A recent study conducted by scientists from Emory, Stanford, and Verily Life Sciences has shed light on the potential use of wastewater testing to track the spread of the H5N1 avian influenza virus. The study analyzed wastewater samples from 59 sewer systems across 18 states and found spikes in influenza A virus levels, indicating a possible connection to the ongoing H5N1 outbreak in dairy cattle.
The US Department of Agriculture has reported over 30 herds of dairy cows infected with H5N1 across nine states, raising concerns about the extent of the outbreak and the ability to monitor it effectively. Despite challenges in testing dairy cows for the infection, recent tests on milk samples from grocery stores revealed genetic material from the H5N1 virus in 1 out of 5 samples, although further testing confirmed the virus fragments were not infectious.
Wastewater testing offers a passive method of tracking infections without the need for individual swabbing. By monitoring genetic markers specific to H5 viruses in wastewater samples, researchers were able to detect a significant rise in H5N1 virus concentrations in samples from the Amarillo, Texas area, where dairy cattle had tested positive for the virus.
The study authors caution that while the presence of H5 genetic material in wastewater suggests a potential link to dairy cattle, the exact sources of the virus remain unclear. Further investigation is needed to determine the extent of the outbreak and identify other potential sources contributing to the virus in wastewater.
Despite the sensitivity of the testing method in detecting H5 viruses, researchers emphasize the need for additional studies to confirm the infectivity of the detected viruses. The US Food and Drug Administration has confirmed that traces of H5N1 virus found in pasteurized milk samples were not infectious and pose no risk to human health.
While the study provides valuable insights into the use of wastewater testing for early detection of avian influenza outbreaks, researchers stress the importance of further research to validate their findings and address unanswered questions surrounding the spread of the virus.
