Bird Flu Detected in Wastewater of Three Arizona Cities

Possible evidence of bird flu has been detected in three cities in Maricopa County, Arizona—Phoenix, Surprise and Tempe—through wastewater sampling. The Maricopa County Department of Public Health (MCDPH) released a statement on Monday reporting the detection of influenza A (H5) in these cities’ wastewater. Bird flu is also known as avian influenza A (H5N1) and it is a type of influenza A (H5). “Wastewater monitoring is one of multiple tools we have to proactively monitor for avian flu in our community,” said Dr. Nick Staab, assistant medical director at MCDPH, in the statement. “Given that no human cases have been identified in Maricopa County though our other disease detection methods and there is no recent documented spread of H5N1 influenza from human to human, the overall risk of avian flu to people remains low.” Scottsdale viewed from Pinnacle Peak trail in Arizona, near Phoenix, from June 2024, with an image of a wastewater pipe inset. Wastewater monitoring in three sites in Arizona, including Phoenix, detected influenza A (H5). Scottsdale viewed from Pinnacle Peak trail in Arizona, near Phoenix, from June 2024, with an image of a wastewater pipe inset. Wastewater monitoring in three sites in Arizona, including Phoenix, detected influenza A (H5). miroslav_1 / Antony Robinson/iStock / Getty Images Plus / Canva In the whole state of Arizona, no human cases of bird flu have been confirmed by the Centers for Disease Control and Prevention (CDC). However, two probable human cases of bird flu were reported by the Arizona Department of Health Services on December 6, linked to exposure to an infected flock of poultry in Pinal County. On December 11, MCDPH also announced the infection of several zoo animals with bird flu at Wildlife World Zoo, Litchfield Park. Testing wastewater, including sewage, can help public health officials monitor the spread of viruses and bacteria such as flu and COVID-19, even picking up cases that are symptomless and unreported. Newsweek has approached the MCDPH and CDC for comment via online form and email, respectively. The CDC last updated their wastewater data on December 26, based on samples from the week of Sunday, December 15, to Saturday, December 21. According to this data, influenza A (H5) was detected in 52 out of 246 sites nationwide, 49 of which were in California. California remains at the center of the U.S. bird flu outbreak, with 37 out of 66 of the country’s confirmed human cases and one extra probable illness reported there. California Governor Gavin Newsom announced a state of emergency on December 18 over bird flu. Three non-Californian sites have also reported influenza A (H5) in local wastewater: Du Page County in Illinois, Wapello County in Iowa and Clark County in Nevada. Of those states, only Iowa has reported a human case of the virus, linked to exposure to infected poultry. The CDC maintains that the current public health risk of bird flu is low and there has been no reported person-to-person spread; human cases of bird flu remain connected to exposure to infected animals, such as poultry, cattle and wild birds. Out of the 66 confirmed human cases in the U.S., only one has been classed as severe: an individual who got sick in Louisiana after exposure to wild birds. But scientists are concerned that the increasing spread of the virus could lead to mutations, which could enable bird flu to be passed among humans, raising the risk of a possible bird flu pandemic. Is there a health problem that’s worrying you? Do you have a question about bird flu? Let us know via health@newsweek.com. We can ask experts for advice and your story could be featured in Newsweek.