Expert panel offers guideline on diagnosis of pertussis

The American College of Chest Physicians issued a new guideline and expert panel report on clinical diagnosis of pertussis-associated cough in adults and children.

The decision to treat a suspected case of pertussis with antibiotics is usually based on a clinical diagnosis rather than laboratory confirmation, the panel noted. The guideline was published by Chest on Oct. 12 and included three recommendations for treating adult patients and three for pediatric patients.

The three recommendations for adults are as follows:

1. 1. For adult patients who report acute cough less than three weeks in duration or subacute cough of three to eight weeks, clinicians should specifically assess the four key characteristics of paroxysmal cough, post-tussive vomiting, inspiratory whooping, and absence of fever in ruling in or out a clinical diagnosis of pertussis. (Grade 2C)
2. 2. For adult patients who report acute or sub-acute cough, clinicians should consider that the cause is unlikely to be pertussis if the patient has a fever or the cough is not paroxysmal in nature. (Grade 2C)
3. 3. For adult patients who report acute or subacute cough, clinicians should consider that the cause is likely to be pertussis if there is post-tussive vomiting or association with an inspiratory whooping sound. (Grade 2C)

The expert panel noted that in adults, after prespecified meta-analysis exclusions, pooled estimates of sensitivity and specificity were found for only four clinical features: paroxysmal cough, post-tussive vomiting, inspiratory whoop, and absence of fever. Both paroxysmal cough and absence of fever had high sensitivity (93.2% [95% CI, 83.2% to 97.4%] and 81.8% [95% CI, 72.2% to 88.7%], respectively) and low specificity (20.6% [95% CI, 14.7% to 28.1%] and 18.8% [95% CI, 8.1% to 37.9%]). Inspiratory whoop and post-tussive vomiting had a low sensitivity (32.5% [95% CI, 24.5% to 41.6%] and 29.8% [95% CI, 8.0% to 45.2%]) but high specificity (77.7% [95% CI, 73.1% to 81.7%] and 79.5% [95% CI, 69.4% to 86.9%]).

In children, after prespecified meta-analysis exclusions, pooled estimates of sensitivity and specificity were generated for only post-tussive vomiting.

“This guideline focuses on how to make the clinical diagnosis of pertussis because this is how the decision to treat with antibiotics is usually made,” the expert group wrote. “This guideline is based upon a high quality systematic review and it identifies gaps in our knowledge and areas for future research; we therefore believe it advances the field.”