Reach of enterovirus infection may have spread to Washington state

UW, Fred Hutch researchers prepare for this and other emerging viruses

A cluster of patients admitted to Seattle Children’s with severe respiratory illness have tested positive for a possible enterovirus infection, and local health officials said Thursday that “it would not be surprising” if additional testing by the Centers for Disease Control and Prevention confirms that it is the same rare strain that has been sending children to hospitals across the country.

If it is enterovirus D68, a large number of children can be expected to develop respiratory infections in a short time period because the virus spreads as easily as the common cold, according to Dr. Jeff Durchin, chief of Communicable Disease and Epidemiology for Seattle and King County.

The vast majority will have a mild illness that will not require medical attention, said Durchin in a statement. But parents should seek medical care immediately if children suddenly develop difficulty breathing, especially if they have asthma.

“It’s important for families to make sure asthma symptoms are under control, and to see a health care provider if a person with asthma develops a respiratory illness that worsens asthma symptoms,” he said.

There are no vaccines or specific treatment for EV-D68 beyond supportive care. In some of the most severe cases, children have needed mechanical ventilation, according to the CDC, but generally supportive care is provided, including oxygen support or medications that can open airways.

The CDC said in an alert issued earlier this week that hospital officials in Kansas City and Chicago reported a rise in severe respiratory illness among children seen in emergency rooms and admitted to hospitals in August. More than half the confirmed cases were in children with a history of asthma or wheezing.

Since then, EV-D68 has been confirmed in Colorado, Iowa, Kansas, and Kentucky, and is being investigated in a dozen other states. No deaths have been reported.

One of a few laboratories in the country that can test for the virus is the University of Washington’s Molecular Virology Laboratory.  The test was developed for research purposes by the UW’s Dr. Jane Kuypers, an affiliate of Fred Hutchinson Cancer Research Center.

“We have an interest in developing new tests for viruses that may be emerging,” said Dr. Keith Jerome, head of the UW Virology Division and an associate member of Fred Hutch’s Vaccine and Infectious Disease Division. “A lot of time we’ll make a test, and not hear about that virus for years.”

In this case, the wait was not long. The test was developed after the virus was seen in California in recent years, and especially after two of five California children who developed a polio-like paralysis in 2012 tested positive for EV-D68.

Both Jerome and said Dr. Anne Schuchat, director of the CDC’s National Center for Immunization and Respiratory Diseases, have stressed that the current outbreak involves respiratory symptoms, not paralysis. Although enteroviruses can cause a wide variety of illnesses, the D68 strain has classically been described as a respiratory virus, Jerome said.

 “Paralytic disease is not something that’s been reported in this outbreak at all,” he said. “We hope it stays that way.”

Enteroviruses are similar to the rhinovirus, which causes colds. The EV-D68 strain was first identified in the United States in 1962. It is not a new virus, but it is a rare one, and consequently, health officials cannot predict with certainty what to expect from the current upturn.

“We don’t know as much about it as we do about some of the other common enteroviruses,” said Schuchat at a press briefing earlier this week. “We’re in a stage where it’s difficult to say how big this is, how long it will go on for, and how widespread it will be.”

Another factor that stood out to federal health officials was the age of the children affected. “Usually the severe cases are in kids under 2,” Schuchat said. “So seeing several cases that are in 5 year olds and 8 year olds and 9 year olds, that’s unusual.” In Missouri and Illinois, the ages affected ranged from 6 weeks to 16 years.

The main warning sign for parents to watch for is difficulty breathing.

“Runny nose and sniffles are not unexpected and can be caused by many different things,” Schuchat said. “But if it looks like your child is having difficulty breathing, you absolutely want to seek medical help.”

Since asthma has been identified as a factor in some of the illnesses, it is important that asthma be well treated and controlled, Schuchat added. She also recommended “common-sense steps” such as washing hands often for 20 seconds with soap and water and disinfecting frequently touched surfaces such as toys and doorknobs, especially if someone in the house is ill.

EV-D68 itself is not a reportable illness, which is just as well, Schuchat said, given that testing is neither simple nor widely available. However, severe illnesses that are unexplained and clusters of severe illnesses are reportable, which is how the current outbreak came to the attention of the CDC.

At his UW lab, Jerome concentrates on diagnostic work. At his Hutch lab, he works on curing chronic viral infections. The work is closely related, and the laboratory works with the Hutch’s Vaccine and Infectious Disease Division and with the Seattle Cancer Care Alliance, particularly in treating patients whose treatment involves immune-suppressing drugs that leave them vulnerable to infectious diseases.

The Hutch and SCCA are particularly alert to new infections that could affect transplant patients. “We certainly are cognizant [of the threat of EV-D68] and are keeping an eye out,” said Jerome. “Those are the first people we’d be concerned about after children.”

You can find more information about the virus, and tips on common-sense ways on how to protect yourself — such as getting enough sleep and washing hands — at Seattle Children’s Hospital web site.


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