Middle East respiratory syndrome coronavirus infection laboratory findings: Difference between revisions
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*Investigations of [[MERS-CoV]] and other [[respiratory]] [[pathogens]] may now be conducted simultaneously and additionally, positive results for another [[respiratory]] [[pathogen]] should not hinder testing for [[MERS-CoV]]. | *Investigations of [[MERS-CoV]] and other [[respiratory]] [[pathogens]] may now be conducted simultaneously and additionally, positive results for another [[respiratory]] [[pathogen]] should not hinder testing for [[MERS-CoV]]. | ||
*Health-care providers in the United States should continue to evaluate patients for [[MERS-CoV]] [[infection]] if they develop [[fever]] and [[pneumonia]] or [[acute respiratory distress syndrome]] within 14 days after traveling from countries in or near the Arabian Peninsula. | *Health-care providers in the United States should continue to evaluate patients for [[MERS-CoV]] [[infection]] if they develop [[fever]] and [[pneumonia]] or [[acute respiratory distress syndrome]] within 14 days after traveling from countries in or near the Arabian Peninsula. | ||
*Providers also | *Providers should also evaluate patients for [[MERS-CoV]] [[infection]], in the presence of [[ARDS]], [[fever]] or [[pneumonia]], and if they have been in close contact with recent travelers from the Arabian Peninsula who have [[fever]] and acute [[respiratory illness]]. | ||
* CDC continues to recommend that clusters of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) be evaluated for common respiratory pathogens and reported to local and state public health departments. If the illnesses remain unexplained, particularly if the cluster includes health-care providers, testing for MERS-CoV should be considered, in consultation with state and local health departments. In this situation, testing should be considered even for patients without travel-related exposure. | * CDC continues to recommend that clusters of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) be evaluated for common respiratory pathogens and reported to local and state public health departments. If the illnesses remain unexplained, particularly if the cluster includes health-care providers, testing for MERS-CoV should be considered, in consultation with state and local health departments. In this situation, testing should be considered even for patients without travel-related exposure. | ||
Revision as of 15:45, 19 June 2014
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Middle East Respiratory Syndrome Coronavirus Infection Microchapters |
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Differentiating Middle East Respiratory Syndrome Coronavirus Infection from other Diseases |
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Middle East respiratory syndrome coronavirus infection laboratory findings On the Web |
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Directions to Hospitals Treating Middle East respiratory syndrome coronavirus infection |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
Overview
Middle East Respiratory Syndrome (MERS) is a viral respiratory illness. It is caused by an emerging coronavirus, specifically a betacoronavirus called MERS-CoV (Middle East Respiratory Syndrome Coronavirus), first discovered in 2012. Being a relatively novel virus, there is no virus-specific prevention or treatment options for MERS patients. Attending to the fact that a vaccine hasn't been developed yet, enhancing infection prevention and control measures is critical to prevent the possible spread of MERS-CoV in hospitals and communities. Persons with symptoms suspicious of MERS-CoV infection need medical evaluation. According to the CDC: a certified case of MERS-CoV infection is considered an individual who shows laboratory confirmation of infection by MERS-CoV. This last one is given by a positive PCR test on ≥2 specific genomic targets or, a single positive target followed by successful sequencing of a second; while a probable case of MERS-CoV infection is an individual who has missing or inconclusive laboratory test results for the infection and that has been in close contact with another individual who is a "laboratory-confirmed case" of MERS-CoV infection. Laboratory tests, such as the PCR for MERS-CoV are available at state health departments, CDC and some international laboratories. Otherwise, MERS-CoV tests are not routinely available, despite the existence of a limited number of non-FDA-approved commercial tests.[1][2][3]
Laboratory Tests
According to CDC guidelines:
- Investigations of MERS-CoV and other respiratory pathogens may now be conducted simultaneously and additionally, positive results for another respiratory pathogen should not hinder testing for MERS-CoV.
- Health-care providers in the United States should continue to evaluate patients for MERS-CoV infection if they develop fever and pneumonia or acute respiratory distress syndrome within 14 days after traveling from countries in or near the Arabian Peninsula.
- Providers should also evaluate patients for MERS-CoV infection, in the presence of ARDS, fever or pneumonia, and if they have been in close contact with recent travelers from the Arabian Peninsula who have fever and acute respiratory illness.
- CDC continues to recommend that clusters of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) be evaluated for common respiratory pathogens and reported to local and state public health departments. If the illnesses remain unexplained, particularly if the cluster includes health-care providers, testing for MERS-CoV should be considered, in consultation with state and local health departments. In this situation, testing should be considered even for patients without travel-related exposure.
- Confirmatory laboratory testing now requires a positive polymerase chain reaction (PCR) of at least two, instead of one, specific genomic targets or a single positive target with sequencing of a second.
