According to the UN, Gaza, now in its 11th month of war, has not registered a polio case for 25 years, although type 2 poliovirus was detected in samples collected from the territory’s wastewater in June.

The head of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, said he is “gravely concerned” and confirmed that efforts are under way to roll out a vaccination programme in the coming weeks. The 10-month-old, who was unvaccinated, is said to be in a stable condition after developing paralysis in one leg.

Poliovirus, most often spread through sewage and contaminated water, is highly infectious.

It can cause disfigurement and paralysis, and is potentially fatal. It mainly affects children under the age of five.