PRINCETON, N.J. — One year into the coronavirus pandemic, it appears social distancing measures have successfully stopped a rare virus — but not the one you think. Researchers at Princeton University say that COVID safety protocols not only helped to curb the spread of coronavirus in 2020, they also prevented an outbreak of the polio-like illness acute flaccid myelitis.
AFM is rare neurological condition which mainly affects children. According to the Centers for Disease Control and Prevention, the illness has infected more than 600 patients since 2014. It can cause fever, respiratory problems, and severe weakness in the arms and legs.
Unlike polio, which has a vaccine and has been virtually extinct in the U.S. since 1979, AFM does not have a specific treatment. The virus typically starts to appear in the summer and fall, with some severe cases even leading to lifelong paralysis or death.
Missing the AFM window in 2020?
Study authors say the condition first appeared in the U.S. in 2012 and outbreaks seem to follow every two years. That had health officials fearing another AFM spike in 2020 however, COVID-19 drastically altered life for the entire world.
According to epidemiological surveillance tools, the Princeton team says social distancing likely halted last year’s outbreak. Previous studies discovered that the illness has a connection to a group of respiratory illnesses called enterovirus D68 (EV-D68). Through pandemic safety mandates which attempt to limit the spread of the SARS-CoV-2 virus, the study finds other viruses also had fewer opportunities to infect the public.
The CDC notes that 90 percent of EV-D68 infections occur in young children. The typical respiratory symptoms include a runny nose, cough, and sneezing.
“Though currently uncommon, this syndrome has been increasing in frequency with each successive outbreak since 2014, making it critically important to better understand the patterns and drivers behind it,” says first author Sang Woo Park, a Ph.D. student in Princeton’s Department of Ecology & Evolutionary Biology in a university release.
“Our results underline the importance of epidemic surveillance for projecting future impact of infectious diseases,” adds study author Bryan Grenfell.
Curbing the spread of polio-like infections
Grenfell and Park partnered with fellow researchers in the U.S. and United Kingdom to examine the infection patterns of EV-D68. To confirm its connection to AFM, researchers analyzed data from BioFire® Syndromic Trends (Trend) — a cloud-based network providing nearly real-time updates on de-identified pathogens.
The results show EV-D68 outbreaks also occur every two years in many states, alongside spikes in cases of AFM. Not all states show this pattern however, like Ohio, which study authors say seems to have a more “intricate” pattern.
The study reveals there were only 31 cases of acute flaccid myelitis in 2020. It’s a major reversal compared to the 153 cases in 2016 and 238 cases in 2018 — leading the team to believe social distancing likely kept many children from getting EV-D68 last year.
“Fortunately, we saw very little EV-D68 circulation in 2020 and few cases of AFM compared to what was expected, but that makes it even more important to be as prepared as possible for what could be coming in 2021 or beyond,” Park concludes.
The study appears in the journal Science Translational Medicine.