Health Alerts

January 14, 2026

Advisory

Animal Leptospirosis in Berkeley

The City of Berkeley Public Health Division and Alameda County Vector Control have identified Leptospirosis infection in rats and at least 2 dogs during November and December of 2025 near the intersection of 8^th^ and Harrison Streets in Northwestern Berkeley. This location is adjacent to Codornices Creek, the boundary between the cities of Albany and Berkeley. Human Leptospirosis is rare in California and no human cases have been identified in connection with the Berkeley animal infections, to date. Leptospirosis does not spread person-to-person. Leptospirosis typically spreads through exposure to water and mud contaminated by the urine of infected animals, especially rodents. Infection is treatable and may be asymptomatic or mild but can be severe and potentially fatal. Persons experiencing homelessness (PEH) without access to clean water and sanitation facilities living near infected animals are at greatest risk; exposure to potentially contaminated water or soil in the immediate vicinity, including along Codornices Creek, may present a risk to others. The goal of the City of Berkeley Public Health Division is to eliminate the risk of Leptospirosis exposure by abating the impacted rodent population at this location.

Notices have been posted around the affected location to alert the neighborhood of the risk of Leptospirosis and City of Berkeley Public Health Division is engaging communities in the impacted area.

Please see the Berkeley Health Alert released January 12, 2026 for more details.

Actions Requested of Alameda County Providers:

• Be aware of the signs and symptoms of Leptospirosis, especially in PEH and those with exposure to potentially contaminated water or soil.
• If evaluating a patient with signs and symptoms of Leptospirosis, please reach out to Alameda County Public Health Department Acute Communicable Diseases Section at (510)268-3250 or AcuteCD@acgov.org for reporting and testing recommendations.
  • During the first week of illness, whole blood and serum is recommended to test for serology and PCR
  • During the convalescent illness (after the first week), serum and urine can be tested for serology and PCR
  • Confirmatory testing is required at the US Centers for Disease Control and Prevention
• In patients with high clinical suspicion for Leptospirosis, consider initiating antibiotic treatment without waiting for laboratory results. 

January 12, 2026

Advisory

Influenza Update: Vaccinate, Test and Administer Influenza Antivirals

• Influenza cases and hospital admissions are increasing in California. A newly emerged influenza A virus strain, H3N2 subclade K, is circulating globally, including in California.  The majority of influenza A specimens subtyped in California are H3N2. Current influenza vaccines are still expected to offer protection against severe disease. 
• Administer 2025-26 influenza vaccine to anyone 6 months of age and older who has not yet received it.
• Test symptomatic patients as quickly as possible. Use rapid molecular (nucleic acid amplification detection) tests for outpatients, and RT-PCR and other influenza molecular tests for hospitalized patients to confirm diagnosis and guide timely treatment. Influenza A positive hospitalized patients, especially those in the ICU, should have specimens sent for subtyping. 
• Initiate antiviral treatment without delay and ideally at point of care. Do not delay treatment while waiting for test results if influenza is suspected in high-risk patients. Treat immediately with oseltamivir or single-dose baloxavir based on recommendations for use. Treatment with influenza antivirals decreases the risk of serious illness and hospitalization in those at higher risk for severe disease.
• Stay aware of respiratory virus activity in your community by visiting the CDPH Respiratory Virus Dashboard this respiratory season. 
• For more information, see California Department of Public Health’s Influenza Update

December 24, 2025

Advisory

Immunization Practice Update for Providers in Alameda County

Summary: 

The purpose of this health advisory is to share with Alameda County health care providers and residents that the Alameda County Public Health Department (ACPHD) is in full alignment with the California Department of Public Health (CDPH) and the West Coast Health Alliance (WCHA) evidence-based immunization guidelines. 

Background: 

Recent federal policy actions have resulted in questions for ACPHD regarding immunization practices. ACPHD is aligned with and endorsing the guidelines issued by CDPH.  

CDPH has issued immunization recommendations for children and adults based on the latest annual updates of the evidence-based guidelines from the following sources: 

• The American Academy of Pediatrics (AAP) 

• The American College of Obstetricians and Gynecologists (ACOG) 

• The American Academy of Family Physicians (AAFP) 

In general, these guidelines continue longstanding, well-established immunization practices grounded in clinical research and methodical expert-review.  

CDPH’s recommendations are issued under the authority established by California Assembly Bill 144 (AB 144). In addition to setting forth CDPH’s authority to issue immunization recommendations, AB 144 requires health insurance plans regulated in California to cover CDPH’s recommended immunizations, authorizes pharmacists to administer CDPH’s recommended immunizations, and includes liability protections for practitioners providing immunizations according to CDPH’s recommendations.  

