Fungus-caused Valley fever is now spreading across U.S. – Here’s what you need to know

Valley fever, previously limited to the southwestern regions, is now spreading across the United States and has the potential to cause significant harm. 

The fungus that causes Valley fever thrives in hot and arid conditions, and with the warming of the climate, scientists anticipate an expansion of its range. Currently, 97% of all Valley fever cases in the US are recorded in California and Arizona. 

However, this could change as cases of fungal infections, including Valley fever, are being detected outside of their traditional areas. 

A study in the journal GeoHealth suggests that, due to climate change, the range of Valley fever may extend north to the Canadian border and east to the Great Plains by the close of the century.

What is Valley fever?

Valley fever is a type of infection caused by inhaling tiny pieces of the coccidioides fungus. This fungus can withstand harsh conditions, including heat and drought, and can persist in the soil. 

When the soil is disrupted, such as through activities like construction, wind, or even walking, the fragments of the fungus can be dispersed into the air.

The coccidioides fungus can be found in the soil in areas such as the southwestern United States, parts of Mexico, and certain regions of Central and South America. 

The fungus has also been recently discovered in south-central Washington. People can contract Valley fever by breathing in the microscopic fungal fragments that are present in the air, although most individuals who inhale these fragments do not experience any illness.

What are the symptoms of Valley fever?

As per the CDC, a significant number of individuals who come into contact with the Coccidioides fungus do not display any symptoms. 

Some individuals may experience symptoms that eventually resolve on their own over the course of several weeks to months. If your symptoms persist for more than seven days, it is recommended that you seek medical attention from your healthcare provider.

Symptoms of Valley fever include:

• Fatigue (tiredness)
• Cough
• Fever
• Shortness of breath
• Headache
• Night sweats
• Muscle aches or joint pain
• Rash on upper body or legs

In very rare instances, the fungal particles can penetrate the skin through a cut, wound, or splinter, leading to a skin infection.

Is Valley fever contagious?

The CDC states that Valley fever caused by the Coccidioides fungus is not contagious. It cannot be transmitted from person to person or from person to animal through the lungs. 

However, in very rare cases, a skin infection with Coccidioides may lead to the spread of Valley fever, or the infection may be transmitted through the transplantation of an infected organ.

Who can get Valley fever?

Valley fever can affect individuals of all ages, but it is most frequently seen in adults who are 60 years or older. 

People who reside in or visit the southwestern United States (including Arizona, California, Nevada, New Mexico, Texas, or Utah), or parts of Mexico, Central or South America are at risk of contracting Valley fever.

Certain populations may be more susceptible to developing severe forms of Valley fever, including those with weakened immune systems due to conditions such as HIV/AIDS, organ transplantation, cancer, or the use of certain medications, as well as pregnant women, diabetics, and Black or Filipino individuals.

Can you get Valley fever more than once?

Valley fever is generally a one-time occurrence, and individuals who have already had the infection are likely protected from getting it again due to the development of immunity by their immune system. 

In rare cases, some individuals may experience a relapse of the infection after previously recovering, but this is uncommon.

Can pets get Valley fever?

Yes, pets, especially dogs, can contract Valley fever, but it is not spread from animals to humans. The symptoms of Valley fever in dogs are similar to those in humans. 

Many dogs who are exposed to the Coccidioides fungus do not show any signs of illness. Dogs that do experience symptoms often display coughing, lethargy, and weight loss. 

If you have concerns about your pet’s risk for Valley fever or suspect that your pet may have contracted it, consult with a veterinarian for further guidance.

How is Valley fever diagnosed?

Diagnosing Valley fever requires information about your medical history, travel history, symptoms, physical examination, and laboratory tests. 

The most commonly used method for testing for Valley fever is through a blood test that checks for the presence of Coccidioides antibodies or antigens. 

Imaging tests such as chest x-rays or CT scans of the lungs may also be performed to diagnose Valley fever pneumonia. 

In some cases, healthcare providers may take a small sample of tissue for examination under a microscope, known as a tissue biopsy. 

The growth of Coccidioides from body fluids or tissues can also be tested in a laboratory culture.

 

How is Valley fever treated?

For most individuals with Valley fever, the symptoms will resolve on their own within a few months without treatment. 

However, healthcare providers may prescribe antifungal medication to some individuals to alleviate symptoms or prevent worsening of the infection. 

Antifungal medication is usually given to those at higher risk for severe Valley fever, and the typical treatment is 3 to 6 months of fluconazole or another antifungal. 

There are no over-the-counter remedies available to treat Valley fever. For those with severe lung infections or infections that have spread to other parts of the body, antifungal treatment is essential and hospitalization may be required. 

In these cases, the treatment period may last longer than 6 months. Valley fever that progresses to meningitis is life-threatening without treatment, requiring lifelong antifungal therapy.

Is there a vaccine for Valley fever?

Currently, there isn’t a vaccine available for Valley fever. Despite efforts to develop one dating back to the 1960s, no vaccine has yet been created. 

However, once a person has had Valley fever, their immune system typically provides protection against future infections, making a vaccine that triggers this response a potential solution for preventing the disease.

How can you prevent Valley fever?

Although the following measures are suggested to reduce the risk of getting Valley fever, there is no guaranteed prevention method.

• Avoid dusty areas, such as construction sites, or if unavoidable, wear a protective N95 respirator mask.
• During dust storms, remain indoors and close windows.
• Refrain from activities that generate a lot of dust, including gardening, digging, and yard work.
• Install air filtration systems in your home.
• Clean wounds thoroughly with soap and water to reduce the chance of skin infection, especially if the injury was exposed to dirt or dust.
• If your healthcare provider recommends it, take prophylactic antifungal medication.