Public Health Departments Investigate Avian Flu in Los Angeles and California
H5N1, the avian influenza, has come into focus again after several incidents have come to light in recent weeks after the discovery of “bird flu” in the wastewater of Los Angeles. The first is confirmation from the CDC that a child was infected in California, with no known source of infection namely the child had no contact with animals that could have passed the infection on to the child and there was no known person-to-person contact either, since other people in the household were found not to be infected.
Currently, there are 55 known cases of avian influenza in human beings in the United States, and 29 of those cases are in the state of California.
After Los Angeles County announced that H5N1 had been discovered in the wastewater of the county on November 1, the levels spiked to a concerning level. On October 30, the day before the announcement, the H5N1 level at the A.K. Warren Water Resource Facility was 20.74 Infa.
The levels then rose from there:
November 4, 2024 87.62
November 6, 2024 109.3
November 8, 2024 81.23
November 11, 2024 172.5
On November 17, the level fell considerably to 28.11 and has risen again on November 20 to 52.25. When we asked the Los Angeles County Health Department for a statement regarding this spike, and received this response, “The risk to LA County residents remains low. People working with infected animals, including cows, poultry, or wildlife, are at higher risk of exposure to bird flu. Public Health has been working with the California Department of Food and Agriculture (CDFA) and the local LA County agricultural community to ensure key risk groups, including farm workers, workers at dairy, egg, and meat processing facilities, and backyard flock owners receive information to help identify and protect against this infection.
Through our Public Health Laboratory, samples from symptomatic birds, cats, and wild mammals in LA County continue to be tested for H5N1. In addition, the Public Health Laboratory routinely tests clinical specimens from humans for H5N1 as part of ongoing surveillance.
Public Health continues to investigate possible sources of H5 bird flu, which has been detected at wastewater sampling sites in Los Angeles County. We are unlikely to determine the exact source of H5 in wastewater given the multiple, large-volume dairy processing plants in LA County receiving milk from multiple sites in California. The most likely source of these detections is from contaminated animal products being discarded at processing plants in the watershed or discarded milk for personal consumption.
Detection levels may vary with changes in concentrations of the virus in milk and the volume of discarded milk products. Wastewater testing does not differentiate between live or dead virus and the pasteurization process kills the bird flu virus. We have not seen unexpected increases in human influenza cases and have not had any human cases of bird flu in LA County, therefore we do not think that these levels are due to human infections. In addition, there is no evidence of human-to-human transmission of this strain of bird flu.”
As of 4:38 today, Los Angeles Public Health has confirmed H5N1 in a wild bird in LA County
Public Health has confirmed a local bird tested positive for highly pathogenic avian influenza H5, also known as H5 bird flu in LA County. Currently, the risk of transmission of H5 bird flu to humans is considered low.
The infected bird was: A Canada goose found on 11/11/24 in Westlake Village. Earlier this year, in January 2024, a Western Gull infected with H5 was found in Manhattan Beach.
To prevent the spread of bird flu:
- Do not feed wild birds; this helps reduce the number of birds gathering together which can spread the virus.
- Keep people and pets away from sick and dead birds.
- Prevent wild birds from getting into or defecating in areas with pet birds/poultry.
- Dead birds, especially geese, ducks, and shorebirds should be reported to your local animal control agency for potential testing.
- Take down bird feeders and communal bird baths to reduce the risk of the virus spreading from bird to bird.
- Residents should also keep pets away from sick and dead birds. There is some risk of the virus being transmitted to mammals such as dogs, cats, and wild mammals, especially if they eat infected, uncooked birds.
Another concerning turn of events is the discovery of avian flu in raw milk for sale from the company Raw Farms LLC in the state of California. After the batch of raw milk contaminated with the virus was discovered by Santa Clara County’s Public Health Department, the lot was recalled and the California Department of Public Health (CDPH) issued a bulletin warning consumers from drinking the milk. Raw Farm, LLC issued a voluntary recall of the lot found to be contaminated, but the milk was on the shelf for purchase when it was found to be contaminated.
Robert F. Kennedy Jr., former presidential candidate and Donald J. Trump’s pick for Secretary of Health and Human Services is a raw milk proponent, despite the dangers inherent in consuming raw milk products. In 2023, he stated that he only drinks raw milk.
CDPH’s website notes, “There is no difference in the nutritional value between raw milk and pasteurized milk. Just because raw milk is called “raw” does not mean it is better for you than pasteurized milk. Raw milk is not the same as organic milk or milk that comes from grass-fed animals. Raw milk can still contain harmful bacteria and other germs even if it is organic, from grass-fed animals, or from very clean farms. Raw milk also cannot give you “good bacteria” (sometimes called probiotics). Probiotics can be found in pasteurized dairy products such as yogurt or kefir, which are safer to eat than raw milk.”
CDPH has reiterated that drinking and consumption of milk products that have been pasteurized is safe and warns against drinking or consuming raw milk products. Raw milk products can also contain Salmonella, Listeria monocytogenes, toxin-producing E. coli, Brucella, Campylobacter, and many other bacteria in addition to the avian flu.
Guidance from LAPDH regarding raw milk products is as follows the current risk of transmission to LA County residents is low, Public Health encourages residents to follow these best practices when around animals or when consuming animal products:
- Do not eat raw milk, raw cheese, and undercooked meat products.
Avian flu refers to various strains of influenza A viruses that typically infect birds. While these viruses mainly affect wild birds, sometimes they also infect other animals, including wild and domestic animals (including seals, foxes, cats, and cows). H5N1 is one type of avian influenza that has been spreading among birds and mammals, leading to a nationwide outbreak. This is the first time these bird flu viruses are spreading in cows.
Signs/symptoms of H5N1 virus infection in humans may include:
- Cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, fatigue
- Fever* or feeling febrile
- Eye redness (or conjunctivitis)
- Shortness of breath or difficulty breathing
- Diarrhea, nausea, vomiting
*It is important to note that infection with influenza viruses, including novel influenza A viruses, does not always cause fever. Fever may not occur in infected persons of any age, particularly in persons aged 65 years and older or people with immunosuppression.
