When Was the Last Case of Polio in the United States?

While we rarely hear about polio anymore, like most other vaccine-preventable diseases, the last case of polio in the United States was a lot more recent than you probably imagine.

In fact, an unvaccinated adult was just recently diagnosed with polio in Rockland County, New York caused by a revertant poliovirus Sabin type 2.

When Was the Last Case of Polio in the United States?

This latest case caused by a vaccine-derived poliovirus (VDPV) in New York follows identification of polio in wastewater samples in June and July in Orange County (June and July) and Rockland County (July), which means someone was shedding the virus at that time in those communities. A virus that is genetically linked to two Sabin-like type 2 (SL2) isolates collected from environmental samples in New York and greater Jerusalem, Israel (in early June), and more recently in London, UK.

cVDPVs can emerge if the weakened live virus contained in oral polio vaccine, shed by vaccinated children, is allowed to circulate in under-immunized populations for long enough to genetically revert to aversion that causes paralysis.

Recommendations for Reporting on Poliovirus Outbreaks

Although this wasn’t a case of wild polio, since it is contagious and can cause paralysis (if you are not vaccinated and protected), it is still considered a case of polio.

Before the case in Rockland County, the previous “last cases” of polio in the United States:

• last endemic case of polio in the United States (1979)
• last imported case of polio in the United States (1993)
• “last” case of VAPP that was acquired in the United States (1999)
• last case of cVDPV occurred in an outbreak of polio among a group of unvaccinated Amish in Minnesota (2005)
• “last” case of VAPP that was acquired outside the United States, an unvaccinated 22-year-old U.S. college student who became infected with polio vaccine virus while traveling in Costa Rica in a university-sponsored study-abroad program (2005)
• last case of VAPP in the United States, a patient with a long-standing combined immunodeficiency who was probably infected in the late 1990s (2009)
• last case of VAPP that was acquired outside the United States (2013), an infant who received the OPV vaccine in India and then immigrated to the US was diagnosed with polio was found to be immunocompromised (he had SCIDS)

But with polio in wastewater samples in New York, these unfortunately might not really be the last cases unless more folks get vaccinated and protected!

More on the Polio Cases

• Milestones Towards the Eradication of Polio
• Why Do We Still Vaccinate If Polio Has Been Eliminated?
• What Happens if We Stop Using Oral Polio Vaccines?
• What Is the Morbidity/Mortality Rate of the Polio Vaccine vs the Wild Virus?
• Are Mutant Strains of Polio Vaccine Now Causing More Paralysis Than Wild Polio?
• Is the Polio Vaccine Causing Polio Outbreaks in Africa?
• Are More Polio Cases Now Being Caused by the Vaccine Than by Wild Polio Viruses?
• Why Do Anti-Vax Folks Get Excited About Polio Outbreaks?
• Polio Information from Rockland County
• Polio in New York State – July 2022
• HEALTH ADVISORY: Update Regarding Poliomyelitis in Rockland County, New York State
• Following the Identification of a Paralytic Polio Case in Rockland County, More Virus Found in Environmental Samples in Rockland and Orange Counties – Evidence of Local Transmission
• Updated statement on report of polio detection in United States
• Recommendations for Reporting on Poliovirus Outbreaks
• MMWR – Vaccine-Associated Paralytic Poliomyelitis and BCG-osis in an Immigrant Child with Severe Combined Immunodeficiency Syndrome — Texas, 2013
• First US polio case in a decade — what are the vaccine facts?
• Polio’s Resurgence
• The Return of Polio
• Eight polio cases in Israel, seven did not receive the vaccine