What Is Valley Fever?
Valley fever, or coccidioidomycosis, is an infection caused by a fungus called coccidioides. It's also known as San Joaquin Valley fever or desert rheumatism.
The fungus that causes valley fever grows in the ground and can be found in the Southwestern part of the U.S. When something stirs up the soil, spores from the fungus fly into the air where people breathe them in.
Valley fever is the first stage of this fungal infection. Most people don’t get sick, but you may experience flu-like symptoms including fever and chills. And when valley fever symptoms do appear, they usually go away on their own.
Medicine can typically clear up symptoms, but in rare cases the fungus spreads to other parts of the body and your symptoms can become more severe.
Pets can come get valley fever, too.
Where Is Valley Fever Found?
The types of fungus that cause valley fever grow when it rains in dry, desert soil. When the wind picks up their spores, it can blow them for hundreds of miles. They exist in these areas of the U.S.:
- Arizona
- Southwestern New Mexico
- Areas around El Paso, Texas
- Central and Southern California, especially the San Joaquin Valley
- Eastern Washington state
- Nevada
The fungus’ area also reaches down into Mexico. And it has turned up in Central and South American countries, including Argentina, Brazil, Colombia, Guatemala, Honduras, Paraguay, and Venezuela. Climate and weather changes could cause valley fever fungus in new areas.
Valley fever outbreaks rarely happen. But when they do, they may be due to weather events that disturb the soil, like earthquakes and dust storms. About 47 outbreaks were recorded from 1940 to 2015.
Valley fever in California
Valley fever cases went up in California from 2000 to 2018. Drought in California affects the number of new valley fever cases. This is because the valley fever fungus lives and grows in soil. Even when it's dry from drought and other organisms are killed, the fungus can live. During the actual drought, there aren't as many new valley fever cases, probably because the fungus is inactive in the soil. But when it rains again and the fungus can grow, more people get sick. Drought in California causes there to be more valley fever cases in the years following.
The Southern San Joaquin (Central) Valley region in California had the highest rates of valley fever. Counties in this region include:
- Fresno
- Kern
- Kings
- Madera
- Tulare
The California Central Coast and Northern San Joaquin (Central) Valley regions had an increasing number of valley fever cases. The counties in this region include:
- Monterey
- San Luis Obispo
- Santa Barbara
- Ventura
- Merced
- San Benito
- San Joaquin
- Stanislaus
When do most people get it?
You can get valley fever at any time of the year. But more people get diagnosed in the fall, between late September to November, compared to other months. Because it takes weeks for people to develop symptoms, this means that people who get the infection usually catch it in the summer, between June to early September.
Valley Fever Risk Factors
If you go to the affected regions, you could be exposed. Someone who is age 60 or older is more likely to get it. The risk is also greater for:
- People with weakened immune systems
- P eople who are p regnant
- People with diabetes
- People of African descent and Hispanic, Native American, and Filipino people, likely due to genetic reasons
If you work, live, or travel in areas where there are high rates of valley fever, you're also at a higher risk. This is especially true if you:
- Work in close contact with dirt or dust (such as in landscaping, construction, military work, field work, or archaeology)
- Are around dirt or soil that is stirred up (like construction or excavation sites)
If you work or live in an area where valley fever is common, you should speak with your employer or landlord about how to prevent infection.
Valley Fever Symptoms
Six out of every 10 people who get infected with valley fever will have no symptoms. Their bodies will fight off the infection. But for others, signs of valley fever usually show up 1 to 3 weeks after the fungus gets into your lungs. You might have:
Valley fever rash
This rash can show up in different ways. Usually it's:
- Painful or tender
- Slightly elevated with red bumps
- On your legs (but it can also happen on your chest, back, and arms)
- A bluish to brown color
If symptoms do appear, recovering from them may take months. The time depends on your general health and how many of the fungus spores have gotten into your lungs.
If symptoms don’t improve on their own or you don’t get treatment, valley fever may develop into a long-term type of pneumonia. This mainly happens in people whose immune systems are weak. The symptoms include fever, unexplained weight loss, chest pains, and coughing up mucus with blood in it.
Is valley fever contagious?
