The World Health Organization (WHO) said on Tuesday it was "very concerned" about possible outbreaks in the Gaza Strip, particularly after it isolated vaccine-derived poliovirus type 2 in sewage samples.
"I am very concerned. I am extremely concerned (...) and it is not just polio. There could be other outbreaks of communicable diseases that could occur," Dr Ayadil Saparbekov, WHO team leader for health emergencies in the Palestinian territories, said in a video conference.
"Hepatitis A was confirmed last year and now we could have polio," while there are already "up to 14,000 people who could" need medical evacuation out of Gaza, he said, during a regular press briefing by humanitarian agencies.
Poliomyelitis is a highly contagious disease caused by a virus (poliovirus) which invades the nervous system and can cause irreversible paralysis within a few hours.
On 16 July, the Global Polio Laboratory Network isolated vaccine-derived poliovirus type 2 from six environmental surveillance samples.
Analysis of the isolates – conducted by the Centers for Disease Control and Prevention (CDC) in Atlanta – shows that there are “close genetic links between them” and that they are also linked to the vaccine-derived poliovirus type 2 that circulated in Egypt in 2023, the WHO said on Tuesday.
The WHO reiterated on Tuesday that there is "a high risk" of the poliovirus spreading in the Gaza Strip and internationally "if this outbreak is not responded to rapidly and optimally."
"We have not yet collected human samples, due to lack of equipment to do so and laboratory capacity to test these samples," Dr. Saparbekov explained.
A team from the WHO and the United Nations Children's Fund (UNICEF), which is travelling to Gaza on Thursday, is expected to bring up to 50 kits to collect human samples which will then be sent to Jordan.
Meanwhile, WHO and its partners are assessing the extent of the spread of poliovirus. Dr Saparbekov hopes that recommendations can be issued on Sunday, but "given the current limitations in terms of hygiene and water sanitation in Gaza, it will be very difficult for people to follow the advice to wash their hands and drink safe water."
The war in the Gaza Strip was triggered on October 7 by an unprecedented attack carried out by Hamas commandos infiltrated in southern Israel, which resulted in the death of 1,197 people, mostly civilians, according to an AFP count based on official Israeli data.
In response, Israel launched a large-scale air and then ground offensive in Gaza, which left more than 39,000 dead, mostly civilians, according to data from the Health Ministry of the Hamas-led Gaza government.
English 
French