H5N1 bird flu
Last content update: 1/16/25
Providers should immediately isolate suspected H5N1 cases, report to the County of Santa Clara Public Health Department, treat empirically, and collect appropriate specimens for testing.
The County of Santa Clara Public Health Department recommends that people do not consume or feed their animals raw milk or raw milk products.
Raw milk and cream products from Raw Farm, LLC were recalled after bird flu virus was detected in products at both retail and dairy storage and bottling sites. Valley Milk Simply Bottled Raw Cow Milk and Desi Milk Raw Cow Milk were recalled after bird flu virus was detected in a raw milk bulk tank at the dairy farm.
Situation status
To date, there have been no reported human H5N1 cases among residents of Santa Clara County.
In 2024, the number of human H5N1 cases in the United States has greatly increased. While there has been no confirmed human-to-human transmission of H5N1 bird flu viruses in the United States, there have been cases in the United States among people with no history of exposure to animals suspected or confirmed to be infected with H5N1. Spread of the virus, especially during flu season, may lead to changes that make it more transmissible to humans or enable it to spread from human to human.
Healthcare providers should be aware of the possibility of infection with H5N1 bird flu in symptomatic persons. This is most likely in people who have had exposure to animals confirmed or suspected to have H5N1 bird flu. While there have been no confirmed cases of people getting infected with H5N1 due to consumption of raw milk, the virus has been found at high levels in raw milk of infected dairy cows and exposure to raw milk has been implicated in H5N1 infections among dairy workers and in animals.
The County of Los Angeles is investigating suspected H5 bird flu cases in two cats who became sick and died after consuming recalled raw milk products. Per the CDC, while it is unlikely for a person to get sick with bird flu through contact with an infected pet, it is possible.
What do to if you suspect H5N1 infection
Isolate the patient
Implement standard, contact, and airborne precautions, and use eye protection.
Report to Public Health
Immediately notify the County of Santa Clara County Public Health Department by phone of a confirmed or suspected H5N1 case.
- Office hours, Monday through Friday, 8 a.m. to 5 p.m.: (408)-885-4214
- After hours, page the on-call Health Officer: (408) 998-3438
Find more information about reporting for providers.
Initiate treatment
Empiric antiviral treatment should be started as soon as possible for all patients with possible H5N1 infection. Antiviral treatment should not be withheld or delayed pending collection of specimens or laboratory testing. More information on dosing and duration of antiviral therapy is available at CDC's Interim Guidance on the Use of Antiviral Medication for Treatment of Human Infections with Novel Influenza A Viruses Associated with Severe Human Disease.
Collect samples for testing
Testing should be performed on persons who meet exposure AND clinical criteria. Specimens should be collected as described below, and decisions about testing will be made in consultation with the Public Health Department.
Exposure criteria
Persons with recent exposure (within 10 days) to H5N1 through one of the following:
- Exposure to animals or materials that may be infected with H5N1 influenza virus, defined as follows:
- Close contact (within six feet) with animals with suspected or confirmed infection; such exposures can include, but are not limited to: handling, slaughtering, defeathering, butchering, culling, caring for, or milking; OR
- Preparing or consuming raw animal products, or consuming uncooked or undercooked food or related undercooked food products, including unpasteurized milk; OR
- Direct contact with surfaces contaminated with feces, unpasteurized milk or other unpasteurized dairy products, or animal parts (e.g., carcasses, internal organs) from animals with suspected or confirmed infection; OR
- Exposure to an infected person: Close (within six feet) unprotected (without use of respiratory and eye protection) contact with a person who is a confirmed, presumptive, or symptomatic suspected H5N1 bird flu case (e.g., in a household or healthcare facility). OR
- Laboratory exposure: Unprotected exposure to H5N1 influenza virus in a laboratory.
Clinical criteria
Persons with signs and symptoms consistent with acute or lower respiratory tract infection or conjunctivitis, or complications of acute respiratory illness without an identified cause. Examples include but are not limited to:
- Eye redness and irritation (conjunctivitis) - this has been the predominant symptom among recent U.S. cases of avian influenza A (H5) virus infection
- Fever (temperature of > 100 F [37.8 C] or feeling feverish)
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headaches
- Fatigue
- Shortness of breath or difficulty breathing
- Pneumonia
- Seizures · Vomiting
- Diarrhea
Specimen collection
Collect appropriate specimens based on clinical presentation. Specimens should ideally be collected within 24–72 hours of symptom onset and no later than 10 days after symptom onset.
NOTE: All suspect patients require respiratory specimens regardless of symptoms. Decisions about which specimens will ultimately be tested and with which assays will be made in consultation with the Public Health Department.
Guidelines for specimen collection | |
|---|---|
| Clinical Presentation | Specimen Collection Practice and Transport |
| EVERYONE (regardless of symptoms) | Always collect a minimum of three (3) respiratory specimens: 1. One nasal swab placed in VTM vial 2. One OP swab placed in VTM vial 3. One NP swab placed in VTM vial |
| Conjunctivitis (with or without respiratory symptoms) | ALSO Collect: 1. One (if unilateral symptoms) or two (if bilateral symptoms) conjunctival swabs in a single VTM vial |
| GI symptoms (with or without respiratory symptoms) | ALSO Collect: 1. One stool specimen in Cary-Blair Media |
VTM = viral transport medium
NP = nasopharyngeal
OP = oropharyngeal
Additional testing recommendations for patients with severe disease:
- Patients with severe respiratory disease also should have lower respiratory tract specimens collected such as an endotracheal aspirate, bronchoalveolar lavage, or sputum.
- For severely ill persons, multiple respiratory tract specimens from different sites should be obtained to increase the potential for detection.
| Avian Influenza A (H5N1) Information for Health Professionals (California Department of Public Health) |
| Interim Guidance on the Use of Antiviral Medications for Treatment of Human Infections with Novel Influenza A Viruses Associated with Severe Human Disease (Centers for Disease Control and Prevention) |
| Prevention and Antiviral Treatment of Avian Influenza A Viruses in People (Centers for Disease Control and Prevention) |
| Educational flyer for agricultural workers - English | Spanish |
| Avian Influenza Fact Sheet - English | Spanish | Vietnamese |
| Raw milk and raw dairy products - English | Spanish (California Department of Public Health) |
| Santa Clara County H5N1 information for the general public |
| Santa Clara County respiratory virus data |