CDC urges doctors to rapidly recognize and report acute flaccid myelitis cases

Jul 10, 2019

As the late summer/early fall “season” for acute flaccid myelitis nears, CDC is calling on medical professionals to quickly recognize acute flaccid myelitis symptoms and report all suspected cases to their health department. Early recognition and reporting are critical for providing patients with appropriate care and rehabilitation, and better understanding acute flaccid myelitis, according to a new Vital Signs report.

The majority of acute flaccid myelitis patients are previously healthy children who had respiratory symptoms or fever consistent with a viral infection less than a week before they experienced limb weakness. Since acute flaccid myelitis can progress quickly from limb weakness to respiratory failure requiring urgent medical intervention, rapidly identifying symptoms and hospitalizing patients are important.

“CDC continues to pursue the definitive cause and mechanisms that define this disease and we sincerely appreciate the important contributions of the Acute Flaccid Myelitis Task Force in helping us get closer to critical answers,” said CDC Director Robert Redfield MD. “I urge physicians to look for symptoms and report suspected cases so that we can accelerate efforts to address this serious illness.”

Late summer and early fall is AFM “season”

CDC began tracking acute flaccid myelitis in 2014, when the first outbreak of 120 cases occurred. Another outbreak occurred in 2016 with 149 cases, and again with 233 patients in 41 states in 2018– the largest outbreak so far. Acute flaccid myelitis cases have so far followed a seasonal and biennial pattern, spiking between August and October every other year.

In an analysis of cases confirmed in 2018, CDC detected enteroviruses and rhinoviruses in nearly half of respiratory and stool specimens. Of the 74 cases with a cerebral spinal fluid specimen, only two were positive for enteroviruses (EV-A71 and EV-D68). CDC and other scientists continue to investigate how enteroviruses, including EV-D68, might initiate acute flaccid myelitis. All specimens tested negative for poliovirus, a related enterovirus that can cause acute flaccid myelitis.

“Our thorough investigation of acute flaccid myelitis will help lead to more answers about this severe disease,” said Tom Clark MD MPH, deputy director, Division of Viral Diseases. “We are monitoring acute flaccid myelitis trends and the clinical presentation, conducting research to identify possible risk factors, using advanced lab testing and research to understand how viral infections may lead to acute flaccid myelitis, and tracking long-term outcomes of acute flaccid myelitis patients.”

CDC, with experts from the National Institutes of Health, academia, health departments, and parent advocacy groups, is committed to increasing awareness of acute flaccid myelitis, and moving national priorities forward to advance our understanding of acute flaccid myelitis and its prevention, treatment, and outcomes.

To read more about the 2018 nationwide outbreak of acute flaccid myelitis in the United States and the entire Vital Signs report, visit

Source: News Release
CDC Newsroom
June 27, 2019