Clinical Utility of Broad Range PCR for Infectious Organisms

Abstract Broad range PCR is used to identify infectious organisms when bacterial, fungal, and mycobacterial cultures are negative despite clinical evidence of infection. We performed a 6-month retrospective chart review to assess the actionability of broad range PCR and identify opportunities to improve the utility of this referral test at our institution. One hundred eleven broad range PCR tests were ordered from July to December 2023. Seventy-five (67.6%) results did not affect patient management, 18 (16.2%) results affected patient management, and the treatment impact of 18 (16.2%) results is unknown because they were from outside consult cases. There were no instances in which antibiotic therapy was completely discontinued due to a negative broad range PCR result. Concurrent in-house microbiology testing yielded a positive result in 15 (13.5%) cases, of which 8 (53%) had a negative broad range PCR result and 2 (13.3%) had a conflicting broad range PCR result. Thirty-eight (34.2%) specimens were formalin fixed paraffin embedded tissue, 29 (26.1%) were fresh tissue, 13 (11.7%) were ESWABS, and the remaining 31 specimens were various fluid types (27.9%). While fresh tissue is the preferred specimen, broad range PCR detected an organism in 20 (53%) formalin fixed paraffin embedded tissue specimens, 11 (37.9%) fresh tissue specimens, 3 (23.1%) ESWAB specimens, and 2 (6.5%) fluid specimens (abscess aspirate and cerebrospinal fluid). Improvements in physician communication and laboratory workflow are necessary to improve the specimen quality and thus the utility of this referral test at our institution.