Poliovirus: New York's Genuine Case Of "Cryptic Transmission"

How Is The Virus Spreading In Wastewater And Not In People?

New York State has made an emergency declaration over New York City's polio “outbreak”.

New York declared a state disaster emergency Friday after poliovirus was detected in wastewater samples from Long Island, signaling growing community spread of the virus which can cause paralytic disease.

The virus samples were linked genetically to a case in Rockland County, the first case of paralytic polio in the US in over ten years.

The first and only case of paralytic polio.

Governor Kathy Hochul declared an emergency over one polio case.

In the early days of the COVID-19 pandemic, the “experts” spoke often about “cryptic transmission”. New York City seems to have the ultimate example of “cryptic transmission” with its polio outbreak, where the disease spreads yet no one gets sick.

The Virus Is Spreading By Wastewater

Polio is not a disease to take lightly. It's capacity to leave people paralyzed makes it a grave public health concern by definition. Moreover, the virus is spreading in wastewater. We have empirical evidence of this.

Polio is the latest medical concern to hit New York. Currently there is only one documented case, in Rockland County. But officials say they have now detected the virus in wastewater in four New York counties and the city.

The extant polio case was first reported to the CDC back in July.

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.

The detection of the virus in wastewater in two additional counties is definitely cause for some concern. Yet the question remains: Where are all the cases? How is there only the one confirmed case?

Non-Polio Enterovirus Has Been Making Children Sick

While lacking the fanfare of polio, there has been a virus circulating and making children sick: enterovirus.

In August, clinicians and health systems in several regions of the U.S. reported an increase in children hospitalized for severe respiratory illnesses who also tested positive for rhinovirus (RV) or enterovirus (EV), the advisory stated. Upon further testing, more of those cases tested positive for enterovirus D68 (EV-D68), a non-polio enterovirus linked to uncommon neurologic complications.

Between April and August 2022, the CDC noted a substantial increase in EV-D68 cases among children who were tested at facilities within the New Vaccine Surveillance Network (NVSN), which has seven sites across the country. The number of EV-D68 cases identified at all sites between July and August this year was greater than those detected in 2021, 2020 and 2019, the agency said.

While producing similar symptoms, EV-D68 is not polio, and the genomic testing done for both makes it highly unlikely the two viruses have gotten conflated. How is there just one confirmed case of paralytic polio in New York City and the surrounding suburbs, while other enteroviruses are making many children sick?

Asymptomatic Spread?

According to the CDC, it is possible for polio to be spread by people who remain asymptomatic.

An infected person can spread the virus to others immediately before and up to 2 weeks after symptoms appear.

• The virus can live in an infected person’s intestines for many weeks. It can contaminate food and water in unsanitary conditions.

• People who don’t have symptoms can still pass the virus to others and make them sick.

Thus, it is not impossible that only Patient Zero showed any signs of paralytic polio.

It is, however, wildly improbable. For poliovirus to show up in wastewater, people have to shed it, most likely from their gut. For wastewater samples to detect poliovirus across four counties, a lot of people have to be shedding the virus.

A large number of people infected with polio and only Patient Zero shows symptoms? What are the odds of that happening?

The CDC Suspects “Several Hundred Cases”

The CDC, while being rather more credulous about the implications of the data, also suspects there are more cases.

José Romero, director of the CDC’s National Center for Immunization and Respiratory Diseases, told CNN the one case detected last month could be “just the very, very tip of the iceberg.”

“There are a number of individuals in the community that have been infected with poliovirus. They are shedding the virus,” Romero said. “The spread is always a possibility because the spread is going to be silent.”

Most people who become infected with poliovirus will not show symptoms, though they can still endanger those who are vulnerable, such as the immunocompromised and unvaccinated.

Yet paralytic polio is not a case of the common cold. The very nature of the symptoms all but ensure a person with paralytic symptoms will see a doctor and be admitted to hospital.

Thus far, New York has had one such case. What are the odds?

How Dangerous Is Polio?

If, as the CDC suspects, there are “several hundred” people in Rockland County and the Greater New York Area infected with poliovirus who have been actively shedding the virus while unaware of the infection, so that out of the “several hundred” cases only one develops severe symptoms, what does that tell us about the severity of the disease itself?

What does that tell us about the public health threat this strain of poliovirus poses for New York and the surrounding area?

One symptomatic case out of several hundred would amount to several thousand symptomatic cases across the entirety of New York City and its surroundings. That could easily become a significant challenge for hospitals and healthcare providers.

At the same time, if only one person out of several hundred is presenting severe symptoms, how easily is the virus spread? How far can it spread with just asymptomatic spread?

The history of polio tells us that this is a dangerous, disabling, even deadly pathogen, one that should never be taken lightly.

The present circulation of polio in New York is telling a far more problematic tale, one in which polio is less dangerous and less disabling.

Which tale is correct?