BOSTON — The Massachusetts Department of Public Health has confirmed two cases of acute flaccid myelitis in the state and has said that an additional four suspected cases of the polio-like disease are being investigated.
The condition, considered rare and mostly seen in children, affects the body’s nervous system, specifically the spinal chord’s ability to send messages to and from the brain. It can lead to muscle weakness in one or more limbs and decreased or absent reflexes, breathing difficulty and problems speaking, swallowing or moving the eyes.
There has been a reported increase in cases nationwide since 2014 with 62 confirmed cases this year in 22 states, according to the Centers for Disease Control and Prevention.
The state DPH said it collaborates with CDC to actively investigate acute flaccid myelitis cases.
A short brief from the DPH referred to the disease as a “serious condition” for which “there is no specific treatment.”
There is also no known cause for the condition that is being studied by infectious disease specialists.
Dr. J. Michael Klatte, a pediatric infectious disease physician at Baystate Children’s Hospital, said enteroviruses may be a source.
Most illnesses caused by enteroviruses are mild and seasonal, but can be more serious if they infect the central nervous system. Some strains cause polio, the only enterovirus for which there is a vaccine, as well as hand, foot and mouth disease.
“We know that enteroviruses can affect the brain and central nervous system and some are more inclined to than other types of enteroviruses,” Klatte said.
“If you look at the CDC timeline as far as peaks of acute flaccid myelitis, it mimics seasonal enteroviruses. This is something that is definitely interesting.”
He added there was much discussion of acute flaccid myelitis and its causes at the recent meeting of the Infectious Diseases Society of America in San Francisco. Its symptoms have been associated with West Nile virus, adenovirus as well as poliovirus.
“Looking at the seasonal and yearly number of cases of acute flaccid myelitis makes me suspicious that there is a possible infectious cause, but again we are still in process of nailing down specifically what is the cause and it may be more than one,” Klatte said.
“There may be a genetic pre-disposition. We are still trying to figure out what the cause or contributing factors are.”
If there is any good immediate news, Klatte said, it is that seasonal enteroviruses should begin to drop in circulation during the next month. Their infections, Klatte added, are easily transmitted with the best protection good hygiene such as frequent hand washing, not sending sick children to school or exposing babies to others who are sick.
The CDC began tracking acute flaccid myelitis in 2014 when there was a multi-state outbreak of enterovirus infections, and Massachusetts was among the states that advised healthcare providers to test in “severe” cases of respiratory distress, many among children with asthma, for the presence of enterovirus strain D68.
The advisory at the time did note that the “outbreak has been predominantly associated with respiratory disease and not nervous system infection.”
The CDC held a media briefing Oct. 16 on acute flaccid myelitis, noting “concern” beforehand on its website and saying since August 2014 it “has seen an increased number of people across the United States with AFM.”
Its data shows that from August 2014 through September 2018 it received information on a total of 386 confirmed cases of acute flaccid myelitis across the country with most in children. The highest number of confirmed cases were 120 in 2014 and 149 in 2016.
The CDC said none of the confirmed cases tested positive for poliovirus, which causes polio or poliomyelitis. In its most severe form it can lead to temporary or permanent muscle paralysis. It has been considered eliminated here since widespread vaccination decades ago. Most children in the United States receive four doses of inactivated poliovirus vaccine.
The CDC noted that even with an increase in cases since 2014, acute flaccid myelitis remains a very rare condition. Less than one in a million people in the United States are said to get diagnosed with it each year.