A cough that hangs on for weeks. Tiredness that will not lift. A fever that comes and goes. It could be many things, but in the South Bay one more cause is worth asking about: valley fever, a fungal lung infection known in Spanish as fiebre del valle. Valley fever symptoms look a lot like flu or COVID-19, so the infection is easy to miss. CDPH also offers a Spanish-language guide.
Why the South Bay Sees More Valley Fever
Valley fever (coccidioidomycosis) is caused by Coccidioides, a fungus that lives in soil in the southwestern United States and parts of Mexico, Central America and South America, according to the CDC. The California Department of Public Health (CDPH) reports that statewide cases have reached a record high and are rising beyond the Central Valley and Central Coast, including in southern coastal areas.
Within San Diego County, the South Bay stands out. A County of San Diego Health and Human Services Agency surveillance report found that reported cases have climbed over roughly two decades. Averaged over five years, the countywide rate was 13.6 cases per 100,000 residents. ZIP code 92173, which covers San Ysidro, had the second-highest rate in the county at 33.5 per 100,000, nearly two and a half times the county average. Two other South Bay ZIP codes, 91902 and 92154, also ranked in the top four.
One caution: rates are based on home ZIP code, which may not be where a person breathed in the spores, and small case counts can shift. The point is awareness, not alarm.
How Spores Spread: Dust, Wind and Construction
Valley fever does not spread from person to person. The County of San Diego explains that people get infected by breathing in outdoor dust that carries fungal spores, which become airborne when strong winds or digging stir up the soil. A county surveillance report lists high winds, dust storms, construction, excavation and farm work as common triggers.
CDPH notes a higher risk of infection for people who work in construction, landscaping or agriculture, and for those who live or work near construction and excavation sites. Because the fungus also lives in parts of Mexico, outdoor time on either side of the border counts. If you work outdoors or cross the border often, mention it at your visit.
To cut down on dust exposure, the county suggests:
- Staying indoors with windows and doors closed when it is windy and dusty.
- Keeping car windows up and using recirculated air when driving where valley fever is common.
- Wearing a fitted N95 respirator if you cannot avoid dusty work, such as at construction or excavation sites.
Valley Fever Symptoms That Look Like Flu or COVID-19
Many people never feel sick: the county estimates that around 60 percent of people with valley fever have no symptoms. When symptoms appear, the CDC says they usually start 1 to 3 weeks after exposure and can include:
- Fatigue, cough, fever and headache
- Shortness of breath and night sweats
- Muscle aches or joint pain
- A rash on the upper body or legs
CDPH adds chest pain and weight loss, and notes that these symptoms are similar to COVID-19 and flu, so laboratory tests are needed to tell them apart. Symptoms usually last a few weeks to a few months. Because valley fever resembles pneumonia caused by bacteria or viruses, the CDC notes that it is often misdiagnosed.
When to Go to the ER or Call 911
Most valley fever is mild, but it can become serious. According to the CDC, about 5 to 10 percent of people with valley fever develop serious lung problems, and in about 1 percent the infection spreads to the brain and spinal cord, skin, or bones and joints. Call 911 or go to the nearest emergency room for:
- Breathing trouble that comes on suddenly or makes it hard to talk (MedlinePlus)
- Sudden crushing, squeezing or pressure-like chest pain, especially with sweating or nausea (MedlinePlus)
- A severe headache with a stiff neck, confusion or sensitivity to light, possible signs of meningitis (MedlinePlus)
When to Ask About Testing
The CDC advises contacting a healthcare provider if valley fever symptoms last more than a week. CDPH suggests talking to a provider about testing when cough, fever and fatigue last more than 7 to 10 days after time around dirt and outdoor dust where valley fever is common. Ask about a test if:
- You have a cough that won't go away, a fever or exhaustion lasting longer than a week.
- You were treated for pneumonia with antibiotics and are not getting better. The CDC recommends asking about testing for valley fever or other fungal pneumonias in this situation.
- Your illness started 1 to 3 weeks after dusty outdoor work, yard work or a windstorm.
- You belong to a higher-risk group described below.
Higher-Risk Groups, Including People With Diabetes
Some people are more likely to become very sick. CDPH lists people who:
- Are 60 years or older
- Are Black or Filipino
- Are pregnant, especially in the later stages
- Have diabetes
- Have a weakened immune system from cancer, HIV, an organ transplant, or medicines such as chemotherapy or steroids
The county also includes people who are Pacific Islander. If you live with diabetes, do not wait out a lingering cough. MedlinePlus lists diabetes among the conditions that raise the chance of severe pneumonia, and advises contacting a provider when breathing symptoms worsen, fevers persist, or symptoms return after you started to feel better.
How the Blood Test Works
Testing usually starts with a blood draw. As the CDC describes, your provider sends the sample to a laboratory, where it is checked for antibodies your immune system makes against the Coccidioides fungus (MedlinePlus). Keep in mind:
- Early tests can miss it. Few antibodies may be present early in the illness, so the test may be repeated several weeks later (MedlinePlus).
- A positive result needs context. Antibodies can mean a current or past infection, and a rise on a repeat test helps confirm an active one (MedlinePlus).
- Other tests may be added. A clinician may order a chest X-ray or CT scan, or test fluid from the airways (County of San Diego).
If the test is positive, the county notes that many people with mild symptoms get better without medication within a few months, while people with more serious infections or risk factors may be prescribed 3 to 6 months of oral antifungal medicine.
At Palm Urgent Care, San Ysidro, walk-in patients can be evaluated for a lingering cough, fever or fatigue, with lab testing when a clinician recommends it. Learn more about how lab testing works at urgent care, or browse all Palm Urgent Care services.
Frequently Asked Questions
What are the first symptoms of valley fever?
Common early signs are tiredness, cough, fever, headache, shortness of breath, night sweats, and muscle or joint aches, sometimes with a rash on the upper body or legs. They usually begin 1 to 3 weeks after breathing in the spores.
Is valley fever contagious?
No. Valley fever does not spread from person to person or between people and animals. People get it by breathing in spores from outdoor dust and soil, or rarely through a cut or wound.
How can I tell valley fever from the flu or COVID-19?
Not by symptoms alone. The illnesses look alike, so a lab test is needed. If symptoms last more than a week, or antibiotics for pneumonia are not helping, ask your provider about valley fever testing.
Where can I get a valley fever test near me in San Ysidro?
Palm Urgent Care, San Ysidro, welcomes walk-in patients and offers lab testing. A clinician can review your symptoms and, if needed, order testing or refer you. Call ahead to confirm which tests are available at this location.
If valley fever symptoms such as a cough, fever or deep fatigue have lasted longer than a week, get checked. Walk in at Palm Urgent Care, 601 E San Ysidro Blvd #170, or visit the San Ysidro location page for hours, directions and coverage details.
This article is for general information and is not a substitute for medical advice from a licensed clinician.