In 1994, Los Angeles experienced a large earthquake which caused massive damage and also instigated an outbreak of valley fever. There were 203 cases reported, including three fatalities. These figures suggest a rate of valley fever that was roughly 10 times the normal rate, in the eight weeks following the earthquake. This was also the first report of such an outbreak following an earthquake, and it’s believed that the spores which cause the disease were carried in large clouds of dust created by seismically triggered landslides.
The epicenter of the earthquake was in an area north of the city, also known as the San Fernando Valley, hence people assume that’s how the name Valley Fever originated. Certainly, this is when this condition literally became a household word.
In truth, this condition has been reported as far back as the turn of the nineteenth century. It was first reported in 1892 in Argentina. The term valley fever actually refers to the San Joaquin Valley in Northern California, which is a desert area.
The condition is an infection caused by the fungus Coccidiodes Immitis (we in the health care world call it cocci). The fungus grows in dry, arid areas like dusty deserts. The disease is common to the western United States, especially California, Nevada and Arizona, and it’s also found in the northern Mexico region.
It can reside in this type of environment for many years, so the deserts are unlimited reservoirs of the fungus. It takes the form of filaments, called hyphae, and with blowing winds becomes airborne, then breaking into small barrel shape fragments called** arthroconidia**. Humans unknowingly inhale the arthroconidia when in the right geographic location, area with specific wind and weather conditions. Once in the human lungs it changes shape, becoming the round form called** spherule.**
At this stage, in most cases when the individual has no chronic disease and a healthy immune system, the fungus lives in the lymph nodes and does not cause symptoms or frank disease. In some cases, the fungus will proliferate and cause an inflammatory reaction resulting in cough, fever, chills or more serious symptoms. Treatment with antifungal medications is then indicated.
When talking to the patient, the typical history I usually encounter is an individual who works outdoors, and develops a non-specific respiratory infection. The person typically goes to an urgent care center and is given a Z pack (a five day package of antibiotics for bronchitis). Since the antibiotic does not treat the cause of the symptoms (a fungus), the person typically gets worse over the ensuing weeks. When he returns to the clinic with this ongoing process, he will finally have a blood test and the result is** a diagnosis of cocci infection.** In the meantime, valuable time was lost and the patient got much sicker. In some instances, a severe pneumonia develops that needs to be treated with a stay in the hospital.
How do you know when you need to ask for a blood test specific to cocci? You should be on alert if you develop the symptoms I described earlier and if you live or work in the area of the desert with exposure to dust – there’s a good chance that it is valley fever caused by cocci. The diagnosis is not made by X-ray or sputum culture but rather by a simple blood test looking for the antibody that develops in response to the presence of the fungus. There are two types of tests looking at the antibody response. One tests specifically for a titer of the antibodies that are elevated within a week of exposure and comes down after 30 days (cocci antibody IgG ). The second test looks at the antibody titer that rises during the 30 days and remains high as long as the organism is in the body (cocci antibody IgM). This second blood test is used to determine the length of treatment that is needed. The drug of choice is called** Fluconazole** (brand name Diflucan) that can be given anywhere from six months to as long as several years. The lengthy treatment is required because this fungus literally hides inside the cells.
In most cases the treatment will result in complete resolution. The most dreaded complication, a spreading of the fungus in the blood (disseminated cocci) can occur when there is inadequate or delayed treatment. This phenomenon has been seen more frequently in AIDS patients. It can also affect the brain, causing meningitis, which requires a spinal tap for diagnosis.
Valley fever can be a potentially dangerous condition. Historically, it was even considered as a possible biological weapon in the 1950s and 1960s. Patients should realize that it is a differential diagnosis when they live in certain geographic locations and present with certain symptoms. Diagnosis and full treatment is key to avoiding disastrous complications.
Eli Hendel, M.D., is a board-certified internist/pulmonary specialist with board certification in Sleep Medicine. An Assistant Clinical Professor of Medicine at Keck-University of Southern California School of Medicine, and Qualified Medical Examiner for the State of California Department of Industrial Relations, his areas include asthma, COPD, sleep disorders, obstructive sleep apnea, and occupational lung diseases. Favorite hobby? Playing jazz music. Find him on Twitter @Lung_doctor.