Wastewater testing in San Diego County has flagged the presence of the H5 influenza virus, commonly known as bird flu, a pathogen more often associated with our feathered friends than with the human population. According to the County of San Diego, the detection was made on Sept. 1, and no subsequent samples have tested positive. This report comes amidst concerns over the virus due to recent cases of cattle and farm workers elsewhere this year.
Despite detection in the wastewater, there's no indication of human or animal infection with H5 in San Diego County this year. "San Diego County has a robust flu surveillance system," Dr. Ankita Kadakia, County interim public health officer, told the County of San Diego. "While we have no evidence of the virus in people or animals, it is important to be transparent with the public both about the detection status and that we are vigilant and working with our partners at the California Department of Public Health, California Department of Food and Agriculture, and California Department of Fish and Wildlife to monitor for signs of H5 presence locally.” Previous encounters with the virus in the region have occurred with wild birds in 2022 and 2023 and a poultry flock in 2022.
Wastewater SCAN's monitoring efforts, covering many pathogens, are privately funded and offer another layer of oversight beyond public health authorities. In this case, their findings serve as a bellwether for potential public health concerns, allowing the county's surveillance system, which tracks human influenza, COVID-19, and Respiratory Syncytial Virus (RSV), to kick into gear. Data on these viruses are made available to the public through regular surveillance updates posted online.
