The measles outbreak isn't showing signs of waning yet, with 13 new cases in the last week, and there are now three separate outbreaks, according to the U.S. Centers for Disease Control and Prevention.
The CDC reported today that it had confirmed 154 cases of the measles since Jan. 1 as part of three separate outbreaks, plus several additional cases not linked to those outbreaks. As of Feb. 20, an outbreak linked to a group of unvaccinated people who visited Disneyland in December had 118 reported cases. Two other unrelated outbreaks are occurring in Illinois and Nevada, according to the agency's latest report.
The measles cases are heating up vaccine discussions nationwide, with daycare chain KinderCare changing its staff policies after several infants in one Illinois location were infected with the virus.
Of the first 34 people with measles for whom the California Department of Public Health had vaccination records, only five had received both doses of the measles vaccine, as generally recommended, according to the agency. One received just the first dose.
Nationally, officials are seeing the same trend, said Dr. Anne Schuchat, who directs the National Center for Immunization and Respiratory Diseases. Some of those 34 cases tracked by California may not be included in the 121 tally by the CDC because they were reported before Jan. 1.
"This is not a problem with the measles vaccine not working," she said during a news conference earlier this year. "This is a problem of the measles vaccine not being used."
The CDC is seeing more adult cases of measles than usual during this outbreak, Schuchat said, adding that children are getting the virus, too.
Cases have now been reported in 17 states: Arizona, California, Colorado, Delaware, District of Columbia, Illinois, Minnesota, Michigan, Nebraska, Nevada, New York, Georgia, Pennsylvania, South Dakota, Texas, Utah and Washington, according to the CDC. The agency issued a health advisory on Jan. 23, at which point the virus had only spread to six states beyond California and Mexico.
The United States last year reported its highest number of measles cases in two decades, with 644 cases as part of 20 separate outbreaks, according to the CDC. Health officials attribute the spike to a measles outbreak in the Philippines and overseas travelers.
The measles virus is contagious long before symptoms appear and it is airborne, which is what makes it so contagious, according to the CDC. One infected person with the measles can spread it to an average of 18 other people, and it can linger in the air and live on surfaces to spread after an infected person has left a room.
Complications include hearing loss, pneumonia and swelling of the brain, according to the CDC. About one or two people out of every 1,000 people infected with the measles die of the virus.