The tally of enterovirus D68 (EV-D68) cases in US children jumped to 443 today, up 166 since Sep 26, federal health officials reported, as an investigation of nine neurologic illnesses in Colorado that may be linked to the virus continued.
The Centers for Disease Control and Prevention (CDC) reported today that confirmed cases number 443 in 40 states, up from 277 cases in the same number of states 3 days ago. All but 1 of the cases are in children.
The contagious respiratory virus had been fairly rare in the United States until clusters of cases surfaced in Chicago and Kansas City, Mo., in August. It causes cold-like symptoms but can lead to serious breathing difficulty, especially in children who have asthma, the CDC says. Infants, children, and teenagers are most at risk for getting sick.
The only states that have not yet had any confirmed cases in the current outbreak, according to a CDC map, are Alaska, Hawaii, Oregon, Nevada, Arizona, Tennessee, Florida, Vermont, New Hampshire, and Maine. Several other states have suspected cases, according to media reports.
Testing for the virus is complex and slow, and only the CDC and a few state health labs can do it, the CDC says.
No deaths have been reported in the outbreak, but a Sep 26 ABC News story said New Jersey authorities were investigating whether the virus contributed to the recent death of a 4-year-old boy who had a respiratory illness. The story gave no other details about his case.
Colorado investigation
On Sep 26 the CDC announced that it was working with Colorado officials to investigate nine cases of acute neurologic illness involving limb weakness in children, four of whom tested positive for EV-D68. The agency reported the cases in a Health Alert Network (HAN) advisory.
The CDC said most of the sick children were from the Denver area, and an ABC News report today said all nine case-patients were at Children's Hospital Colorado in Denver.
Disease signs included "focal limb weakness" and "non-enhancing lesions" in the gray matter of the spinal cord, revealed by magnetic resonance imaging (MRI), according to the HAN advisory. Some of the children also had acute cranial nerve dysfunction with non-enhancing brainstem lesions on MRI, but none had altered mental status or seizures.
Most of the children reported a febrile respiratory illness in the 2 weeks before the neurologic symptoms appeared, the CDC said. Analysis of the cerebrospinal fluid (CSF) showed increased cell counts, suggesting inflammation or infection.
"Nasopharyngeal specimens were positive for rhinovirus/enterovirus in six out of eight patients that were tested," the notice said. "Of the six positive specimens, four were typed as EV-D68, and the other two are pending typing results." It said no viruses were found in testing of CSF samples, but other samples were still being tested.
The CDC said 8 of the 9 children are up to date on polio vaccinations and that epidemiologic and lab investigations were continuing. A CDC official told CIDRAP News today that there was no new information about the investigation.
The ABC News story said doctors have not confirmed a link between the respiratory infections and neurologic problems and that it could take a week to get conclusive test results.
Parallels to California cases
The Colorado cases show apparent parallels to five cases of polio-like illness that were retrospectively reported in February in California children. Two of those children tested positive for EV-D68, but no cause of the illness was found in the other three, the American Academy of Neurology (AAN) reported at the time.
The five children had paralysis of one or more limbs, and three of them had a respiratory illness before the paralysis began. The children's conditions did not improve with treatment, and they still had poor limb function after 6 months, the AAN reported.
See also:
Sep 26 CDC HAN advisory
CDC information on current outbreak
CDC list of states with confirmed cases
Sep 29 ABC News story on Colorado cases
Sep 26 ABC News story on New Jersey death
Feb 24 CIDRAP News story on five California cases
Related Feb 23 AAN press release
