AFM Peak Season: What Physicians Should Keep in Mind
In July 2019, the Centers for Disease Control and Prevention (CDC) issued an advisory requesting increased vigilance among physicians during the late summer and autumn months, which is peak season for acute flaccid myelitis (AFM).
According to the CDC, AFM resulted in 233 confirmed cases reported in 2018 alone—the highest number since surveillance first began in 2014. Respiratory symptoms or fever were reported in approximately 92% of confirmed cases within 4 weeks of onset of preceding limb weakness. Additionally, upper limb involvement was found to affect 42% of confirmed cases.
The CDC continues to emphasize the importance of prompt recognition, early specimen collection, and rapid reporting of AFM cases. With this advisory in mind, Gary R. Nelson, MD, told Consultant360 what physicians should know as peak AFM season approaches:
Dr Nelson: First, it is important for physicians to know that many conditions may look similar to AFM on initial presentation, which may make AFM difficult to recognize initially. Any focal weakness in a child requires immediate evaluation. If a cause cannot be clearly identified, prompt neurological evaluation or imaging should be obtained.
Early identification is important for preventing and treating complications related to AFM, such as respiratory distress, that can occur as weakness progresses. Many patients can have dangerous complications as AFM progresses and will require hospitalization for a period of time. Some treatments may be considered to stop the progression of weakness, but there is limited data regarding the efficacy of these treatments, and consultation with experts in AFM is recommended before treating for this. Therapies to help with weakness are universally thought to be beneficial after the acute phase has resolved.
Other than typical measures to prevent the spread of illness such as hand-washing, staying home if ill, and avoiding known ill contacts, there is no known way to prevent AFM, and it is not understood why some children are susceptible to AFM and some are not.
Although AFM is seen more often between August and December and tends to be more severe in even calendar years (ie, 2014, 2016, 2018), AFM should still be a consideration in any child with a recent illness consistent with a viral illness and new onset of focal flaccid weakness at any point during the calendar year.
There are a number of things physicians should communicate to parents about AFM. Physicians should ensure that parents know to practice typical infection reduction methods with their children. However, it is also important to communicate that if their child is exposed to another child who has AFM, it is not likely that their child will develop AFM, as this type of direct-contact infectious spread pattern has not been observed in AFM. If parents notice new focal weakness in their child for any reason, they should not wait to have their children evaluated. If parents are told to just wait for it to get better, they should seek a second opinion unless a clear diagnosis is established. If a patient has been given a diagnosis of AFM, the patient and their family should be counseled that, although some improvement is to be expected, all patients have some residual deficits.
Therapies and sometimes surgery can be of great benefit, but need to be managed by physicians with experience in AFM. Because time should be allowed for healing, pursuing surgeries early is not recommended. Some improvement will occur in the early recovery stages and may negate the need for surgery in some patients. Early physical and other therapies do not seem to have any negative effects if administered via normal, appropriate methods.
All diagnoses of AFM should be reported to the state health department and CDC, with samples sent to both places to allow further testing and characterization of the illness. Physicians may contact their health department for more information, or may contact the CDC directly if the state is not participating in the reporting process. The voluntary reporting process and samples provided are being used to increase our understanding of the etiology and treatment of this increasingly prevalent acute paralyzing neurological condition.
Gary R. Nelson, MD, is a general pediatric neurologist and assistant professor in the Department of Pediatrics in the Division of Pediatric Neurology at the University of Utah School of Medicine and Primary Children’s Hospital.
—Christina Vogt
Reference:
Lopez A, Lee A, Guo A, et al. Vital Signs: surveillance for acute flaccid myelitis — United States, 2018. MMWR Morb Mortal Wkly Rep. 2019;68(27):608-614. http://dx.doi.org/10.15585/mmwr.mm6827e1.