Wastewater Testing and Detection of Poliovirus Type 2 Genetically Linked to Virus Isolated from a Paralytic Polio Case — New York, March 9–October 11, 2022

In July 2022, a case of paralytic poliomyelitis resulting from infection with vaccine-derived poliovirus (VDPV) type 2 (VDPV2)^§ was confirmed in an unvaccinated adult resident of Rockland County, New York (1). As of August 10, 2022, poliovirus type 2 (PV2)^¶ genetically linked to this VDPV2 had been detected in wastewater** in Rockland County and neighboring Orange County (1). This report describes the results of additional poliovirus testing of wastewater samples collected during March 9–October 11, 2022, and tested as of October 20, 2022, from 48 sewersheds (the community area served by a wastewater collection system) serving parts of Rockland County and 12 surrounding counties. Among 1,076 wastewater samples collected, 89 (8.3%) from 10 sewersheds tested positive for PV2. As part of a broad epidemiologic investigation, wastewater testing can provide information about where poliovirus might be circulating in a community in which a paralytic case has been identified; however, the most important public health actions for preventing paralytic poliomyelitis in the United States remain ongoing case detection through national acute flaccid myelitis (AFM) surveillance^†† and improving vaccination coverage in undervaccinated communities. Although most persons in the United States are sufficiently immunized, unvaccinated or undervaccinated persons living or working in Kings, Orange, Queens, Rockland, or Sullivan counties, New York should complete the polio vaccination series as soon as possible.

High rates of poliovirus vaccination coverage (2) resulted in the elimination of paralytic polio caused by wild-type poliovirus in the United States in 1979.^§§ Only inactivated polio vaccine (IPV) has been used in the United States since 2000; 3 doses of IPV confer 99%–100% protection from paralytic poliomyelitis (3). Some countries still use oral poliovirus vaccine (OPV); advantages to this approach include low cost, ease of use, and high efficacy in stopping outbreaks. However, in rare cases, the live attenuated virus in OPV can regain neurovirulence, circulate in underimmunized populations, and cause paralytic disease. A previous report confirmed that paralysis of the Rockland County patient resulted from infection with VDPV2, and that related viruses had been detected in wastewater collected from Orange and Rockland counties (1). Since then, the New York State Department of Health (NYSDOH); Nassau, Orange, Putnam, Rockland, Suffolk, Sullivan, Ulster, and Westchester counties’ health departments; New York City Department of Health and Mental Hygiene (NYC DOHMH); New York City Department of Environmental Protection; and CDC have expanded poliovirus wastewater testing as part of an emergency response. This report summarizes findings from the more extensive wastewater testing conducted in the New York metropolitan area as part of investigations to understand the extent of poliovirus circulation and to direct polio vaccination efforts.

Wastewater samples, including some originally collected for SARS-CoV-2 surveillance, were collected from a subset of sewersheds during March 9–October 11, 2022. Samples were collected approximately once or twice weekly from each site. Wastewater samples were processed using either ultracentrifugation or polyethylene glycol precipitation followed by nucleic acid extraction. The extracts were forwarded to the Wadsworth Center (part of NYSDOH) or the New York City Public Health Laboratory (part of NYC DOHMH) where they were packaged and shipped to CDC. At CDC, total nucleic acids were screened for the presence of PV2 using the pan-poliovirus real-time reverse transcription–polymerase chain reaction (RT-PCR) assay, and positive samples were sequenced (4,5).

To investigate the number of indeterminate^¶¶ results from some of the New York City samples from large sewersheds (those servicing more than 700,000 residents), NYC DOHMH collected additional larger volume (500 mL) wastewater samples from two sewersheds on August 11, one receiving wastewater from parts of New York County, and another with combined wastewater from parts of Kings, New York, and Queens counties (two distinct upstream sub-sewersheds*** were sampled, one feeding only from the New York County area and another feeding from Kings and Queens counties combined). CDC then concentrated virus from the samples using the filtration and elution method, followed by inoculation of concentrates onto susceptible cell lines to isolate polioviruses (6). Cultures exhibiting viral cytopathic effect were screened by real-time RT-PCR to identify polioviruses (4) and sequenced as described. Data presented are from samples collected during March 9–October 11, 2022, and testing conducted through October 20, 2022.

