U.N. Secretary-General Antonio Guterres on Friday called for Gaza combatants to provide guarantees of humanitarian pauses so that a polio vaccine campaign can be conducted.

Guterres, speaking to reporters at the United Nations, warned that preventing the spread of polio in the enclave would take a massive coordinated and urgent effort.

"Let’s be clear: The ultimate vaccine for polio is peace and an immediate humanitarian cease-fire," Guterres said. "But in any case, a polio pause is a must. It is impossible to conduct a polio vaccination campaign with war raging all over."

The Palestinian health ministry said in a statement Friday that it had detected the first confirmed case of polio in the Gaza Strip in the city of Deir al-Balah in a 10-month-old baby who had not received any polio vaccination dose.

Guterres said that the U.N. was poised to launch a polio vaccine campaign in Gaza for children younger than 10 but that the "challenges are grave."

At least 95% vaccination coverage will be needed during each of the two rounds of the campaign to prevent polio's spread and reduce its emergence given the devastation in Gaza, Guterres said. He added that a successful campaign would require the facilitation of transport for vaccines and refrigeration equipment at every step, the entry of polio experts into Gaza, reliable internet and phone services, and other elements.

Polio was detected in sewage in Gaza's Deir al-Balah and Khan Younis governorates, Dr. Hamid Jafari, a WHO polio specialist, said during a news conference earlier this month, adding it was possible the virus had been circulating since September.

A senior Western official, speaking on condition of anonymity, said it was understood that there was at least one confirmed case and two suspected ones among Palestinians in the enclave, adding that there might not be a single humanitarian pause but multiple shorter ones.

The danger is that the threat of disease outbreaks is not confined to Gaza, which the official said was a "contagion time bomb." The official explained that when the rainy season begins late this autumn, the contaminated raw sewage could be “pushed” down to an aquifer from which Israel, Egypt and Jordan draw water.

Poliomyelitis, which is spread mainly through the fecal-oral route, is a highly infectious virus that can invade the nervous system and cause paralysis.

Children younger than 5 are most at risk from the viral disease, and especially infants younger than 2, since normal vaccination campaigns have been disrupted by 10 months of conflict.

Without proper health services, the population of Gaza is particularly vulnerable to outbreaks of disease, public health officials and aid groups say.