Additionally, in light of the recent ACIP vote regarding the Hepatitis B (Hep B) birth dose for HBsAg-negative mothers, ACPHD reaffirms its alignment with CDPH/WCHA recommendation for the routine offering of the universal Hepatitis B birth dose to all newborns, regardless of the mother's HBsAg status. AB 144 allows CDPH recommendations to prevail in California, regardless of recent changes in federal policy. Information regarding specifics of coverage is available through health plans and insurers. 

Actions Requested of Health Care Providers:  

• Providers should follow the immunization schedules recommended by CDPH for both Child and Adolescent Vaccinations and Adult Vaccinations.  
• Perinatal care providers, labor and delivery hospitals, and pediatric providers should continue to follow the established CDPH guidelines for HBV prevention care including offering the Hepatitis B vaccine to all newborns at birth. 
• Providers should ensure clinical protocols are updated to reflect the recommendations from CDPH and should ensure staff are educated accordingly.  
• Providers must continue to report any pregnant person with a positive HBsAg and any infant with an active case of Hepatitis B virus (HBV) infection to ACPHD Perinatal Prevention Program as mandated by California State law (California Code of Regulations Title 17, Section 2500)  

  RESOURCES:  

• CDPH Assembly Bill 144 Vaccine Recommendations 

• CDPH/WCA Hepatitis B vaccination recommendation  

• Additional CDPH Vaccine Resources 

• The American Academy of Pediatrics (AAP)  

• The American College of Obstetricians and Gynecologists (ACOG)  

• The American Academy of Family Physicians (AAFP)  

• California Assembly Bill 144 (AB 144) 

• Preventing Perinatal HepB-Guidelines for Prenatal Care Providers  

• Perinatal HepB - Labor Delivery Quicksheet  

December 12, 2025

Advisory

Report Cases of Wild Mushroom Toxicity to ACPHD

CDPH is closely monitoring increased hospitalizations after the consumption of foraged toxic mushrooms. Between mid-November and early December, the California Poison Control System identified twenty-one cases of Amanita phalloides (death cap mushroom) poisoning, including one adult death, with clusters reported in the Monterey area and San Francisco Bay Area.  

Actions Requested of Health Care Providers: 

1. Contact the California Poison Control System (1-800-222-1222) to report cases of illness after consumption of wild mushrooms and/or for advice on medical management of these patients. 
2. Report all mushroom toxicity cases to the Alameda County Public Health Safety and Nursing Education Unit at 510.268.7865 during normal business hours or E-Fax at 510.273.3791. 
3. Any patient with recent or active GI symptoms after consumption of foraged wild mushrooms warrants careful evaluation for amatoxin poisoning and consideration for hospital admission. 
   • Initial symptoms (typically 6-24 hours post-ingestion) include profuse, watery diarrhea as well as other GI complaints such as nausea, vomiting, or abdominal pain. Fluid loss may lead to hypovolemia, acute kidney failure, circulatory shock, and death. Patients often experience a gradual resolution of GI symptoms within 24 hours of onset, which falsely suggests toxicity has resolved. Elevations in liver enzymes are typically seen within 24 to 36 hours after ingestion.  
   • Severely poisoned patients may develop irreversible hepatic failure within 48 to 96 hours after ingestion, which may be accompanied by acute kidney failure or pancreatitis.  
4. Ask patients presenting with symptoms consistent with mushroom toxicity about mushroom consumption.  
   • Collect and record information about when and where the mushrooms were collected, sourced, or purchased, and if they have any remaining mushrooms which could be analyzed. 

For more information, including about patient management, please consult Severe, Potentially Fatal Liver Damage in Children and Adults Associated with Consumption of Foraged Wild Mushrooms (CAHAN, 12/5/25) 

December 08, 2025

Advisory

First Reported Outbreak Caused by Marburg Virus in Ethiopia

CDPH, in coordination with CDC, is monitoring an outbreak of Marburg Virus Disease (MVD) in Ethiopia that was first reported on November 14, 2025. No MVD cases related to this outbreak have been reported outside of Ethiopia. CDPH supports CDC guidance in the 12/3/2025 CDC HAN, which includes recommendations for clinicians, healthcare facilities, laboratories, public health departments and the general public. This outbreak is evolving, and CDPH recommendations may be modified as the situation changes and further guidance from CDC becomes available. Please see the full CDC HAN for additional details.  

Clinicians, healthcare facilities and clinical laboratories should do the following: 

• Clinicians should obtain a detailed travel and exposure risk history from patients with an acute febrile illness, especially those who have been in affected areas of Ethiopia recently, while also ruling out more common causes of febrile illnesses.  

