Polio Travel Advisory: CDC Updates Guidance Amid Global Circulation

Recent detections of poliovirus in wastewater, including in London, have prompted the U.S. Centers for Disease Control and Prevention (CDC) to update its global travel health notice regarding polio. The advisory, classified as Level 2 – Practice Enhanced Precautions, highlights the ongoing risk of poliovirus circulation in over 30 countries.

Polio Resurgence and Wastewater Surveillance

The CDC advisory, issued on March 3, 2026, underscores the importance of vaccination as poliovirus continues to be detected in environmental samples, particularly in sewage systems. In the United Kingdom, detections have been concentrated around the Beckton Sewage Treatment Works, serving millions in northern and eastern London. A circulating vaccine-derived poliovirus type 2 (cVDPV2) was identified in a sample collected around January 28, 2026, according to the UK Health Security Agency (UKHSA).

These findings follow earlier detections in late 2024 in East Worthing, Leeds, and London’s Beckton and Crossness treatment plants, and similar detections in London sewage began as early as 2022. While the UK has not reported a case of paralytic polio since 1984, these environmental detections suggest potential silent transmission, particularly in communities with low vaccination rates.

Understanding Vaccine-Derived Poliovirus

Vaccine-derived poliovirus occurs when the weakened live virus used in oral polio vaccines (OPV) mutates and regains the ability to spread, especially in populations with low immunization coverage. Although the UK switched to the inactivated polio vaccine (IPV) in 2004 – which does not carry this risk – international travel can introduce strains from regions where OPV is still used. The novel OPV (nOPV2) vaccine has been administered over 2 billion times in recent years in global efforts to combat the virus.

Countries Affected by the Advisory

The updated CDC advisory includes both endemic hotspots and countries where wastewater detections have been reported. Affected countries include:

• Afghanistan
• Algeria
• Angola
• Benin
• Burkina Faso
• Cameroon
• Central African Republic
• Chad
• Côte d’Ivoire
• Democratic Republic of the Congo
• Djibouti
• Ethiopia
• Finland
• Germany
• Ghana
• Guinea
• Israel
• Niger
• Nigeria
• Pakistan
• Papua New Guinea
• Poland
• Senegal
• Somalia
• South Sudan
• Spain
• Sudan
• Tanzania
• United Kingdom
• Yemen
• Zimbabwe

CDC Recommendations for Travelers

The CDC urges travelers to ensure they are up to date on their polio vaccines before any international trip. For individuals who are unvaccinated or incompletely vaccinated and planning to travel, clinicians should prioritize completing the IPV series. Adults who have completed the full routine polio vaccine series are advised to receive a single lifetime IPV booster dose before traveling to affected areas.

Polio can cause lifelong paralysis or even death in rare cases, making vaccination a critical preventative measure. Wastewater surveillance serves as an early warning system, allowing public health officials to intervene before outbreaks occur.

Key Takeaways

• Polio remains a global health concern, with detections in over 30 countries.
• The CDC has issued a Level 2 travel advisory, recommending enhanced precautions.
• Vaccination is the most effective way to protect against polio.
• Travelers should verify their vaccination status and consider a booster dose.
• Wastewater surveillance is a crucial tool for early detection, and prevention.

With intensified global efforts and early warning systems like wastewater surveillance, there is hope that the spread of poliovirus can be contained, protecting both travelers and communities worldwide.