A Look Inside: Oral Sampling for Detection of Non-Oral Infectious Diseases.

Efforts to control transmissible infectious diseases rely on the ability to screen large populations, ideally in community settings. These efforts can be limited by the requirement for invasive or logistically difficult collection of patient samples such as blood, urine, stool, sputum, and nasopharyngeal swabs. Oral sampling is an appealing, non-invasive alternative that could greatly facilitate high-throughput sampling in community settings. Oral sampling has been described for the detection of dozens of human pathogens, including pathogens whose primary sites of infection are outside of the oral cavity, such as the respiratory pathogens Mycobacterium tuberculosis and SARS-CoV-2. Oral sampling can demonstrate active infections as well as resolving or previous infection, the latter through the detection of antibodies. Its potential applications are diverse, including improved diagnosis in special populations (e.g. children), population surveillance, and infectious disease screening. In this minireview, we address the use of oral samples for the detection of diseases that primarily manifest outside of the oral cavity. Focusing on well-supported examples, we describe applications for such methods and highlight their potential advantages and limitations in medicine, public health, and research.