The diagnostic testing of COVID-19 is critical to track the coronavirus, understand disease control & distribution patterns (epidemiology), formulate case management, and suppress transmission.
Several assays that detect 2019-nCoV are under development. Some assays may detect only the novel coronavirus and some may also detect other strains that show genetically similar nomenclature. For example, SARS-CoV.
Sample Collection Guidelines
For ambulatory patients
Specimen to collect: Upper respiratory nasopharyngeal and oropharyngeal swab or wash
For patients with severe/critical respiratory disease
Specimen to collect: Upper respiratory swab samples or wash and/or lower respiratory material — sputum (if produced) and/or endotracheal aspirate or bronchoalveolar lavage
Note the high risk of aerosolization; adhere strictly to infection prevention and control procedures.
Specimens to be Collected from Symptomatic Patients
How to collect COVID-19 specimen from symptomatic patients for the given coronavirus test -
Method of Testing Samples
Nucleic Acid Amplification Tests (NAAT) are used to detect the coronavirus in a patient. The routine confirmation of COVID-19 cases is based on unique sequence detection in the RNA of the virus by NAAT such as real-time reverse-transcription polymerase chain reaction (rRT-PCR) with confirmation by nucleic acid sequencing when necessary. The viral genes targeted so far include the N, E, S and RdRP genes.
Positive results are indicative of the presence of coronavirus RNA; clinically correlating with patient history and other diagnostic information is necessary to determine patient infection status. Positive results do not preclude bacterial infection or co-infection with other viruses.
Negative results do not rule out SARS-CoV-2 infection and should not be used as the sole basis for patient management decisions. Negative results must be combined with the patient’s clinical observations, health history, and epidemiological information.
Biosafety Practices in the Laboratory
The information on the risk posed by 2019-nCoV is limited, but all procedures should be carried out based on a risk assessment. National guidelines on laboratory biosafety should be followed in all circumstances. Recommended usage of PPE is essential for every worker working in the medical facility.
Specimen handling for molecular testing requires Biosafety Level 2 (BSL-2) or equivalent facilities.
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Reporting of Cases and Test Results
All laboratories must follow national reporting requirements. All positive and negative COVID-19 test results should be immediately reported to the national authorities. States Parties to the International Health Regulations (IHR) are reminded of their obligations to share with WHO relevant public health information for events for which they notified WHO.
Patient Safety & Contact Details
All patients that the lab is in contact with are recommended to be screened for clinical symptoms, travel history, etc. mentioned in the screening form by WHO, link here.