The US Centers for Disease Control and Prevention (CDC) and New York State health authorities are coordinating on the investigation into a case of paralytic polio in an unvaccinated individual in Rockland County, New York.
Initial sequencing confirmed by CDC indicates that the case is type 2 vaccine-derived poliovirus (VDPV), a strain related to the weakened live poliovirus contained in the oral polio vaccine (OPV).
New York state Health Commissioner Mary Bassett warned that the confirmed polio case in an unvaccinated adult and the detection of the virus in sewage could indicate a larger outbreak is underway.
“Based on earlier polio outbreaks, New Yorkers should know that for every one case of paralytic polio observed, there may be hundreds of other people infected,” Bassett said.
State health officials are urgently calling for people who are unvaccinated to receive their shots as soon as possible.
Three cases of disease caused by VDPVs have been identified in the United States since 2000, all related to viruses in people who were not vaccinated against polio or had a weakened immune system.
- In 2005, a VDPV was found in the stool of a child in Minnesota who was not vaccinated and had a weakened immune system. The child most likely caught the virus through contact in the community with someone who had received OPV in another country two months before. Subsequently, seven other unvaccinated children in the Minnesota community were found to have poliovirus infection. None of the infected children had paralysis.
- In 2008, an adult with a weakened immune system developed paralytic polio and later died of polio-associated complications. VDPV was isolated, and the infection likely occurred when the adult’s child received OPV 12 years before disease onset.
- In 2013, a fatal case was reported in an infant who immigrated to the United States from India after having received OPV there and who was severely immunodeficient because of an inherited disease.
Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus, which spreads from person to person and can infect the spinal cord, causing paralysis.
Following the detection, the Global Polio Laboratory Network (GPLN) confirmed that the VDPV2 isolated from the case is genetically linked to two Sabin-like type 2 (SL2) isolates, collected from environmental samples in early June in both New York and greater Jerusalem, Israel, as well as to the recently-detected VDPV2 from environmental samples in London, UK.
Further investigations – both genetic and epidemiological – are ongoing to determine the possible spread of the virus and the potential risk associated with these various isolates detected from different locations around the world.
Before polio vaccines existed, this dreaded disease affected thousands of children around the world every year. Not so long ago it was common for a healthy child to suddenly be unable to walk, and those who were fortunate enough to recover from the disease were left with lifelong sequelae.
Those less fortunate spent their days in hospital wards hooked up to huge machines — known as steel lungs — that allowed them to keep breathing. Many others lost their lives.
Polio was endemic in all countries, and when there was an outbreak, communities had to close schools and other public spaces to protect the children.
Discovery of the polio vaccine in the mid-1950s changed the world forever. Once vaccinations began, the disease quickly started to wane. It was clear that vaccines worked, and that they could be used to prevent the disease.
A year after his nomination as a Democratic vice presidential candidate, rising political star Franklin D. Roosevelt contracted polio while vacationing at his summer home on Campobello Island in 1921. The disease left the legs of the 39-year-old future president permanently paralyzed.
In 1938, five years after entering the White House, Roosevelt helped to create the National Foundation for Infantile Paralysis, later renamed the March of Dimes Foundation, which became the primary funding source for Dr. Jonas Salk’s vaccine trials.
While most scientists believed that effective vaccines could only be developed with live viruses, Salk developed a “killed-virus” vaccine by growing samples of the virus and then deactivating them by adding formaldehyde so that they could no longer reproduce. By injecting the benign strains into the bloodstream, the vaccine tricked the immune system into manufacturing protective antibodies without the need to introduce a weakened form of the virus into healthy patients.
After several countries succeeded in controlling polio, leaders decided that eliminating polio permanently was possible, but only if it was done in a coordinated way in all countries of the region. And so, in 1985, all the region’s countries committed to eradicating polio. In 1988, the rest of the world joined this massive effort.
The political commitment to end the disease was furthered by the work of vaccinators, who traveled to the farthest reaches of the continent, by land, sea, and air, so that no one would be left unvaccinated.
Along with these efforts, on-site personnel worked to investigate all probable cases, one by one; laboratory staff worked to confirm the absence of cases; and numerous other health workers helped in combating the disease, so that no one would ever again suffer from polio.
Participating in this great effort were community leaders, politicians at all levels, partnerships with international organizations, and parents who were convinced that vaccination saves lives.
In 1991, in a show of Pan-Americanism and commitment to health, the countries of the Americas conquered polio, and the Americas became the first world region to eliminate the disease.
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