Valley fever isn’t contagious, so you can’t catch it from someone else. You get the infection when you breathe in fungal spores in the air. Once you breathe them in, they change form in your body. You can't spread them to other people or animals once this happens.
Is valley fever serious?
Valley fever can be serious or fatal. In California, there have been over 1,000 hospitalizations each year with the infection. About 1 in 10 of these people have died in the hospital.
How long does valley fever last?
The symptoms of this this infection will usually go away on their own after a few weeks or months. A small group of people will have ongoing symptoms in their lungs. If this continues, it's called chronic pulmonary coccidioidomycosis and not valley fever anymore. With this, you may have no symptoms or have chest pains, shortness of breath, weight loss, cough up blood, of have a chronic cough.
Valley Fever Complications
Valley fever is unlikely to lead to complications. Only 1% of people with valley fever symptoms have complications, which involve lung or breathing problems.
Valley fever complications include:
- Pleural effusion or fluid buildup around your lungs
- Acute respiratory distress syndrome (ARDS)
- Pneumonia
- Hydropneumothorax or fluid or air in your lungs
- Lung scarring
- Lung abscess or pus in the lungs
Disseminated valley fever
In the most serious cases, the infection moves beyond the lungs into other parts of the body. Disseminated valley fever is the most intense version, but it's uncommon. It happens when the infection moves to your skin, bones, brain, liver, heart, and the membranes that guard your spinal cord and brain.
The effects include skin sores that are worse than the rash mentioned above; painful, swollen joints; and meningitis, which is an infection around the brain and spinal cord.
Other complications include:
- Pneumonia
- Air, pus, or water in the lung cavity or space outside of your lungs
- Acute respiratory distress syndrome (ARDS)
Valley fever lung nodules
Lung nodules are small tissues on the lungs that look like white spots in an X-ray. Only a few people with valley fever have them. Even if you don’t have valley fever symptoms or your symptoms have cleared, your doctor might find lung nodules on your chest X-ray. Though they can look like cancer, these nodules are generally harmless and often go away on their own.
However, they could break, too. When this happens, you may have chest pain and breathing problems. Your doctor will put a tube in the area around the lungs to let out air. They might also recommend surgery to treat it.
Nodules in the lungs can also be a sign of pneumonia from valley fever and disseminated valley fever.
When to Call the Doctor
Make the call if you have symptoms of valley fever and they last more than a week. Checking with a professional is especially important if you’re in a high-risk group.
Valley Fever Diagnosis
Most people with valley fever have no obvious symptoms, and if symptoms appear, they're usually mild. Your doctor will examine your symptoms, ask about your travel history, and perform a physical exam. They may also order a few tests, such as blood tests, X-rays, a biopsy, or a skin test, to help diagnose the condition.
Valley fever tests
The main test for valley fever is for your doctor to take a blood sample. The results should come back in a few days.
You may also be asked to cough up a mucus sample so it can be tested.
Your doctor might perform an X-ray or CT scan of your lungs to look for signs of valley fever or pneumonia.
They might also take a sample of tissue from your body. If the tissue or blood needs to go to a lab for more tests, the results might take a few weeks to get back to your doctor.
Another way your doctor can check if you have or had valley fever is through a skin test. They will give you a small injection on your forearm. If you have had valley fever, a bump should appear where you were injected. Your doctor will look at the bump again after two days to see how big it is.
However, you might not see a bump even if you’ve had the infection. This might happen if you have or had severe valley fever, have other health issues, or are taking medications interfering with your result.
Valley Fever Treatment
Valley fever usually doesn’t need medical treatment. For people who are otherwise healthy, bed rest and drinking plenty of fluids are enough. Your doctor will keep a close watch on how you’re doing.
Valley fever medication
If the symptoms hang on, get worse, or the infection spreads, your doctor might prescribe a drug that attacks illnesses caused by fungus. You may have to take the drug for three to six months. There are several options depending on how severe the symptoms are.
