Are injections part of the "mystery" of acute flaccid myelitis/AFM? Is the CDC interested in finding out?
By coincidence, on October 31, I sent a Rapid Response to The BMJ about the recent US rise in AFM, just before Owen Dyer’s News item appeared. He provides a useful and more complete overview of the developing public debate between the CDC and some US pediatric experts. I now supplement this with the information that the CDC’s Division of Infectious Diseases say they have investigated and dismissed in 2014 the possibility that IM injections, vaccinations and provocation paralysis play a role in the causation of AFM. However, they have declined to share their data with me. (Email exchanges Oct.17 to Nov.1) They also say that they are continuing to investigate the possibility of an association, but the AFM Patient Summary Forms that they supply to US state health departments contain no questions about injections or vaccinations.
Last night (Nov.1) I heard a BBC interview with Olwen Murphy, a neurologist at Johns Hopkins Hospital. She is one of the experts who believe that enterovirus D68 plays an important part in the causation of AFM. This is supported by experiments showing that EV-D68 produces paralytic myelitis in mice, most efficiently when administered by IM injection; intracerebral, intraperitoneal, and intranasal routes are much less efficient. (Hixon, PLoS Pathogens 2/23/17) Owen Dyer refers to a CNN interview with Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, in which she states, “If this virus was causing this damage, we’d expect to be able to find the virus in the spinal fluid of most of these patients, and we’re not.” This is probably incorrect, since the poliovirus is usually not found in the spinal fluid of patients with poliomyelitis.
The urgency of finding causes and co-factors of AFM is reinforced by Dr. Murphy’s statement that over ¾ of patients have long-term disabilities, some of which are quite severe. We need to know which viruses cause AFM, but we also need to know the co-factors, such as IM injections, that might facilitate virus access to the spinal cord and the rest of the CNS.
What, exactly, is the CDC looking for? Are US pediatric experts looking for anything besides viruses? It is possible that the safest and most effective way to prevent AFM and other virus-associated CNS syndromes will be to modify co-factors rather than chasing a host of neurotropic viruses.
ALLAN S. CUNNINGHAM
Competing interests: No competing interests