Microbiology
A fungus. C. immitis or C. posadasii.
Epidemiologic Risks
Inhaling dust from the US SW (Coccidioides immitis) as well as parts of South and Central America (C. posadasii). It is in Eastern Washington (PubMed)(PubMed). I hate saying Washington State. I live in Oregon. There is Washington and Washington DC. And in Washington, it infects animals, dogs, and horses(PubMed).
The clade in Washington is relatively new to the region (PubMed). As usual. Damn Californians moving to the NW for cheap real estate.
And now Missouri (PubMed). I have to wonder if this is due to climate change.
And Baja Mexico (PubMed).
People can have minimal exposure and get the disease. I see it in truckers who travel the I-5 from LA to Seattle. It can be spread in dusts that coat cars, planes and food, and the winds can take it to odd places. There was a sea otter off the California coast who died of cocci and you know it never visited Bakersfield. Earthquakes, which kicks up dust, are associated with an increase in disease.
Rates have been going up this decade (the teens) in California (PubMed). And there was a 58% increase in Arizona cases in 2017 (PubMed) Wet winters followed by dry hot summers lead to more disease.
Where it is endemic (Phoenix/Tucson) physicians miss the diagnosis all the time, markedly increasing cost and morbidity (PubMed) (PubMed). So the one place you would think they would be up to snuff, Arizona, they aren't.
Often missed in those who return from endemic areas as HCW's don't ask a good travel history (PubMed).
Reactivates in those on biologics like TNF inhibitors; those at risk should be screened.
Syndromes
PubMedValley Fever: cough, headache, pneumonia (29% of people presenting with pneumonia in Az had cocci (EID)), hilar lymphadenopathy, +/- erythema nodosum or erythema multiforme; will often leave a thin-walled cavity to later become colonized/infected with Aspergillus.
Chronic progressive pneumonia: looks and acts like tuberculosis. Commonly found in those with borderline immune systems: diabetics for 17.
Disseminated disease: It can disseminate (especially in non-Caucasians (Philippino/Asians > Hispanic/Blacks), pregnancy, immunoincompetent) anywhere and reactivate in patients with advanced immunodeficiency like AIDS or infliximab or other biologic, therapy (PubMed).
American Indians have increased risk as well (PubMed).
Meningitis: especially in non-Caucasians, pregnancy, immunoincompetent. There is a CSF antigen test to aid in diagnosis (PubMed).
Treatment
For details read the IDSA guidelines.
Valley Fever: It probably needs no therapy in normal people. However, everyone probably gets fluconazole. And treatment has little effect on clinical course for mild to moderate pneumonia, which is protracted "Median times from symptom onset to 50% reduction and to complete resolution for patients in treatment and nontreatment groups were 9.9 and 9.1 weeks, and 18.7 and 17.8 weeks (PubMed)."
It is under-diagnosed as a cause of CAP in endemic areas (I'm talking to you California), especially in non-Hispanic black, Filipino, or Hispanic patients (PubMed).
Chronic progressive pneumonia: High dose fluconazole OR itraconazole OR Amphotericin B. Posaconazole is effective in pneumonia and non meningeal disseminated disease (PubMed).
Disseminated disease: High dose fluconazole OR itraconazole OR Amphotericin B. Type and duration of therapy depends on the host and extent of disease. Posaconazole 800 mg a day may be effective in refractory disease (PubMed).
Meningitis: Amphotericin B at 1 mg/kg until titer has fallen, then followed by lifetime high dose fluconazole OR itraconazole. Unlike love, cocci meningitis is forever.
If a patient has a stroke as a complication of meningitis, steroids will prevent a second. (PubMed). But steroids from primary prevention? No idea as of 2018.
If fluconazole fails, voriconazole and posaconazole (PubMed) are reasonable alternatives, but not 'infallible' (PubMed).
Notes
Complement fixation serology >= 1:32 means disseminated disease. Not that you can get a complement fixation test anymore. Despite 30 years of literature on the complement fixation tests, most of my referral labs have changed to the worthless ELISA. Sometimes, I hate progress. Do not get me started on electronic medical records. echinocandins work in mice and in vitro but only against the mycelial but not yeast forms. My one case I treated failed two months of therapy. See in my experience. The >=1:32 is based on information from the 1950s. More recent data suggests "The median maximal CF titers were 1:4 for pulmonary uncomplicated coccidioidomycosis patients, 1:24 for pulmonary chronic coccidioidomycosis patients, 1:128 for disseminated coccidioidomycosis patients, and 1:32 for coccidioidal meningitis patients (Pubmed)."
Fluconazole used early in disease (within 2 weeks of symptom onset) will prevent an IgG response (PubMed).
Cocci is not infectious person to person but the form on the plate is very infectious. I know of one ID person who, not knowing, smelled the plate in the micro lab. He converted his serology but never became ill and is the only person who knows what cocci smells like. And no, it wasn't me.
Hypercalcemia can occur, as with all granulomatous diseases (PubMed).
Curious Cases
Relevant links to my Medscape blog
My motto: Frequently in Error, Never in Doubt.
One would think they would know better
Last Update: 12/05/19.