- Lab tests (PCR) for MERS-CoV are available at state health departments, CDC, and some international labs. Otherwise, MERS-CoV tests are not routinely available. There are a limited number of commercial tests available, but these are not FDA-approved.
Confirmed Case
A confirmed case is a person with laboratory confirmation of MERS-CoV infection.
Probable Case
A probable case is a PUI with absent or inconclusive laboratory results for MERS-CoV infection who is a close contact of a laboratory-confirmed MERS-CoV case.
Collecting, Handling, and Testing Clinical Specimens
Respiratory Specimens
Lower respiratory tract Broncheoalveolar lavage, tracheal aspirate, pleural fluid
Collect 2-3 mL into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container. Refrigerate specimen at 2-8°C up to 72 hours; if exceeding 72 hours, freeze at -70°C and ship on dry ice.
Sputum
Have the patient rinse the mouth with water and then expectorate deep cough sputum directly into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container. Refrigerate specimen at 2-8°C up to 72 hours; if exceeding 72 hours, freeze at -70°C and ship on dry ice.
Upper respiratory tract
Nasopharyngeal AND oropharyngeal swabs (NP/OP swabs)
Use only synthetic fiber swabs with plastic shafts. Do not use calcium alginate swabs or swabs with wooden shafts, as they may contain substances that inactivate some viruses and inhibit PCR testing. Place swabs immediately into sterile tubes containing 2-3 ml of viral transport media. NP/OP specimens can be combined, placing both swabs in the same vial. Refrigerate specimen at 2-8°C up to 72 hours; if exceeding 72 hours, freeze at -70°C and ship on dry ice.
Nasopharyngeal swabs
Insert a swab into the nostril parallel to the palate. Leave the swab in place for a few seconds to absorb secretions. Swab both nasopharyngeal areas.
Oropharyngeal swabs
Swab the posterior pharynx, avoiding the tongue.
Nasopharyngeal wash/aspirate or nasal aspirates
Collect 2-3 mL into a sterile, leak-proof, screw-cap sputum collection cup or sterile dry container. Refrigerate specimen at 2-8°C up to 72 hours; if exceeding 72 hours, freeze at -70°C and ship on dry ice.
Blood Components
Serum (for serologic testing)
For serum antibody testing: Serum specimens should be collected during the acute stage of the disease, preferably during the first week after onset of illness, and again during convalescence, ≥ 3 weeks after the acute sample was collected. However, since we do not want to delay detection at this time, a single serum sample collected 14 or more days after symptom onset may be beneficial. Serologic testing is currently available at CDC upon request and approval. Please be aware that the MERS-CoV serologic test is for research/surveillance purposes and not for diagnostic purposes - it is a tool developed in response to the MERS-CoV outbreak. Contact CDC’s Emergency Operations Center (EOC) (770-488-7100) for consultation and approval if serologic testing is being considered.
Serum (for rRT-PCR testing)
- For rRT-PCR testing (i.e., detection of the virus and not antibodies), a single serum specimen collected optimally during the first week after symptom onset, preferably within 3-4 days, after symptom onset, may be also be beneficial.
- Children and adults: Collect 1 tube (5-10 mL) of whole blood in a serum separator tube. Allow the blood to clot, centrifuge briefly, and separate sera into sterile tube container. The minimum amount of serum required for testing is 200 µL. Refrigerate the specimen at 2-8°C and ship on ice- pack; freezing and shipment on dry ice is permissible.
- Infants: A minimum of 1 mL of whole blood is needed for testing of pediatric patients. If possible, collect 1 mL in an EDTA tube and in a serum separator tube. If only 1 mL can be obtained, use a serum separator tube.
EDTA blood (plasma)
Collect 1 tube (10 mL) of heparinized (green-top) or EDTA (purple-top) blood. Refrigerate specimen at 2-8°C and ship on ice-pack; do not freeze.
Stool
Collect 2-5 grams of stool specimen (formed or liquid) in sterile, leak-proof, screw-cap sputum collection cup or sterile dry container. Refrigerate specimen at 2-8°C up to 72 hours; if exceeding 72 hours, freeze at -70°C and ship on dry ice.
References
- ↑ Dyall J, Coleman CM, Hart BJ, Venkataraman T, Holbrook MR, Kindrachuk J; et al. (2014). "Repurposing of clinically developed drugs for treatment of Middle East Respiratory Coronavirus Infection". Antimicrob Agents Chemother. doi:10.1128/AAC.03036-14. PMID 24841273.
- ↑ "Clinical management of severe acute respiratory infections when novel coronavirus is suspected: What to do and what not to do" (PDF).
- ↑ "MERS Prevention and Treatment".