Michigan Wastewater Testing for Poliovirus Begins Months Later Than Expected
In a delay that has raised concerns among health officials, Michigan’s wastewater testing for poliovirus didn’t begin until last week, months after it was initially scheduled to start. The testing is part of an effort by state and federal health leaders to monitor the spread of poliovirus in areas with low vaccination rates and connections to New York communities where a paralytic polio case was identified in July 2022.
Although wastewater surveillance cannot determine who is infected or the specific number of affected individuals or households, it helps public health authorities understand where poliovirus is spreading and aids in prioritizing vaccination efforts in surrounding areas. According to Chelsea Wuth, a spokesperson for the Michigan Department of Health and Human Services, the delayed start of the testing was due to a variety of factors, including the need to find sampling locations that met specific criteria and address funding and data-sharing concerns.
The wastewater samples collected will be screened for the poliovirus, with samples dating back to March 2023 being included in the testing. However, the exact locations and communities in Oakland County that are part of the testing have not been disclosed.
Polio, a virus that caused severe illness and paralysis in children during the 1940s and 1950s, spreads through person-to-person contact and primarily affects the brain and spinal cord. It can lead to paralysis or death. Dr. Natasha Bagdasarian, Michigan’s chief medical executive, emphasized the importance of vaccination in preventing polio and stated that wastewater monitoring helps identify potential risks while ensuring community safety.
Most people infected with poliovirus do not exhibit any symptoms, making its spread difficult to detect. However, severe cases can cause symptoms such as sore throat, fever, exhaustion, headache, nausea, stomachache, and in some cases, paralysis and death.
The detection of a polio case in Rockland County, New York, in 2022—marking the first known instance of community transmission of poliovirus in the United States since 1979—prompted a large-scale vaccination campaign and a state of emergency in New York. Wastewater surveillance in southeastern New York later revealed over 100 positive samples, suggesting that the virus had been spreading undetected for months in the region. As a result, the United States is now classified as a country with circulating poliovirus.
To protect oneself and loved ones from polio, health officials recommend vaccination. Unvaccinated individuals and those who have not completed their full vaccine series are particularly vulnerable. The vaccine provides 99% protection against severe disease. The Oakland County Health Division offers free polio vaccines to residents at certain locations.
The results of the wastewater testing will be posted on the state health department’s website, with routine samples expected to take two weeks to process. Wastewater testing will continue on a weekly basis for up to six months, and if no detections are found, sampling may be discontinued.
Overall, the delayed start of wastewater testing in Michigan underscores the complexities and challenges associated with monitoring the spread of poliovirus. It has shed light on the need for continued efforts to boost vaccination rates and protect public health.