Note: Does not reflect latest Michigan Herd
UPDATED: No sooner had I posted this, the USDA announced another 15 infected herds in California (N=120)
#18,347
Twelve days ago, before I was so rudely interrupted by Hurricane Milton, California's CDPH was Investigating their 3rd Suspected Case Of H5 Avian Flu, and 56 dairies had reported H5 in cows. In less than two weeks, the number of infected dairies has nearly doubled (n=105), and the number of confirmed and presumed positive human cases has nearly quadrupled (n=11).
SACRAMENTO, CA — Following an investigation by the California Department of Food and Agriculture (CDFA) and rapid disease detection by California Animal Health and Food Safety Laboratory System (CAHFS), the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories (NVSL) has confirmed H5N1 Bird Flu in one hundred five dairies in Central California. CDFA has implemented a surveillance strategy with the goal of finding affected farms as early as possible. Early detection provides the opportunity to work with farms to quickly implement enhanced biosecurity, cow care, and employee protection.
This from the CDPH:
State Continues Proactive Testing for Human Cases of Bird Flu; Reports 6 Confirmed, 5 Possible Cases
October 14, 2024
NR24-034
New possible cases identified over three-day stretch following direct contact with infected dairy cows in Central Valley
What You Need To Know: CDPH continues to work with federal, state and local partners to monitor and respond to human cases of bird flu in the state. The risk to the general public remains low, although individuals who interact with infected animals are at higher risk of getting bird flu.
Sacramento – As California continues to proactively test symptomatic individuals for bird flu, the California Department of Public Health (CDPH) reports that new possible positive human bird flu cases have been identified in the Central Valley since last Friday. To date, the state has identified six confirmed and five possible human cases. The individuals had direct contact with infected dairy cattle at nine different farms.
The five possible human cases are pending confirmatory testing by the Centers for Disease Control and Prevention (CDC). Due to shipping delays late last week, and today’s federal holiday, the possible (or presumptive positive) specimens are expected to arrive at the CDC early this week.
Given the amount of exposure to infected cows, evidence continues to suggest only animal-to-human spread of the virus in California. Additionally, based on CDC’s genomic sequencing of three California bird flu cases, there is no evidence to suggest an increased ability for the virus to infect or spread between people and no known reduced susceptibility to antiviral medications.
All individuals with confirmed or possible cases of bird flu have experienced mild symptoms, including eye redness or discharge (conjunctivitis), and have been treated according to CDC guidance. None of the individuals have been hospitalized.
While the risk to the general public remains low, additional human cases of bird flu are expected to be identified and confirmed in California among individuals who have regular contact with infected dairy cattle. CDPH continues to work closely with local health jurisdictions to identify, track, test, confirm, and treat possible and confirmed human cases of bird flu.
More information on CDPH’s response can be found at CDPH’s Bird Flu website and in recent CDPH news releases.
It has now been more than 8 weeks since Missouri's first (and only confirmed) H5 case was hospitalized, and while there were 7 symptomatic contacts, we've yet to hear anything about their serology testing. Nor do we know how this index case was infected.
Since testing - of both cattle and symptomatic workers - remains largely voluntary, it is frankly anyone's guess how far this virus has spread across the nation. Until late August, California was assumed free of the disease.
Today, California accounts for more than 1/3rd (of all known) infected U.S. dairies, and nearly half of all human H5 infections in the nation.
This slow-rolling of information, and a general lack of urgency - particularly at the local level - is both perplexing and frustrating. And if this were happening in another country, our own government would be decrying the lack of progress.
It is, of course, possible that HPAI H5 is currently incapable of sparking a larger public health crisis. We've seen it threaten before - in Egypt, and Indonesia, and Vietnam - only to fizzle and recede.
But we've never seen HPAI H5 affects so many mammals (cattle, cats, dolphins, seals, bears, skunks, foxes, mice, mink, etc.) before. The longer it persists in cattle, and the more it spreads to other species, the more chances it will have to adapt or mutate into a more formidable foe.
Even if the odds are greatly against the virus, the downsides of a long-shot coming in could be enormous.
