Coccidioidomycosis laboratory tests: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
m (Bot: Removing from Primary care)
 
(33 intermediate revisions by 7 users not shown)
Line 4: Line 4:


==Overview==
==Overview==
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]].
The [[fungal infection]] can be demonstrated by microscopic detection of diagnostic [[Cells (biology)|cells]] in body [[fluids]], [[Exudate|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 ''[[Coccidioides immitis|C.immitis]]'' [[RNA]].<ref name="pmid26739609">{{cite journal |vauthors=Stockamp NW, Thompson GR |title=Coccidioidomycosis |journal=Infect. Dis. Clin. North Am. |volume=30 |issue=1 |pages=229–46 |year=2016 |pmid=26739609 |doi=10.1016/j.idc.2015.10.008 |url=}}</ref><ref name="pmid26398540">{{cite journal |vauthors=Twarog M, Thompson GR |title=Coccidioidomycosis: Recent Updates |journal=Semin Respir Crit Care Med |volume=36 |issue=5 |pages=746–55 |year=2015 |pmid=26398540 |doi=10.1055/s-0035-1562900 |url=}}</ref><ref name="pmid25577855">{{cite journal |vauthors=DiCaudo DJ |title=Coccidioidomycosis |journal=Semin Cutan Med Surg |volume=33 |issue=3 |pages=140–5 |year=2014 |pmid=25577855 |doi= |url=}}</ref><ref name="pmid24575994">{{cite journal |vauthors=Malo J, Luraschi-Monjagatta C, Wolk DM, Thompson R, Hage CA, Knox KS |title=Update on the diagnosis of pulmonary coccidioidomycosis |journal=Ann Am Thorac Soc |volume=11 |issue=2 |pages=243–53 |year=2014 |pmid=24575994 |doi=10.1513/AnnalsATS.201308-286FR |url=}}</ref>
==Laboratory Findings==
===CBC===
*CBC with differential shows  [[Eosinophilia|peripheral eosinophilia]]
===Serology===
*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 test|complement fixation]]), [[Immunodiffusion]] and EIA ([[enzyme immunoassay]]).
*EIA assay picks up [[IgM]] and [[IgG|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.
*[[Complement-fixation|CF]] titres can be used as a measure of disease progression and to diagnose [[meningitis]] by measuring CF antibodies in [[CSF]].
{| class="wikitable" !Type of test !Specificity !Sensitivity !Comment |- |EIA | ++++ | ++++ |IgM and IgG  |- |CF | ++++ | +++ |Used to confirm EIA IgG |- |IDCF | ++++ | +++ |Used to confirm EIA IgG |- |IDTP | +++ | +++ |Not employed now |} EIA based rapid diagnostic commercial kits are available but are not as sensitive or specific as lab based tests and have a risk of false positives.|}
{| class="wikitable"
!Type of test
!Specificity
!Sensitivity
!Comment
|-
|EIA
|<nowiki>++++</nowiki>
|<nowiki>++++</nowiki>
|
* Detects both IgM and IgG
|-
|CF
|<nowiki>++++</nowiki>
|<nowiki>+++</nowiki>
| rowspan="2" |
* Used for confirming EIA IgG
 
* Quantitative analysis
 
* Also employed for CSF analysis of diagnosis
 
* Used for follow up response of treatment
|-
|IDCF
|<nowiki>++++</nowiki>
|<nowiki>+++</nowiki>
|-
|IDTP
| +++
| +++
|Not employed now
|-
| colspan="4" |IDCF-Immuno diffusion compliment fixation, IDTP -Immuno diffusion tube-precipitin
|}
{| class="wikitable" !Type of test !Specificity !!Sensitivity ! |- | | | | |- | | | | |- | | | | |} These form the mainstay of commercial testing for the diagnosis of coccidioidomycosis.


===Staining & Culture===
===Staining & Culture===
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.
*The gold standard for diagnosis of coccidioidomycosis is positive culture or histopathological identification of the organism in clinical specimens.
Even biopsy specimens can be stained by methamine silver stain to demonstrate spherules surrounded by inflammation.  
*Usual [[KOH test|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.
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.
*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.
 
[[Image:Lab culture.jpg|frame|center|Laboratory culture of Coccidioides immitis]]
[[Image:Coccidioidomycosis27.jpeg|center|500px]]
 
===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 [[Coccidioides immitis|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.
 
==Gallery==
<gallery>
 
Image: Coccidioidomycosis31.jpeg| Smear of an exudate from an infected mouse, reveals spherules of Coccidioides immitis. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis29.jpeg| Spherule of Coccidioides immitis with endospores. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis26.jpeg| Spherule with endospores of Coccidioides immitis. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis27.jpeg| Large spherule containing endospores in a case of coccidioidomycosis. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis21.jpeg| Methenamine silver stain reveals spherules of Coccidioides immitis fungus. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis20.jpeg| Methenamine silver stain reveals reveals spherules of Coccidioides immitis fungus. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis11.jpeg| Slant culture growing Coccidioides immitis fungal organisms on a medium of glucose PhytoneTM, yeast extract. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
 
Image: Coccidioidomycosis10.jpeg| Photomicrograph reveals presence of two round, thick-walled, spherule-staged Coccidioides immitis fungal organisms. <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>


[[Image:Lab culture.jpg|frame|center]]
Image: Coccidioidomycosis09.jpeg| Photomicrograph reveals presence of numerous thick-walled Coccidioides immitis arthroconidia and arthrospores (500x mag). <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>


===Serology===
Image: Coccidioidomycosis08.jpeg| Photomicrograph reveals presence of numerous thick-walled Coccidioides immitis arthroconidia and arthrospores (500x mag). <SMALL><SMALL>''[http://phil.cdc.gov/phil/home.asp From Public Health Image Library (PHIL).] ''<ref name=PHIL> {{Cite web | title = Public Health Image Library (PHIL) | url = http://phil.cdc.gov/phil/home.asp}}</ref></SMALL></SMALL>
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) and EIA(enzyme immuno assay) assays. 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 meningitits by measuring CF antibodies in CSF.
EIA based rapid diagnostic commercial kits are available but are not as sensitive or specific as lab based tests and have a risk of false positives.


===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.


</gallery>


==References==
==References==
{{Reflist|2}}
{{Reflist|2}}
{{WH}}
{{WS}}


[[Category:Pulmonology]]
[[Category:Pulmonology]]
Line 29: Line 105:
[[Category:Fungal diseases]]
[[Category:Fungal diseases]]
[[Category:Biological weapons]]
[[Category:Biological weapons]]
[[Category:Disease]]
[[Category:Emergency medicine]]
[[Category:Up-To-Date]]
[[Category:Infectious disease]]
[[Category:Infectious disease]]
[[Category:Disease]]
{{WH}}
{{WS}}

Latest revision as of 21:00, 29 July 2020

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

Home

Patient Information

Overview

Historical Perspective

Pathophysiology

Causes

Coccidioides immitis
Coccidioides posadasii

Differentiating Coccidioidomycosis from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Chest X Ray

CT

MRI

Treatment

Medical Therapy

Surgery

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

Images

American Roentgen Ray Society Images of Coccidioidomycosis laboratory tests

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

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

Overview

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

CBC

Serology

  • 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.

Gallery

References

  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

Retrieved from "https://www.wikidoc.org/index.php?title=Coccidioidomycosis_laboratory_tests&oldid=1636213"