Vaccines and the U.S. Mystery of Acute Flaccid Myelitis
Since August 2, 2014 our Centers for Disease Control has received reports of 107 cases of 'acute flaccid myelitis' (AFM), a polio-like illness in children in 34 states. During the same interval there have been 1153 cases of respiratory illnesses associated with enterovirus D-68 (CIDRAP News 1/16/15. CDC update 1/15/15. Catherine Saint Louis, NY Times 1/13/15). AFM affects motor neurons in spinal cord gray matter, resulting in asymmetrical limb weakness; 34% of patients have cranial nerve motor dysfunction. Median age of patients is 7.6 years/range: 5 months-20 years (MMWR 63: 1243--January 9, 2015). So far only one child has fully recovered. EV-D68 is a suspected cause but, thus far, no viruses have been found in the spinal fluid of patients, and only a minority have had an antecedent illness associated with EV-D68. Case-control studies are planned to look for clues, but presently AFM is a mystery disease of unknown cause.
It is taboo to suggest a role for vaccines, but some old-timers remember "provocation poliomyelitis" or "provocation paralysis." This is paralytic polio following intramuscular injections, typically with vaccines. PP was most convincingly documented by Austin Bradford Hill and J. Knowelden during the 1949 British polio epidemic when the risk of paralytic polio was increased 20-fold among children who had received the DPT injection (BMJ 2:1--July 1, 1950). Similar observations were made by Greenberg and colleagues in New York City; their literature review cited suspected cases as far back as 1921 (Am J Public Health 42:142--Feb.1952). I first became aware of PP 10 years ago while browsing through "Krugman's Infectious Disease of Children" (page 128 of the 2004 edition).
AFM may result from a direct virus attack on the spinal cord, or by an immune attack triggered by a virus, or by something else. If a polio-like virus is circulating in the U.S., the possibility of its provocation by one or more vaccines has to be considered.
Competing interests: No competing interests