The Centers for Disease Control and Prevention warns of the spread of a common childhood virus that can cause muscle weakness or paralysis in rare cases.
The CDC issued an alert Friday about enterovirus D68, which most commonly causes respiratory disease in children, with symptoms that are often mild but can become severe. The family of enteroviruses is vast and poliomyelitis is one of them; EV-D68 and poliovirus can invade the nervous system and cause muscle weakness.
Sometimes EV-D68 can lead to a condition called acute flaccid myelitis, or AFM, which is characterized by inflammation of the neck region of the spinal cord. Some people with MFA have difficulty moving their arms, while others experience weakness in all four extremities. During a large outbreak in the United States in 2014, approximately 10% of people with EV-D68 continued to develop the AFM.
Full recovery from AFM is rare, and although most patients improve to some degree, the process is often difficult and requires rehabilitation.
This year, the CDC has identified more cases of EV-D68 in children with severe respiratory illnesses than in the past three years combined. There were 84 such cases between March and August 4. By comparison, the CDC identified six such cases in 2019, 30 in 2020 and 16 in 2021.
However, these numbers are likely underestimated because not everyone with respiratory symptoms is tested for EV-D68.
As of September 2, 13 cases of AFM have been confirmed this year in the United States. The CDC said it is investigating 20 additional cases.
In the past, the CDC has recorded spikes in EV-D68 cases every two years. Before the coronavirus pandemic, that was 2014, 2016, and 2018. Dr. Benjamin Greenberg, a neurologist at UT Southwestern’s O’Donnell Brain Institute who treats patients at Children’s Health in Dallas, said the pattern appears very probably because children develop immunity to the enterovirus as it spreads, resulting in “off” years with higher population immunity. Once immunity wanes, the number of cases increases again.
Dr Sarah Hopkins, a pediatric neurologist at Children’s Hospital of Philadelphia, said: ‘We really thought this was going to happen in 2020 because we had the last spike in 2018. But then with mask-wearing and the social distancing and all those things that limit the spread of a respiratory virus, we haven’t had the expected spike. »
Greenberg said cases would most likely rise again this year because children are back in school and other public spaces.
“We now have a group of children who have never seen the virus because they weren’t exposed at school. So we think the population at risk is larger than in 2020,” he said. -he declares.
The seven pediatric medical centers affiliated with the CDC’s new vaccine monitoring network – in Nashville, Tennessee; Houston; Kansas City, Missouri; Cincinnati; Seattle; Pittsburgh; and Rochester, New York – detected cases of EV-D68 this year. The CDC said it has also received reports of an increase in serious respiratory illnesses among children in Minnesota, Arizona and Utah, raising concerns that some of these infections may also be EV-D68.
The agency is asking health care providers to be on the lookout for cases of EV-D68 in children and to strongly consider AFM as a potential diagnosis for patients with limb weakness.
But it can be difficult to distinguish the symptoms of EV-D68 from those of respiratory viruses, Greenberg said. Like the common cold, EV-D68 can cause a runny nose, sneezing, muscle aches or pains. Children who need to be hospitalized tend to have cough, shortness of breath, wheezing and, in about half of cases, fever.
AFM could also be mistaken for a severe case of poliomyelitis, which results in a similar condition called acute flaccid paralysis. The United States recorded a case of poliomyelitis in July, and they detected the virus in sewage from several New York counties.
Greenberg said polio detection calls for “increased awareness of health care providers so they can send the appropriate tests.”
“It’s really important to know which virus causes paralysis in patients,” he added.
What is enterovirus D68?
Scientists first identified enterovirus D68 in 1962. At the time, the virus didn’t circulate widely and it caused milder disease than it does today, Greenberg said.
The CDC has started doing more reviews for EV-D68 in 2014, when scientists noticed a change in the behavior of the virus.
“The virus changed over time to acquire the ability to kill neurons to damage the spinal cord,” Greenberg said.
The total number of cases this year is lower than that of 2018. From July to November of that year, the United States recorded 382 cases of EV-D68 in children with acute respiratory illness.
“It doesn’t look like things have suddenly gotten worse,” said Dr. Keith Van Haren, assistant professor of neurology at Stanford University, adding, “Hopefully at least there won’t be a raz -tide of new neurological cases at the moment.”
Most EV-D68 cases occur at this time of year, August through November, he said.
If past years are any indication, Greenberg said, “in the coming weeks we’ll see an obvious increase in the number of AFM cases unless the virus has improved.”
Van Haren said it takes one to four weeks for an EV-D68 case to progress to AFM, although the condition can take a variety of forms.
“Findings range from mild shoulder weakness to difficulty moving all extremities and sometimes even requiring prolonged respiratory support,” Hopkins said.
Van Haren said patients usually begin to recover from their respiratory symptoms before neurological symptoms set in.
“When neurological symptoms start, they can start quite suddenly. They can peak within hours in a way that can be a little surprising,” he said.
Children who develop AFM usually need to be hospitalized. For reasons scientists haven’t fully understood, the children most at risk are those with a history of asthma.
There is no specific treatment for AFM. Doctors may provide antibody therapy to improve a patient’s immune response or give supportive care, such as ventilators or fluids.
According to experts, the best way to protect yourself or your children from EV-D68 is to be diligent about hand washing and wearing a mask in public.