Hundreds of children were sickened last year with a mysterious illness known as acute flaccid myelitis, which resulted in polio-like paralysis and weakened limbs. However, federal health officials are still unsure about what is causing the problems, or how to best treat the condition.
According to an acute flaccid myelitis (AFM) update released by the U.S. Centers for Disease Control and Prevention (CDC), there were at least 201 cases of the mysterious condition nationwide in 2018, impacting children in at least 40 different states. In addition, another 163 reports of possible AFM are still being investigated.
Because of the widespread number of confirmed acute flaccid myelitis cases, the CDC indicated it will provide updated information on a bi-weekly basis moving forward.
The illness primarily affects young children, resulting in paralysis and other symptoms that are similar to polio. However, no definitive cause has been determined or linked to the condition.
So far, only four cases have tested positive for specific viruses among the more than 500 positively identified cases of AFM since 2014. Those viruses include coxsackievirus A16, EV-A71, and EV-D68. Those were tested positive in the spinal fluid of four confirmed cases of AFM.
AFM is a condition that resembles polio because it affects the nervous system; specifically the gray matter in the spinal cord. Patients suffer weakened limbs and paralysis. Some patients become severely disabled, suffer damage to the spinal cord, and some children have required a ventilator to breathe.
No pathogen has been found in the spinal fluid of the more than 500 other cases spanning over four years. However, researchers warn it is difficult to detect a virus with AFM because the symptoms appear when the infection wanes. It can often take doctors days to suspect the condition and begin testing to confirm a virus.
More than 80 percent of patients have experienced a respiratory illness of some sort in the weeks before getting AFM.
Researchers also note AFM is following the every other year pattern that typically indicates a virus. Viruses fit a pattern of circulating some years and not others.
AFM cases also fit this pattern. More than 200 cases were confirmed in 2018. Yet, only 35 cases were confirmed in 2017 across 16 states. In 2016, 149 cases were confirmed in 39 states, but in 2015, only 22 cases were confirmed in 17 states. As for 2014, 120 cases were confirmed since August of that year.
The CDC plans to improve surveillance efforts, facilitate focused sampling and testing for suspected cases, and collaborate with experts to review MRIs for patients from the past 10 years to estimate how many cases occurred before 2014.
The agency is exploring treatment options and consulting with national experts in infectious diseases, neurology, pediatrics, critical care medicine, public health epidemiology, and virology. It is also establishing an AFM task force.