Concerns about polio-like illness grow; Maryland confirms cases this year

by Kate Evans

Public health concerns about a polio-like illness called acute flaccid myelitis (AFM) have been growing this year.

According to the Centers for Disease Control and Prevention, some 134 cases have been confirmed in 33 states this year as of November 30, mostly in young children.

In our region, as of November 30, Pennsylvania had eight confirmed cases and Maryland and Virginia have three cases each.

Ohio has had 10 cases of acute flaccid myelitis in 2018. Texas has reported 16 cases and Colorado 15 cases.


Acute flaccid myelitis is a rare and serious illness that affects the nervous system. It specifically affects the spinal cord, causing muscular weakness in one or more limbs. Most develop a sudden onset of arm or leg weakness and loss of muscle tone and reflexes. Some people also experience facial drooping and weakness, difficulty moving the eyes, drooping eyelids, difficulty swallowing or slurred speech.   If you or your child develop any of these symptoms, seek medical care immediately.

Numbness or tingling is rare, but some hit by the illness have leg or arm pain or are unable to urinate. Respiratory failure may occur when the breathing muscles become weak, which requires a ventilator. In very rare cases, other serious neurological complications could be triggered that could lead to death.

There have been 460 cases confirmed since 2014.

The CDC estimates that less than one or two children in the United States per million will get acute flaccid myelitis each year.

Increased cases are new

Acute flaccid myelitis is not a new condition, but CDC officials have been investigating the possible causes and risk factors since August 2014, when a large number of cases was first reported.

Large increases in the disease have occurred every two years since. Some 120 cases were reported in 34 states from August to December, 2014 and 149 cases were reported in 39 states in 2016.

Since 2014, more than 90% of the cases had a mild respiratory condition or fever consistent with a viral infection before they developed acute flaccid myelitis. Cases have occurred in 46 states and Washington D.C and over 90% of the cases have been in children.

The illness is difficult to diagnose as it has many of the same symptoms of other neurological diseases including Guillain-Barre syndrome and transverse myelitis. Physical examinations, nerve response testing, magnetic resonance imaging (MRIs) and cerebrospinal fluid tests help determine the diagnosis.


According to CDC information, certain viruses including enteroviruses are known to cause acute flaccid myelitis, such as poliovirus, enterovirus A71 and West Nile virus. All stool samples they received from acute flaccid myelitis patients tested negative for poliovirus.

Most people recover from viral infections such as enterovirus and it’s unknown why a small percentage develop acute flaccid myelitis. Enteroviruses usually cause mild illness and can also cause neurological illness, such as meningitis, encephalitis, and acute flaccid limb weakness, but these cases are rare.

CDC task force

CDC Director Robert R. Renfield announced on November 19 that an Acute Flaccid Myelitis Task Force of scientific, medical and public health experts is being established to help with the ongoing investigation of this illness to determine its cause and improve patients’ treatment and outcomes.

The task force’s first report and recommendations is expected at a CDC Office of Infectious Diseases’ Board of Scientific Counselors public meeting on December 6.

Treatment and prevention

There is no specific treatment for the disease, but neurologists may advise physical or occupational therapy to help with arm or leg weakness.

The cause of most acute flaccid myelitis cases or what triggers the condition is still unknown. However, there are steps individuals can take to protect against some of the viruses that are known to cause it, said CDC officials.

People can protect themselves and children from poliovirus by making sure that polio immunizations are up to date.

Mosquitoes carry the West Nile virus. Protect from mosquito bites by using mosquito repellent, staying indoors at dusk and dawn when mosquito bites are more common and by removing standing or stagnant water around a home where mosquitoes can breed.

Protect against enteroviruses by washing hands frequently with soap and water, avoiding close contact with people who are sick and cleaning and disinfecting frequently touched surfaces, including toys.