The New York Department of Health has confirmed that a Rockland County man has contracted polio, the first verified case of the disease in the United States in nearly a decade, CNN reports.

The variant of the virus, revertant polio Sabin type 2 virus, is consistent with the virus used in the oral vaccine for polio, which is used in many poorer countries and which contains a weakened version of the virus.  That vaccine triggers the patient’s system to help improve immunity.

The New York man was not vaccinated for polio, making him susceptible to the virus.  It is unknown if the patient was not vaccinated by choice, if he had a compromising condition that prevented him from getting the vaccine, or if he was from an area of the world that didn’t require polio vaccinations.

The last case of polio in the United States was identified in 2013.  There is no cure for polio, but there are treatments for the symptoms.  The New York patient developed weakness and paralysis about a month ago.  About one in four people develop and recover from flulike symptoms, but one in 200 will develop severe paralysis.

Vaccines do not destroy viruses.  They help the body’s immune system develop defenses to fend off an infection and prevent the virus from multiplying in the body.  The viruses that cause the diseases target by the viruses continue to exist and circulate; mass inoculations reduce the number of possible hosts for the virus and cut down on the time someone may have an active infection.

The emergence of the case comes about a month after British health officials identified active polio virus in the sewers of London, raising fears of an outbreak there.