With a report showing that 2018 yielded the highest case numbers seen so far of a paralyzing condition largely among children who had been sick with a respiratory virus, U.S. health officials today urged physicians to be ready to quickly test for and report acute flaccid myelitis as the season in which is its likeliest to be seen begins.
While muscle weakness and paralysis can be a complication of illnesses that include vector-borne diseases, as well as some respiratory and intestinal intestinal infections, the condition commonly referred to as AFM has been tracked as a specific illness since the first recognized outbreak of the condition across the United States in 2014. That year, with diagnostic imaging providing confirmation of the condition of 120 patients, the agency opened a central database collecting information on the cases. Since then, officials from the U.S. Centers for Disease Control and Prevention noted today, outbreaks have occurred every two years, with lower numbers of cases in alternate, odd-number years. In total since 2014 then 570 confirmed cases have been reported, with the most recent outbreak in 2018 showing the highest numbers — 233 confirmed cases — as well as 26 probable, but unconfirmed cases, across 41 states.
CDC officials highlighted those numbers, in a Vital Signs report released today, as they emphasized needs for awareness of the condition, and rapid reporting of cases even in a supposed off — odd-numbered — year, and particularly as the late summer and early fall months in which the highest numbers have been seen begin.
While awareness of the AFM has increased in the last year, with patients showing indications of the condition hospitalized, on average, within a day, and undergoing an MRI to confirm AFM, on average, within two days, the lag in reporting time for confirmed cases ran from 18 to 36 days, CDC Division of Viral Diseases Deputy Director Dr. Tom Clark said. That lag, he added, has hampered efforts to better understand the illness, as well as the quest for ways to prevent and treat it.
While data have indicated that AFM could be linked to a severe respiratory virus identified as enterovirus D68, or EV-D68 identified in affected patients, among unanswered questions are why some children who have been sick with the virus then experience AFM while the vast majority do not. While five years old is the average age for those who do get AFM, and from 93 to 95 percent of those affected are children, a handful of adults have been affected, Dr. Clark said.
In addition, while early and “aggressive” physical therapy and rehabilitation have been linked to improved recovery of strength and ability, follow-up on cases has been insufficient to predict long-term outcomes.
Knowledge of the illness remains in early stages. While the condition has been reported in most states across the country, CDC Principal Deputy Director Dr. Anne Schuchat noted, “the vast majority of pediatricians” have never seen a case.
The little that is known about AFM also is subject to change, she said. “While the alternate year pattern is intriguing,” she added, “we can’t assume it will hold.”