Upper respiratory tract sampling in COVID-19.

Area of Science:

• Virology
• Infectious Diseases
• Diagnostic Microbiology

Background:

• Upper respiratory tract sampling is crucial for diagnosing COVID-19.
• Current literature on sampling methods requires review to optimize healthcare practices.
• Understanding viral load dynamics in the upper respiratory tract is key for effective testing.

Purpose of the Study:

• To review existing literature on upper respiratory tract sampling techniques for COVID-19.
• To provide evidence-based recommendations for improving diagnostic yield and patient comfort.
• To guide future research directions in COVID-19 diagnostics.

Main Methods:

• A comprehensive literature search was conducted across PubMed, Medline, and Google Scholar.
• Twelve relevant manuscripts were selected from over 7000 search results.
• Manuscripts were analyzed by all authors, including those not yet peer-reviewed due to the topic's urgency.

Main Results:

• SARS-CoV-2 RNA viral load peaks 4-6 days post-symptom onset, making this period optimal for sampling.
• Nasopharyngeal swabs generally show higher viral loads and sensitivity compared to oropharyngeal swabs, particularly within 9 days of illness onset.
• Patient self-collected throat washing demonstrated superior viral load and sensitivity compared to both nasopharyngeal and oropharyngeal swabs.

Conclusions:

• Throat washing is recommended as a replacement for oropharyngeal swabs due to its higher diagnostic accuracy and safety.
• Nasopharyngeal swab use should consider nasal cavity anatomy to enhance patient comfort and diagnostic yield.
• Further research should focus on optimizing sampling methods for improved COVID-19 detection.