Increase in Acute Flaccid Myelitis- United States, 2018

  • Acute flaccid myelitis (AFM) is a rare, but serious paralytic illness, primarily in children, with no proven treatments or methods of prevention. Increases in AFM cases have occurred every other year since 2014, with most cases occurring in late summer and early fall. In 2018, CDC confirmed 228 cases of AFM in 41 states.
  • We think viruses likely play a role in AFM. Almost all patients with AFM had a mild respiratory illness or fever consistent with a viral infection before they developed AFM. About half of patients with AFM had evidence of a virus, usually from a respiratory specimen. However, very few patients with AFM had detectable virus in their spinal fluid which is where we would expect to find a pathogen causing the paralysis seen with AFM. CDC has established an AFM task force of national experts in multiple disciplines to help us further understand AFM, including potential causes and risk factors.
  • Parents and caregivers should seek medical care right away for a child who develops sudden limb weakness. Clinicians should be vigilant for acute flaccid limb weakness and immediately report these cases to their health departments.
Quote from the Disease Detective

“Enteroviruses have been implicated in AFM but these infections are common, especially in children, and most people recover. We don’t know why a small number of people develop AFM. The more we know about AFM risk factors, potential causes, and how the disease develops, the better we will be able to develop treatment and prevention strategies.”

– Susannah McKay, PhD, MPH, EIS Class of 2017

EIS officer Susannah McKay, PhD, MPH, works at her desk[JPG - 1 MB]

EIS officer Susannah McKay, PhD, MPH, works at her desk in Atlanta, GA

Contact Information

CDC Media Relations
(404) 639-3286

Conference Information
Susannah McKay


Susannah McKay, PhD, MPH,
EIS Class of 2017
CDC National Center for Immunization and Respiratory Diseases
Division of Viral Diseases

Education: PhD UC San Diego
MPH UC Berkeley
BA Rice University

Work Experience: Epidemiologist: California Department of Public Health (Richmond)
Postdoctoral Fellow: UC Berkeley, Department of Molecular and Cellular Biology Peace Corps Volunteer, Republic of Vanuatu

Volunteer Experience: Science Outreach Co-chair, Association for Women in Science (AWIS), La Jolla, California
NSF Peer advocate for GUIDE (Graduates United in the Interests of Diversity and Equity), UC San Diego
Stars Summer Program Mentor, UC LEADS (Leadership Excellence through Advanced DegreeS), UC San Diego, California