On Aug. 19, representatives from Children's Mercy Hospital in Kansas City, Mo., notified the CDC that compared with the same period in previous years, the facility was experiencing a significant increase in the number of patients presenting and being hospitalized with severe respiratory illness, including some requiring admission to the pediatric ICU.
According to a CDC Morbidity and Mortality Weekly Report(www.cdc.gov) released Sept. 8, CDC tests of nasopharyngeal specimens sent from the hospital identified enterovirus D68 (EV-D68) in 19 of 22 specimens.
Mary Anne Jackson, M.D., division director for infectious diseases at Children's Mercy Hospital, told AAFP News that as of Sept. 12, the facility had seen more than 550 suspected cases, including 100 children who were admitted to the ICU with this viral infection.
And this is not an isolated situation. As of Sept.16, 12 states had reported clusters of laboratory-confirmed cases of EV-D68: Alabama, Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Missouri, New York, Oklahoma and Pennsylvania, according to the CDC. The agency explained that more states likely will have confirmed cases of the viral infection in the coming weeks because specimens are still being tested.
The fact that this uncommon virus was identified in several locations as the cause of these clusters raised concern that it could spread quickly among a susceptible population, Jackson said.
- As of Sept. 16, 12 states had reported clusters of laboratory-confirmed cases of enterovirus-D68 (EV-D68) to the CDC.
- On Sept. 8, the CDC released a Morbidity and Mortality Weekly Report describing clusters of confirmed cases of EV-D68 infection in Chicago and Kansas City, Mo.
- The CDC recommends that clinicians who see suspected cases of EV-D68 infection contact their state and local health departments about the availability of testing for the virus.
"This was consistent with our experience, where we saw an increase of 25 percent to 30 percent beyond the usual numbers of children that we would generally see this time of year, in terms of visits to our emergency rooms, urgent cares and hospital admissions," she said. "Admissions to our pediatric intensive care unit also were higher than what would normally be seen with other respiratory viruses."
AAFP Board Chair Jeff Cain, M.D., runs a family medicine practice in Denver and also works at Children's Hospital Colorado -- one of the hardest-hit hospitals dealing with the EV-D68 outbreak.
Since Aug. 18, Children's Hospital Colorado has treated more than 2,520 children for severe respiratory illness in the Denver metro area, with more than 240 admitted for hospital stays, according to Ann-Christine Nyquist, M.D., M.S.P.H., the hospital's medical director of infection control. Of the 2,520-plus cases seen, 1,160 occurred between Sept. 8 and Sept. 14, she told AAFP News on Sept. 15. CDC testing confirmed that 19 of 25 specimens submitted by the hospital tested positive for EV-D68.
"We recognized the increase in cases early at Children's Hospital Colorado and instituted respiratory precautions for hospitalized children even before the virus was identified," Cain said.
Preparing for Infected Patients
According to the CDC, enteroviruses are very common and include more than 100 types. The agency estimated that 10-15 million enterovirus infections occur in the United States each year, mostly during the summer and fall. Infants, children and teenagers are most likely to be infected with enteroviruses and become ill.
But EV-D68 is much less common than other enteroviruses and has rarely been reported in the United States.
On a CDC call(www.cdc.gov) on Sept. 8, Anne Schuchat, M.D., director of the CDC's National Center for Immunization and Respiratory Diseases, said there are no confirmed cases of EV-D68 infection in adults. She noted that there was a recent outbreak of respiratory illness in a nursing home, but tests for the virus came back negative.
Current CDC Advisory Committee on Immunization Practices Chair and family physician Jonathan Temte, M.D., Ph.D., of Madison, Wis., said EV-D68 was first identified in California in 1962 and is fairly indistinguishable from a "run-of-the-mill" rhinovirus.
Infection with the virus presents as an acute respiratory infection and has a wide spectrum of illness -- from relatively benign to quite severe (like rhinovirus), he said.
"What the clinician should be looking for are the individuals with significant symptoms, often superimposed upon pre-existing chronic respiratory, such as asthma," Temte told AAFP News. "The most susceptible are those (patients) with underlying respiratory conditions: asthma, cystic fibrosis, bronchiectasis or chronic obstructive pulmonary disease."
Schuchat said that the length of illness from EV-D68 infection would probably be about a week, which is typical for most enteroviral illnesses that don't lead to longer-term sequelae.
Within two weeks of the start of the school year, there generally is a doubling in the rate of medically attended visits for acute respiratory infection, said Temte. But EV-D68 seems a bit more aggressive than the usual virus among patients with underlying conditions.
"This will spread quickly across the country," he said. "There is little likelihood of containment as this has a wide spectrum of illness, and the primary spreaders (children) will probably be frequenting the likely venues of spread: school, churches, sporting events, etc."
Temte said droplet precautions should be in place when caring for patients who have possible EV-D68 infection -- the same precautions physicians use with any respiratory infection. This includes wearing a face mask when working closely with a patient suspected of having this viral infection.
Supportive care is really the only option for treating infected patients who do not have additional respiratory issues, said Schuchat. For patients with a history of asthma who have EV-D68 infection, physicians need to make sure asthma medication is administered to stabilize breathing.
If a patient experiences significant respiratory distress, he or she should be hospitalized with respiratory support, Temte added.
"This is a reminder of the pervasiveness and the transmissibility of respiratory viruses," he said. "Cover your cough and sneeze, wash hands frequently, and stay at home when ill."
Cain added that given the rapidly evolving outbreak of EV-D68 infection, when children come into the family physician's office with what looks like a common cold, it is important to discuss with parents the signs and symptoms of potential respiratory distress so that they are aware of when to call the office or to seek emergent care.
Testing Suspected Cases
Cain said that although Denver is currently a hotbed for EV-D68, he has not knowingly seen a case in his family medicine office. He qualified his statement, however, by explaining that his office hadn't tested any specimens for the virus because doing so requires a rarely used and expensive immunoassay test.
During the Sept. 8 CDC call, Schuchat encouraged clinicians with suspected cases to contact their state and/or local health departments about the availability of testing for EV-D68, because some offices at this level are equipped to do so. The CDC also is available to support testing as a back-up option when state health departments are unable to provide the test.
Commercial assays to test for respiratory viral panels are available, Schuchat added, but they usually can only determine whether the specimen is a rhinovirus or enterovirus and will not specify the type, such as EV-D68.