American Board of Family Medicine (ABFM) Practice Exam 2026 - Free ABFM Practice Questions and Study Guide

PCR (Polymerase Chain Reaction) testing is preferred over cultures for pertussis due to its speed and sensitivity. PCR can provide rapid results, often within a few hours, whereas cultures can take several days to yield results, as they require bacterial growth in specific media. The timely identification of pertussis is crucial for patient management and for initiating appropriate public health measures.

Furthermore, PCR is significantly more sensitive than culture methods, meaning it can detect lower quantities of the Bordetella pertussis DNA, allowing for the diagnosis of cases that may not be picked up by culture, especially in patients who are in the early stages of the illness or have already received antibiotics. This higher sensitivity helps in identifying cases during outbreaks and ensuring proper containment and treatment strategies.

While cost and strain detection capabilities are important considerations in diagnostics, they do not primarily drive the preference for PCR in clinical settings specifically for pertussis testing. The priority lies in the accuracy and timeliness of the diagnosis, making PCR the preferred choice.