TOWARDS A BETTER DIAGNOSIS OF THROAT INFECTIONS (WITH GROUP-A BETA-HEMOLYTIC STREPTOCOCCUS) IN GENERAL-PRACTICE

Background. Sore Throat is a common complaint in general practice. How ever, management strategies are not very clear. A better diagnostic pr ocedure is needed to prevent the overuse of antibiotics. Aim. To asses s the diagnostic value of a rapid streptococcal antigen detection test in addition to four clinical features in patients with sore throat, u sing throat culture and antibody titres as reference tests. Method. Fo ur clinical features [fever (history) greater than or equal to 38.0 de grees C, lack of cough, tonsillar exudate, and anterior cervical lymph adenopathy] were registered in 558 patients aged 4 to 60 years present ing with sore throat of no more than 14 days' duration. A rapid diagno stic test was performed, as well as a throat culture and antibody titr es [fourfold increase in anti-streptolysin-O (ASO) and/or anti-deoxyri bonuclease B (anti-DNAase B)] in patients aged 11 years and older. Res ults. Throat cultures were positive for group A beta-haemolytic strept ococcus (GABHS) in 33% of the patients. Rapid tests were positive in 2 4%. Compared with the throat culture, the sensitivity of the rapid tes t was 65%, the specificity 96%, the positive predictive value 88%, and the negative predictive value 85%. However, for patients with three o r four clinical features, the sensitivity of the rapid test was consid erably higher at 75%. Children (less than or equal to 14 years) had a slightly raised specificity and raised positive predictive value and p revalence. With the antibody titres as a reference, the rapid test per formed as well as the throat culture with regard to its predictive val ue. Conclusion. For the management of patients with sore throat in gen eral practice, a rapid test may have an additional value, especially i n patients with a high chance of having GABHS infection. However, as t he sensitivity of the test studied is low, tests with a higher sensiti vity are needed.