Q: I just heard about the poliovirus being found in wastewater in New York. Do I need to worry about my son potentially being exposed to polio? I thought it had been eradicated.
A: The good news is that if your son is up to date on his immunizations then you have nothing to worry about. The bad news is that this is a preventable viral infection that no one should ever have had to suffer from again.
You may have family members or neighbors who remember growing up in a time when their parents would not let them swim in the public pool or go to the movie theater out of fear of them catching polio. They were witness to an infection that caused many people to become ill, have long-term complications or die.
In the 1950s there were more than 15,000 cases of paralytic polio annually. There were no types of preventive measures, no treatments and no cure.
Most people who become infected with polio have no symptoms at all or mild flu-like symptoms including fever, sore throat, nausea, and fatigue. Less than 1% of those with polio experience paresthesias (numbness and tingling) or paralysis. This muscle paralysis causes long-term limb deformities and can also cause death if the muscles one uses to breathe become paralyzed.
There are many historic photographs of children and adults lying inside “iron lung” machines that helped them breathe. Polio can also cause problems decades after having healed from an infection. The post-polio syndrome causes muscle weakness, joint pain, and both physical and mental fatigue.
Polio is mainly spread by coming into contact with infected stool (poop) through poor hygiene practices, contaminated food or water sources, or when young children put contaminated toys in their mouths. It is much less commonly spread through respiratory droplets.
The first polio vaccine, created by Dr. Jonas Salk, became available in 1955. This injectable polio vaccine (IPV) provides protection against the virus and prevents paralytic polio by stimulating one’s immune system.
It does not make the individual sick when they receive the vaccine, nor does it allow them to pass the virus to another person right after they are vaccinated. In the 1960s, an oral polio vaccine (OPV) created by Dr. Albert Sabin was licensed. The OPV provides protection by giving an attenuated, or weakened, version of the virus orally that provides protection at the level of one’s gut.
For a period of time following vaccination with the oral vaccine the weakened virus is shed in the recipient’s stool. Exposure to this weakened virus by an unimmunized person can help protect them, as well.
If, however, this circulating vaccine-derived poliovirus (cVDPV) continues to spread due to low vaccination rates in a community, the virus can mutate into a form that can cause illness and paralysis.
The case of paralytic polio that was recently reported in New York was caused by an infection with a cVDPV in an unimmunized individual. The cVDPV comes from the oral vaccine and only the IPV has been used in the U.S. since 2000.
This is the first case of community acquired polio that has been reported in the U.S. since 1979 (there was a case of polio reported in 2013 in an immunocompromised infant who had received an OPV in another country just before traveling to the U.S.).
Additionally, different strains of cVDPV had been detected in wastewater in the surrounding areas for several weeks prior to the report of this infection.
What this means is that not only are polio infections now circulating in the U.S., but that they are circulating in high enough numbers to produce a case of paralytic polio.
This is of great concern as those who are un- or under-immunized, and those who cannot be immunized, are at risk of infection and the associated complications.
The safest and most effective way to protect your child from getting polio is through vaccination. The IPV is routinely given at two months of age, four months of age, 6 to 18 months of age, and a booster given between four and six years of age.
There has been over a 99% reduction in polio worldwide through ongoing vaccination efforts. The only remaining countries that still have endemic polio are Afghanistan and Pakistan.
August is National Immunization Awareness Month. Some great and reliable resources for vaccine information are: immunize.org and cdc.gov. Another trusted resource for vaccine information is your pediatrician.
Vaccines save lives.
Melissa Mason is a general pediatrician with Journey Pediatrics in Albuquerque. Please send your questions to melissaemason@gmail.com.