• Clinicians should consider MVD in patients with compatible symptoms and epidemiological risk factors within the 21 days prior to symptom onset. Immediately isolate and notify ACPHD of a suspect MVD patient by phone at (510) 267-3250; after hours, call (925) 422-7595 and ask for the On-Call Duty Officer.   

• Marburg virus testing must be coordinated through ACPHD, as CDPH and CDC must approve testing before specimens are collected.  

• Healthcare facilities should be prepared to follow CDC's Infection Prevention and Control Recommendations for Patients in U.S. Hospitals who are Suspected or Confirmed to have Selected Viral Hemorrhagic Fevers and CDPH Interim Guidance on Personal Protective Equipment (PPE) to Be Used by Healthcare Personnel (HCP) in the Inpatient Hospital Setting During Management of Patients Suspected or Confirmed to Have Selected Viral Hemorrhagic Fevers (VHFs) in California.  

• Clinical laboratories should review established protocols for MVD testing and specimen handling as well as be prepared to follow CDC's Standard Precautions for All Patient Care. 

November 12, 2025

Alert

Outbreak of Infant Botulism Linked to ByHeart Infant Formula

Centers for Disease Control and Prevention (CDC) and California Department of Public Health (CDPH) along with multiple other public health departments are investigating an unprecedented multi-state outbreak of infant botulism linked to infant formula.

• Fifteen infants with suspected or confirmed infant botulism have been identified including two in California and 13 in eleven other states: Arizona, Illinois (2), Minnesota, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas (2), Washington, Kentucky, and Illinois. As of November 11, 2025, 10 cases have been confirmed and 5 have testing underway.
• Illness onset dates range from mid-August to the present. All infants were hospitalized and received BabyBIG®. No deaths have been reported. Infants ranged in age from 2 weeks to 5 months olds. All 15 were fed ByHeart Whole Nutrition infant formula.
• Preliminary testing of ByHeart Whole Nutrition infant formula at the CDPH Center for Laboratory Sciences Microbial Diseases Laboratory (CDPH CLS MDL) laboratory indicates the presence of C. botulinum type A spores in the sample of the powdered infant formula. Additional testing is in progress.
• On November 11, 2025, ByHeart, Inc. has expanded the voluntary recall to all ByHeart formula nationwide - this includes both cans and single-serve Anywhere Pack™ sticks. FDA is working to ensure all potentially impacted products are removed from the market. CDPH is working on obtaining distribution information and will share with local health departments as soon as it becomes available to inform follow up with retailers. FDA's investigation is ongoing to determine the point of contamination and if any additional products are impacted.
• Parents should discontinue use of ByHeart formula immediately.
• ByHeart Whole Nutrition Infant Formula is available online and at major retailers nationwide. FDA reports that ByHeart Whole Nutrition Infant Formula makes up ~1% of all infant formula sales in the United States. This recall will not create shortage concerns of infant formula for parents and caregivers.
• Clinicians should call the CDPH Infant Botulism Treatment and Prevention Program (IBTPP) directly for consultation for suspected infant botulism cases at 510-231-7600 (available 24/7).
• Health care providers should report suspected cases of infant botulism to their local health department immediately, to facilitate investigation, testing and timely treatment with BabyBIG if indicated.

For more information review Outbreak of Infant Botulism Linked to ByHeart Infant Formula.

October 17, 2025

Advisory

Community Spread of Clade I Mpox Within California

CDPH/Health Advisory - October 17, 2025 – The California Department of Public Health (CDPH) would like to alert healthcare providers, local health jurisdictions and laboratories about three unrelated clade I mpox cases, which have been confirmed in Southern California with no history of recent international travel. Public health investigation indicates that community transmission of clade I mpox is occurring in California. Persons at increased risk of mpox should be encouraged to be vaccinated.  Mpox testing should be considered for patients with compatible signs and symptoms (PDF), regardless of vaccination status or previous infection.

See CDPH Health Advisory

October 15, 2025

Advisory

Masking Recommendations for Staff and Visitors in Licensed Health Care Facilities When Respiratory Viruses Circulate

To prevent the spread of respiratory viruses, such as COVID-19, Influenza (flu), and Respiratory Syncytial Virus (RSV), to vulnerable patients and residents, and to minimize the associated risk of severe illness and death among these persons, the Health Officers of Alameda County and the City of Berkeley strongly recommend that staff and visitors in patient care areas of licensed health care facilities in Alameda County, including the City of Berkeley, wear high-quality, well-fitting masks, regardless of vaccination status, during winter respiratory virus season (November 1 to March 31) and other times of increased respiratory virus circulation. Please see the attached Health Advisory for additional information.

