Diagnostic polymerase chain reaction

Area of Science:

• Microbiology
• Immunology
• Diagnostic Technologies

Background:

• Pertussis, caused by Bordetella pertussis, remains a significant public health concern, necessitating accurate diagnostic methods.
• Traditional diagnostic methods like culture have limitations in sensitivity.
• Polymerase chain reaction (PCR) has emerged as a sensitive molecular technique for pathogen detection.

Purpose of the Study:

• To evaluate the sensitivity and specificity of PCR for diagnosing B. pertussis across various pertussis vaccine studies.
• To compare the diagnostic yield of PCR when added to culture versus when added to both culture and serology.

Main Methods:

• Systematic review and analysis of PCR performance data from seven distinct pertussis vaccine studies.
• Assessment of PCR sensitivity using colony-forming units (cfu) and diagnostic sensitivity against culture as a reference standard.
• Calculation of the proportional increase in case detection by PCR among samples negative for culture and/or serology.

Main Results:

• PCR performance sensitivity ranged from < or = 1 to 10 cfu, with diagnostic sensitivity between 73% and 100% compared to culture.
• Positive PCR results in culture-negative samples increased case detection by 71% to 293% in four trials.
• The gain in detection was more moderate (6% to 11%) when PCR was added to both culture and serology-negative samples in two trials.

Conclusions:

• Adding PCR to culture significantly enhances the sensitivity for diagnosing B. pertussis.
• The incremental benefit of PCR is moderate when employed in conjunction with both culture and serology.
• Variations in sampling, sample selection, and PCR protocols across studies necessitate cautious interpretation of absolute figures.