Biorepositories (biobanks) of Human Body Fluids and Materials as Archives for Tracing Early Infections of COVID-19

Human body fluids and biological materials that were collected before the COVID-19 pandemic may serve as archives for detecting early COVID-19 infections before the recent outbreaks. In most countries, these have been routinely donated, collected, and stored on a continuous basis, creating biorepositories or “biobanks” of human biological materials for clinical uses or research purposes. These materials are immensely useful for look-back investigations on tracing the early infections, propagation, and possible origins of novel infectious agents. Various studies identified antibodies of coronaviruses in pre-epidemic blood samples, suggesting their circulation in humans or animals long before their eventual outbreaks. Although no such study has been reported for COVID-19, evidence was found in a recent survey where 2% of serum samples (n = 300) in archived blood donations collected before the first known case of COVID-19 in northern Italy were found to be seropositive. SARS-CoV-2 and its antibodies have been found in various types of body fluids and bodily materials of COVID-19 patients, including blood, sperm, umbilical cord blood, lung, heart, kidney and so on, making these archived biological samples as candidates for detecting early COVID-19 infections. This strategy was successfully used in an early look-back investigation on tracing the origin and transmission of a previously unrecognized rabies infection in the United States. Unlike sewage-based epidemiology which provides information on the geographical aspect, viruses identified in archived human biological materials provide direct links to host individuals, from whom a wealth of personal information including their profession, hobbies and activities, travel history, and earlier exposure to wildlife can be retrieved. By analyzing patterns and links in the behavior of those early infected individuals, it is possible to find the origin of the virus, for instance, in certain wild animals or local natural environments.