Health Alerts & Advisories

California Health Alert Network (CAHAN)

The California Health Alert Network (CAHAN) is the State of California’s web-based information and communications system for distribution of health alerts, dissemination of treatment and prevention guidelines, coordination of disease investigation efforts, preparedness planning, and other initiatives that strengthen state and local preparedness.

Health Advisories 2023

October 2023

  • October 01, 2023 - Order for Mandatory Masking of Healthcare Workers

Summary: Effective November 1st, masking is required of healthcare workers in specified healthcare facilities including hospitals, inpatient psychiatric facilities such as crisis stabilization units, skilled nursing facilities, and dialysis and infusion centers. This will be a standing order applicable each “respiratory virus season,” annually from November 1 through April 30 unless rescinded. Click for full text of Health Order. 

March 2023

  • March 28, 2023 - Presence of Xylazine in Illicit Fentanyl

Summary: On March 20th, the California Department of Public Health (CDPH) released a Xylazine Alert Letter (ca.gov) requesting Local Health Officers share this FDA xylazine alert for health professionals with medical providers in our jurisdiction. Xylazine, a veterinary tranquilizer with no approved human use, is showing up in the nation’s street drug supply, where it is also known as “tranq” and “tranq dope.” It is increasingly present in overdose deaths, compounding the overdose crisis. There is no evidence to suggest that xylazine is currently prevalent in California’s drug supply, however experts note that xylazine may be mirroring the path of fentanyl in the illicit drug market with a westward expansion. A sedative and not an opioid, xylazine is not known to be reversed by naloxone. However, since xylazine is typically combined with opioids like fentanyl and sometimes heroin, administering naloxone is still recommended for reversing an overdose. Napa County Public Health Xylazine Alert 3-28-2023


  • March 10, 2023 - CDPH Updates COVID-19 Guidance  

Summary: On March 3rd, the California Department of Public Health (CDPH) announced several updates to the State Public Health Officer orders that have been guiding California’s healthcare providers on best practices throughout the pandemic. The updated orders will be taking effect in the coming weeks and provide updates related to vaccination, masking, and hospital surges. As we continue to navigate the winter virus season and the upcoming changes in guidance, healthcare sites are encouraged to develop and review their own policies around vaccination, masking, and hospital surges. As a reminder, for the 2022-2023 influenza season, Napa County continues to have the annual Health Officer Order in place requiring healthcare workers to vaccinate or mask. Masking and staying up to date on all recommended vaccinations remain an effective mitigation measure for the current respiratory season and are still recommended. Click for full text Health Advisory

February 2023

  • February 24, 2023 - Increase in Extensively Drug-Resistant Shigellosis in the United States  

Summary: The Centers for Disease Control and Prevention (CDC) has been monitoring an increase in extensively drug-resistant (XDR) Shigella infections (shigellosis) reported through national surveillance systems [1]. In 2022, about 5% of Shigella infections reported to CDC were caused by XDR strains, compared with 0% in 2015. Clinicians treating patients infected with XDR strains have limited antimicrobial treatment options. Shigella bacteria are easily transmissible. XDR Shigella strains can spread antimicrobial resistance genes to other enteric bacteria. Given these potentially serious public health concerns, CDC asks healthcare professionals to be vigilant about suspecting and reporting cases of XDR Shigella infection to their local or state health department and educating patients and communities at increased risk about prevention and transmission. Click for full text CDC Health Advisory

  • February 16, 2023 - Emergence of Candida auris in Healthcare Facilities in Northern California

The development of cases has been identified in Sacramento and Stanislaus counties since September 2022. Additionally, at the end of January 2023, CDPH was alerted to a case in Contra Costa county associated with an ACH and long-term care setting. These were the first reported C. auris cases in each county, and the patients had no known exposures in healthcare facilities outside of Northern California. These findings suggest there is more transmission in the region than has been identified to date. We continue to see C. auris transmission in Southern California. Patients and residents who have had prolonged admission in healthcare settings, particularly high-acuity care settings including long-term acute care hospitals (LTACH), ventilator-equipped SNF (vSNF), high-acuity ACH units (e.g., intensive care units (ICU) and step-down units (SDU)), are at highest risk of C. auris and other multidrug-resistant organism (MDRO) colonization and infection. Click for full text here

This list of health alerts and advisories is not comprehensive, but is here as an archive of previous alerts. 

Monkeypox 2022

Coronavirus (COVID-19) 2020

Zika 2018

Influenza 2017

Zika 2017

Fentanyl 2016

Zika 2016

Zika information for the public:

Influenza 2016