US wastewater samples are showing an alarming increase in a respiratory virus that has been linked to polio-like symptoms.
Enterovirus D68 (EV-D68) can lead to acute flaccid myelitis (AFM), which can cause weakness or paralysis, typically in kids.
“We are detecting EV-D68 nucleic acids in wastewater across the country now, and the levels are increasing,” Alexandria Boehm — program director of WastewaterSCAN, a nonprofit monitoring network and a professor of civil and environmental engineering at Stanford University — told NBC News this week.
EV-D68 is quite common, with most people over 5 showing evidence of prior infection. The virus is transmitted via respiratory secretions like saliva or nasal mucus or by touching a contaminated surface and the mouth or nose.
Infections peak in summer and fall — infants, children and teenagers, particularly those with asthma, are most vulnerable.
EV-D68 symptoms are typically mild and include a runny nose, sneezing, coughing, malaise and body aches. In severe cases, wheezing and difficulty breathing have been reported.
Most concerningly, EV-D68 is believed to play a part in the development of AFM.
A rare but serious neurological condition, AFM symptoms include muscle weakness, slurred speech, difficulty swallowing, facial drooping, and, in some cases, paralysis. In these cases, AFM begins with cold-like symptoms and, within a week, progresses to paralysis.
While intensive physical therapy can be helpful, there is no specific treatment or cure, and many patients are left with serious, life-altering disabilities.
Similar to polio, AFM only causes paralysis in some people.
While these neurological complications are rare, outbreaks of severe EV-D68 and AFM follow a peculiar pattern.
Since the US Centers for Disease Control and Prevention (CDC) began monitoring the condition in 2014, AFM has flared up in waves, spiking in an every-other-year pattern — infecting far more people in 2016 and 2018 than in 2015 and 2017.
The every-other-year pattern halted in 2020 thanks to COVID-19 shutdowns. EV-D68 resumed its surge in 2022 as lockdowns lifted, but curiously, that uptick was not associated with a rise in AFM cases.
Dr. Kevin Messacar, an infectious disease specialist at Children’s Hospital Colorado, told NBC News, “We saw the virus that was previously driving the AFM cases, but we didn’t see the AFM cases associated with it.”
The CDC has confirmed 13 AFM cases so far this year.
Viruses are notoriously hard to predict, and experts believe EV-D68 may have evolved or mutated or more people have been exposed to it and developed immunity.
There is no vaccine for EV-D68 — medical professionals recommend protecting yourself by thoroughly washing your hands, avoiding close contact with people who are sick, cleaning and disinfecting surfaces and managing asthma if you have it.
Meanwhile, Dr. Buddy Creech, a pediatric infectious disease physician at Vanderbilt University Medical Center in Nashville, is studying a monoclonal antibody he hopes could stop EV-D68 before it becomes AMF.
“In mouse studies, it prevented infection that would lead to AFM,” Creech told NBC News. Still, it could take years before the treatment becomes available.
