SYDNEY — A mysterious illness likened to polio that led to paralysis in children across the U.S., Canada, and Europe in recent years is believed the result of a virus, according to a new study, and researchers warn the number of infected patients continues to grow globally.
Medical researchers from the University of New South Wales believe the virus, known as enterovirus D68 (EV-D68), is behind the widely-reported cases of acute flaccid myelitis, a neurological condition that leads to paralyzed limbs in children.
“In 2014, children in the US began to be diagnosed with a mystery illness that caused a polio-like paralysis,” says Professor Raina MacIntyre, the lead researcher of the study, in a university news release. “More than 120 children developed the condition … in the US alone but experts were baffled as to the cause.”
Around the same time that doctors began treating more children for paralysis from acute flaccid myelitis that year, more than 2,200 people, particularly kids, in America, Canada, and Europe were infected with enterovirus D68. The illness causes a range of respiratory issues, from severe cough and cold symptoms to muscle aches and difficulty breathing.
The timing raised the suspicions of medical experts, but the virus had never been shown to cause paralysis in patients.
So the researchers turned to a set of criteria that was named for and created by renowned British epidemiologist Sir Austin Bradford Hill in 1965 to prove a cause-and-effect relationship between smoking and lung cancer. Known as the Bradford Hill criteria, the method requires the matching of nine principles to prove one condition causes another, and is often used by scientists to verify other causal relationships.
Applying the Bradford Hill criteria to the enterovirus D68 cases and those who contracted acute flaccid myelitis, the researchers were able to make a positive link.
“We are first to use his approach to analyse the relationship between EV-D68 and acute flaccid myelitis. Our results show that it is very likely that EV-D68 is the cause of the mystery illness and the paralysis of children,” says MacIntyre. “This link needs to be acknowledged so that public health strategies can focus on prevention of infection.
MacIntyre warns that a new strain of EV-D68 has come to light and cases continue to mount worldwide. She preaches the importance of washing your hands with soap and water for at least 20 seconds to help stop the spread of the virus and keep new cases of acute flaccid myelitis from popping up.
“The incidence of EV-D68 infections is increasing worldwide, and a genetically distinct strain has recently evolved,” she says. “There is no treatment or vaccine for the polio-like illness caused by EV-D68, which makes it important to act quickly to stop outbreaks.”
The study’s findings were published last month in the journal Eurosurveillance.