A polite state leaving more than 100 children in the United States, at least partially paralyzed in 2014, is back,…
A polite state leaving more than 100 children in the United States, at least partially paralyzed in 2014, is back, and not much more is known this time, officials say with U.S. Centers for Disease Control and Prevention. CDC does not exclude any possible trigger from infections to toxins, autoimmune responses to bugbites.
“We have been unable to find a cause for most of these” cases, Nancy Messonnier, director of the CDC National Center for Immunization and Respiratory Diseases, said Wednesday at a press conference. “And I’m frustrated that despite all our efforts, we have not been able to identify the cause of this mystery disease.”
But researchers who have studied the muscle weakness called acute weak myelitis (AFM) say they now have a good understanding of their main cause, although they still do not know how to treat the condition or stop their progression.
Researchers at the University of Colorado School of Medicine infected mice with a virus circulating during 201
4 AFM outbreaks and under similar nails of the disease 2016 and this year. The virus triggered a paralysis of the mice that “looked very much like what we saw in children,” said Kenneth Tyler, chair of the school’s neurological institution. Tyler thinks that the virus, called enterovirus D68, has changed since it was first identified in 1962 and became more dangerous. He has raised mice that develop paralysis after infection with the current version of enterovirus D68 but not from previous strains. He has tested a number of possible treatments on his mice but has not yet found anyone who makes a significant difference in his AFM-like disease.
Enterovirus D68 has been linked to some of the human cases of the disease, and although it is not the only cause it clearly has been a driving force behind the last three outbreaks, says Kevin Messacar, an infectious disease physician and researcher at Children & s Hospital Colorado. He and Tyler say that CDC is excessively careful not to recognize the role of enterovirus D68 in the disease.
The symptoms of the virus are similar to colds and may include coughing, breathlessness and other asthma breathing difficulties. “Many will get the infection and very few will get the neurological disease” which leads to paralysis, “Messacar says. In rare cases, about one week after infection, the child will develop weakness in his or her arms, legs or muscles in the face or throat, he says. Although there is no definitive diagnosis, doctors can identify AFM from a combination of symptoms and an MRI scan, which may reveal spinal cord inflammation.
The CDC’s Messonnier describes AFM as “quite dramatic” and says that the federal agency increases its response compared to that in previous years. She also emphasizes that it is extremely rare to turn on about one million children so parents do not panic – but they should seek medical attention if their children show signs of sudden weakness or loss of muscle tone in the arms or legs. Since July, the CDC has confirmed 62 cases of AFM in 22 states and examines 65 more possible cases. A child with AFM died last year. Ninety percent of cases have been in children, she says.
Messonnier did not address enterovirus D68 directly during the press conference and said that CDC has not yet had time to fully analyze the cases from the summer and autumn. She said the cases were definitely not caused by the poliovirus, which has not been found in any of the palladium samples from affected children. There is no evidence of infection with the mosquito-borne Western virus either, she says, although she still encourages parents to send their children with abdominal drugs. Some AFM children recover full movement and strength – usually within a few months – while others look nervous, she says.
Mitchel Seruya, a surgeon at Los Angeles Children’s Hospital, says when he has worked with children with AFM, he has been surprised at how they respond to their affected nerves. He can hit them with an electric shock that is sensitive to moving a car battery, he says, but they do not move. It suggests that the disease can completely wipe out the nerves. Seruya has been working on 15 children whose AFM-induced paralysis lasted at least three months. He redirects redundant nerves from other parts of the arm or abdomen to replace those lost to the disease. He says he has had very good results in 14 of the 15 patients; The one girl who did not regain her full function had “a suboptimal result, but [her parents are] glad she got something back.” However, treatments for the infection itself remain difficult.
Mark Hicar, a childhood specialist for infectious diseases and assistant at the University of Buffalo, SUNY, has treated two children with AFM, one in 2014 and one this year. Both were boys – an age of six, a tree; each had a cold disease and spotted a fever about a day before they stopped using a leg. Neither the boy tested positive for the enterovirus D68 or A71, a similar virus also linked to the AFM, but the test is not definitive, he says. The three-year-old improved significantly within the first two days but then plateau and is now back in the hospital treated with anti-inflammatory drugs, says Hicar, who hopes the drugs will prevent the boy’s immune response to make the damage worse. But data about the effect of treatments is so thin that he says he is not sure if the treatment helps the boy or not.
A vaccine against enterovirus D68 would be scientifically feasible but not economically feasible, says Messacar. Polio is a very similar virus – and there is a vaccine that protects against it. The Chinese have developed a vaccine against enterovirus A71, but it is not available in the United States, he adds. Because AFM is so rare and has several potential causes, it would be difficult for a company to earn a vaccine, says Messacar.
The sickness pattern resembles the 1920s and 1950s outbreaks of poles, says Andrew Pavia, director of the Division of Infection Diseases in Children at the University of Utah, in addition to his scale. While polio-infected tens of thousands of children have AFM slaughtered more than 100 every two years. Many who had polio as a child recovered recovered muscle weakness decades later. It is unclear of mice studies if AFM symptoms will return in affected individuals . According to the CDC, 19659002, 120 confirmed cases were reported by AFM in the second half of 2014, 22 years 2015, 149 2016 and 33 in 2017. “There is an increase in equal years that do not seem to be random,” says Messacar, and states that infections are most commonly from July to October in the north, although they are less seasonal in Söder. Research suggests dew points – a combination of moisture and temperature seems to affect the transmittability of the virus, he says.
Pavia is dealing with enterovirus D68 is the most likely cause of most AFM cases, but “we must wait and see.” This year’s outbreak will follow the same patterns as 2014 and 2016. The primary methods to prevent infection with the virus is the same as for any cold: Wash your hands frequently, sneeze your arm or elbow and try to avoid close contact with people who are ill, says Pavia.
Enterovirus D68 is probably contagious for about a week, as long as the cold, Messakar says. The disease itself develops near the end of the contagious period and does not spread from person to person.
It was certainly true in Sarah Pilarowski’s family. Her eight-year-old son Liam became terrible in 2014 but recovered, but her six-year-old daughter, Lydia, developed a cold and fever that seemed to linger forever, says Pilarowski, a pediatrician from Denver. When Lydia was not strong enough to hold an ear of corn in her left hand, Pilarowski was worried. Lydia was diagnosed with AFM and received months of occupational and physical therapy, followed by psychotherapy to solve her nightmares and prolonged anxiety. She did not test positive for enterovirus D68, but Pilarowski is convinced that both her children had the virus, making the rounds in the Denver area summer her children became ill.
Although it is not likely to be a vaccine or specific treatment anytime soon there are still things that researchers can do to fight AFM, Messacar says, like keeping a closer look at infections of the enterovirus D68 and A71, learn more about the link between the virus and the AFM and understand the genetic changes that have occurred in the enterovirus D68 to make it more dangerous. “Let’s start doing something about it. Let’s get funding,” he says. “Let’s not act this is a surprise if this comes back in 2020, but let’s be more prepared.”