Valley Fever Concerns After Fire and Mudslide
Source: Public Health Department
The Public Health Department has received many questions about Valley Fever after the recent Thomas Fire, mudslide event, and dusty conditions due to drying mud. The County Health Officer states that risk of infection from Valley Fever is low, although possible.
Dr. Charity Dean, the County Health Officer, notes, “The health effect I’m most concerned about related to the dust is irritation to the lungs and eyes. The risk of acquiring Cocci is low, though not zero, in Southern Santa Barbara County. People who are concerned about the dust should wear an N95 mask and take measures to protect their lungs in dusty conditions.”
Southern Santa Barbara County, where the Thomas Fire and mudslide event took place, is not an area where Valley Fever is highly endemic. From December 4, 2017 to present, there is one confirmed case in south county, and 18 confirmed cases in north county.
The fungus is highly endemic in Kern County, Tulare County, and San Luis Obispo County. The highest risk for infection is during the dry season between Spring and Fall.
Valley Fever is caused by the fungus Coccidioides, also called “Cocci”. It is a dimorphic fungi, meaning it exists in two forms. It grows as a mold inches beneath desert soil and it also exists as a spore in the air. In dry conditions, the soil can be blown into the air causing the mold beneath it to break into tiny spores. These spores, which are 3-5 microns in diameter, can be suspended in the air and inhaled into the lungs.
Many people who inhale Coccidioides spores never develop symptoms. Of those who do develop symptoms, they can either manifest acutely as “primary disease” (7 to 21 days after inhaling spores) or later as “reactivation disease” (months or years after inhaling spores).
Of those who do develop symptoms 7-21 days after exposure, most are mild and resolve without treatment. It is estimated that less than 50% of acute Valley Fever cases are diagnosed because symptoms are mild and medical evaluation is not sought.
Severe cases of Valley Fever can be successfully treated with anti-fungal therapy. Recent or past infection with Coccidioides spores can be determined by a simple blood test for the IgM or IgG antibody.