The Times Australia
The Times World News

.

What does this mean for the region and the world?

  • Written by Michael Toole, Associate Principal Research Fellow, Burnet Institute
what does this mean for the region and the world?

As war continues to devastate Gaza and its people, we learnt last week that a variant of poliovirus[1] has been detected in the region. The virus was isolated in six sewage samples collected in late June from Khan Younis and Deir al Balah.

Most infections with poliovirus don’t cause symptoms, but a minority of those who contract the virus develop paralysis[2] (paralytic polio).

No cases of paralytic polio have been reported in Gaza. But detecting the virus in wastewater is concerning nonetheless.

There are different types of polio

The cases of polio we’ve seen historically have generally been caused by “wild poliovirus”. For centuries, wild poliovirus affected both poor and wealthy countries, including Australia. The deployment of effective vaccines[3] in the 1960s led to a dramatic decrease in cases in the following decades among those countries that could afford the vaccines.

The introduction of the Global Polio Eradication Initiative[4] in 1988 enabled more equitable vaccination. There were only 12 cases of paralysis[5] caused by wild poliovirus in 2023, in just two countries: Pakistan and Afghanistan.

However, as the number of wild poliovirus cases decreased there was an increase in cases of vaccine-derived poliovirus causing paralysis.

There are two types of polio vaccines: one is given orally, and the other by injection (the type used in Australia). The oral polio vaccine is based on a weakened virus – so it doesn’t cause disease, but can still reproduce. Vaccine-derived poliovirus emerges when people vaccinated with the oral polio vaccine[6] excrete the vaccine virus in their stool and it spreads to other people.

Over time, it may mutate to become a virus that circulates and causes paralysis in populations with low levels of immunity. In 2023, there were 524 polio cases[7] in 32 countries caused by vaccine-derived poliovirus.

It’s a strain of vaccine-derived poliovirus that has been detected in the wastewater in Gaza – type 2[8].

High vaccination coverage is key, but not always enough

The most important indicator of eradicating polio, both wild and vaccine-derived, is vaccine coverage. This is usually measured as the percentage of children under five who have received at least four vaccine doses, ideally 95%.

High vaccination coverage has been achieved by a combination of routine immunisation in early childhood plus national or local catch-up vaccination campaigns, particularly in areas where the virus pops up[9].

However, high vaccination coverage is not always enough to eliminate the virus.

Early in the 21st century, India and Nigeria[10] were reporting the highest number of polio cases in the world. After an accelerated immunisation campaign in India, vaccine coverage rates were high by 2007 and cases were decreasing. But many cases continued to be reported in impoverished districts of western Uttar Pradesh (a state in northern India), where access to clean water and sanitation was poor.

Research shows a high level of pathogens in children’s intestines can make the absorption of the oral vaccine[11] less effective, while unsanitary conditions make it easier for the virus to spread. After a sanitation and hygiene project began in 2007[12], the last case of polio in Uttar Pradesh occurred in 2010[13], and the entire country eradicated polio in 2014[14].

Wild polio was eradicated[16] from Gaza more than 25 years ago. But it’s possible the re-emergence of vaccine-derived poliovirus is due to a combination of poor hygiene and sanitation[17], as we saw in Uttar Pradesh, and reduced vaccine coverage.

Polio vaccination coverage in the Palestinian territories was 99% in 2022[18]. By the end of 2023, coverage had dropped to 89%. However, the data were not separated by each of the territories (the West Bank, East Jerusalem and Gaza), so coverage may be lower in Gaza.

Recent outbreaks

We saw the detection of a similar strain[19] of poliovirus in wastewater in Jerusalem, London and New York in early 2022.

Parts of these cities have high concentrations of ultra-Orthodox Jews, which may have lower rates[20] of vaccination than the overall population. In Rockland County[21], 65 kilometres north of New York City, a young, unimmunised Orthodox Jewish man became the first case of polio transmitted locally in the United States in 30 years[22].

There’s no evidence of vaccination hesitancy among Ultra-Orthodox Jews in Australia. However, there are other communities where vaccination rates are low, including some shires in the Northern Rivers district[23] of New South Wales.

Communities with low vaccination rates, whatever the reason, are vulnerable to infectious diseases such as polio.

So where did this virus come from?

The oral vaccine used in Gaza has not contained type 2 since 2016[24], so it must have come from elsewhere.

In 2023, most outbreaks of type 2 vaccine-derived poliovirus[25] were in the Democratic Republic of Congo, Yemen, Nigeria, Sudan and Somalia. There was also one case in Egypt, which borders on Gaza. Egypt could be the source of this virus, but we’ll need further investigation.

It’s unlikely to have come from Israel as there have been no detections of poliovirus in wastewater there since 2022[26].

What can the world learn?

First, we must not forget that poliovirus can cross borders and maintaining high vaccination rates in Australia and elsewhere is the most effective protective strategy. It’s also crucial to contain the virus inside Gaza. UNICEF and partners are preparing for a vaccination campaign[27] focusing on young children.

Second, it’s important to maintain wastewater surveillance for polio, which is an early warning mechanism that can initiate public health action before symptomatic cases occur.

