Diagnostic Technologies

Detecting poliovirus through environmental surveillance

The bag-mediated filtration system being tested in Pakistan. Photo: PATH/S. Khan


Following decades of intensive vaccination programs, poliovirus (PV) has been eliminated from large parts of the world, thanks in part to the focused efforts of the World Health Organization (WHO), the Bill & Melinda Gates Foundation, and Rotary International. The virus remains endemic in three countries (Afghanistan, Nigeria, and Pakistan) that are now the primary focus of eradication programs. In both endemic and non-endemic countries, environmental surveillance (ES) is critical to monitor populations for silently circulating PV that threaten to cause outbreaks.


The goal of this project is to develop a new environmental surveillance tool to assist in the global eradication of PV. The University of Washington (UW) developed a bag-mediated filtration system (BMFS) that collects wastewater or sewage in a bag, and then passes it through a simple filter that binds PV, which can be sent to a laboratory for testing.

PATH is collaborating with the UW to test and improve the BMFS in typical field settings. Validation of the BMFS prototype was conducted in Kenya and Pakistan, where the BMFS demonstrated a higher degree of sensitivity than the WHO two-phase method in detecting the Sabin-like viruses (Kenya and Pakistan) and wild poliovirus serotype 1 (Pakistan). As a result, the BMFS remains in use in Pakistan via a field pilot study.

Learn more about PATH’s work on polio diagnostics:

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Contact information

David Boyle, Scientific Director, Diagnostics

This project is funded by the Bill & Melinda Gates Foundation.