The 48 sewersheds tested serve parts of 13 counties in New York, with a total population of approximately 11,413,000 persons (7). A total of 1,076 wastewater samples were collected during March 9–October 11, 2022. Among these, 89 (8.3%) samples from 10 sewersheds tested positive for PV2. Of the 82 PV2-positive samples in the state of New York (outside of New York City), 81 (98.8%) sequences from six sewersheds in Nassau, Orange, Rockland, and Sullivan counties were linked to the virus isolated from the Rockland County patient, and the sequencing results for one sample were not adequate to determine whether it was linked to the virus isolated from the patient (Table) (Figure 1) (Figure 2). Of the seven PV2-positive samples in New York City, only one, from a sub-sewershed receiving wastewater from parts of Kings and Queens counties, was linked to the virus isolated from the patient; this sample was from one of the larger-volume samples. The other six PV2-positive New York City samples included one from Kings County that was not genetically linked to the virus isolated from the patient, and five from three different sewersheds serving parts of Kings, New York, and Richmond counties that were inadequate for sequencing. PV2-positive samples genetically linked to the virus isolated from the patient were collected on more than one occasion in Orange (June 13–October 6), Rockland (May 23–October 4), and Sullivan (July 21–October 5) counties. Only a single sample each from Nassau County on August 18 and the sub-sewershed serving parts of Kings and Queens counties on August 11 tested positive for a PV2 linked to virus isolated from the patient.

In addition to wastewater testing for poliovirus in New York, a multifaceted public health response is underway that includes efforts to enhance case detection and increase vaccination access and demand. Efforts to improve case detection include testing of persons with nonparalytic, nonspecific viral symptoms consistent with poliovirus infection^††† and review of syndromic surveillance databases. Strategies to increase vaccination include communication campaigns, community engagement, vaccination clinics, and outreach to providers and patients, focused on communities with the lowest IPV coverage. On August 12, NYSDOH and NYC DOHMH issued a press release and health alert to guide the public and the health care community about the importance of polio vaccination, emphasizing the imperative to protect unvaccinated and undervaccinated children through vaccination.^§§§ On September 9, New York declared a state of emergency,^¶¶¶ which allowed additional health professionals (including certain emergency medical service providers, midwives, and pharmacists) to administer poliovirus vaccine in the state.

Acknowledgment

New York State Wastewater Surveillance Network.

Corresponding author: A. Blythe Ryerson, [email protected], 770-488-2426.

¹2022 CDC Domestic Poliovirus Emergency Response Team; ²New York State Department of Health; ³Department of Public Health, Syracuse University, Syracuse, New York; ⁴Department of Biomedical Science, State University of New York at Albany, Albany, New York; ⁵Rockland County Department of Health, Pomona, New York; ⁶Orange County Department of Health, Goshen, New York; ⁷Sullivan County Department of Public Health, Liberty, New York; ⁸Nassau County Department of Health, Mineola, New York; ⁹New York City Department of Health and Mental Hygiene, New York, New York; ¹⁰Epidemic Intelligence Service, CDC; ¹¹Department of Epidemiology and Biostatistics, State University of New York at Albany, Albany, New York.