This guidance replaces the expired joint Alameda County and City of Berkeley Health Officer Order requiring staff masking in licensed health care facilities during the 2024-25 winter respiratory virus season.

October 02, 2025

Advisory

Health Officer Order for Reporting Carbapenem-Resistant Organisms (CROs)

This is a message from the Alameda County Public Health Department.

The Alameda County Health Officer Order dated June 13, 2017, requiring health care providers and clinical laboratories to report all cases of carbapenem-Resistant Enterobacterales (CRE) to Alameda County Public Health Department (ACPHD) and submit associated specimens to Alameda County Public Health Laboratory (ACPHL) is hereby rescinded and replaced with this order, effective November 3, 2025:

Providers must report CRO cases meeting the following criteria to ACPHD:

• For CRE: resistance to any carbapenem antimicrobial, with a MIC of ≥ 4 µg/ml for doripenem, imipenem, or meropenem; or MIC ≥ 2 µg/ml for ertapenem; OR
• For carbapenem-resistant Acinetobacter Baumannii (CRAB): resistance to any carbapenem antimicrobial, with a MIC of ≥ 8 µg/ml for doripenem, imipenem, or meropenem OR
• For carbapenem-resistant Pseudomonas aeruginosa (CRPA): resistance to any carbapenem antimicrobial, with a MIC of ≥ 8 µg/ml for doripenem, imipenem, or meropenem AND nonsusceptible (intermediate or resistant MIC ≥ 16 µg/ml) to cefepime or ceftazidime, or, resistant to ceftolozane/tazobactam (MIC ≥ 16/4μg/ml); OR
• For any CRO: Documented carbapenemase production, demonstrated using a phenotypic CLSI-endorsed or FDA cleared test (modified Hodge, Carba-NP, metallo-β-lactamase, etc.); OR
• For any CRO: demonstrated to possess a carbapenemase gene (such as KPC, NDM, VIM, IMP, OXA-48-type) using a CLSI-endorsed or FDA cleared test (Carba-R, PCR, Whole Genome Sequencing, etc.) 

Laboratories must submit CRO microbiologic isolates meeting the following criteria to ACPHL:

• The isolate is CRAB, regardless of carbapenemase test results OR
• The isolate has not already undergone carbapenemase testing at a facility or commercial laboratory OR
• The isolate had a positive phenotypic test, but a specific carbapenemase was not identified OR
• The isolate is pan-nonsusceptible (intermediate or resistant to all drugs tested to date) OR
• The isolate is specifically requested by the public health department OR
• The isolate belongs to an Alameda County resident residing in a LTCF or SNF

Please refer to Carbapenem-Resistant Organisms (CROs) for additional information and direct questions to acutecd@acgov.org.

September 04, 2025

Advisory

Alameda County Mpox Updates

There has been a recent increase in mpox in Alameda County, as well as other areas in the San Francisco Bay Area (CDPH Health Advisory).   In Alameda County, we have had a 4-fold increase in mpox cases (from 3 cases to 12 cases) since July 2025.  

Mpox is characterized by a diffuse or localized rash; the rash can be preceded by a prodrome or other symptoms such as fever, malaise, or lymphadenopathy. Mpox is usually transmitted by close and sustained physical contact.  Mpox has two clades; the large global mpox outbreak in 2022 was caused by Clade II mpox and it is still circulating in the US.  Clade I mpox is primarily occurring outside the United States. JYNNEOS vaccine (mpox vaccine) prevents both clades.  One dose of the vaccine has 36-75% efficacy, and two doses has 66-89% efficacy for prevention of mpox.

See Mpox Updates Health Advisory

Actions requested of Providers: 

• Test for mpox when a patient presents with new rash and other symptoms (compatible signs and symptoms (PDF)). 
• Recommend mpox vaccination for persons at risk, and a second dose for anyone who has not completed the 2-dose series. Getting more than 2 doses (“booster”) is not recommended. Anyone who thinks they need the vaccine should get it. 
• Vaccines are available at many chain pharmacies and certain clinics—see Mpox Vaccine Locator.  JYNNEOS (mpox) vaccine will also be available with limited supply at Oakland PRIDE (9/7), Oakland LGBTQ center, and Steamworks (9/5, 9/6, 9/9). 
• Ensure persons know the signs and symptoms of mpox illness so they are evaluated and tested in a timely way if they are symptomatic.  
• Submit a confidential morbidity report (CMR) to Alameda County Public Health Department for suspect and confirmed cases of mpox that reside in Alameda County.  
• Ask about planned travel and recommend mpox vaccine for those at risk.  
• For persons with suspect mpox that have had recent travel to specific locations or exposure to someone with known mpox Clade I, test for mpox Clade I.  Contact Alameda County Public Health Department at sexualhealth@acgov.org and follow the procedures for testing for Clade I mpox by sending the test to VRDL.    

