Minnesota reports a seventh case of rare, polio-like illness that causes paralysis or reduced limb mobility in children.

Federal health officials are trying to confirm that the child has acute flaccid myelitis, or AFM, but the symptoms match those of other children in the state diagnosed, said Kris Ehresmann, who heads the Department of Minnesota Department of Infectious Diseases. Health.

"It's too much of a case," she said.

The additional child was announced Tuesday by the state, while the Centers for Disease Control and Prevention (CDC) in the United States reported an increase in the number of cases and a slight progress in reducing the mysterious causes of the MFA.

The condition caught the country's attention in 2014, when outbreaks in California and Colorado resulted in a total of 120 cases among American children. In 2016, a further 149 cases were reported. This year, the CDC received 127 reported cases from 22 states, but only confirmed 62.

Paralyzing symptoms of AFM are caused by inflammation of the spinal cord. Experts suspect a combination of viral, genetic and environmental causes at work.

CDC officials said Tuesday that they had eliminated the polio virus, which was causing similar debilitating symptoms until its eradication in North America through vaccination. Just to be sure, they checked the children with AFM and found no trace. The West Nile virus, born in Mosquito, was also suspected to be a cause, but it does not appear in the latter cases either.

Despite these findings, the CDC could not identify a common cause, said Dr. Nancy Messonnier, director of the CDC National Center for Immunization and Respiratory Disease. "We do not know much about the AFM and I am frustrated that despite all our efforts, we have not been able to identify the cause of this mysterious disease."

All of Minnesota's cases involved children with common symptoms of colds for the first time, but Dr. Ehresmann said it was just about all they had in common. Children, all ages 10 and under, came from different parts of the state.

"We are talking about a time cluster, a cluster in time," said Ehresmann, "but we have not seen any commonalities for the location – the same city, the same school, even the same part of the state. "

The presence of viruses among Minnesota children only adds to the mystery. Not all children in the country first suffered from the virus before experiencing the symptoms of AFM. And among those who did, the tests revealed different types of viruses at work.

MFA cases appear to be increasing in August and September, as well as every two years. Why we do not understand, but Messonnier said that this trend is not seen in other countries.

One in a million

State and federal health officials said that parents should follow good public health practices, such as washing their hands and coughing, and seeing a doctor if their children report a sudden weakness. A member. But they also called for calm, knowing that only one in a million children suffers from this disease.

"As a parent myself, I understand what it's like to be afraid for your child," said Messonnier. "Parents need to know that AFM is rare, even with the increase in the number of cases we are currently seeing."

The AFM can be fatal if it causes paralysis of the stomach muscles that support breathing, but none of Minnesota's children died, Ehresmann said.

Recovery has been varied. Some Minnesota children have regained control of their hands and wrists, for example, but still can not move their upper arms.

Five of Minnesota's children are undergoing physical therapy through Gillette Children's Specialty Healthcare in St. Paul and Minnetonka. The exercises sometimes include electrical stimulation to activate the nerves and muscles. Some AFM children undergo a nerve transplant to regain their lost mobility.

"We are doing our best to see how many functions they can recover and how much we can stop the progression of nerve damage," said Dr. Angela Sinner, pediatric rehabilitation specialist at Gillette.

AFM cases are not officially monitored; States have therefore voluntarily reported them to the CDC. The public disclosure of six Minnesota cases earlier this month has caused a national interest in AFM, said Ehresmann.

Dr. Ehresmann said that this would hopefully accelerate public reporting of cases, research and understanding of causes and treatments, as the state did not have enough cases to resolve it. The state interviewed the children and families and provided their medical records and laboratory samples to the CDC for investigation.

"Six cases, that's too much," said Mr. Ehresmann, "but that's not necessarily enough to get to the bottom of things."