California may be seeing a rise in valley fever cases, but employers could use a preventative care idea from the COVID-19 pandemic to help prevent occupational exposures to the valley fever fungi.

John P. Kamin

Wired Magazine had this fascinating write-up about how climate change is probably playing a role in the spread of valley fever. I highly recommend you read it. (Note: The article originally appeared on a website called Grist.)

In summary, the article explores the idea that hotter and dryer weather is causing valley fever to spread to new geographic areas. In order to understand why that might happen, one has to first understand how infection occurs: Hot and dry weather dehydrates mouse poop that contains the disease’s fungal spores, which makes it easier for dry winds to blow the spores into the air. This makes it easier for people in the area to unknowingly inhale those spores, which can lead to a valley fever infection.

Fortunately, the COVID-19 pandemic has quite literally normalized a preventative measure that employers could use to prevent both COVID-19 and valley fever: masks.

“Wearing a mask, particularly an N-95 mask, can also be a good way to prevent valley fever,” said Dr. David Hatfield, chief medical officer at Hatfield Medical Group, to Cronkite News Service in this July 2021 article. That Cronkite article notes that the greater Phoenix area had more than 6,800 cases from January 2021 through July 29, 2021.

Employers in dry, dusty areas such as California’s Central Valley may be able to dodge both COVID-19 and valley fever by encouraging mask-wearing among their employees. So mask up early, and mask often.

We understand that after two years of the pandemic, wearing masks outdoors sounds like another annoyance. However, if doing so helps avoid multiple respiratory diseases, then it sounds like a preventative measure that is definitely worth taking.

Background: a rise in valley fever cases

The Wired article begins with a personal recollection of how a college student named Jesse Merrick helped his family dig through the wreckage of their family’s ranch-style home in Ventura, only to develop valley fever symptoms in the weeks that followed. This is alarming in and of itself, as Ventura is not known as a valley fever hotspot. It is not in the Central Valley, the geographic area where valley fever derives its name. It is far from areas that we think of as the “Central Valley,” such as Bakersfield.

The Wired piece later goes into more detail about how valley fever cases have skyrocketed in California by as much as 800% from 2000 through 2018, and as much as 32% in the United States from 2016 through 2018.

What made this article especially interesting for me was the fact that an old friend from the University of Arizona was one of the experts interviewed.

I met Bridget Barker, a valley fever researcher with a credentials list longer than "The Matrix," via a circle of friends who were mostly post-doctorates in various scientific fields at the time, including plant pathology, neurology and physics, just to name a few.

Back in 2001, Bridget told me that she was researching valley fever. As I replied, I mentioned that I had seen warning signs about valley fever that were in the Sonoran Desert as I’d drive to my newspaper internship in Tombstone, Ariz.

Bridget tried to explain to me that the signs were warning about airborne valley fever and even tried to explain how transmission works. I don’t think my warped 21-year-old brain fully understood at the time, and I probably still (stupidly) drove with my windows down through those areas on occasion while wondering if that rookie named Tom Brady was good enough to get the Patriots to the Super Bowl.

So what role does Bridget play in sourcing the article? In short, she acknowledges that it is worrying that the valley fever fungus known as Coccidiodmycosis (cocci for short) could be spreading to new geographic regions.

"There’s reason to believe this cocci expansion could be happening already," Bridget Barker, a researcher at Northern Arizona University, told Grist. Parts of Utah, Washington and northern Arizona have all had valley fever outbreaks recently.

“That’s concerning to us because, yes, it would indicate that it’s happening right now,” Barker said. “If we look at the overlap with soil temperatures, we do really see that cocci seems to be somewhat restricted by freezing.”

Barker is still working on determining the soil temperature threshold for the cocci fungus. But in general, the fact that more and more of the U.S. could soon have conditions ripe for cocci proliferation, she said, is worrying.

Work comp takeaways

So what does this mean for workers’ compensation practitioners?

Well, regardless of the cause, valley fever cases are rising. Therefore, it makes sense that we could see more work comp claims for valley fever.

It is important to know that the somewhat random nature of inhaling a fungal valley fever spore and the two- to four-week incubation time it takes for symptoms to develop can make determining causation and date of injury quite difficult. For instance, someone could just as easily get valley fever from gardening as from working outdoors.

So each case will turn on the individual facts of when and where symptoms began, and what the employee did in his personal time versus what he did for the employer. Thus, a strong factual investigation at the outset of the claim is highly recommended.

The fact that it is really difficult to identify the date and time of causation is one similarity valley fever has with COVID-19. Another similarity is that the vast majority of valley fever and COVID-19 cases are relatively minor, with a small subset of them having severe symptoms that can affect multiple body systems.

And a third similarity is that we recommend using qualified medical evaluators in the field of pulmonary-internal to evaluate both COVID-19 and valley fever.

However, there is one key difference between how the workers’ compensation system treats valley fever and COVID-19 cases. In short, the Workers' Compensation Appeals Board has taken a different approach between the two on the topic of whether it is a specific or cumulative trauma date of injury.

As you know from our blog post on Senate Bill 1159 and the COVID-19 presumptions last year, LC 3212.86-3212.88 calls for COVID claims to have a specific date of injury. That specific date of injury is the last date the employee worked for the employer.

In valley fever cases, the WCAB has generally ruled that the disease is a cumulative trauma ending around the time that symptoms began.

In the case of Manns v. State  (2014), the WCAB amended a judge’s finding of a cumulative trauma date of injury to reflect an earlier date of January 2001, despite the fact that he worked for the employer after that date and his symptoms worsened afterward.

“The period subsequent to his diagnosis in 2001 did not contribute to the injury,” the court wrote in Manns. “Rather, he has suffered repeated flare-ups with major complications requiring invasive medical treatment. None of this negates the fact that applicant did sustain a cumulative trauma injury arising out of and occurring in the course of employment. The only issue is the date of injury, and the medical evidence supports a finding that the cumulative trauma injury occurred as of January 2001.”

And in the cases of Abernathy v. Harris Woolf California Almonds (2017) and Pablo Gonzales v. KVS Transportation (2013), different WCAB panels of commissioners found that valley fever was a cumulative trauma date of injury.

So, paying attention to the subpoenaed records and initial medical records in a valley fever case can be quite helpful for determining when that cumulative trauma injury occurs.

Conclusion

I hope that the theory that climate change will cause an increase in valley fever cases is erroneous. However, if valley fever fungi are expanding their reach into a larger geographical area, employers should be taking preventative measures.

Fortunately, Cal/OSHA regulations already encourage donning masks to prevent COVID-19, so if the fungi do persist, encouraging N-95 masks for employees in high-risk areas could be a solution to preventing the spread of COVID and valley fever.

In the meantime, there may be a vaccine for valley fever in the works. Researchers at the Valley Fever Center for Excellence at the University of Arizona College of Medicine have developed a vaccine candidate for our canine buddies, which is apparently good news for the development of a vaccine for humans. If that does come to pass, then perhaps Central Valley employers will have a few vaccines to consider asking employees to take.

John P. Kamin is a workers’ compensation defense attorney and partner at Bradford & Barthel’s Woodland Hills location. He is WorkCompCentral's former legal editor. This entry from Bradford & Barthel's blog appears with permission.