Polio Outbreaks

Poliovirus Outbreaks April 2025

The World Health Organization (WHO) confirmed during the 41st meeting of the IHR Emergency Committee for Polio in April 2025 that the spread of the poliovirus remained a Public Health Emergency of International Concern (PHEIC) and updated its polio outbreak map. As of April 27, 2025, the Global Polio Eradication Initiative (GPEI) confirmed that various countries had reported cases of wild poliovirus type 1 (WPV1), circulating vaccine-derived poliovirus type 2 (cVDPV2), vaccine-derived poliovirus type 2 (VDPV2), and circulating vaccine-derived poliovirus type 1 (cVDPV1). 

The U.S. Centers for Disease Control and Prevention (CDC) reissued a Global Polio Alert—Level 2, Practice Enhanced Precautions Travel Health Notice on April 22, 2025, regarding polio outbreaks and poliovirus detections in 38 countries. The CDC published an MMWR on March 6, 2025, confirming that the Nigeria virus lineage had been detected in wastewater samples in 16 cities across five European countries. On October 17, 2024, the CDC announced (MMWR Vol. 73, No. 41) that from January 2023 to June 2024, 74 cVDPV outbreaks were detected in 39 countries, with 672 confirmed cases of acute flaccid paralysis (AFP) identified in 27 countries. Less than 1% of wild poliovirus infections result in Acute Flaccid Paralysis (AFP). In 2024, the GPEI reported 243 cases of AFP worldwide. 

Polio Cases in the Americas

The WHO / Pan American Health Organization (PAHO) issued an Epidemiological Update (Year 39, 51-52) - Poliomyelitis in the Americas Region and reported AFP Surveillance in 2024. The PAHO/WHO reminds Member States that the risk of the emergence of a cVDPV1 or circulating vaccine-derived poliovirus type 3 (cVDPV3) has increased due to low vaccination coverage. In addition, the PAHO/WHO reports a continuing risk of importing a WPV1 or VDPV, mainly cVDPV2. cVDPV2 cases peaked in 2020, with over 1,000 cases of paralysis in 24 countries. As of January 2025, the PAHO reported 1,856 AFP cases in 2024.  

Polio in the United States

The United States was added to a list of polio-identified countries in 2022. The CDC reported (Volume 30, Number 11—November 2024) that wastewater surveillance for poliovirus identified ongoing transmission of poliovirus in Rockland County and adjacent New York counties in 2022. In June 2022, a case of paralytic polio caused by VDPV2 was identified in an unvaccinated adult in Rockland County, New York. In addition, poliovirus type 2, genetically linked to the VDPV2 isolated from the patient, was detected in wastewater samples from Rockland and several surrounding counties, indicating community transmission. This case was the first known case of paralytic polio in the U.S. since 2013 and the first documented instance of community transmission of poliovirus in the U.S. since 2005. The New York State Department of Health (NYSDOH) confirmed the presence of poliovirus in wastewater in March 2023  and October 2024. The CDC states that the detection of poliovirus in wastewater cannot be used to determine the total number of infected individuals in a community or the proportion of the infected population. The minimum number of infected individuals that can be reliably detected through wastewater testing is not known. 

The International Health Regulations classify the U.S. as a country or state infected with cVDPV2, with or without evidence of local transmission. Therefore, the U.S. is subject to Temporary Recommendations issued by the International Health Regulations Emergency Committee on Polio Eradication. 

Afghanistan Polio Outbreak

Afghanistan is affected by the ongoing endemic transmission of wild poliovirus. In 2024, 25 WPV1 cases were reported. In 2023, 18 WPV1-positive environmental samples were reported. According to the Ministry of Health, Afghanistan detected its initial human polio case in May 2023. As of June 2, 2023, local media reported four confirmed cases of polio in the province of Nangarhar. Two polio patients were confirmed in 2022, four in 2021, and 56 in 2020.

Africa Polio Outbreaks

Kenya's Ministry of Health announced on October 1, 2024, that five polio cases have been confirmed, and one positive environmental surveillance sample has been taken in Kamukunji Sub-County, Nairobi. In June 2024, Somalia launched a significant polio vaccination campaign for children. On May 24, 2024, Angola reported AFP and environmental detections. On May 14, 2024,  the closure of the WPV1 outbreaks in Malawi and Mozambique was announced. Over 100 million vaccine doses have been administered in the areas most at risk. Zimbabwe is inoculating more than 4 million children against polio in February 2024, following the detection of three cases caused by a rare mutation of the weakened virus in oral vaccines.

Australia Poliovirus Detections

On December 2, 2024, Australia's poliovirus surveillance program detected vaccine-derived poliovirus in pre-treated sewage from the Western Treatment Plant in Melbourne. This detection is likely linked to an individual who received a live polio vaccine and shed the virus in Victoria. Australia remains polio-free, as there has not been a detection of wild-type poliovirus.

