Table 3.

Symptom clusters and recent Bordetella pertussis infection in adults and children

Adult
Presence of exercise intolerance, wheezing and vomiting, or exercise intolerance and wheezing but without headache or muscle
		Recent Bordetella pertussis infectiona
		Yes	No
Symptom complex present	Yes	8	39
	No	3	106
Sensitivity = 0.73 (95% CI = 0.43 to 0.90)
Specificity = 0.73 (95% CI = 0.65 to 0.80)
Positive predictive value = 0.17 (95% CI = 0.09 to 0.30)
Negative predictive value = 0.97 (95% CI = 0.92 to 0.99)
Child
Presence of vomiting and exercise intolerance but not wheezing or sneezing OR vomiting but not headache OR phlegm but not headache or wheeze OR phlegm and exercise intolerance but not wheeze or sneeze.
		Recent Bordetella pertussis infectiona
		Yes	No
One of these four symptom complexes present	Yes	8	7
	No	4	47
Sensitivity = 0.67 (95% CI = 0.39 to 0.86)
Specificity = 0.87 (95% CI = 0.76 to 0.94)
Positive predictive value = 0.53 (95% CI = 0.30 to 0.75)
Negative predictive value = 0.92 (95% CI = 0.82 to 0.97)

^aAs defined by an oral fluid IgG antibody titre to PT titre of 70 arbitrary units or more.¹¹