Valley fever, caused by Coccidioides fungi, remains a serious concern, particularly in regions like California and Arizona. Antifungal treatments are effective for many patients, but for others, they’re not enough. George Thompson, MD, professor of infectious disease at UC Davis Medical Center, sheds light on this issue and the ongoing research efforts to better understand and treat valley fever.
Thompson explains that despite the availability of antifungal drugs, some patients, even when treated with the correct medication, simply do not respond. “We know what the susceptibility is in the lab, but for whatever reason, it just doesn’t work. The patient doesn’t respond and clear the infection,” Thompson says.
This challenge is particularly pronounced in patients with severe disease manifestations, such as bone, brain, or skin infections, where the body’s immune system has failed to effectively control the infection. “There’s a key defect somewhere,” Thompson said. “They don’t all have HIV or AIDS or are on immunosuppressive medications. It’s a very small innate immune deficit that is probably only significant for valley fever. Most commonly, it’s just valley fever that they suffer with.”
In response to these treatment challenges, Thompson and a group of researchers from UC San Diego, UCLA, Texas, and Northern Arizona University (NAU) have spent the past years focusing on the host response to valley fever. By better understanding why certain patients fail to clear the infection, the team aims to improve treatment strategies and explore preventative measures. “If we really understand how we control the infection, perhaps we can create a vaccine that will prevent it completely. That would be just fantastic,” Thompson said. He emphasizes that understanding the nuances of the immune system’s response to valley fever is a key step in making significant progress for treatment and future vaccine development.
Thompson notes that patients diagnosed early in the course of their illness tend to have better outcomes, “The infection really hasn’t fully established itself, so to speak, and they generally do better the earlier they’re diagnosed,” he said. Educational initiatives and heightened awareness have been key to improving early diagnosis. Efforts led by the state and the CDC have significantly contributed to raising awareness about valley fever, prompting more patients to seek testing sooner. In Arizona, patients can even order their own valley fever tests without needing a doctor’s referral, which Thompson believes is a major step forward in facilitating earlier diagnosis, “The goal is to move up the diagnosis date and not allow the disease to establish itself for weeks or even months before it comes to clinical attention,” he said.
While much of the focus has been on diagnosis and immune response, there is also news in the development of new antifungal treatments. Thompson highlights two promising drugs currently in phase two and three clinical trials, Lorafin and Fasmanid. While these drugs are not yet available on the market, early results have been promising, and they are already being used in compassionate use programs for patients who have failed standard therapies. “These drugs are really needed, and we’re hopeful they’ll be available soon,” said Thompson. Until then, the medical community continues to rely on existing therapies, though these new options could offer hope for patients whose infections do not respond to current treatments.
Thompson also emphasizes the importance of a comprehensive patient history, especially when dealing with respiratory illnesses. Valley fever is often diagnosed outside its traditional regions of California and Arizona. He advises healthcare providers to take a thorough travel history when patients present with pneumonia or other respiratory symptoms that don’t respond to initial antibiotic treatments. “Think about not only valley fever but also other fungal infections like Histoplasma and Blastomyces, as well as atypical bacteria,” he advises. By considering these factors, doctors can improve diagnosis and treatment outcomes for patients who might otherwise be misdiagnosed.
