Enlarge / A Pakistani health worker administers polio vaccine drops to a child during a vaccination campaign in Karachi on December 10, 2018. Pakistan is one of only two countries in the world where polio remains endemic. (credit: Getty | RIZWAN TABASSUM )

The United States, one of the world's richest and most developed countries, has met the World Health organization's criteria to be listed as a country with circulating vaccine-derived poliovirus, the US Centers for Disease Control and Prevention announced Tuesday.

The US now joins the ranks of around 30 other polio outbreak countries , largely low- and middle-income, including Ethiopia, Mozambique, Somalia, and Yemen. Notably, the list includes just two other high-income countries—the United Kingdom and Israel—which have detected the circulation of a poliovirus strain genetically linked to the one spreading in the US .

Specifically, the US met the criteria for WHO's list by documenting a patient with vaccine-derived poliovirus and having at least one environmental sample of vaccine-derived poliovirus. In July, health officials in New York's Rockland County reported a case of paralytic polio in an unvaccinated resident who had not recently traveled. Since then, New York officials and the CDC surveilled the spread of the virus in wastewater, finding 57 positive samples from four New York counties and New York City. The dates of the positive samples span from April to a recent sampling in August.

Enlarge / Students listen to their teacher during their first day of transitional kindergarten at Tustin Ranch Elementary School in Tustin, Calif., on Wednesday, August 11, 2021. (credit: Getty | Media News Group )

The Centers for Disease Control and Prevention is warning that a common respiratory virus in children is surging in several regions of the US, raising concern that an unusually large and alarming spike in a polio-like condition could soon follow .

The virus—a non-polio enterovirus called EV-D68—typically causes mild respiratory illness, much like a cold, and is often an indistinguishable drip in the constant stream of snotty childhood illnesses. But in recent years, experts have pinned EV-D68 to a rare but serious polio-like neurological condition called acute flaccid myelitis (AFM). In a small number of children (median age of 5 years), the condition trails an EV-D68 illness by around a week, causing muscle and limb weakness that can lead to long-term or even permanent paralysis.

In 2014, a surge in EV-D68 cases raised the virus's profile despite being identified in 1962. Since then, the CDC has recorded closely linked spikes of EV-D68 and AFM cases that follow a two-year pattern, landing in late summer and fall. Why every other year? While EV-D68 circulates continuously at low levels, epidemiological modeling suggests that two years is how long it takes for a large enough pool of susceptible children to build up and EV-D68 transmission to take off. (Adults are generally unfazed by the virus, following wave after wave of exposure to non-polio enteroviruses during childhood.)

Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP )

New York Governor Kathy Hochul declared a " state disaster emergency " Friday after p oliovirus was detected in wastewater from a fourth county , indicating that the dangerous virus continues to spread, potentially in areas with abysmal vaccination rates.

Today's emergency declaration aims to boost access to polio vaccines in the state, allowing more types of health care providers to authorize and administer polio vaccines. It also makes it a requirement for health care providers to report vaccination data to the state, allowing health officials to better identify vulnerable areas.

The emergency stretches back to July when officials reported paralytic polio in an unvaccinated adult in Rockland County whose symptoms began in June. As of September 9, the Centers for Disease Control and Prevention has detected poliovirus in 57 wastewater samples from four counties (Rockland, Orange, Sullivan, and newcomer Nassau) and New York City, with the earliest detection in April from Orange County.

Enlarge / A polio vaccine box is displayed at a health clinic in Brooklyn, New York on August 17, 2022. (credit: Getty | Ed Jones )

A third county in New York with a low vaccination rate has detected poliovirus in its wastewater, suggesting that spread of the dangerous virus is expanding, which continues to pose a significant threat to anyone unvaccinated.

Wastewater sampling in Sullivan County detected poliovirus twice in July and twice in August, the New York State Health Department announced . Genetic sequencing determined that the positive samples are linked to the case of paralytic polio reported from Rockland County in July, which was genetically linked to viruses circulating in London and Israel.

Sullivan Country joins nearby Rockland County, Orange County, and New York City in having poliovirus detected in sewage. At least 13 sewage samples from Rockland and eight from Orange have tested positive since April. The three counties are all in a northwest-pointing line from New York City, along the state's southern border. Earlier this month, New York City also announced finding poliovirus in wastewater surveillance

Enlarge / Robert F. Kennedy Jr., heads up to a meeting at Trump Tower on January 10, 2017 in New York City. (credit: Spencer Platt | Getty Images )

As the Centers for Disease Control and Prevention continues to ramp up efforts to halt the spread of poliovirus in New York, anti-vaccine activists are celebrating dips in childhood vaccination rates, calling them a "COVID silver lining."

