Thirty-two states now have confirmed cases of Enterovirus-D68 (EV-D68). But that is not cause for alarm, according to the US Centers for Disease Control and Prevention (CDC). The new numbers are actually older cases. The reporting lag is because the CDC's testing laboratories have been overwhelmed with requests to test specimens.
Thirty-two states now have confirmed cases of Enterovirus-D68 (EV-D68). But that is not cause for alarm, according to the US Centers for Disease Control and Prevention (CDC). The new numbers are actually older cases. The reporting lag is because the CDC’s testing laboratories have been overwhelmed with requests to test specimens.
Also, it is enterovirus season, and outbreaks of respiratory illness are to be expected. The increase in cases, and with more likely to come, “will not necessarily reflect changes in real time, or mean that the situation is getting worse,” the agency wrote in a Sept. 24 update on EV-D68.
“The testing is complex and slower and can only be done by the CDC and a small number of state public health laboratories,” the CDC said. So far only one of 220 confirmed cases was an adult patient.
Christopher Carroll, MD, an asthma specialist at Connecticut Children’s Medical Center in Hartford, CT, last week predicted that the epidemic was waning, at least in his area. “We may have plateaued,” said Carroll.
While children are still being admitted for respiratory problems, Carroll said, “Now it’s more a mix of symptoms, not those of classic enterovirus.” Though he could not say for certain the outbreak has peaked, he noted “Things are not continuing to get worse.”
Carroll said the CDC asked the hospital to stop sending specimens because its lab had a growing backlog. “They said don’t send any more samples; they are overwhelmed,” Carroll said.
Meanwhile, as EV-D68 continues to make headlines and parents may pressure family doctors to tell them whether a sick child has the virus, making that diagnosis in a primary care setting is just not practical, Carroll said.
The role of primary care physicians in fighting the outbreak is simply to continue to treat patients’ symptoms, he said. “It makes no sense for a primary care physician to provide testing,” Carroll said.
Confirming EV-D68 is of interest mostly from the standpoint of epidemiology, he said. The virus is not a “superbug” and not hard to treat in a hospital setting. There are no anti-virals effective in treating it or vaccines to prevent it.
The tests require a PCR laboratory, a very expensive and specialized testing facility. In New York, where more than a dozen EV-D68 cases have been confirmed, the tests were done in-state. NY is one of the few states that has such a facility. It is located at the Wadsworth Center in Albany, NY, run by the NY State Department of Health (NYSDOH).
The first stage of testing rules out rhinovirus and determines that there is sufficient enterovirus (EV) to test, a NYSDOH spokesman explained. The next test is “nested conventional RT-PCR, followed by bi-directional dideoxy sequencing,” he said. Once the virus is sequenced, it is edited and compared to an international online database to see which of the more than 100 types of EV is the best match. “It can take at least 3 days and can take 5 or more,” he said.
That is why most states are relying on the CDC to do the tests, even though EV-D68 reporting is not mandatory. Since the virus can also cause a mild cold, it is also likely that most cases are not being reported.