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__NOTOC__
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{{Monkeypox}}
{{Monkeypox}}
{{CMG}} {{AE}} Bassel Almarie, M.D.
{{CMG}}; {{AE}} {{Bassel}}


==Overview==
==Overview==
The laboratory findings of [[chickenpox]] include [[blood]] tests that can be done to identify the response to acute [[infection]] ([[IgM]]) or previous [[infection]] and subsequent [[Immunity (medical)|immunity]] ([[IgG]]). [[Prenatal]] diagnosis of [[Fetus|fetal]] [[Chickenpox|varicella infection]] can be performed using [[ultrasound]] at 5 weeks following primary [[maternal]] [[infection]]. A [[PCR]] test of the mother's [[amniotic fluid]] can also be performed, though the risk of [[spontaneous abortion]] due to the [[amniocentesis]] procedure is higher than the risk of the baby developing fetal [[Chickenpox|varicella syndrome]].
 
Polymerase chain reaction (PCR) is the preferred test to confirm monkeypox virus (MPXV) given its sensitivity and accuracy. Samples should be obtained from skin lesions, precisely, the roof or fluid from vesicles and pustules, and dry crusts<ref name="urlLaboratory testing for the monkeypox virus: Interim guidance">{{cite web |url=https://www.who.int/publications/i/item/WHO-MPX-laboratory-2022.1 |title=Laboratory testing for the monkeypox virus: Interim guidance |format= |work= |accessdate=2022-06-15}}</ref>. PCR blood tests are usually inconclusive because the virus does not live long in the blood<ref name="urlMonkeypox">{{cite web |url=https://www.who.int/en/news-room/fact-sheets/detail/monkeypox |title=Monkeypox |format= |work= |accessdate=2022-06-15}}</ref>.


==Laboratory Findings==
==Laboratory Findings==
Line 11: Line 12:
====Polymerase chain reaction (PCR)====
====Polymerase chain reaction (PCR)====


*Confirmation of monkeypox virus (MPXV) infection is based on nucleic acid amplification testing, using real-time or conventional PCR, for detection of unique sequences of viral DNA. PCR can be used alone, or in combination with sequencing.
*Confirmation of monkeypox virus (MPXV) infection is based on nucleic acid amplification testing, using real-time or conventional PCR, for detection of unique sequences of viral DNA. PCR can be used alone, or in combination with sequencing<ref name="urlwww.cdc.gov">{{cite web |url=https://www.cdc.gov/poxvirus/monkeypox/pdf/pcr-diagnostic-protocol-508.pdf |title=www.cdc.gov |format= |work= |accessdate=2022-06-15}}</ref><ref name="urlLaboratory testing for the monkeypox virus: Interim guidance">{{cite web |url=https://www.who.int/publications/i/item/WHO-MPX-laboratory-2022.1 |title=Laboratory testing for the monkeypox virus: Interim guidance |format= |work= |accessdate=2022-06-15}}</ref>.
*PCR kits detecting MPXV are under development but no commercial validated PCR kits are currently available widely.
* It is the preferred test due to its accuracy and sensitivity.
*Samples advisably obtained from skin lesions, precisely, the roof or fluid from vesicles and pustules, and dry crusts.
*PCR blood tests are usually inconclusive because the virus does not live long in the blood<ref name="urlMonkeypox">{{cite web |url=https://www.who.int/en/news-room/fact-sheets/detail/monkeypox |title=Monkeypox |format= |work= |accessdate=2022-06-15}}</ref>.


===DNA extraction===
===DNA extraction===


*DNA can be extracted from samples using any standard extraction protocols or kits.
*DNA can be extracted from samples using any standard extraction protocols or kits<ref name="urlLaboratory testing for the monkeypox virus: Interim guidance">{{cite web |url=https://www.who.int/publications/i/item/WHO-MPX-laboratory-2022.1 |title=Laboratory testing for the monkeypox virus: Interim guidance |format= |work= |accessdate=2022-06-15}}</ref>.
**Sample lysis in DNA extraction inactivates live virus. Therefore, sample lysis should be performed under a biosafety cabinet.
**Sample lysis in DNA extraction inactivates live virus. Therefore, sample lysis should be performed under a biosafety cabinet.
**For crust samples, DNA extraction kit for tissue samples should be used to insure appropriate sample lysis.
**For crust samples, DNA extraction kit for tissue samples should be used to insure appropriate sample lysis.
Line 22: Line 25:
===Molecular detection===
===Molecular detection===


