A virus appears to be the cause of an outbreak of polio-like illness that struck Minnesota last fall, causing paralyzing symptoms in several children, including a girl who lost motor function and remains hospitalized .

Researchers in Minnesota and US Centers for Disease Control and Prevention reported Thursday that they have found enterovirus D68 in the cerebrospinal fluid of one of six children with acute flaccid myelitis (AFM).

The virus has caused the disease in this child, and is presumed to be the cause in the other five, according to the researchers, who described their discovery as a key element of a disconcerting national epidemic.

"(AFM) incredibly scares patients and their families," said Dr. Heidi Moline, lead author of the report and chief resident of the University of Minnesota in Pediatrics. "The fact that we were able to definitively identify the EV-D68 virus as a cause of paralysis in one of our Minnesota patients suggests that this virus is a likely cause in our other recent cases of AFM."

Moline said the researchers were working with public health officials to better understand the virus and its impact on children.

The EV-D68 has been suspected for some time as a cause in the United States, in part because of surveillance since 2012, which shows that the virus has appeared twice in a row, with case-case peaks of MFA in 2014, 2016 and 2018.

The virus had previously been found in the cerebrospinal fluid of a California child, but the contamination of the fluid had altered these findings, said Moline.

"This is the first confirmation we had," she added.

AFM is a neurological disorder that affects the spongy gray matter surrounding the spinal cord and damages the nerves and their communication with the muscles. The first public AFM reports in 2018 appeared in Minnesota, which closed the year with 10 of the country's 228 confirmed cases.

The new research report was based on six children aged 1 to 9 who had been hospitalized from September 19 to October 1 after initial headaches or flu symptoms developed into limb weakness or paralysis. The CDC published the results in its weekly journal MMWR.

James Hill, of Lakeville, said he still could not believe how fast his 7-year-old son, Quinton, went from mild symptoms to loss of motion in the upper left arm.

"It's hard to look at images, looking back, because it was the healthiest child you've ever met," said Hill.

Weakness of the limbs was reported in the left arms of two children, the right arms of two others and the left legs of two others. Five of the children improved with immunoglobulin infusions to strengthen the immune system and physical therapy exercises.

A 7 year old girl suffered from a quick paralysis that did not improve. The report says that she has lost all voluntary limb movements but remains cognitively intact.

Research like this week's, coupled with public awareness at the AFM, should help clinicians if the trend continues and if cases come up again in the fall of 2022, but doctors do not still unclear how best to treat her, even with the role Anupama Kalaskar, co-author of the report and infectious disease specialist for hospitals and children's clinics in Minnesota, confirms the confirmation of the virus.

"Some patients have received multiple treatments," she said, "so it's hard to determine who may have worked and who has not worked."

Surgery in Los Angeles

Hill's son regained arm movements during the winter through physical therapy in clinics and at home exercises designed to give a boost to nerves damaged by the AFM.

Quinton was operated on in Los Angeles two weeks ago to transplant healthy nerves into his dormant left arm. The procedure was somewhat disappointing, said his father, because the ideal nerves for the transfer were found unusable during the operation. The Hills are hopeful that the procedure will restore mobility after the withdrawal of the Quinton distribution.

Quinton has been resilient and optimistic, and has even shown some signs of strengthening his biceps this winter, but he still can not get up with his left arm or lift him over his head.

"From our point of view," said his father, "we firmly believed that we should be able to give him every chance to move."

Despite suspicions about the EV-D68, doctors and clinicians have struggled to find any presence of it in the cerebrospinal fluid of affected children. The virus has been found in their nose, but this does not prove that it played a role in a neurological disorder, said Moline. One possibility is that the virus has already left the cerebrospinal fluid before the paralyzing symptoms appear, so the tests take place too late.

Confirmation of EV-D68 does not exclude other viruses as potential causes. This also does not remove the role of environmental factors, which could explain why most children suffer from colds, but one in a million children contract the AFM because of exposure.

Moline said that he emphasized the importance of basic public health measures aimed at reducing the spread of germs: "Our current goal is really to cover coughs, wash hands and try to prevent the spread of respiratory diseases, especially in the fall.

AFM cases were confirmed last year in 41 states, but were discovered in regional groups, probably in states where the EV-D68 virus and other viruses are prevalent. California and Colorado have both reported a high number of cases since 2014.

A frustration for disease investigators is that the afflicted children seem to have little in common. In Minnesota, four of the children had no underlying health problems, while one had cerebral palsy and convulsions. Five of the six were girls. One of them had no symptoms of colds, while the others had reported headaches, vomiting or diarrhea before they lost their movement.

"These kids did not go to the same daycare they did not live in the same street," said Moline. "In addition to living here in Minnesota, nothing was a common factor."