For the second consecutive year, California is expected to have record-breaking cases of valley fever, which public health officials say is driven by longer, drier summers.
From January to April, there were 4,000 cases of valley fever across the state, an increase of more than 3,000 from the same period in 2024 and 2,000 from 2023, according to the California Department of Public Health.
The number of recorded cases reached 12,605 last year; in 2023, there were more than 9,000 cases.
According to the Centers for Disease Control and Prevention, valley fever or coccidiosis is a lung infection in which people breathe in fungal spores, spores of coccidi agents, which live in dry soil.
Spores of fungi that grow in dry soil are released into the air when the soil is disturbed by wind, buildings and other activities.
The fungus is available in the Pacific Northwest and Southwest, Mexico, Central and South America.
Last year, in Kern County, a bottle of music festival lightning became a hot spot for the disease, after 19 people reported a valley fever, with several of them experiencing severe symptoms including pneumonia-like illness, rash, headache and fatigue.
Valley fever cases usually increase statewide in late summer and fall in winter, but state public health officials say the onset of valley fever spread begins earlier and lasts longer.
Climate change is expected to cause drier spring and fall and more rainfall in winter, according to researchers at the University of California, Berkeley. Prolonged dry seasons can prolong the period of high-risk exposure to valley fever.
Because the symptoms (cough, fever, and chest pain) are similar to other infectious diseases, valley fever is often misdiagnosed, which can make it difficult for health officials to accurately report the number of cases.
The number of valley fever cases is trending toward a new record so far this year, but public health officials say it is too early to determine whether this will be a record-breaking disruptor.
Here are some precautions to help locals, hikers and tourists in counties with reported high numbers of fever cases in valleys to avoid the disease this summer.
How to protect yourself from shrinking valley heat
Public health officials in Fresno County, including part of the John Muir Trail, shared the following warnings from hikers:
- Stay on well-maintained trails and avoid dusty activities such as digging or cycling.
- Consider wearing the proper N95 mask when hiking in dusty or dry conditions.
- Avoid hiking on windy days or immediately after interference, which may increase dust in the air.
- Clean any skin wounds thoroughly with soap and water, especially when they are exposed to soil or dust.
For anyone living, working or traveling in areas where the fever fungus in the valley grows, the CDC recommends:
- Please stay indoors when the wind is strong outside and the air is dusty.
- On windy days, close windows and doors to prevent dust and possible spores from entering the house.
- Keep your windows closed and use circulating air where possible when you pass through dusty areas.
- Before digging, wet the soil and dirt to prevent dust from being stirred into the air.
- If you have to be in the dusty air outdoors in these areas, consider wearing the right N95 mask.
Who is at risk of staining valley fever
Those who spend a lot of time outdoors exposed to dirt and dust in areas with valley fever are more likely to contract the disease, according to the Los Angeles County Department of Public Health. These include construction workers, farmers, military workers and archaeologists.
People who live and work in dry and dusty areas also have a risk of exposure to valley heat.
People at increased risk of disease include:
- Adults are over 60 years old.
- Those with diabetes or health conditions that can weaken the immune system, including cancer, HIV, autoimmune diseases, patients with organ transplants, or those undergoing chemotherapy or steroids.
- Pregnant women, especially those in the late stages of pregnancy.
- Children aged 5 and under.
- Those are black, Latino, Native American or Filipino decent people, although experts say they have no clear answers on why these people are more susceptible to impact.
What are the symptoms of valley fever
Fungal infections in the lungs can cause respiratory symptoms, including:
- cough
- fever
- Chest pain
- fatigue
- Difficulty in breathing
- Muscle or joint pain
- Night sweat
- lose weight
- rash
Valley fever has many of the same symptoms as other respiratory diseases, including Covid-19, but valley fever symptoms take about one to three weeks and the disease can last for a month or more.
Los Angeles County public health officials say some people with a valley fever may only experience mild symptoms and will get better within a few weeks, so there is no treatment required.
However, some others have symptoms that last for a month or longer and may require treatment based on a doctor’s consultation.
In very few severe cases, the disease can spread from the lungs to other parts of the body.
The disease is usually diagnosed as a blood test.
If you have tested negative for Covid-19 and your respiratory symptoms last for more than a week and you live or recently travel to an area where the valley fever is more prevalent, public health officials recommend you speak to your doctor.
Since valley fever affects each person differently, treatment will be determined based on the severity of the disease. The disease is usually treated with antifungal drugs.
