“This looks like a classic case of all of COVID-19, H5N1 bird flu, and polio.”

Polio escaping isn’t a big deal of the surrounding areas have polio vaccines, medical facilities, and food available for the general population.

It is a massive concern for Gaza, where the medical infrastructure has been destroyed, there is widespread malnutrition, and combined that means even vaccinated people are going to be at risk of falling ill and being susceptible to diseases they would normally be able to shrug off or receive care for.

It sounds like there have been outbreaks in past years in Israel. Lot of poor countries with infrastructure issues in the area.

https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON366

WHO was notified on 7 March 2022 of the detection of circulating vaccine-derived poliovirus type 3 (cVDPV3) in an unvaccinated child from Jerusalem city. Investigations (including environmental, epidemiological and virological) are ongoing to determine the origin of cVDPV3 and the scope of circulation. As of 15 April, a total of seven VDPV3 positive have been confirmed, including the index case and six asymptomatic children.

https://www.health.ny.gov/press/releases/2023/2023-03-10_immunized_against_polio.htm

ALBANY, N.Y. (March 10, 2023) – The New York State Department of Health today urged all New Yorkers planning travel this spring to Israel and other countries with circulating poliovirus to get fully immunized against polio and to follow CDC recommendations for such travel.

In recent days, Israel’s Ministry of Health confirmed four children had tested positive for poliovirus in Northern Israel, after one unvaccinated child presented symptoms of paralysis. The other three children are currently asymptomatic. Israel has additionally reported widespread detection of poliovirus in wastewater systems. This latest outbreak follows one that was detected in February 2022 when seven children tested positive for poliovirus in Jerusalem, six of whom were asymptomatic, and after which Israel launched a nationwide vaccination campaign to prevent further spread of the virus.

https://www.ecdc.europa.eu/en/news-events/epidemiological-update-polio-israel-14-october-2013

Event Background

In February 2013, WPV1 was first isolated from sewage samples collected for routine environmental surveillance in southern Israel.

WPV1 has subsequently been isolated in stool samples from 42 carriers (4.4% of the sampled population) tested in area of WPV1 circulation [2]. Forty of 42 were children from the age group of 0-9. They were reported to have been fully vaccinated with IPV, according to Israeli national recommendations [3].

Also from 2013:

https://www.science.org/doi/10.1126/science.342.6159.679

Polio outbreaks are raging nearby in Pakistan and war-torn Syria. But in developed, prosperous Israel, no one saw this coming. The country has an impressively high immunization rate of at least 95%, and it uses the inactivated polio vaccine (IPV), the vaccine of choice in high-income countries, which unlike the oral live-virus vaccine used in … .

The Gaza ministry said tests carried out with the UN children’s agency, Unicef,

Though I suppose that that doesn’t necessarily mean that UNICEF is doing the sampling, just the testing. Could be that someone in Gaza is providing the samples.