General practitioners seldom diagnose, or even consider, pertussis in older children who present with ongoing cough as a main symptom. Should this change in the light of new information in a paper by Harnden and colleagues in this week's issue (p 174)?1 They found that nearly 40% of a cohort of children aged 5-16 years presenting in UK general practice with a cough lasting 14 days or more had serological evidence of recent pertussis infection. This figure is perhaps even double that expected from previous research.²³

The authors conclude that GPs should make a “secure diagnosis of whooping cough” to prevent inappropriate worry and treatment and demand for further tests. GPs are likely to follow this disease focused approach only if they feel that diagnosing whooping cough more often is both feasible and clinically important. The problem is that most of the currently available approaches to laboratory diagnosis either do not perform adequately …