Spikes of influenza A virus seen in wastewater samples from 59 sewer systems across 18 different states this spring may point to the spread of the H5N1 avian influenza virus in dairy cattle, according to a new study. Researchers from Emory, Stanford and Verily Life Sciences have developed a test that can distinguish H5 influenza from other circulating A-strain flu viruses in wastewater. This passive method of tracking the spread of infections could serve as an early warning system for bird flu outbreaks in farm animals.
The study, which has been posted as a preprint on the BioRxiv server, suggests that wastewater testing could reveal information about circulating pathogens before it becomes publicly available. The researchers cautioned that no H5N1 outbreaks in cows have been reported in the sewersheds they tested. However, they suspect that the large spikes in H5 virus detected in early March were likely caused by the permitted dumping of milk from dairy cattle.
Wastewater testing relies on evidence flowing into the wastewater every time a toilet is flushed or someone dumps material down a drain. By monitoring sludge samples from wastewater treatment plants, researchers can detect genetic markers for influenza A viruses and specific markers for H5 viruses. As levels of the markers for influenza A viruses began to rise in early March, the markers for H5 viruses rose as well, suggesting a large fraction of the viruses in the samples were H5N1.
The implications of this research are significant, as wastewater testing has proven to be a harbinger of rising Covid-19 infections in the past. Now, it shows promise as a means of detecting and tracking bird flu outbreaks in farm animals. By monitoring wastewater, health authorities may be able to identify areas where the virus is spreading and take swift action to prevent further spread.
The use of wastewater testing could have a broader impact on public health. Just as it has been used to track Covid-19 infections, it could potentially be applied to monitor the spread of other infectious diseases. By analyzing wastewater samples, scientists may gain insights into the circulation of various pathogens in a community, allowing for targeted interventions and prevention measures.
Furthermore, this method of testing could be expanded to include other agricultural sectors. Monitoring wastewater from other livestock facilities, such as poultry farms, could provide early warnings for avian influenza outbreaks, helping to prevent the spread of the virus to humans and other animals.
It is important to note that while this study focuses on the detection of avian influenza in