On August 16, 2022, this report was posted as an MMWR Early Release on the MMWR website (https://www.cdc.gov/mmwr).On July 18, 2022, the New York State Department of Health (NYSDOH) notified CDC of detection of poliovirus type 2 in stool specimens from an unvaccinated immunocompetent young adult from Rockland County, New York, who was experiencing acute flaccid weakness. The patient initially experienced fever, neck stiffness, gastrointestinal symptoms, and limb weakness. The patient was hospitalized with possible acute flaccid myelitis (AFM). Vaccine-derived poliovirus type 2 (VDPV2) was detected in stool specimens obtained on days 11 and 12 after initial symptom onset. To date, related Sabin-like type 2 polioviruses have been detected in wastewater* in the patient's county of residence and in neighboring Orange County up to 25 days before (from samples originally collected for SARS-CoV-2 wastewater monitoring) and 41 days after the patient's symptom onset. The last U.S. case of polio caused by wild poliovirus occurred in 1979, and the World Health Organization Region of the Americas was declared polio-free in 1994. This report describes the second identification of community transmission of poliovirus in the United States since 1979; the previous instance, in 2005, was a type 1 VDPV (1). The occurrence of this case, combined with the identification of poliovirus in wastewater in neighboring Orange County, underscores the importance of maintaining high vaccination coverage to prevent paralytic polio in persons of all ages.

Neurogenesis is a highly-regulated process occurring in the dentate gyrus that has been linked to learning, memory, and antidepressant efficacy. MicroRNAs (miRNAs) have been previously shown to play an important role in the regulation of neuronal development and neurogenesis in the dentate gyrus via modulation of gene expression. However, this mode of regulation is both incompletely described in the literature thus far and highly multifactorial. In this study, we designed sensors and detected relative levels of expression of 10 different miRNAs and found miR-338-3p was most highly expressed in the dentate gyrus. Comparison of miR-338-3p expression with neuronal markers of maturity indicates miR-338-3p is expressed most highly in the mature neuron. We also designed a viral “sponge” to knock down in vivo expression of miR-338-3p. When miR-338-3p is knocked down, neurons sprout multiple primary dendrites that branch off of the soma in a disorganized manner, cellular proliferation is upregulated, and neoplasms form spontaneously in vivo. Additionally, miR-338-3p overexpression in glioblastoma cell lines slows their proliferation in vitro. Further, low miR-338-3p expression is associated with increased mortality and disease progression in patients with glioblastoma. These data identify miR-338-3p as a clinically relevant tumor suppressor in glioblastoma.

The first case of paralytic poliomyelitis in nearly a decade in the US was discovered in a 20-year-old unvaccinated man from Rockland County, New York, in July 2022, who developed acute flaccid myelitis. The isolated virus from stool sampling was found to be a circulating vaccine-derived poliovirus type 2, derived from the oral polio vaccine. Since the discovery of this case, local wastewater surveillance has revealed evidence of circulating vaccine-derived poliovirus type 2 in local counties, as well as in New York City, representing community transmission. In the wake of the coronavirus disease 2019 pandemic, routine vaccination administration has declined globally, with increasing numbers of communities not vaccinated for poliovirus. Now, with evidence of local community transmission, the clinical implication for at-risk unvaccinated individuals is significant. Here, we review the epidemiological origin of this discovered strain of poliovirus, national and international methods of surveillance for poliovirus, and neurological features of poliovirus. We also highlight the opportunities and challenges involved in monitoring suspected cases, as well as the unique role neurologists might play in national and global poliomyelitis surveillance.

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