CDC warns of possible fall outbreak of dangerous, life-threatening illness that can paralyze children
There could be an outbreak of a dangerous and potentially life-threatening illness this year in the US that affects mostly children and is likely to be seen with other flu and infectious diseases, the US Centers for Disease Control and Prevention (CDC) has warned. The agency anticipates that 2020 will be another peak year for cases of acute flaccid myelitis (AFM), an uncommon but serious neurologic condition that impacts children mostly.
The disease has peaked every two years between August and November in the US since 2014. The CDC began surveillance for AFM in the US in 2014, when the nation experienced the first peak of 120 cases, followed by peaks in 2016 (153 cases) and 2018 (238). Enteroviruses, particularly enterovirus-D68 (EV-D68), are likely responsible for these peaks in cases. “EV-D68 is the most common virus identified among specimens collected from patients with AFM. However, other viruses can cause AFM and may also be contributing to the biennial peaks. Although AFM symptoms resemble those of polio, all specimens have tested negative for poliovirus. There is currently no specific test, proven treatment or prevention method for AFM,” says the CDC.
CDC Director Dr Robert Redfield said his agency is watching to see how the Covid-19 pandemic and social distancing measures will affect the expected circulation of the viruses that can cause AFM. “We do not know how the Covid-19 pandemic and the social distancing measures may affect the circulation of enteroviruses or if Covid-19 will impact the healthcare system’s ability to promptly recognize and respond to AFM. AFM cases may be fewer this year or the outbreak delayed. But we know this, that AFM is a public health priority. Together with other public health agencies, clinicians and partners, including parent advocates, CDC is continuing to advance our knowledge of AFM, discover how best to prevent and to treat and improve patient outcomes,” he said.
AFM affects the nervous system, specifically the area of the spinal cord called the gray matter. Most patients develop sudden arm or leg weakness. Timing is critical for AFM and delays in AFM recognition and care can put patients at risk. According to the CDC, this condition is a medical emergency and patients should seek immediate medical care, even in areas with high Covid-19 activity. They explain that AFM can progress rapidly over the course of hours or days, leading to permanent paralysis and/or the life-threatening complication of respiratory failure in previously healthy patients, so delays in care can be serious.
The agency has released a new CDC Vital Signs report to alert healthcare providers to a possible outbreak this year. The report reveals a delay in care for some patients in 2018: 35% of patients were not hospitalized until two or more days after limb weakness.
“This vital signs report is intended to provide an anticipatory alert as we prepare for a possible outbreak this year. Parents and doctors should suspect AFM in patients with sudden limb weakness, especially during August through November. Recent respiratory illness or fever and the presence of neck or back pain or any neurologic symptom should heighten their concern,” say experts.
The vital signs report provides a more detailed view of clinical characteristics of AFM, which can help clinicians better recognize signs and symptoms, evaluate patients, and provide optimal medical management and rehabilitation. It shows that the third and largest peak of AFM occurred in 2018, with 238 cases in 42 states. The analysis reveals that in 2018, 76% sought medical care within one day, 64% presented to the emergency department. While 98% of patients with AFM were hospitalized, 54% of patients were admitted to an intensive care unit. One in four hospitalized patients needed mechanical ventilation to help them breathe.
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Most cases were in children (94%) and most patients (86%) had AFM onset from August through November. Most patients had a fever and/or respiratory illness approximately six days before limb weakness onset. Other common early symptoms were difficulty walking, neck or back pain, fever, and limb pain. While most patients were hospitalized within one day of limb weakness onset, 25% were not hospitalized until two to three days after, and 10% were not hospitalized until four or more days after their limb weakness began. This could indicate delays in recognition and presents an opportunity for improvement, says the CDC.
“One reason we wanted to do this report as vital signs now is that the virus causing this condition enterovirus d68 tends to come in two-year cycles. This means it will be circulating at the same time as flu and other infectious diseases including Covid-19 and could be another outbreak for clinicians, parents, and children to deal with. With this vital signs (report), the CDC presents a more detailed view of the cases that happened two years ago in the 2018 outbreak. This has allowed us to learn more about AFM, better recognize the signs and symptoms, and respond faster,” said Dr Redfield.
The CDC says that clinicians must remain vigilant for AFM and promptly evaluate patients even as frontline healthcare workers, family physicians, and other medical professionals continue to work under the constraints of the ongoing Covid-19 pandemic. “While phone and telemedicine can be used for initial evaluations, clinicians should not delay in hospitalizing patients when they suspect AFM. Pediatricians and frontline providers in emergency departments and urgent care centers should be prepared to quickly recognize symptoms of AFM and immediately hospitalize patients. When healthcare providers recognize symptoms as soon as possible, there is a better chance of detecting the cause of AFM, which might help predict the outcome. Other laboratory tests and an MRI of the brain and spinal cord can distinguish AFM from other conditions with limb weakness,” says the CDC.