As the H5N1 avian influenza virus continues to spread through California’s dairy and commercial poultry herds, Central Valley state officials are expressing concern about the lack of wastewater monitoring in the region.
State Sen. Melissa Hurtado (D-Sanger) said there are gaps in tracking the spread of avian influenza in the Central Valley, where many of the state’s most vulnerable populations (dairy and poultry workers) live and work. I am dissatisfied with it.
“If you’re tracking diseases that jump from animals to humans, you want to focus on rural areas like Tulare County, where there are more cows than people. But sewage testing anywhere south of Fresno “Valley,” Hurtado said.
As of December 30, 37 people in California had tested positive for H5N1. All but one were dairy workers. Additionally, more than two-thirds of the state’s dairy herd (697 animals) and 93 commercial or backyard poultry flocks, or approximately 22 million birds, have been infected.
Gov. Gavin Newsom declared a state of emergency on Dec. 18 after the virus jumped from dairy herds in the state’s Central Valley to dairy cows in Southern California, despite quarantine restrictions to stop the spread. did.
The virus has also moved into migratory bird and wildlife populations, and has been detected at wastewater sites in states including Los Angeles, San Francisco and San Jose.
However, sampling is sparse in the Central Valley, where the majority of human cases have been reported and the risk is high. In fact, some of the highest-risk counties, such as Tulare and Kings, have no wastewater sampling for avian influenza.
Why current tests aren’t good enough
Wastewater sampling helps public health officials track the spread of the virus. This was a tactic employed by authorities during the COVID-19 pandemic to monitor the spread of the coronavirus. In California, officials used wastewater to predict waves of infection and how well the virus was circulating in the population.
California health officials said they are monitoring various viruses at 78 facilities in 36 counties. All but two sites say they are looking for bird flu.
State officials said in an email to the Times that the state’s Cal Sewers Network monitors six locations in the Central Valley, including Kern, Merced, Stanislaus and San Joaquin counties. .
The most recent sample from Kern County was submitted on Dec. 7 and tested positive for the virus, according to the Centers for Disease Control and Prevention.
State officials acknowledge this is a major blind spot in the state’s surveillance system, but say it’s still a problem they have little control over.
“Using on-site wastewater monitoring…requires utility company participation, which is voluntary,” said Ali Bey, a spokesperson for the state agency. “Competing priorities and resource constraints can reduce[utilities’]ability to participate.”
Tulare and Kings counties have the highest number of cases in the state, according to numbers released by each county.
Tulare County Public Health Department spokeswoman Laura Flores said the county’s independent wastewater treatment plants chose not to participate in the state’s monitoring program. Tulare has reported 18 cases, the most of any county and nearly half of the state total.
Everardo Legaspi, deputy director of the Kings County Department of Public Health, told the Times that the state only knows of “less than 10” cases, and could not confirm the exact number of human cases reported to the state. The number was not disclosed. He added that the county has not been able to participate in the state’s wastewater monitoring project since October due to staffing shortages, but the county is working to begin collecting wastewater and expand it to other parts of the county. .
For months, experts have worried that public health officials have been lethargic in responding to the rapidly expanding pandemic, putting public safety ahead of agricultural profits. Only last month, the U.S. Department of Agriculture began a program to test the domestic raw milk supply for the virus. It comes nearly a year after experts believe the virus was leaked to cows, infecting more than 900 dairy herds and 60 people. .
“I think people are continuing to minimize this outbreak and this virus,” said Rick Bright, a virologist and former director of the Biomedical Advanced Research and Development Agency. “Our government officials have not conducted the thorough investigation they should have done.”
Even after the USDA announcement about the new bulk milk testing program, only 13 states are included in the initial rollout. Many were already testing milk, including California, Colorado and Michigan.
And the incoming Trump administration has threatened to withdraw the United States from the World Health Organization, which would further blind the United States and other countries to the movement of the virus. The Biden administration on Thursday announced an additional $306 million to prevent possible outbreaks of bird flu in humans, money that will be distributed before he leaves office later this month.
