In a recent study published in the Morbidity and Mortality Weekly Report, researchers investigated the public health response to a case of paralytic polio in an unvaccinated person.
Study: Public health response to a case of paralytic poliomyelitis in an unvaccinated person and detection of poliovirus in wastewater — New York, June-August 2022. Image credit: Maryna Olyak/Shutterstock
On July 18, 2022, the New York State Department of Health (NYSDOH) reported the identification of poliovirus type 2 in stool samples collected from an immunocompetent, unvaccinated youth residing in Rockland County, New York, showing acute flaccid weakness. The patient reported symptoms of fever, gastrointestinal problems, neck stiffness, and limb weakness. The patient was subsequently admitted to a hospital with possible acute flaccid myelitis (AFM). However, laboratory results detected vaccine-derived poliovirus type 2 (VDPV2) in stool samples collected 11 and 12 days after the onset of symptoms. To date, Sabin-like poliovirus type 2 was detected in the patient’s county of residence up to 25 days before and 41 days after the patient’s date of symptom onset.
Case meetings
In June 2022, a young man who was not vaccinated against polio presented with a five-day history of fever, back and abdominal pain, neck stiffness, constipation, and two days of bilateral lower extremity weakness. The patient visited an emergency department and was admitted to the hospital with suspected AFM. The patient was subsequently transferred to a rehabilitation center approximately 16 days after the initial onset of symptoms with continued flaccid lower extremity weakness.
Nasopharyngeal or oropharyngeal swabs and cerebrospinal fluid samples collected from the patient tested negative by reverse transcription-polymerase chain reaction (RT-PCR) for human parechoviruses, enteroviruses, as well as common respiratory pathogens and encephalitis viruses . In addition, sequencing and RT-PCR of stool samples performed by the NYSDOH laboratory detected poliovirus type 2. Samples tested at the Centers for Disease Control and Prevention (CDC) further confirmed the presence of poliovirus type 2. Additional sequencing also identified the virus as VDVP2, which differed from the Sabin 2 vaccine strain, suggesting that viral transmission had occurred for up to a year; however, the location of the transmission is unknown.
Public health response
NYSDOH, CDC, and local health authorities investigated and responded to the notification of the VDVP2-positive specimen on July 18, 2022. On July 22, 2022, an NYSDOH advisory was issued to increase awareness of health care providers and improve the detection of potentially infected people. Wastewater from Rockland and other New York counties was tested to assess vaccination coverage in the patient’s local community. Authorities also provided inactivated polio vaccine (IPV) to appropriate immunization providers and set up vaccination clinics throughout Rockland County.
Enhanced surveillance was conducted for persons under investigation (PUI) who met clinical criteria and who resided in or traveled to certain counties, boroughs of New York, or other countries since May 1, 2022. On 10 As of August 2022, three additional individuals were classified as PUIs. . However, the specimens provided by the PUIs tested negative for poliovirus.
Additionally, on August 10, 2022, 260 wastewater samples were collected from treatment plants in Orange and Rockland counties and tested for poliovirus. Of these, 8% tested RT-PCR positive for poliovirus, including 13 and eight samples from Rockland and Orange counties, respectively. In particular, 20 sewage samples obtained from May to July were genetically matched to the virus in the patient’s stool specimen. Also, in April, an additional sample from Orange County was found to have poliovirus type 2.
Authorities also initiated additional clinical and public health surveillance activities to detect the presence of symptomatic nonparalytic infection or more severe symptoms along with asymptomatic infections in counties with poliovirus-positive wastewater findings. The Rockland County Health Department also launched a countywide vaccination program on July 22, 2022.
The present study highlighted the risk of contracting paralytic disease among unvaccinated individuals. The researchers believe that citizens should stay up to date with the recommended vaccination schedule to combat the virus.