Current Countries With Polio Detection
As of the latest available reports from the Global Polio Eradication Initiative (GPEI) and WHO, no country can be said to have ongoing, widespread wild poliovirus transmission in 2024, but surveillance and sewage data continue to detect very limited risk. Wild poliovirus type 1 (WPV1) has been documented through acute flaccid paralysis (AFP) and environmental samples in only a handful of settings, while circulating vaccine-derived poliovirus type 2 (cVDPV2) remains the primary public health concern in some countries due to under-immunization. This profile clarifies where the virus has been recently detected, what the different detection types mean, and what measurable milestones mark progress toward global eradication.
Definitions: Wild Poliovirus vs Vaccine-Derived Poliovirus
Understanding the difference helps interpret which countries truly have ongoing transmission risk. Wild poliovirus is the naturally occurring virus historically responsible for paralytic disease; it is targeted by routine immunization and trivalent oral polio vaccine (tOPV), which contained type 2. In contrast, circulating vaccine-derived poliovirus emerges in communities with low population immunity and prolonged replication, typically where oral polio vaccine (OPV) use has been suboptimal. Because tOPV contained type 2 virus that could revert to neurovirulence, cVDPV2 is now more common than WPV in residual detection.
Wild Poliovirus Type 1: Recent Detection Settings
Countries currently reporting WPV1 detection usually do so through AFP case surveillance or environmental sewage sampling rather than sustained community transmission. The last known endemic reservoirs for WPV1 were Afghanistan and Pakistan; however, continued travel- or sewage-linked detections mean these nations remain the primary areas of concern. In rare instances, WPV has been traced to travelers from or contacts of affected regions, underscoring the importance of high routine immunization coverage everywhere. No country outside these contexts has documented indigenous WPV1 transmission in recent years.
Afghanistan
Afghanistan remains the principal setting for ongoing WPV1 transmission. Challenges include conflict-impacted access, population displacement, and variable routine immunization coverage, all of which hinder interruption of the last remaining lineage of wild poliovirus globally.
Pakistan
Pakistan has similarly reported WPV1 cases, particularly in Sindh and other provinces where routine coverage gaps persist. Despite intensified vaccination campaigns and security measures, the virus continues to circulate at low levels in high-risk districts.
Circulating Vaccine-Derived Poliovirus Type 2: Where It Is Detected
cVDPV2 typically emerges in under-immunized populations and is the dominant type detected in environmental surveillance and AFP cases worldwide. Detection indicates vulnerability rather than active epidemic spread, prompting rapid response vaccination campaigns. Countries may report cVDPV2 in the context of protracted under-immunization, routine system weaknesses, or following use of novel oral polio vaccine type 2 (nOPV2) in outbreak response.
Democratic Republic of the Congo
Multiple provinces have reported cVDPV2 linked to prolonged low coverage and sanitation challenges.
Madagascar
Environmental and case detections of cVDPV2 have driven supplementary immunization activities to raise population immunity.
Myanmar
Border regions and internally displaced populations have experienced cVDPV2 detection, prompting coordinated campaign responses.
Nigeria
Though previously declared free of WPV, the country has seen cVDPV2 detection in the north, often tied to routine immunization gaps.
Somalia
Persistent cVDPV2 detections have led to repeated mass vaccination rounds supported by international partners.Syria
Conflict-driven disruptions to routine immunization and sewage surveillance have resulted in cVDPV2 detection in several governorates.
Environmental Surveillance and Travel-Related Detection
Beyond AFP, many countries conduct sewage surveillance to detect poliovirus remnants. Positive sewage samples can appear in settings with no recent paralytic cases, reflecting either recent importation or low-level residual circulation. Most countries with travel-related detection implement targeted responses—such as supplemental immunization activities or strengthened surveillance—rather than sustained transmission. This proactive approach aims to prevent any detection from escalating into widespread outbreaks.
Global Eradication Milestones and Impact
Since the launch of the Global Polio Eradication Initiative in 1988, paralytic polio cases have dropped by more than 99 percent. A factual table summarizing key milestones and regional progress follows, illustrating how coordinated vaccination, routine system strengthening, and rapid outbreak response have shaped the current landscape. Continued investment, data-driven targeting of zero-dose and under-immunized children, and maintenance of high immunity through reliable routine services remain essential to ensure no country has polio in the future.
Practical Global Polio Status and Milestones at a Glance
The following table distills verifiable attributes and measurable milestones most relevant to understanding the current footprint of poliovirus. Figures reflect peak versus current baselines and the nature of detection (WPV1, cVDPV2, or both).
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Countries with indigenous WPV1 transmission (2023 peak) | 2 (Afghanistan and Pakistan) | GPEI case reporting and official statements |
| Number of countries reporting WPV1 in 2024 (as of mid-year) | Afghanistan, Pakistan | GPEI situation reports |
| cVDPV2-positive countries (2024 detections) | More than 30 across Africa, Asia, and the Eastern Mediterranean | WHO polio reports and GISRS publications |
| Global paralytic polio cases (1988 peak) | Approximately 350,000 | GPEI historical records |
| Global paralytic polio cases (2023 reported) | Fewer than 20 WPV1 cases | GPEI annual summary |
| Number of trivalent OPV serotype 2 cessation rounds | Global synchronized cessation in 2016 | GPEI policy implementation records |
| Countries using novel OPV type 2 (nOPV2) in outbreaks (2024) | More than 30 in response to cVDPV2 | WHO nOPV2 deployment dashboards |
Risk Context and Public Health Implications
For the general population in most countries, the risk of paralytic disease from polio remains extremely low thanks to high routine immunization coverage and organized outbreak response. Where detection occurs, public health authorities typically conduct rapid risk assessments, enhance surveillance, and deliver targeted vaccines to close immunity gaps. The continued presence of cVDPV2 in some regions highlights the need to strengthen routine immunization and address barriers to care, rather than treating detections as isolated events. International coordination remains central to stopping all poliovirus transmission and certifying global eradication.
Key Takeaways
- Wild poliovirus type 1 is currently limited to Afghanistan and Pakistan, with no endemic transmission confirmed elsewhere in recent years.
- Circulating vaccine-derived poliovirus type 2 is detected in more than 30 countries, primarily where routine immunization coverage is insufficient.
- Environmental surveillance and travel-related detections are common tools to measure risk; they often trigger focused vaccination campaigns rather than widespread epidemics.
- Global milestones since 1988 include a drop of paralytic cases by more than 99 percent and coordinated cessation of trivalent OPV serotype 2.
- Sustained reductions in polio require robust routine immunization, rapid outbreak response, and continued investment in primary health systems.
Transmission Pathways and Containment Measures
Poliovirus spreads primarily via the fecal-oral route, often through contaminated water or poor sanitation. In settings with high population immunity—achieved through quality routine immunization and timely outbreak responses—transmission chains are quickly interrupted. Countries with recent detections typically strengthen surveillance, conduct supplementary immunization activities, and improve water, sanitation, and hygiene (WASH) services. Travelers can contribute to risk when immunity gaps exist; public health guidance emphasizes up-to-date polio vaccination before international travel, particularly to areas with known detection. Transparent reporting and data sharing enable coordinated containment and build public trust in eradication efforts.