The Center for Disease Control (CDC) is urging doctors and researchers to investigate and to collect new data before the disease strikes again.
An article in Ars Technica reports that the next wave of this mysterious illness, which usually affects children, may occur in 2020. There have been many more cases of this specific type of paralysis documented in 2018 than in previous years. There is every indication that the number of cases has been increasing at each new stage. The disease has a name: acute flaccid myelitis (AFM), but little else is known about it.
Symptoms of AFM
The symptoms of AFM occur suddenly. They usually begin with weakness in the upper limbs and then paralysis. Spinal lesions can be found during MRI scans. Doctors are not able to determine which children will survive. Some children recover their muscle strength over a period of time while others do not.
Information About AFM is Sparse
- It is thought to be related to a poliovirus
- It most often occurs in otherwise healthy children
- The cause is unknown
- The reason for its increase is unknown
- There is no established treatment
- There is no indication of how or whether patients will survive
- When respiratory failure occurs the patient may not survive
- The majority of cases occur between August and November
A Brief History of AFM
In 2014 doctors noticed an increase in the number of cases nationwide involving children who each had a similar type of polio-like paralysis. As they began documenting the new cases through the years, it was clear that the disease en masse was occurring every other year.
In 2018, in 42 states, 233 cases were reported by the CDC. Almost all patients were hospitalized. Sixty-one percent were admitted to the ICU. Twenty-seven percent required respiratory support. The patients on average were five years old.
Some Clues Worth Following
About the time of the AFM outbreak in 2014, doctors also noted a rise in cases of Enterovirus D68 (EV-D68). Typically, the symptoms of EV-D68 are confined to respiratory illnesses.
But the experts saw a relationship between EV-D68 and AFM. The chain runs like this:
- Paralytic illnesses are linked to enteroviruses
- A Poliovirus is a form of enterovirus
- Enterovirus type 71 (EV-A71)(hand-foot-and-mouth disease) is also connected to polio-like illnesses
Most notably, California researchers discovered EV-D68 infections in a few cases they examined in 2014. They discovered that some of the damage in patients’ spinal cords was characteristic of EV-A71 and poliovirius infections.
Although the evidence seems clear, the statistics have thus far shown otherwise. In 2018 there were 233 cases of AFM confirmed but the health officials only collected respiratory samples from 123 patients. Then they discovered that out of that group only thirty were EV-D68 positive and only ten were EV-A71 positive. Fourteen tested positive for miscellaneous enterovirus infections.
Even more discouraging were the tests of cerebrospinal fluid from a total of 233 cases which produced only one positive result for EV-D68 and one positive result for EV-A71.
CDC researchers theorized that the viruses were just not shedding into the spinal fluid. Another possibility was that the doctors were not collecting the samples in a timely manner. This is the reason the CDC urges doctors to contact the health departments immediately if they suspect a case of AFM. It will not only expedite reporting but it may save a child’s life.
The Researchers Have Other Questions
Dr. Tom Clark is deputy director of the Division of Viral Diseases at CDC. In an interview with Ars, Dr. Clark admitted that there are many questions that must be answered such as:
- Why are these cases showing up at this time?
- Why are they occurring every two years?
- Why are they showing up in basically healthy children?
- What is a preferable treatment for AFM?
- What are the risk factors that cause the disease to appear in just one sibling?
Other Diseases and an Out of Control Immune Response
The researchers are currently of the opinion that AFM is the result of a virus infection that causes damage to spinal cord tissue. There is a second theory that the damage results from an out-of-control immune response.
Guillain-Barré syndrome (GBS): In similar fashion to AFM, GBS generally occurs as a result of viral infections. It can be noted that GBS cases increased during the Zika outbreaks. GBS differs from AFM in that it begins with weakness in the legs and back. It tends to cause paralysis more slowly over a period of weeks instead of days.
West Nile Virus: A 2006 study of thirty-two patients that was conducted in Colorado showed a possible connection between the West Nile virus, AFM, and GBS.
Hand-Foot-and-Mouth disease (HFMD): In 2003 researchers reported that eight AFM cases in Malaysia appeared during a rash of HFMD that was caused by EV-A71. The researchers were of the opinion that a second virus, the adenovirus, was involved.
But the question remains as to whether the EV-A71 epidemic that was associated with HFMD was a coincidence or was there a connection between the two viruses.
Dr. Clark concluded his interview with Ars Technica on a note of caution to parents. He advises that they be vigilant. Should a child develop sudden weakness in the legs or arms the child should be examined by their physician immediately.