References

1. Link-Gelles R, Lutterloh E, Schnabel Ruppert P, et al.; 2022 U.S. Poliovirus Response Team. Public health response to a case of paralytic poliomyelitis in an unvaccinated person and detection of poliovirus in wastewater—New York, June–August 2022. MMWR Morb Mortal Wkly Rep 2022;71:1065–8. https://doi.org/10.15585/mmwr.mm7133e2 PMID:35980868
2. Hill HA, Yankey D, Elam-Evans LD, Singleton JA, Sterrett N. Vaccination coverage by age 24 months among children born in 2017 and 2018—National Immunization Survey-Child, United States, 2018–2020. MMWR Morb Mortal Wkly Rep 2021;70:1435–40. https://doi.org/10.15585/mmwr.mm7041a1 PMID:34648486
3. McBean AM, Thoms ML, Albrecht P, Cuthie JC, Bernier R. Serologic response to oral polio vaccine and enhanced-potency inactivated polio vaccines. Am J Epidemiol 1988;128:615–28. https://doi.org/10.1093/oxfordjournals.aje.a115009 PMID:2843039
4. Gerloff N, Sun H, Mandelbaum M, et al. Diagnostic assay development for poliovirus eradication. J Clin Microbiol 2018;56:e01624–17. https://doi.org/10.1128/JCM.01624-17 PMID:29212703
5. Sun H, Harrington C, Gerloff N, et al. Validation of a redesigned pan-poliovirus assay and real-time PCR platforms for the global poliovirus laboratory network. PLoS One 2021;16:e0255795. https://doi.org/10.1371/journal.pone.0255795 PMID:34358268
6. Belgasmi H, Miles SJ, Sayyad L, et al. CaFÉ: a sensitive, low-cost filtration method for detecting poliovirus and other enteroviruses in residual waters. Front Environ Sci 2022;10:914387. https://doi.org/10.3389/fenvs.2022.914387 PMID:35928599
7. Hill DT, Larsen DA. Using geographic information systems to link population estimates to wastewater surveillance data in New York State, USA. medRxiv [Preprint posted online August 24, 2022]. https://doi.org/10.1101/2022.08.23.22279124
8. CDC. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding routine poliovirus vaccination. MMWR Morb Mortal Wkly Rep 2009;58:829–30. PMID:19661857
9. Prevots DR, Burr RK, Sutter RW, Murphy TV; Advisory Committee on Immunization Practices. Poliomyelitis prevention in the United States. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2000;49(RR-5):1–22. PMID:15580728

Abbreviations: NYC = New York City; PV2 = poliovirus type 2.
* Sampling sites are sewersheds defined as the community area served by a wastewater collection system.
^† Indeterminate results include those from samples that tested positive using real-time reverse transcription polymerase chain reaction, but not enough viral material was available to complete sequencing.
^§ In July 2022, paralytic poliomyelitis resulting from infection with vaccine-derived PV2 was confirmed in an unvaccinated adult resident of Rockland County, New York.
^¶ Sequencing insufficient to determine relation to Rockland County patient.
** Totals include two samples from Kings County that were pending sequencing results as of October 20, 2022.
^†† Sewershed includes portions of Bronx and New York counties.
^§§ Sewershed includes portions of Kings, New York, and Queens counties.
^¶¶ Large-volume sample collected from the sub-sewershed serving parts of Kings and Queens counties tested positive, but the sub-sewershed serving New York County tested negative.

FIGURE 1. Wastewater* polio test results,^† by jurisdiction^§ (N = 1,053) — 13 counties in New York and New York City, March 9–October 11, 2022

Abbreviation: PV2 = poliovirus type 2.

* Sampling sites are sewersheds defined as the community area served by a wastewater collection system.

^† Testing was conducted to determine if a sample was negative or positive for PV2, and if positive for PV2, whether the PV2 was genetically linked to an unvaccinated paralytic poliomyelitis patient from Rockland County, New York identified in July 2022. Some samples had sequencing insufficient to determine relation to the Rockland County patient (i.e., linkage to patient unknown). Indeterminate results are excluded from this figure. Indeterminate results include those from samples that tested positive using real-time reverse transcription polymerase chain reaction, but not enough viral material was available to complete sequencing. Specimens pending sequencing results are also excluded.

^§ Number of samples in each jurisdiction include New York City (408) and the following New York counties: Rockland (124), Putnam (20), Orange (280), Nassau (85), Sullivan (21), Westchester (83), Suffolk (14), and Ulster (18).

FIGURE 2. Sewersheds* with detections of poliovirus type 2 genetically linked to the virus isolated from a paralytic polio patient^† — Sullivan (A), Orange (B), Rockland (C), Kings and Queens (D),^§ and Nassau (E) counties, New York, March 9–October 11, 2022

Abbreviation: PV2 = poliovirus type 2.

* Sampling sites are sewersheds defined as the community area served by a wastewater collection system. Sub-sewersheds are upstream sampling locations within a larger sewershed.

^† In July 2022, paralytic poliomyelitis resulting from infection with vaccine-derived PV2 was confirmed in an unvaccinated adult resident of Rockland County, New York.

^§ A single large-volume sample from a sub-sewershed serving parts of Kings and Queens counties tested positive for the PV2 genetically linked to the virus isolated from the patient.