IDSE Review
Rapid Diagnostic Methods and Technologies in the Management Of Infectious Diseases
BY KAREN FONG, PHARMD, BCIDP
I
n the realm of infectious diseases management, rapid diagnostic tests (RDTs) have modernized the field profoundly by providing microbiological diagnoses more quickly and robustly. Modern molecular techniques include direct-specimen rapid amplification and detection platforms and next-generation sequencing, which provide more rapid, sensitive, and comprehensive laboratory diagnoses never before possible compared with conventional microbiology.1 RDTs have revolutionized the microbiological diagnostic pathway, serving as the cornerstone for pathogen identification and resistance testing.
Despite significant progress in diagnostic technologies, broad-spectrum antimicrobials continue to be heavily overused during empiric treatment of infectious disease syndromes.2,3 The detection of genotypic markers of resistance has been made available through newer technologies, but rapid phenotypic antimicrobial susceptibility testing (AST) has been accessible only recently. Genotypic (nucleic acid-based) methods are limited by detecting only searchable resistance patterns and potentially finding resistance genes that are not necessarily from the pathogenic organism.4 According to the Clinical Laboratory Standards Institute (CLSI) and European
Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines, reliable antibiotic resistance diagnostics requires phenotypic testing. Thus, these commercial advances are not yet a replacement for bacterial and fungal cultures, but could provide information to the clinical presentation and support empiric antimicrobial selection by facilitating the anticipation of susceptibility patterns based on local antibiograms.1 Classic AST techniques include broth microdilution, disk diffusion, gradient tests, agar dilution and breakpoint tests, which are based on continuous exposure of a bacterial isolate to a set of
INFECTIOUS DISEASE SPECIAL EDITION • SUMMER 2022
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