* In case a of monkeypox suspected case, swabs from lesions, crusts and vesicular fluids to be obtained and tested for MPXV using a real-time PCR. Positive findings should be reported to healthcare authorities, followed by distinction of clades: Congo Basin and West African.  
*Swabs from lesions, crusts and vesicular fluids can be obtained and tested for MPXV using a real-time PCR. Positive findings should be reported to healthcare authorities, followed by distinction of clades: Congo Basin and West African<ref name="pmid20643162">{{cite journal| author=Li Y, Zhao H, Wilkins K, Hughes C, Damon IK| title=Real-time PCR assays for the specific detection of monkeypox virus West African and Congo Basin strain DNA. | journal=J Virol Methods | year= 2010 | volume= 169 | issue= 1 | pages= 223-7 | pmid=20643162 | doi=10.1016/j.jviromet.2010.07.012 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20643162  }} </ref>.
* Some protocols advise to detect OPXV via real-time PCR. Upon positive findings, additional testing for MPXV via real-time PCR to be performed. Confirmed cases of MPXV to be reported to healthcare authorities.  
*Some protocols advise to detect OPXV via real-time PCR. Upon positive findings, additional testing for MPXV via real-time PCR to be performed. Confirmed cases of MPXV must be reported to healthcare authorities<ref name="urlLaboratory testing for the monkeypox virus: Interim guidance">{{cite web |url=https://www.who.int/publications/i/item/WHO-MPX-laboratory-2022.1 |title=Laboratory testing for the monkeypox virus: Interim guidance |format= |work= |accessdate=2022-06-15}}</ref>.
 
 


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Latest revision as of 20:11, 20 October 2022

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

Overview

Polymerase chain reaction (PCR) is the preferred test to confirm monkeypox virus (MPXV) given its sensitivity and accuracy. Samples should be obtained from skin lesions, precisely, the roof or fluid from vesicles and pustules, and dry crusts[1]. PCR blood tests are usually inconclusive because the virus does not live long in the blood[2].

Laboratory Findings

Molecular Methods

Polymerase chain reaction (PCR)

  • Confirmation of monkeypox virus (MPXV) infection is based on nucleic acid amplification testing, using real-time or conventional PCR, for detection of unique sequences of viral DNA. PCR can be used alone, or in combination with sequencing[3][1].
  • It is the preferred test due to its accuracy and sensitivity.
  • Samples advisably obtained from skin lesions, precisely, the roof or fluid from vesicles and pustules, and dry crusts.
  • PCR blood tests are usually inconclusive because the virus does not live long in the blood[2].

DNA extraction

  • DNA can be extracted from samples using any standard extraction protocols or kits[1].
    • Sample lysis in DNA extraction inactivates live virus. Therefore, sample lysis should be performed under a biosafety cabinet.
    • For crust samples, DNA extraction kit for tissue samples should be used to insure appropriate sample lysis.

Molecular detection

  • Swabs from lesions, crusts and vesicular fluids can be obtained and tested for MPXV using a real-time PCR. Positive findings should be reported to healthcare authorities, followed by distinction of clades: Congo Basin and West African[4].
  • Some protocols advise to detect OPXV via real-time PCR. Upon positive findings, additional testing for MPXV via real-time PCR to be performed. Confirmed cases of MPXV must be reported to healthcare authorities[1].

References

  1. 1.0 1.1 1.2 1.3 "Laboratory testing for the monkeypox virus: Interim guidance". Retrieved 2022-06-15.
  2. 2.0 2.1 "Monkeypox". Retrieved 2022-06-15.
  3. "www.cdc.gov" (PDF). Retrieved 2022-06-15.
  4. Li Y, Zhao H, Wilkins K, Hughes C, Damon IK (2010). "Real-time PCR assays for the specific detection of monkeypox virus West African and Congo Basin strain DNA". J Virol Methods. 169 (1): 223–7. doi:10.1016/j.jviromet.2010.07.012. PMID 20643162.