Journal of Infectious Diseases & Therapy
Open Access

The emergence of the COVID-19 pandemic has created a public health emergency worldwide. The coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus named SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2). The clinical manifestations of COVID-19 can range from asymptomatic cases to severe acute respiratory syndrome and fatal pneumonia. Early detection and diagnosis of COVID-19 are essential for controlling the spread of the disease and providing appropriate medical care to infected individuals. In this essay, we will discuss the diagnostic procedures of COVID-19, including laboratory-based tests, imaging studies and clinical assessment.

Laboratory based tests

The laboratory based tests for COVID-19 include molecular diagnostic tests and serological assays. Molecular diagnostic tests detect the genetic material of the virus in respiratory samples obtained from patients, such as nasopharyngeal swabs, sputum or bronchi alveolar lavage fluid. Polymerase Chain Reaction (PCR) is the most common molecular diagnostic test used for COVID-19 detection. The PCR test amplifies the viral RNA and detects it by fluorescence-based detection methods. Several commercial PCR-based tests are available for COVID-19 diagnosis, including the Abbott real time SARS-CoV-2 assay, Roche cobas SARS-CoV-2 test and thermo fisher scientific path COVID-19 Combo Kit.

Another molecular diagnostic test for COVID-19 is the Loop Mediated Isothermal Amplification (LAMP) assay. The LAMP test amplifies the viral RNA at a constant temperature and can provide results within 30 minutes. The LAMP assay is less sensitive than PCR but has the advantage of being a simple and rapid test suitable for point of care settings.

Serological assays detect the antibodies produced by the immune system in response to the SARS-CoV-2 virus. Serological assays can be used for detecting past infections or monitoring the immune response to COVID-19 vaccination. The two main types of serological assays are Enzyme Linked Immunosorbent Assay (ELISA) and Lateral Flow Immunoassay (LFIA). ELISA tests are more sensitive and specific than LFIA tests but require laboratory equipment and trained personnel. LFIA tests are rapid and easy to perform but have lower sensitivity and specificity than ELISA tests. Several commercial serological assays are available for COVID-19 diagnosis, including the Euroimmun SARS-CoV-2 ELISA IgG, Roche Elecsys anti SARSCoV- 2 assay and Abbott Panbio COVID-19 IgG/IgM rapid test.

Imaging studies

Imaging studies can help in the diagnosis and management of COVID-19 patients. Chest radiography and Computed Tomography (CT) are the two most common imaging modalities used for COVID-19 diagnosis.

Chest radiography can detect the characteristic findings of COVID-19, such as bilateral interstitial and alveolar infiltrates, but has low sensitivity and specificity. CT imaging can detect the typical ground glass opacities and consolidations seen in COVID-19 pneumonia and has higher sensitivity and specificity than chest radiography. However, CT imaging should be used judiciously due to the risk of radiation exposure and the limited availability of CT scanners in some settings.

Clinical assessment

Clinical assessment is an essential component of COVID-19 diagnosis and management. The clinical presentation of COVID-19 can range from asymptomatic or mild disease to severe acute respiratory syndrome and multi organ failure. The typical symptoms of COVID-19 include fever, cough, dyspnea, fatigue, myalgia and anosmia. However, some patients may present with atypical symptoms, such as gastrointestinal symptoms, headache or confusion. COVID-19 should be suspected in patients with a history. The two main types of serological tests for COVID-19 are Lateral Flow Assays (LFAs) and Enzyme Linked Immunosorbent Assays (ELISAs). LFAs are rapid, point of care tests that can be performed in a doctor's office or clinic. They provide results in as little as 15 minutes but are less sensitive than ELISAs. ELISAs are laboratory based tests that are more sensitive than LFAs but take longer to perform and require specialized equipment.

In conclusion, diagnostic procedures for COVID-19 play a crucial role in controlling the spread of the disease. Molecular tests such as RT-PCR and LAMP are used to diagnose active infections, while serological tests such as LFAs and ELISAs are used to detect past infections. Each test has its strengths and weaknesses and healthcare providers must consider several factors when selecting the most appropriate test for their patients. Ongoing research and development in this field are essential to improve the accuracy, speed and availability of COVID-19 diagnostic procedures.