Some medicines your doctor may recommend include
- Amphotericin B (Amphocin)
- Fluconazole (Diflucan)
- Isavuconazonium sulfate (Cresemba)
- Itraconazole (Tolsura)
- Posaconazole (Noxafil)
- Voriconazole (Vfend)
These medicines may cause side effects like
- Nausea
- Vomiting
- Stomach pain
- Diarrhea
- Hair loss
- Dry skin and mouth
- Chapped lips
But they will likely go away when you stop taking your medicines. Never stop taking your medicine without first talking to your doctor. If you have any side effects that bother you, talk to your doctor about them.
In the most extreme cases, such as in people who develop meningitis, lifelong medication may be necessary.
Valley Fever Prevention
There’s no valley fever vaccine yet, but a potential vaccine is in the works.
if you live in or visit a region where valley fever is a possibility, it helps to take commonsense precautions, such as:
- Avoid dusty areas such as construction sites.
- Stay indoors during dust storms, and keep the windows shut.
- Avoid activities that put you in contact with dust and soil, such as yard work and gardening.
- Filter the air inside your home.
- When you drive, keep your windows closed and use recirculating air.
- Use an N95 mask if you can't avoid dusty areas.
- Control dust by covering dirt around your home with plants, grass, or gravel.
These steps are particularly important for people who are at high risk.
Valley fever immunity
One bit of good news: In many cases, people who have valley fever become immune for the rest of their lives.
But in rare cases, especially if you have a weakened immune system, you might get valley fever again.
Since you can’t spread it to other people, you don’t have to stay home for that reason. But it’s important to get as much rest as possible until your symptoms are gone.
Face masks
You can wear a properly fitted, National Institute for Occupational Safety and Health (NIOSH)-approved mask to protect against this infection. These include N95, N99, N100, P100, or HEPA.
Cloth masks, KN95s, or other non-certified masks won't help as much.
Valley Fever in Dogs
You can’t spread valley fever to, or get it from, your pet. But animals can get it on their own.
Valley fever symptoms in dogs
Dogs are most vulnerable. Just like with people, many of the animals that inhale the fungus don’t get sick. When they do, they may cough, lack energy, or lose weight. If you think your pet may have valley fever, check with your vet. Other symptoms include:
- Pain or swelling in their joints and limbs
- Neck or back pain
- Skin wounds that drain fluid
- Lumps and bumps under their skin
- Limping or trouble walking
- Neurologic signs (seizures, vision changes, and loss of muscle control)
- Swollen lymph nodes around their jaw, in front of their shoulder blades, or behind their back legs
- Swelling, pain, cloudiness, and redness in their eyes and around the skin
Cats can also get valley fever. They might have symptoms like fever, lowered appetite, and weight loss. Breathing issues, limping, neurologic signs, and eye issues are less common in cats.
Livestock can also get the infection. But they don't show signs as often. If they do, it's usually just a cough that lasts weeks to months.
Camels, llamas, and alpacas can get valley fever. They usually will develop intense infection that spreads to their entire body and is fatal. Other symptoms could include weight loss, coughing, low energy, lowered appetite, limping, skin wounds, and hair loss.
Takeaways
Valley fever is an infection caused by a fungus called coccidioides. You’ll likely have this infection if you visit places like California or Arizona, where there are high rates of valley fever. Most people with valley fever don’t show any symptoms, but for some, the symptoms can be mild and may go away on their own. Resting a lot and drinking fluids can help. In rare and severe cases, you might need antifungal medicines. If you have symptoms for more than a week, see a doctor.
Valley Fever FAQs
What is the life expectancy of someone with valley fever?
Most people with valley fever recover completely. It’s very rare for anyone to die from this infection.
How do you heal from valley fever?
You can heal from valley fever by resting, eating well, and hydrating. Taking your medicines as prescribed will also help.
Can coccidioidomycosis be cured?
Coccidioidomycosis can be treated with antifungal medicines like fluconazole (Diflucan).
Who is the most common victim of valley fever?
The people most likely to get valley fever include people who live in or have visited regions where it is common, like California, people 60 and over, people with weakened immune systems, pregnant people, people with diabetes, and people of African descent and Hispanic, Native American, and Filipino people.
What can be mistaken for valley fever?
Depending on your symptoms, valley fever can be mistaken for the flu, tuberculosis, cancer, chronic obstructive pulmonary disease, or myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).