Stewardship of Molecular Diagnostics in Transplant Viral Infections

The transplant environment requires special considerations when testing for viral infections as immunosuppression results in atypical infection profiles. Microbes otherwise considered commensals or causing mild disease can lead to severe infections in transplant environments. Therefore, guidelines tend to recommend broader microbial testing in these populations. In parallel, advances in molecular diagnostics have led to the availability of a wide selection of tests, including highly multiplexed nucleic acid amplification tests (NAATs) and direct next generation sequencing (NGS) based options. These newer technologies may provide information on many potential pathogens simultaneously, more rapidly, and while avoiding invasive specimen collection procedures. However, they are generally more expensive than conventional methods such as culture, and nucleic acid detection of multiple potential pathogens may be nonspecific and confuse the diagnosis. Navigating the complexity of the available molecular test landscape in immunocompromised patients is an opportunity for diagnostic stewardship. Here we discuss the clinical value of different molecular testing strategies for diagnosis of viral infectious diseases in immunocompromised transplant patients using several common transplant infection syndromes as a framework.