Maricopa County's wastewater has thrown up a warning signal: traces of influenza A associated with avian flu have been detected across several sampling sites. The local Department of Public Health hastened to assert, however, that human cases have not surfaced and the risk to the population is minimal. The monitoring, which involves picking up genetic hints of microbes like influenza subtypes, has turned up the A(H5) variant in Phoenix, Surprise, and Tempe's wastewater systems, as reported by Maricopa County.
Pinning down the exact origin of this viral detection proved elusive, as is often the case with such environmental surveillance efforts. Avian influenza has, nonetheless, been confirmed in both a commercial poultry farm in adjacent Pinal County and, closer to home, a backyard flock and zoo animals in Maricopa County. Genomic testing has linked the flu strain in these bird populations to the same H5N1 strain spreading among wild birds. It's a different case for wastewater samples, where “strain-specific testing in wastewater samples is not available so this link cannot be confirmed,” said Dr. Nick Staab, assistant medical director at MCDPH, in a statement covered by Maricopa County's news release.
With respiratory virus season in full swing, the health department's focus is on reinforcing general prevention measures for illnesses such as COVID-19 and the seasonal flu. Dr. Staab reminds residents to practice good hygiene, get vaccinated, and keep their distance when ill, “To prevent illness, we want residents and visitors to focus on taking general respiratory virus prevention measures,” as stated by Maricopa County.
As for the threat of bird flu to humans, the word is caution, not panic. Maricopa County officials encourage the reporting of sick or dead birds, whether domestic or wild, to the appropriate authorities. For anyone seeking more details on their avian flu message and the ins and outs of wastewater surveillance, resources and FAQs are available on the Maricopa County website.
