Coccidioidomycosis laboratory tests

Jump to navigation Jump to search

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: ; Vidit Bhargava, M.B.B.S [2]

Coccidioidomycosis Microchapters


Patient Information


Historical Perspective



Coccidioides immitis
Coccidioides posadasii

Differentiating Coccidioidomycosis from other Diseases

Epidemiology and Demographics

Risk Factors


Natural History, Complications and Prognosis


History and Symptoms

Physical Examination

Laboratory Findings

Chest X Ray




Medical Therapy


Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Coccidioidomycosis laboratory tests On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides


American Roentgen Ray Society Images of Coccidioidomycosis laboratory tests

All Images
Echo & Ultrasound
CT Images

Ongoing Trials at Clinical

US National Guidelines Clearinghouse

NICE Guidance

FDA on Coccidioidomycosis laboratory tests

CDC on Coccidioidomycosis laboratory tests

Coccidioidomycosis laboratory tests in the news

Blogs on Coccidioidomycosis laboratory tests

Directions to Hospitals Treating Coccidioidomycosis

Risk calculators and risk factors for Coccidioidomycosis laboratory tests


The fungal infection can be demonstrated by microscopic detection of diagnostic cells in body fluids, exudates, sputum and biopsy-tissue. With specific nucleotide primers C.immitis DNA can be amplified by PCR. It can also be detected in culture by morphological identification or by using molecular probes that hybridize with C.immitis RNA.[1][2][3][4]

Laboratory Findings



  • These form the mainstay of commercial testing for the diagnosis of coccidioidomycosis.
  • Several techniques are available such as the older Tube-precipitin method as well as the newer CF (complement fixation), Immunodiffusion and EIA (enzyme immunoassay).
  • EIA assay picks up IgM and IgG antibodies against the coccidioidal antigens. IgM antibodies are found early in the disease progression and are not useful for assessing prognosis, while IgG antibodies appear late and persist longer.
  • CF titres can be used as a measure of disease progression and to diagnose meningitis by measuring CF antibodies in CSF.
Type of test Specificity Sensitivity Comment
EIA ++++ ++++
  • Detects both IgM and IgG
CF ++++ +++
  • Used for confirming EIA IgG
  • Quantitative analysis
  • Also employed for CSF analysis of diagnosis
  • Used for follow up response of treatment
IDCF ++++ +++
IDTP +++ +++ Not employed now
IDCF-Immuno diffusion compliment fixation, IDTP -Immuno diffusion tube-precipitin

Staining & Culture

  • The gold standard for diagnosis of coccidioidomycosis is positive culture or histopathological identification of the organism in clinical specimens.
  • Usual KOH staining doesn't help in diagnosis of this fungal infection but organisms can be stained by using special stains such as papanicolaou stain or gomori methamine silver stain on sputum or other respiratory fluids.
  • Even biopsy specimens can be stained by methamine silver stain to demonstrate spherules surrounded by inflammation.
  • Coccidioides is easy to culture, grows in about 3-7 days at 37°C on simple media such as blood agar, however precautions needs to be exercised as it poses a significant health hazard to lab personnel.
Laboratory culture of Coccidioides immitis

PCR based methods

  • PCR assays are useful to detect a target gene one DNA has been extracted from the target tissue.
  • It is highly sensitive and much safer compared to lab cultures.
  • The C.immitans DNA can be amplified by PCR and then hybridised to molecular probes to aid in identification.

Antigen Testing

  • Galactomannan antigen testing techniques employed for more rapid diagnosis but is limited due to their crossreactivity to other endemic fungi, leading to false positive cases.
  • It can detect antigen even in blood, urine sample specimens.



  1. Stockamp NW, Thompson GR (2016). "Coccidioidomycosis". Infect. Dis. Clin. North Am. 30 (1): 229–46. doi:10.1016/j.idc.2015.10.008. PMID 26739609.
  2. Twarog M, Thompson GR (2015). "Coccidioidomycosis: Recent Updates". Semin Respir Crit Care Med. 36 (5): 746–55. doi:10.1055/s-0035-1562900. PMID 26398540.
  3. DiCaudo DJ (2014). "Coccidioidomycosis". Semin Cutan Med Surg. 33 (3): 140–5. PMID 25577855.
  4. Malo J, Luraschi-Monjagatta C, Wolk DM, Thompson R, Hage CA, Knox KS (2014). "Update on the diagnosis of pulmonary coccidioidomycosis". Ann Am Thorac Soc. 11 (2): 243–53. doi:10.1513/AnnalsATS.201308-286FR. PMID 24575994.
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 "Public Health Image Library (PHIL)".

Template:WH Template:WS