The accuracy of COVID-19 RT-qPCR testing is influenced by several key variables:

• Viral Mutations: SARS-CoV-2 is known for rapid evolution and genetic drift. Mutations in primer target sequences can cause mismatches, leading to false negatives or positives.
• Sample Source: Nasal and throat swabs are most commonly used for patient comfort. Bronchoalveolar lavage fluid (BALF) offers higher accuracy but requires a medical suction device and a licensed operator. Non-respiratory samples like stool and blood can also be utilized.
• Timing and Handling: The phase of infection during collection and prompt, careful transport to testing sites are critical to prevent false reads.