Two years after launching surveillance of acute flaccid myelitis, and amid climbing cases, CDC continues to seek cause, and notes gaps in knowledge of long term outcomes
With three times the number of cases of a paralyzing illness, mostly affecting children, from the start of 2018 to the beginning of November than during that period during the preceding year, the U.S. Centers for Disease Control and Prevention is stepping up efforts to better track, understand and treat the condition.
The condition, acute flaccid myelitis, or AFM, is characterized by sudden loss of mobility in at least one limb, usually following symptoms of a viral illness, and is confirmed by diagnostic imaging showing lesions in the spinal cord. Some of those affected recover full mobility, according to the CDC, but more than half don’t.
CDC began to track cases confirmed by diagnostic imaging in 2014, when 120 patients were reported, an apparent sharp increase in numbers of patients with a condition that had been previously noted, but not reported to a central database. The peak coincided with the nationwide spread of a severe respiratory virus identified as enterovirus D68, or EV-D68, and was suspected to be a possible effect of the virus. By contrast the next year only 22 AFM cases were reported. When cases next rose sharply — to 149 — in 2016, however, cases of severe respiratory illnesses had not. On November 2, according to the CDC Morbidity and Mortality Weekly Report to be released Friday, 106 cases had been investigated, and 80 confirmed. By Tuesday, 90 cases had been confirmed. While patients ranged from 7-months-old to 32-years-old, most patients have been from 2-to-8-years-old, with a median age of 4.
This is what the CDC does know. Still unknown, however is whether one of the viruses that have been identified in AFM patients causes the condition, whether a virus yet to be identified does, or whether an interaction of patients’ immune responses and a virus sets off the condition. Also unknown are long term after-effects, including whether patients confirmed with AFM died as a result of the condition in the years that have followed.
The CDC is seeking answers through a multi-disciplinary task force of experts, has increased funding for state health departments to ensure that physicians identify and report cases, and is working with health departments to cross reference confirmed AFM cases with death registries. This week the agency will release updated recommendations for clinicians treating patients with symptoms, or confirmed cases of AFM. And, working with the CDC,to track patients, the Council of State and Territorial Epidemiologists, released a statement reminding states to report all AFM cases to the CDC.