On Tuesday, the CDC published new details on the case of paralytic polio in New York's Rockland county that was first announced in mid-July. The case, which occurred in an unvaccinated, immune-competent young adult male, began in June. Among the report's revelations is that the infection left the man with ongoing flaccid weakness in both legs.

As of August 10, officials had tested 260 wastewater samples in Rockland and nearby Orange county. Twenty-one of those 260 samples—8 percent—tested positive, with positive detections spanning samples collected in May, June, and July, the report notes. Separately, New York officials announced last Friday, August 12, that sewage samples in New York City had also tested positive .

Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP )

Health officials in New York are ramping up efforts to boost polio vaccination rates in local children as yet more poliovirus has surfaced in sewage sampling.

On Friday, August 12, New York state and New York City health officials announced that poliovirus had been detected for the first time in New York City sewage , suggesting local circulation of the virus.

The finding follows similar detections in sewage sampling in nearby Rockland and Orange counties during May, June, and July. On July 21 , health officials in Rockland county reported a case of paralytic polio in a young, unvaccinated male resident who had not recently traveled out of the country. The man's symptoms began in June.

Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP )

The vaccine-derived poliovirus that left an unvaccinated US resident with the country's first case of paralytic polio in nearly a decade has been genetically linked to spread in two other countries: the United Kingdom and Israel. Now that it has been detected in the US, health officials fear it has spread to hundreds or even thousands of people in a poorly vaccinated New York county.

On Monday, officials in New York urgently encouraged unvaccinated residents to get vaccinated "as soon as possible" to prevent further spread of the virus.

"Polio is very contagious, and an individual can transmit the virus even if they aren't sick," the New York State Department of Health said in a news release today. The virus spreads easily via a fecal-oral route through poor hygiene and sanitation. The virus transmits through direct contact with an infected person or contaminated food or water. "Symptoms, which can be mild and flu-like, can take up to 30 days to appear, during which time an infected individual can be shedding virus to others," the health department added.

Enlarge / Kids line up to get their polio vaccines at the Woodbury Avenue School in Huntington, New York, on April 27, 1954. (credit: Getty | Newsday LLC )

Health officials in New York have detected a case of polio , marking the first case of the dangerous viral disease in the United States in years.

The case was detected in a Rockland County, which in 2019 struggled with an explosive measles outbreak fueled by pockets of the community with low vaccination rates . Health officials in Rockland, neighboring New York City, and the state are now urging unvaccinated residents, particularly children, to get vaccinated, and those vaccinated, but at high risk, to get boosted.

"Many of you may be too young to remember polio, but when I was growing up, this disease struck fear in families, including my own," Rockland County Executive Ed Day said in a statement. "The fact that it is still around decades after the vaccine was created shows you just how relentless it is. Do the right thing for your child and the greater good of your community and have your child vaccinated now."

Enlarge / A health worker administers a polio vaccine to a child out of Kabul Afghanistan on May 17, 2016. (credit: Getty | Anadolu Agency )

A vaccine-derived version of poliovirus has repeatedly surfaced in London sewage over the past several months, suggesting there may be a cryptic or hidden spread among some unvaccinated people, UK health officials announced Wednesday .

No polio cases have been reported so far, nor any identified cases of paralysis. But sewage sampling in one London treatment plant has repeatedly detected closely related vaccine-derived polioviruses between February and May. This suggests "it is likely there has been some spread between closely-linked individuals in North and East London and that they are now shedding the type 2 poliovirus strain in their feces," the UK Health Security Agency (UKHSA) said.

Though the current situation raises alarm, the agency notes that it's otherwise common to see a small number of vaccine-like polioviruses pop up in sewage from time to time, usually from people who have recently been vaccinated out of the country. This is because many countries use oral polio vaccines that include weakened (attenuated) polioviruses, which can still replicate in the intestines and thus be present in stool. They can also spread to others via poor hygiene and sanitation (i.e., unwashed hands and food or water contaminated by sewage), which can become concerning amid poor vaccination rates.