Stalked by polio, Gaza faces another siege Premium

If medical conditions in Gaza do not improve, the infectious poliovirus may win back one more territory for itself and endanger the Israeli population as well

The United Nations Office for Disarmament Affairs describes biological weapons as those that “disseminate disease-causing organisms or toxins to harm or kill humans, animals or plants”.

War itself is a nasty thing during which humans, animals, and plants are killed en masse. We often contend today with the death of animals and plants in the context of climate change — mindful of the role of animals in maintaining ecosystem services and the carbon sequestration potential of plants — and know that the remains of incendiary explosives and building debris drive toxic effects, often entrenched enough for their effects to last for generations. This is separate from the large carbon footprints of armies in motion plus the operations required to equip them.

Climate change can also create environments conducive to the spread of some disease-causing microbes. The chemically toxic outcomes of war can diminish people’s and the beleaguered state’s ability to respond optimally to this challenge, allowing these dysfunctional environments to persist and sow more threats. The operations of the conflict itself can finally strike a killing blow by bombing hospitals, blocking medical aid, and cutting off water and electricity supplies — such as what Israel has been doing in Gaza.

In the third week of July, Israel’s Health Ministry said it had found poliovirus particles in the sewage flowing out of Gaza. Haaretz reported that the Israel Defense Forces (IDF) responded by initiating a campaign to vaccinate its soldiers in Gaza and those slated to enter the territory. As of July 21, the IDF reportedly said it had not recorded any clinical cases of poliomyelitis but expected there to be an outbreak.

This is a debatable statement for two reasons. First, according to the UN, as of May 21, 2024, “only around one-third of Gaza’s 36 hospitals still function, leaving critical health care facilities inaccessible to patients and healthcare workers impacted by the violence or evacuation orders.” As Israeli bombs have devastated hospitals and civilian shelters and ground forces have restricted access to medical aid, a Gazan is not likely to be diagnosed with a poliovirus infection except by aid workers at shelters, which are also grossly overcrowded, or in areas outside the conflict zone.

Second, the poliovirus is an obligate human pathogen, meaning it can replicate only inside cells of the human body. This virus has no other known animal reservoirs. So, if Israeli researchers have detected poliovirus in Gaza’s sewage, the virus must already have infected some residents of Gaza. On July 29, Gaza’s Health Ministry declared a polio “epidemic” in the Gaza Strip.

The severity of infections is of course unknown. But equally, allowing the virus to spread is irreconcilable with the efforts of most of the rest of the world to eradicate polio, which — after three decades of intense efforts — is currently limited to cases of wild poliovirus type 1 in rural Pakistan and Afghanistan. The virus circulating in Gaza is believed to be vaccine-derived poliovirus type 2.