Australian Regenerative Medicine Institute

Postinfectious Cough: Recommendations

Postinfectious Cough: RecommendationsThe first serum sample should be taken within 2 weeks of the onset of cough, and the second should be taken 3 to 4 weeks later. The reported specificities and sensitivities of this test are 99% and 63%, respectively, when used for documenting community outbreaks of pertussis in-fection. Although widely used in epidemiologic surveys, paired sera titers have shown less usefulness in the clinical evaluation of cough because patients often delay seeking medical care and paired samples cannot be obtained. While a single serum specimen that shows high titers when compared to reference values is highly suggestive of a recent pertussis infection when there is a compatible clinical picture, no serologic method for diagnosis has been validated and approved for diagnostic use in the United States.
When a patient has a cough lasting for > 2 weeks without another apparent cause and it is accompanied by paroxysms of coughing, post-tussive vomiting, and/or an inspiratory whooping sound, the diagnosis of a B pertussis infection should be made unless another diagnosis is proven. Level of evidence, low; net benefit, substantial; grade of evidence, B buy ventolin

For all patients who are suspected of having whooping cough, to make a definitive diagnosis order a nasopharyngeal aspirate or polymer (Dacron; INVISTA; Wichita, KS) swab of the nasopharynx for culture to confirm the presence of B pertussis. Isolation of the bacteria is the only certain way to make the diagnosis. Level of evidence, low; net benefit, substantial; grade of evidence, B
PCR confirmation is available but is not recommended as there is no universally accepted, validated technique for routine clinical testing. Level of evidence, low; net benefit, conflicting; grade of evidence, I
In patients with suspected pertussis infection, to make a presumptive diagnosis of this infection, order paired acute and convalescent sera in a reference laboratory. A fourfold increase in IgG or IgA antibodies to PT or FHA is consistent with the presence of a recent B pertussis infection. Level of evidence, low; net benefit, intermediate; grade of evidence, C
A confirmed diagnosis of pertussis infection should be made when a patient with cough has B pertussis isolated from a nasopharyngeal culture or has a compatible clinical picture with an epidemiologic linkage to a confirmed case. Level of evidence, low; net benefit, substantial; grade of evidence, B

Category: Respiratory Symptoms

Tags: Bordetella pertussis, pertussis infection, postinfectious cough, postviral cough