CDC officials on Tuesday said they have been unable to determine the cause of a recent increase in cases of the rare polio-like disease acute flaccid myelitis (AFM), causing frustration and concern.
What is AFM?
According to CDC, AFM mainly affects children. The disease targets the spinal cord and can lead to muscle weakness and paralysis. Other symptoms of the disease include difficulty swallowing and slurred speech. In some rare cases, the disease can lead to extremity pain, respiratory failure, and sometimes death.
CDC began tracking cases of AFM in 2014, when an increase in cases first occurred. Disease investigators have attributed the 2014 nationwide uptick in AFM cases to an outbreak of Enterovirus D 68. The virus is related to the rhinovirus, which is responsible for the common cold, and causes symptoms similar to a cold, including runny nose and coughing. But those symptoms can rapidly escalate into more serious symptoms, such as wheezing, low blood oxygen, and difficulty breathing.
Marc Patterson, a pediatric neurologist at the Mayo Clinic, said the Enterovirus also can invade the nervous system of some patients—possibly due to genetic predispositions—and result in conditions such as AFM.
Janette Nesheiwat, a family physician, said the disease "starts off with a cold, cough, runny nose, congestion, and then before you know it, you have weakness and paralysis of your arms and your legs."
Patterson said there is no vaccine against enteroviruses and treatment options are limited. Doctors might prescribe physical therapy or surgery to help repair nerves, Patterson said. Other treatment options include immunoglobulin and corticosteroids, but there is no evidence indicating these therapies effectively treat AFM, according to NIH.
Some patients fully recover from the disease while others can suffer lasting neurological damage.
Recent uptick in AFM cases
Overall, there have been 386 known cases of AFM in the United States, according to Nancy Messonnier, director of CDC's National Center for Immunization and Respiratory Diseases. Messonnier said there are fewer than one-in-one million cases of AFM in the United States each year, and CDC is aware of only one AFM-related death that occurred in the country in 2017.
According to CDC, there have been 127 cases of AFM reported in the United States so far in 2018. Sixty-two cases from 22 states have been confirmed, and the remaining 65 cases are being investigated. States are not required to report information on AFM cases to CDC, but have voluntarily provided the agency with the data, according to "To Your Health."
Messonnier said more than 90% of the AFM cases in 2018 involved patients ages 18 or younger. She said the average age of patients with confirmed cases of AFM in 2018 was four years. Messonnier noted many of the patients with AFM developed symptoms of the illness in August and September.
Meissonier said current data on AFM cases show 2018 is on track to be a severe year for AFM cases—similar to 2014 and 2016, when dozens of AFM cases occurred in late summer and early fall. However, she cautioned that it is too early to tell whether there will be more cases in 2018 than in previous years.
CDC says it's not sure what's causing the recent uptick
CDC investigators have determined a few individuals developed AFM from an infection with a type of virus that causes a severe respiratory illness, but for the majority of cases investigators have not been able to find a cause.
"There is a lot we don't know about AFM, and I'm frustrated that despite all of our efforts, we haven't been able to identify the cause of this mystery illness," Messonnier said.
Messonnier said CDC investigators have examined whether environment toxins, polio, the West Nile virus, vaccinations, and other viruses found in patients have played a role in the increase in AFM cases, but so far have not found an association between those factors and the sudden surge.
As a result, CDC is unaware of who might be at a higher risk of developing AFM or why an individual might be at a higher risk. Messonnier noted the AFM cases do not appear to be clustered in any particular geographic region of the United States. She added that no other country has reported a similar pattern in AFM cases, with the number of cases increasing every two years.
CDC officials said, because it has been unable to determine the cause of the surge in AFM cases, the agency is changing how it counts AFM cases. CDC officials said the agency will begin to count confirmed and unconfirmed cases to provide a better estimate of increases in AFM cases in the coming months.
Meissonier said parents and clinicians should remember the condition is rare, but noted AFM is a "pretty dramatic disease." To protect children against AFM, parents can take preventative measures, such as ensuring their children wash their hands, use insect repellant, and are up to date on recommended vaccinations, she said.
Meissonier added that health officials are seeking to raise awareness of AFM symptoms to ensure parents seek medical care for their children if they show signs of the condition (McKay, Wall Street Journal, 10/16; Sun, "To Your Health," Washington Post, 10/16; Branswell, STAT News, 10/16; Baker, "Vitals," Axios, 10/16).
The case for improving coordination between behavioral health and pediatrics
The CDC estimates that nearly $247 billion is spent annually on the treatment and management of childhood mental disorders. Further, pediatric patients and caregivers often struggle to access high-quality behavioral health expertise due to a limited number of specialists and fragmented approaches to behavioral health services.
In this presentation, we review the case for improving coordination between behavioral health and pediatrics, and describe four successful models that increase access to behavioral health care.