In 2022, Victoria was the only Australian state conducting routine polio wastewater surveillance until NSW[28] adopted the practice when the outbreaks in Jerusalem, New York and London occurred. Wastewater surveillance is worthwhile in all states and territories.

Third, but not least, this should be a wake-up call highlighting the need to cease hostilities and provide unrestricted access by aid agencies to improve the provision of clean water, sanitation and effective health services throughout Gaza. This is an urgent global health priority.

References

  1. ^ poliovirus (polioeradication.org)
  2. ^ develop paralysis (theconversation.com)
  3. ^ effective vaccines (www.who.int)
  4. ^ Global Polio Eradication Initiative (www.cdc.gov)
  5. ^ 12 cases of paralysis (polioeradication.org)
  6. ^ oral polio vaccine (theconversation.com)
  7. ^ 524 polio cases (www.cdc.gov)
  8. ^ type 2 (polioeradication.org)
  9. ^ the virus pops up (theconversation.com)
  10. ^ India and Nigeria (polioeradication.org)
  11. ^ absorption of the oral vaccine (pubmed.ncbi.nlm.nih.gov)
  12. ^ began in 2007 (www.iapsmupuk.org)
  13. ^ in 2010 (iple.unicef.in)
  14. ^ in 2014 (www.bbc.com)
  15. ^ Talukdar David/Shutterstock (www.shutterstock.com)
  16. ^ was eradicated (news.un.org)
  17. ^ hygiene and sanitation (edition.cnn.com)
  18. ^ 99% in 2022 (polioeradication.org)
  19. ^ a similar strain (www.reuters.com)
  20. ^ lower rates (www.sciencedirect.com)
  21. ^ Rockland County (www.cdc.gov)
  22. ^ in 30 years (www.bmj.com)
  23. ^ Northern Rivers district (www.echo.net.au)
  24. ^ since 2016 (www.nejm.org)
  25. ^ type 2 vaccine-derived poliovirus (applications.emro.who.int)
  26. ^ 2022 (www.mdpi.com)
  27. ^ a vaccination campaign (gna.org.gh)
  28. ^ NSW (www.thenewdaily.com.au)

Read more https://theconversation.com/polio-in-gaza-what-does-this-mean-for-the-region-and-the-world-235178

Times Magazine

Headless CMS in Digital Twins and 3D Product Experiences

Image by freepik As the metaverse becomes more advanced and accessible, it's clear that multiple sectors will use digital twins and 3D product experiences to visualize, connect, and streamline efforts better. A digital twin is a virtual replica of ...

The Decline of Hyper-Casual: How Mid-Core Mobile Games Took Over in 2025

In recent years, the mobile gaming landscape has undergone a significant transformation, with mid-core mobile games emerging as the dominant force in app stores by 2025. This shift is underpinned by changing user habits and evolving monetization tr...

Understanding ITIL 4 and PRINCE2 Project Management Synergy

Key Highlights ITIL 4 focuses on IT service management, emphasising continual improvement and value creation through modern digital transformation approaches. PRINCE2 project management supports systematic planning and execution of projects wit...

What AI Adoption Means for the Future of Workplace Risk Management

Image by freepik As industrial operations become more complex and fast-paced, the risks faced by workers and employers alike continue to grow. Traditional safety models—reliant on manual oversight, reactive investigations, and standardised checklist...

From Beach Bops to Alpine Anthems: Your Sonos Survival Guide for a Long Weekend Escape

Alright, fellow adventurers and relaxation enthusiasts! So, you've packed your bags, charged your devices, and mentally prepared for that glorious King's Birthday long weekend. But hold on, are you really ready? Because a true long weekend warrior kn...

Effective Commercial Pest Control Solutions for a Safer Workplace

Keeping a workplace clean, safe, and free from pests is essential for maintaining productivity, protecting employee health, and upholding a company's reputation. Pests pose health risks, can cause structural damage, and can lead to serious legal an...

The Times Features

Tricia Paoluccio designer to the stars

The Case for Nuturing Creativity in the Classroom, and in our Lives I am an actress and an artist who has had the privilege of sharing my work across many countries, touring my ...

Duke of Dural to Get Rooftop Bar as New Owners Invest in Venue Upgrade

The Duke of Dural, in Sydney’s north-west, is set for a major uplift under new ownership, following its acquisition by hospitality group Good Beer Company this week. Led by resp...

Prefab’s Second Life: Why Australia’s Backyard Boom Needs a Circular Makeover

The humble granny flat is being reimagined not just as a fix for housing shortages, but as a cornerstone of circular, factory-built architecture. But are our systems ready to s...

Melbourne’s Burglary Boom: Break-Ins Surge Nearly 25%

Victorian homeowners are being warned to act now, as rising break-ins and falling arrest rates paint a worrying picture for suburban safety. Melbourne residents are facing an ...

Exploring the Curriculum at a Modern Junior School in Melbourne

Key Highlights The curriculum at junior schools emphasises whole-person development, catering to children’s physical, emotional, and intellectual needs. It ensures early year...

Distressed by all the bad news? Here’s how to stay informed but still look after yourself

If you’re feeling like the news is particularly bad at the moment, you’re not alone. But many of us can’t look away – and don’t want to. Engaging with news can help us make ...