First polio case in U.S. in nearly a decade confirmed in unvaccinated Rockland County man

The patient has since been discharged and living at home with his wife. He is able to stand, but is having difficulty walking, the official said.

Rockland County and New York State health officials on Thursday alerted clinicians to be vigilant for additional cases. Asked about the possibility of more polio cases emerging locally, Rockland County Health Commissioner Patricia Schnabel Ruppert said at a news conference, “We only have the one case. Let’s hope that’s all we find.”

Rockland County Executive Ed Day said the patient who is infected is not contagious.

“Right now, the risk to the vaccinated public is low, but experts are working to understand how and where this individual was infected,” the Centers for Disease Control and Prevention said in a statement.

Polio is a life-threatening viral disease that causes permanent paralysis in people who are not fully vaccinated in about 5 out of every 1,000 cases. Most of the U.S. population has protection against the disease because they were vaccinated during childhood. But in areas with low vaccination coverage, such as the ultra-Orthodox Jewish community in Rockland County, people who are not vaccinated are at high risk. There is no treatment for polio, but vaccination prevents the disease.

Due to the success of a national vaccination program after the vaccine was introduced in 1955, polio cases were cut dramatically. The last naturally occurring cases in the United States were recorded in 1979.

While still rare, more recent polio infections in the United States were imported through travel or contact with someone who had received oral polio vaccine in another country. The last known U.S. case was recorded by the CDC in 2013.

Polio is very contagious, and a person can spread the virus even if they aren’t sick. Symptoms, which can be mild and flu-like, can take up to 30 days to appear, during which time an infected individual can shed the virus to others. Though rare, some polio cases can result in paralysis or death.

The virus typically enters the body through the mouth, usually from hands contaminated with the fecal matter of an infected person. Respiratory transmission and oral to oral transmission through saliva may also account for some cases.

Up to 95 percent of people infected with polio have no symptoms, yet they can still spread the virus. About 4 to 5 percent of infected people have minor symptoms such as fever, muscle weakness, headache, nausea, and vomiting. One to two percent of infected people develop severe muscle pain and stiffness in the neck and back. Less than 1 percent of polio infections result in paralysis.

The Rockland County man lives in a community that has been historically undervaccinated and was the epicenter of the measles outbreak in 2019, according to the public health official who spoke on condition on anonymity.

In this case, genetic sequencing performed by the Wadsworth Center, New York state’s public health laboratory, and confirmed by the CDC, showed a type of polio virus that indicates transmission from someone who received the oral polio vaccine, according to an alert issued Thursday by the New York State Health Department and Rockland County, N.Y.

There are two types of vaccine that can prevent polio. Inactivated poliovirus vaccine, or IPV, is given as an injection in the leg or arm, depending on the patient’s age. Only IPV has been used in the United States since 2000.

Oral poliovirus vaccine, or OPV, is still used throughout much of the world. The oral polio vaccine is no longer authorized or administered in the United States because of its potential to cause vaccine-derived poliovirus. This case suggests that the virus may have originated in a location where the oral vaccine is administered, outside of the United States, the alert from New York state and Rockland County said.

Wild type polio is the naturally occurring form of the virus. However some people can become infected from a weakened strain of the virus that was used to make the oral polio vaccine early on. Most countries, including the U.S., immunize children using vaccine made from a form of the virus that is no longer alive.

Vaccine-derived polio can emerge if the weakened live virus contained in the oral polio vaccine, shed by vaccinated children, is allowed to circulate in under-immunized populations for long enough to genetically revert to a version that causes paralysis, the CDC said in its statement. Cases of vaccine-derived polio “are not caused by a child receiving the polio vaccine.”

“Many of you may be too young to remember polio, but when I was growing up, this disease struck fear in families, including my own,” Day said in a statement. “The fact that it is still around decades after the vaccine was created shows you just how relentless it is. Do the right thing for your child and the greater good of your community and have your child vaccinated now.”

The coronavirus pandemic has resulted in a drop in routine immunization rates, according to recent reports. Nearly 400,000 fewer children entered kindergarten in the United States during the last school year because of pandemic-related disruptions, raising concerns that no one knows how many kids received childhood vaccinations for common diseases, according to federal health data released this spring. All states require childhood vaccinations for illnesses such as polio, measles and whooping cough.

Rockland County plans to host polio vaccination clinics starting Friday. Health officials are urging anyone who is unvaccinated, including those who are pregnant, or are concerned they might have been exposed, to get vaccinated. Individuals who are already vaccinated but are at risk of exposure should receive a booster, which will also be available at the clinics.