Bordetella pertussis is a gram-negative bacillus which causes mild respiratory symptoms in adults but can be a life-threatening infection in children. In 2017, a group of researchers led by Mark Ebell, M.D. did a systematic review on the clinical diagnosis of this infection.
Bordetella pertussis is a gram-negative bacillus which causes a mild respiratory infection in adults but can be life-threatening to children due to their narrower airways. Although adults may not suffer from an infection caused by this organism, recognition and diagnosis of pertussis is important as they may serve as vectors and pass the infection to more vulnerable groups. However, the diagnosis of this infection can be quite challenging, as its disease presentation tend to overlap with other respiratory diseases.
In an article published in The Journal of the American Board of Family Medicine, this 2017, a group of researchers led by Mark Ebell, M.D. did a systematic review on the clinical diagnosis of Bordetella pertussis. A total of 22 prospective cohort studies consisting of patients who presented with an acute cough, prolonged cough, or a clinical suspicion of pertussis and undergone subsequent diagnostic tests such as PCR, serology or culture were gathered in this review. The studies were then examined for their potential biases with a study classified as high-bias if the only diagnostic test done was serology and low-bias if an additional test other than serology was done to confirm the diagnosis.
The results of the study show that out of the 22 cohort studies included, 14 were classified as low-bias. A patient presenting with a whooping cough and post-coughing vomiting were more likely to be diagnosed with Bordetella pertussis infection while the absence of whooping cough and sputum production decreased the likelihood of having the disease. The clinical criteria provided by the Center of Disease Control (CDC), defined as having a cough of at least 14 days plus the presence of one of the following:
1) Cough paroxysms,
2) Inspiratory whoop, or
3) Post-coughing vomiting.
Patients who met these criteria had a sensitivity of 90% but were found to be nonspecific. Overall, clinical judgment was found to be the most accurate way to determine the likelihood of Bordetella pertussis infection. This study has important implications for patients with persistent coughing – trust your doctor!
Written by Karla Sevilla
Resource: Ebell, M.H., Marchello, C., & Callahan, M. (2017). Clinical diagnosis of Bordetella Pertussis infection: a systematic review. JABFM. doi: 10.3122/jabfm.2017.03.160330