The gloomy square of the COVID-19 pandemic ensures that 2020 will fall as an infamous year in the history of human diseases.
But this dark chapter had some surprises for which we can be grateful. In a new study, researchers found that an estimated outbreak in 2020 of a mysterious paralyzing disease failed to materialize over time – and strangely enough, we actually have the coronavirus to thank for that.
The condition is called acute flaccid myelitis (AFM). This polio-like neurological disease mainly affects children, causing muscle weakness and, in some cases, permanent paralysis and even death.
For decades, cases of AFM have been very rare, but in recent years there have been larger outbreaks in the United States and elsewhere, apparently reappearing every two years.
Previous research has linked AFM to a rare virus called enterovirus D68 (EV-D68), and although it is not yet known how the virus manifests symptoms of AFM, the pair’s coincident outbreaks have led researchers to believe they are almost certainly linked. .
In the new research, a team led by the first author and modeler of infectious diseases Sang Woo Park at Princeton University followed the patterns of EV-D68 cases between 2014 and 2019, the virus showing significant rebirths in even years – 2014, 2016, and 2018 – which are thought to be attributable to climatic factors.
The suggested data for 2020 was due for another success.
“We predicted that a major EV-D68 outbreak, and therefore an AFM outbreak, would still be possible in 2020 under normal epidemiological conditions,” the researchers explain in their study.
Of course, as the world was painful to witness, the epidemiological conditions in 2020 were different than usual, and the expected combined hit of EV-D68 and AFM never came.
In the US – a country with significantly more cases of COVID-19 than any other – the combined effects of physical distancing, quarantine and isolation policies, and economic and civic closures all seemed not to diminish the spread of SARS-CoV- 2, EV-D68 as well.
“Our preliminary analysis indicates that the response to the COVID-19 pandemic may have affected the dynamics of an EV-D68 outbreak in 2020,” the authors write.
According to the researchers, there were 153 cases of AFM in 2016 and 238 cases in 2018, but only 31 cases in 2020.
Given everything the US has been through lately, here are some numbers to make you feel good about.
However, there is no time for satisfaction – especially since the unplanned year of EV-D68 could have left a larger gap than usual in population viral immunity.
“Based on the small number of [predicted] EV-D68 cases in 2019, we would expect the number of sensitive people to have increased, increasing the probability of a large outbreak, “says the team.
“If social distancing prevents the outbreak, then the susceptible risk may increase further.”
The findings are reported in Science of Translational Medicine.