South-East Asia Polio Outbreaks

Singapore reported one polio case in February 2025. Indonesia reported four instances of cVDPV2 from October 2022 to February 2023. In late December 2023, the Indonesian Ministry of Health notified WHO of two new confirmed cases of cVDPV2. Despite Indonesia having a strong capacity to respond to poliovirus outbreaks and West Java having a moderate to strong outbreak response capacity to interrupt transmission, the population remains highly susceptible to poliovirus type 2 after switching from trivalent to bivalent OPV. The ongoing polio outbreak in Indonesia poses a high risk at the national level, a moderate regional threat, and a low global risk as of 2024. The GPEI published a report of the Indonesia Polio Outbreak Response Assessment – July 2023. BMC Public Health published in March 2021 - Scaling up public health interventions: a case study of the polio immunization program in Indonesia.

Europe Polio Outbreaks

This Eureopen CDC dashboard provides an overview of the global poliovirus situation in April 2025. The European Centre for Disease Prevention and Control (ECDC) published an interactive map in 2025 displaying countries currently confirming polio or poliovirus cases. From September through December 2024, vaccine-derived poliovirus type 2 (VDPV2) was detected in wastewater systems of 14 cities in five European countries. The isolated VDPV2 viruses are linked to a lineage (NIE-ZAS-1) first detected in Nigeria in July 2020. Poliovirus has been detected in Germany, Finland, Poland, and Spain. Poland's health ministry confirmed that a sample of municipal sewage collected in Win 2024 Warsaw in 2024 revealed the presence of poliovirus type 2. The last poliovirus cases in Poland were recorded in 1982 and 1984. Finland's Institute for Health and Welfare identified VDPV2 in wastewater samples from Tampere in 2024. The WHO declared the European Region polio-free in 2002. 

India Polio Outbreaks

The World Health Organization declared India polio-free in 2014. National Immunization Days are held twice a year across India, and the government aims to administer two drops of OPV to every child under five, as reported by The Times of India in 2023. Polio vaccination campaigns for children are expected to continue in 2024.

Israel Polio Outbreaks

On April 24, 2025, the Ministry of Health's Central Virus Laboratory in Israel detected poliovirus in an environmental sample in the Jerusalem area. In March 2025, Israel discontinued offering the live attenuated polio vaccine (oral). It now provides the IPV. As of March 2023, four VDPV3-positive polio cases in children were confirmed. On February 27, 2023, the Israel Ministry of Health issued an official alert describing a local case of Acute Flaccid Paralysis (AFP). As of April 15, 2022, a total of seven VDPV3-positive cases were confirmed. A cluster of VDPV3 was previously detected in environmental samples from Jerusalem and Bethlehem city, collected between September 2021 and January 2022. 

Gaza Strip Polio Outbreak

In February 2025, the WHO confirmed a polio case that had occurred in August 2024. New environmental samples from Deir al Balah and Khan Younis, collected in December 2024 and January 2025, confirm the transmission of poliovirus, genetically linked to the poliovirus detected in the Gaza Strip in July 2024. 

Pakistan Polio Outbreaks

In 2025, 3 WPV1 cases were reported. In 2024, 73 WPV1 cases were confirmed, and numerous WPV1-positive environmental samples were reported this year. Of these, 27 were from Balochistan, 22 from Khyber Pakhtunkhwa, 22 from Sindh, and one from Punjab and Islamabad. In 2022, 20 WPV1 cases and 20 paralyzed children were reported in the southern KP province.

South America Poliovirus Detections

The Pan American Health Organization (PAHO) published an alert on October 14, 2024, confirming the detection of circulating vaccine-derived poliovirus type 3 (cVDPV3) in wastewater samples collected in Cayenne, French Guiana. Additional testing identified positive samples collected in Remire-Montjoly and Saint-Georges-de-l'Oyapock. In 2024, the PAHO identified Argentina, Haiti, and Peru as at very high risk for the reintroduction of polio. In 2024, the PAHO reported that 176 virus isolation test results were pending in the Americas.

Spain Poliovirus

In Spain, circulating vaccine-derived poliovirus type 2 (cVDPV2) was isolated from a single positive sample collected in Barcelona for the first time in September 2024.

United Kingdom Poliovirus 

In December 2024, one cVDPV2-positive environmental sample was collected in London. Five cVDPV2-positive environmental samples were collected in November 2024 from Yorkshire and the Humber, the South East, and London in the U.K. The UKHSA National Polio Guidelines outline public health actions to be taken when a cVDPV2 is detected in environmental samples. In May 2022, six positive samples were reported following the isolation of VDPV2 from ecological samples in London. U.K. public health authorities continue to intensify surveillance efforts, including for potential cases of paralysis, offering an additional dose of inactivated polio vaccine to all children across London.

Polio Vaccines

As of April 2025, various polio vaccines are available worldwide. Due to the high vaccination rate (93%), the CDC reports very few cases of polio. According to the CDC, the IPV has been the only vaccine in the U.S. since 2000. The New York City Health Department and the CDC recommend that adults who received polio vaccines as children receive a one-time lifetime IPV booster dose if traveling to an area with poliovirus transmission.