identified by its distinctive red rash).
The CDC recommends that children get two doses of MMR vaccine, with the first dose administered at between 12 and 15 months of age and the second dose at four to six years of age.
According to Washington state data, 7.9 percent of kindergarten-aged children in Clark County in the 2017 to 2018 school year did not receive the two-dose course for measles that the CDC recommends. Only 1.2 percent of kindergarten-aged children had a medical reason for not receiving the vaccination, which means that almost 7 percent of kindergarten-aged children were not immunized for personal or other reasons.
"It's alarming," Douglas J. Opel, a pediatrician at Seattle Children's Hospital, said in a recent interview with The Washington Post. "Any time we have an outbreak of a disease that we have a safe and effective vaccine against, it should raise a red flag."
Peter J. Hotez, a professor of pediatrics and dean of the National School of Tropical Medicine at Baylor College of Medicine, recently told the Post that he expected an outbreak to occur in Clark County because it is an anti-vaccination "hotspot."
In a study published on June 12, 2018, in the Public Library of Science, Hotez found that there are several "hotspot" metropolitan areas that have large numbers of "philosophical-belief" nonmedical vaccine exemptions, including Portland, Seattle, Phoenix and Detroit.
According to the CDC, symptoms of measles typically appear seven to 14 days after a person is infected with the virus and usually result in a high fever, cough, runny nose and red, watery eyes. A few days after these symptoms appear, tiny white spots may show up inside infected individuals' mouths.
So far, people infected with the virus in Clark County have gone to schools, churches, doctors' offices, Ikea, Costco and Amazon locker pickup stations, according to city officials.
"If other people breathe the contaminated air or touch a contaminated surface, then touch their eyes, noses or mouths, they can become infected," the CDC warns on its website. "Measles is so contagious that if one person has it, 90 percent of the people close to that person who are not immune will also become infected."