Oct. 22 (UPI) -- The U.S. Centers for Disease Control and Prevention said Monday it is investigating 28 new cases of a rare neurological condition known as acute flaccid myelitis in the United States.
A total of 62 cases of the condition, which primarily affects children and can cause paralysis, have been confirmed and the CDC is investigating 155 cases across 22 states, up from 127 last week.
"CDC is actively investigating AFM cases and monitoring disease activity," the agency said. "We are working closely with healthcare providers and state and local health departments to increase awareness for AFM."
The CDC said it also is testing specimens, including stool, blood and cerebrospinal fluid, from suspected AFM cases and working with healthcare providers, health departments, policymakers, the public and other partners to gather information on the condition.
Last week, Dr. Nancy Messonnier, director of CDC's National Center for Immunization and Respiratory Diseases said 90 percent of the cases involved children 18 years old or younger with an average age of 4 years old, and no deaths related to the condition have been reported this year.
The CDC observed an increase in AFM cases in 2014 when it confirmed 120 from August to December, coinciding with a national outbreak of severe respiratory illness among people caused by enterovirus D68 .
"Since August 2014, CDC has seen an increased number of people across the United States with AFM. We have not confirmed the cause for the majority of these cases," the agency said. "CDC has been actively investigating these AFM cases, and we continue to receive information about suspected AFM cases."
The CDC confirmed 22 cases in 2015, 149 cases in 2016 and 33 cases in 2017, although the exact cause of the condition, and who is at higher risk for developing AFM and why have not been confirmed.