What is the gold standard diagnostic test for Pertussis?

What is the gold standard diagnostic test for Pertussis?

• A. Chest X-ray
• B. Serology
• C. Blood culture
• D. PCR of nasopharyngeal swab

Answer: (D)

Detecting Bordetella pertussis quickly in the early phase of illness relies on PCR of a nasopharyngeal swab. This nucleic acid amplification test directly detects the bacterial DNA from the upper airway secretions, providing rapid results and high sensitivity when the patient has recently developed symptoms or has started antibiotics. Because of its speed and ability to pick up infection even with low bacterial load, PCR on a nasopharyngeal specimen is the most practical choice for acute diagnosis and prompt treatment and public health action. Culture from the same specimen is historically definitive and important for confirmatory testing and susceptibility data, but it is slower and less sensitive, particularly after antibiotic exposure. Other options, like chest X-ray, can help evaluate complications but do not diagnose pertussis, and serology is less reliable in the acute setting due to timing and cross-reactivity.

Detecting Bordetella pertussis quickly in the early phase of illness relies on PCR of a nasopharyngeal swab. This nucleic acid amplification test directly detects the bacterial DNA from the upper airway secretions, providing rapid results and high sensitivity when the patient has recently developed symptoms or has started antibiotics. Because of its speed and ability to pick up infection even with low bacterial load, PCR on a nasopharyngeal specimen is the most practical choice for acute diagnosis and prompt treatment and public health action.

Culture from the same specimen is historically definitive and important for confirmatory testing and susceptibility data, but it is slower and less sensitive, particularly after antibiotic exposure. Other options, like chest X-ray, can help evaluate complications but do not diagnose pertussis, and serology is less reliable in the acute setting due to timing and cross-reactivity.