Resources: 

• Mpox updates Alameda County Public Health Department https://mpx.acgov.org/ 
• Bavarian Nordic: Mpox Vaccine Locator 
• California Prevention Training Center | Mpox Clinical Recognition & Testing Overview (PDF)  
• CDC Updates on Tecoviromat  [+Tecovirimat (TPOXX) for Treatment of Mpox | Mpox | CDC+|https://www.cdc.gov/mpox/hcp/clinical-care/tecovirimat.html] 
• CDPH | Local Health Department Communicable Disease Contact List 
• CDPH | Mpox Treatment Information for Providers 
• CDPH | Provider and Health System Access to Commercially Available JYNNEOS Vaccine in California (PDF) 
• CDPH | Health Advisory: First Clade I Mpox Case Confirmed in California and the United States in a Returned Traveler (11/19/2024) 
• CDPH VRDL (for clade I testing): 510-307-8585 or VRDL.Submittal@cdph.ca.gov 
• CDC Poxvirus and Rabies Branch | poxvirus@cdc.gov or after hours via the CDC Emergency Operations Center (EOC) at (770) 488-7100 
• CDC | Mpox Vaccination 
• CDC | Clinical Features of Mpox 
• CDC | Safer Sex, Social Gatherings, and Mpox 
• CDC | Clade I Mpox Outbreak Originating in Africa

August 28, 2025

Advisory

Letter to Healthcare Providers Regarding Title 17 Section 2500 California Code of Regulations Updates

California Department of Public Health (CDPH), in consultation with the California Conference of Local Health Officers (CCLHO), recently updated Title 17 Section 2500 of the California Code of Regulations. For more information, please refer to CDPH Reportable Diseases and Conditions. 

The following conditions have been added and are now required to be reported to the local health department:  

• Melioidosis – report immediately by telephone  
• Cronobacter sakazakii infections in infants less than one year of age – report within one working day  
• Multisystem inflammatory syndrome in children (MIS-C) – report within one working day  
• Silicosis – report within seven calendar days  

The following conditions have been renamed or modified:  

• Neisseria meningitidis (invasive disease), previously appeared as meningococcal infection  

• Coronavirus disease 2019 (COVID-19) (hospitalizations only) via the National Healthcare Safety Network (NHSN). Previously all cases were reportable and appeared as Coronavirus disease 2019 (COVID-19).  COVID-19 outbreaks also remain reportable in all settings with specific thresholds: Reporting Requirements | COVID-19 | Alameda County Public Health

The following conditions have a change in the reporting timeframe:  

• Brucellosis, human – report within one working day, previously was immediately reportable  
• Cyclosporiasis – report within one working day, previously was seven working days  
• Hemolytic uremic syndrome – report within one working day, previously was immediately reportable  
• Legionellosis – report within one working day, previously was seven working days  
• Shiga toxin detected in feces – report within in one working day, previously was immediately reportable Additionally, Section 2500 now requires healthcare providers to include the patient’s hospitalization status, if known, when reporting to public health. 

Additionally, Section 2500 now requires healthcare providers to include the patient’s hospitalization status, if known, when reporting to public health.  

August 15, 2025

Update

Outbreak of Candida auris at an Alameda County Acute Care Hospital Has Ended

Alameda County Public Health Department (ACPHD) has been working with Wilma Chan Highland Hospital (HH) in Oakland to investigate and control an outbreak of Candida auris (C. auris) among adult patients admitted to the intensive care unit (ICU), step-down unit (SDU) and medical/surgical units. ACPHD no longer considers HH in active outbreak and will continue surveillance monitoring. Therefore, additional screening measures that were recommended for healthcare facilities accepting patients from HH may cease. In coordination with ACPHD, HH was able to implement aggressive measures to control the outbreak and prevent further transmission. In addition to addressing opportunities to improve general infection control measures, HH has been conducting bi-weekly unit-based screening of patients in affected units and screening of patients upon discharge to lower levels of care.

Patients should not be denied admission or transfer due to colonization, infection, or a pending screening result for C. auris. Furthermore, all healthcare facilities should follow the C. auris testing recommendations outlined in the California Department of Public Health (CDPH) June 9, 2025 Health Advisory Ongoing Transmission of Candida auris in Healthcare Facilities in Northern and Central California.

• ACPHD C. auris Health Update