An unusual outbreak of polio-like symptoms has made its way across the US. So far this year, the CDC reports 38 confirmed cases of AFM, a condition that causes muscle weakness and paralysis, primarily in children.
October 15, 2018
Health officials report an unusually high number of cases of a rare polio-like illness known as acute flaccid myelitis (AFM) that causes muscle weakness and paralysis, usually in children. So far this year, the Centers for Disease Control and Prevention (CDC) has received reports of 127 possible cases of AFM across the United States, and 62 cases have been confirmed as AFM in 22 states.
“Of the confirmed cases, the average age is about 4 years old,” said Nancy Messonnier, MD, director of the National Center for Immunization and Respiratory Diseases (NCIRD), in a press briefing. “More than 90 percent of the cases are in children age 18 years and younger.”
While public health officials say they are getting better at diagnosing and tracking the condition, which affects the nervous system, it remains unclear why cases of the condition have spiked each autumn since 2014.
“Despite extensive laboratory testing, we have not determined what pathogen or immune response caused the arm or leg weakness and paralysis in most patients,” said Dr. Messonnier. “We don’t know who may be at higher risk for developing AFM or the reasons why they may be at higher risk.”
Diagnosed mostly in children, AFM specifically strikes the spinal cord. Some children have mild cases, such as temporary limb weakness — flaccid or floppy limb strength — and fully recover. But children with severe cases often experience sudden paralysis or weakness in the arms or legs that persists. They can also have droopy eyelids and difficulty swallowing and speaking. In the worst cases, respiration is suppressed, requiring life-saving use of a ventilator.
A Rare but Alarming Condition
Fewer than one in one million people develop the illness in the United States each year, but the recent increase in cases has alarmed public health officials because not all of the children fully recover.
“It’s a concern any time you have something recurring every few years and we don’t know exactly what causes it,” says Mobeen Rathore, MBBS, chief of the division of pediatric infectious diseases and immunology at the University of Florida College of Medicine in Jacksonville, who serves on the American Academy of Pediatrics committee on infectious diseases. “This has a significant impact on the children, and it occurs in mostly healthy kids.”
Mild cases can be especially difficult to diagnose, Dr. Rathore says. No diagnostic test exists; doctors use criteria from the CDC to make a diagnosis, which includes an MRI exam to look for lesions in the spinal cord.
“Many of the cases are not recognized unless you are attentive to it or suspect it,” he says. “It’s probably the tip of the iceberg.”
|Read on: Polio-Like Illness Continues to Spread Across United States|