“I don’t think the right questions are being asked to understand this bird flu,” Hurtado said. “This is primarily due to a lack of guidance from the federal government.”
What we can learn from bird flu surveillance if it’s done right
Certainly, finding avian influenza in sewage does not mean there was a human outbreak of the virus.
Unlike COVID-19, mpox and seasonal influenza (which, if found in wastewater, indicates human infection), positive samples for avian influenza can come from a variety of sources, including pasteurized milk. There is. That’s because the methods used to sample avian influenza in wastewater look for markers of the virus, not the whole virus.
That means the test could detect inactivated virus fragments, such as those found in commercially available pasteurized milk.
“I don’t think we really know what that means,” said Richard Webby, director of the World Health Organization’s Collaborating Center for Animal and Avian Influenza Ecology Research. “How much milk goes down the drain in urban areas? We know we can consume a lot of supermarket milk. I have no idea what they are dealing with.”
It may also come from raw milk or raw meat. Or even waste from wild birds and mammals, where viruses are currently circulating.
Since the outbreak began, California officials have found the virus in wild birds such as rock pigeons, great ibises and turkey vultures, as well as wild mammals such as mountain lions, raccoons and skunks.
Additionally, people may be shedding the inactivated virus in their feces, said Alexandra Boehm, professor of civil and environmental engineering at Stanford University and principal investigator and program director of WastewaterSCAN.
The fight to improve the system
Regardless of what the sample shows, it provides evidence that the virus is circulating somewhere in the environment.
Bright also said the fact that health and water authorities in certain parts of the state are intentionally not investigating the outbreak is another example of the government’s failure to contain the outbreak and track its spread. said.
“The virus is rapidly evolving… Without full participation in surveillance and testing programs, coupled with full and timely transparency, we will always be behind the virus.” Bright said. “Without full cooperation and collaboration at the federal, state, local and community levels, our ability to address this issue will be hampered.”
For Hurtado, the situation is also personal.
She said her father and niece, who live in the Central Valley, showed symptoms of bird flu earlier this year, but no tests were available to confirm her suspicions.
Her father contracted the virus and suffered from severe muscle and body aches, symptoms of bird flu, and almost died. Her 7-year-old niece, who lives in Sanger, a town with a large poultry processing plant, had recently developed a rare autoimmune reaction to the virus and had red, swollen eyes, a symptom of the H5N1 virus. Her doctors don’t know what caused the reaction.
Despite having symptoms, neither of them had been tested for bird flu, but she said she suspected they had bird flu. Dairy farmers, workers and families also told the Times that the numbers reported by the state were likely an undercount because some workers may not report illness for fear of losing their jobs. He said he was thinking about it.
“I don’t have the science or the information to back it up, but in my heart I feel that both my father and my niece contracted bird flu,” she said. “Both patients suffered severe symptoms from an unknown virus.”
This personal experience led her to demand answers from the state about tracking the spread of the virus. She said she has asked the state health department about the lack of testing in the Central Valley but has not received a clear answer.
Hurtado also called for increased testing in high-risk communities. Despite testing at-risk populations, such as dairy and poultry workers, the state does not provide a comprehensive way to test agriculturally active areas.
Hurtado, whose jurisdiction covers vast swaths of the Central Valley, said he would propose legislation to expand the state’s wastewater monitoring program to include facilities in rural, underserved and high-risk areas. Ta. The bill would also develop criteria to identify priority sites based on health risk, population density and socio-economic factors.
Hurtado worries about communities like her hometown of Sanger. Poultry processing plants, one of the city and county’s largest employers, have been hit hard by bird flu.
Since the end of October, more than a dozen commercial poultry farms in Fresno County have been affected by the virus, resulting in the culling of more than 1.5 million birds.
She has heard stories of workers losing hours of work because animals got sick and poultry farms were completely depopulated. The price of eggs has also increased due to the spread of infection.
“More could have been done sooner,” she said. “But here we are, so we have to be able to improve on where we went wrong.”
