Polio

What is polio?
Poliomyelitis (polio) is a highly infectious viral disease. The virus is transmitted by person-to-person spread mainly through the fecal-oral route or, less frequently, contaminated water or food. It multiplies in the intestine, from where it can invade the nervous system and cause paralysis.

Symptoms of polio 
Most people who get infected with poliovirus will not have any visible symptoms.

A smaller proportion of people with poliovirus infection will develop serious symptoms that affect the brain and spinal cord:

• Paresthesia (feeling of pins and needles in the legs)

• Meningitis (infection of the covering of the spinal cord and/or brain)

• Paralysis (can't move parts of the body) or weakness in the arms, legs, or both, occurs in about 1 out of 200 people with poliovirus infection

Paralysis is the most severe symptom associated with polio, because it can lead to permanent disability and death. Between 2 and 10 out of 100 people who have paralysis from poliovirus infection die, because the virus affects the muscles that help them breathe.

Polio Circulation and Vaccination
Circulation only happens or continues if overall vaccination rates remain low. If the community has sufficient immunized individuals, the polio virus cannot circulate. This is how the poliovirus was eradicated in our country.

Those who are unvaccinated, incompletely vaccinated, or unsure, should arrange for vaccination. This step will protect both the person getting vaccinated and our community.

On July 21, 2022, RCDOH and NYSDOH alerted the public to a case of confirmed poliomyelitis in an unvaccinated, previously healthy, young adult, county resident who presented with leg paralysis.

The individual suffered from poliomyelitis because of two events – they were 1) Unvaccinated and 2) they got exposed to a certain polio strain.

This strain, in its origin, is the same strain used in oral polio vaccines. Prior to being used as a vaccine, the virus is modified and weakened, such that it cannot cause disease but would induce immunity. This is administered only outside of the US.

As a person gets the OPV, it is shed, and can rarely remain in circulation, which happens if overall immunization rates remain low. As time goes by, if there is ongoing circulation and replication of this virus, it acquires mutations, and in time, it can regain the ability to cause disease, i.e. it "reverted" to a virulent strain. When it reaches an unimmunized person, it can make them sick.

Since OPV is not given in the US, the virus detected in our county case, likely originated from a traveler from abroad where OPV was administered, and there was a transmission chain reaching the patient. The inactivated polio vaccine (IPV) is the only polio vaccine given in the US since 2000. It is safe and effective. There is no risk of getting or spreading polio with IPV.

To be very clear, the individual in this case did not get it from a vaccine, and in fact, had they been vaccinated, they would not have gotten poliomyelitis.

• Rockland Polio Joint DOH-CDC Letter to Residents

Wastewater surveillance activities are used to determine if a virus is circulating. Visit the New York State Department of Health's Wastewater Surveillance Program for more information. The Rockland County Department of Health continues to monitor wastewater for polio.

• Polio (NYS)
• What is Polio? (CDC)
• Wastewater Surveillance (NYS)
• Polio: What Parents Need to Know (Bifold Brochure)
• Vaccine-Derived Poliovirus Fact Sheet
• For Residential Pool and Hot Tub Owners Flyer 1; For Residential Pool and Hot Tub Users Flyer 2 - Polio Can Spread in the Water! Help keep the Water, Yourself, and Those You Care About Safe.