Coccidioidomycosis

most deadly fungus in the world
- Coccidioides immitis & C. posadasii
- コクシジオイデス症とは｜感染研

Distribution

southwest US
- 70% of US cases concentrated in AZ, 20% in CA
- geographical association of creosote bush in AZ
- San Joaquin Valley in CA, "Valley fever"
  - spores fly into town from deserts miles away
some central and south American countries

live in 10-20 cm underground soil
dimorphic fungus
- filamentous in environment - arthroconidia
  - cultured coccidia is impossible to distinguish from other filamentous fungi macroscopically
- yeast form in human parasitism - spherules
incubation 1-4 weeks
recurrence/reactivation possible for years even in decades
all healthy people susceptible
African American > Hispanic > Asian > Caucasian
very short time exposure may cause disease
- even during transit at an airport in endemic area
- earthquake in 1994 developed massive landslide in the valley, resulting in dispersion and spreading of spores and large outbreak of Valley fever
- if accidentally cultured on petri dish, it is quite easily dispersed in aerosol = laboratory infection, highly biohazardous
no human to human transmission
- the yeasts proliferate by endospore forming, clearly different from filamentous proliferation by sporing in environment
- lab infection including autopsy or inappropriate handling of specimen possible

acute pulmonary form
- most common
- influenza like
- erythema nodosum
  - EN in coccidiomycosis is allergic reaction, not infectious
- spontaneous relief in most cases
diffuse pneumonia form
- fatal
- mostly in immunocompromised
chronic pulmonary form
- most common in Japan cases
- cough, hemoptysis
- weight loss
- low grade fever
- or asymptomatic with incidental discovering of lung lesions
- cavity development possible leading to rupture of the cavity and pneumothorax
disseminated form
- meninge - mild symptoms
- skin
- bone
- multiple organs in the most severe case