Acute flaccid myelitis, or AFM, is an uncommon but serious neurologic condition whose symptoms can look similar to those of polio. AFM can be caused by enteroviruses, which are common and usually cause mild illness.
AFM affects the nervous system, specifically the area of the spinal cord called gray matter, which causes the muscles and reflexes in the body to become weak. Sudden onset of arm or leg weakness, loss of muscle tone and loss of reflexes are the most common symptoms. It can also lead to permanent paralysis.
More than 90% of AFM cases occur in young children.
The Centers for Disease Control and Prevention has been tracking AFM since 2014. Outbreak cases of AFM have occurred in the U.S. in 2014, 2016, 2018 and 2020.
The largest number of AFM cases occurred in 2018, when there were 238 confirmed cases in 42 states. In 2020, there were 32 confirmed cases out of 59 reported cases. In 2021, as of Aug. 31, there have been 15 confirmed cases of AFM in nine states out of 36 reported cases.
Despite the lower numbers this year, posts on social media are wrongly claiming that the CDC is “warning of polio-like outbreak coming in children this fall.”
The claim seems to have originated from a year-old news article written by Sputnik, a state-owned Russian news service, on Aug. 4, 2020. The story — “CDC Warns of New Outbreak of Polio-Like Illness in Children Later This Year in US” – was correctly based on an actual CDC warning for the fall of 2020.
A year later on Aug. 19, Asian News International, a wire service, mistakenly posted a version of the outdated CDC warning, crediting Sputnik for the report. Zenger News, a Texas-based wire service, ran an article a day later with the headline, “US Warns Of Polio-Like Illness Outbreak In Four Months,” adding that its story was written “[w]ith inputs from ANI.”
Zenger News deleted the outdated article from its website and “terminated its relationship with ANI after this episode,” Zenger told us in an email.
But the inaccurate story remains on the ANI website. The claim also has been shared by other social media users, and publications in Florida, Georgia and Tennessee have reposted the article, wrongly attributing the article to Zenger.
The article that ran on Zenger – and those attributed to Zenger on other websites – claimed that on Aug. 17, the CDC “alerted of an expected outbreak of the polio-like disease Acute Flaccid Myelitis (AFM) in the next four months.”
But a spokesperson for the CDC’s AFM team — which maintains an official channel for AFM information — told us in an email that while monitoring the disease “remains a priority for CDC,” the CDC “has not issued an official warning such as a [Health Alert Network] or an [Epidemic Information Exchange] alert to clinicians in 2021.”
“At this time, CDC has not received reports of an increase in suspected cases of AFM,” the spokesperson said. “In collaboration with our partners, we continue to closely monitor the situation and are prepared to respond to any increase in cases. CDC’s AFM Team continues to work with state health departments and professional medical organizations to educate clinicians about AFM in case we do see an increase in cases this year. Early recognition and hospitalization of patients suspected to have AFM is critical, as AFM can lead to respiratory failure.”
The latest CDC alert for AFM came in August 2020, when the CDC anticipated a “peak year” in AFM cases, because “the disease has peaked every two years between August and November in the United States since 2014.”
The alert — which was the basis for the Sputnik story a year ago — also questioned how protective measures put in place for the COVID-19 pandemic would affect the circulation of viruses that can cause AFM, stating, “AFM cases may be fewer than expected or the outbreak may be delayed” if “social distancing measures decrease circulation of enteroviruses.”
In 2018, Robert R. Redfield, then director of the CDC, ordered the AFM Task Force to assist an investigation into the origin, treatments and outcomes of the disease.
The task force is working to learn why a few people develop AFM after having a virus. The CDC says since it doesn’t know what triggers AFM, “there is no specific action to take to prevent AFM.”
However, the CDC says, you can take steps to prevent getting sick from a virus by:
- Washing your hands often with soap and water for at least 20 seconds.
- Avoiding touching your face with unwashed hands.
- Avoiding close contact with people who are sick.
There is no specific treatment for AFM, but a clinician who specializes in diseases such as AFM may recommend certain interventions on a case-by-case basis.
Although the symptoms of polio and AFM look similar, none of the AFM cases in the U.S. have been caused by the poliovirus.
Poliomyelitis, or polio, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis.
The first polio vaccine was available in the U.S. in 1955. Because of widespread vaccinations, the U.S. has been “polio-free since 1979,” according to the CDC.