The first known case of polio in the U.S. since 2013 has turned up in the New York City metropolitan area, and healthcare workers are being advised to be "vigilant" for more potential cases.
New York health officials said the affected individual is a Rockland County resident with revertant polio Sabin type 2 virus confirmed in laboratory sequencing and by the CDC.
"This is indicative of a transmission chain from an individual who received the oral polio vaccine (OPV)," according to from the New York State Department of Health. "This suggests that the virus may have originated in a location outside of the U.S. where OPV is administered, since revertant strains cannot emerge from inactivated vaccines."
OPV is no longer authorized in the U.S., and since 2000 only the inactivated polio vaccine (IPV) is administered.
Starting Friday, Rockland County will be hosting local vaccine clinics for individuals who are unvaccinated, those who did not complete their standard polio vaccine series as children, or community members who are concerned about being exposed. Those who are already vaccinated are considered low risk, but may nevertheless receive a booster if there is a risk of exposure.
"Based on what we know about this case, and polio in general, the Department of Health strongly recommends that unvaccinated individuals get vaccinated or boosted with the FDA-approved IPV polio vaccine as soon as possible," State Health Commissioner Mary Bassett, MD, MPH, said in the statement.
"The polio vaccine is safe and effective, protecting against this potentially debilitating disease, and it has been part of the backbone of required, routine childhood immunizations recommended by health officials and public health agencies nationwide," she added.
Polio is a viral disease that affects the nervous system and causes muscle weakness and breathing problems. Symptoms can be mild and flu-like and take up to 30 days to appear. In rare instances, paralysis or death may occur.
The virus is very contagious and spreads via human-to-human contact, either through respiratory droplets, saliva, or contact with the feces of an infected person, .
The polio vaccine was introduced in 1955 and was responsible for the large reduction in polio cases by the 1970s.
In the U.K., poliovirus has recently been found circulating and evolving . Researchers believe that to be a strain derived from the OPV as well.