Faster Enterovirus Tests Spike Confirmed Cases

A perceived increase in confirmed cases of enterovirus D68 (EV-D68) may be attributable to a faster lab test recently put in place by the US Centers for Disease Control and Prevention (CDC).

The ongoing outbreak of EV-D68 has mainly affected children, with the most severe impact seen among those with asthma. As of October 27, 2014, the severe respiratory illness has infected 1035 people across 47 states and the District of Columbia.

With a backlog of specimens as far back as mid-September awaiting testing, the CDC believes the new tests will provide researchers with a more accurate picture of the full scope of the outbreak.

“CDC has received substantially more specimens for enterovirus lab testing than usual this year, due to the large outbreak of EV-D68 and related hospitalizations,” said Anne Schuchat, MD, director of CDC’s National Center for Immunization and Respiratory Diseases, in a press release. “When rare or uncommon viruses suddenly begin causing severe illness, CDC works quickly to develop diagnostic tests to enhance our response and investigations. This new lab test will reduce what would normally take several weeks to get results to a few days.”

Since the dawn of the EV-D68 outbreak in August, the CDC has tested 1163 specimens from 45 states, with approximately half of them testing positive for EV-D68 through October 10, 2014. Roughly one-third of those specimens tested positive for a rhinovirus or an enterovirus other than EV-D68.

The new process, which was put in place in mid-October, sped up testing from about 40 specimens per day to up to 180 per day, which allowed the CDC to report results for new specimens within a few days after receiving them.

“The new lab test will allow us to process the approximately 1000 remaining specimens at a much faster rate,” the CDC said in a press release.

Thus far, 2 fatalities have been attributed to EV-D68. Four other children who died tested positive for the virus, though it remains unknown what role, if any, EV-D68 played in their deaths.

On October 10, 2014, 21-month-old Michigan child Madeline Reid died due to complications related to EV-D68 and a stomach virus. New Jersey child Eli Waller, 4, died of the virus on September 4, 2014, though he showed no symptoms prior to his death.

Despite the expected increase in reported cases, the CDC said the spread of the outbreak may be starting to subside. As with other enteroviruses, EV-D68 infections are expected to decline markedly by the late fall.

“The real-time lab results combined with data on hospital admissions will help us understand when and where the EV-D68 outbreak is ending,” the CDC said. “CDC has received informal reports from some hospitals and states who are seeing signs of decreasing EV-D68 infections. CDC is gathering more information from states and assessing whether this represents a national trend.”