Mixed HSV-1 and HSV-2 infection in a patient attending a GUM clinic

The advantage of using the direct antigen test is that GUM staff receive a preliminary result ('negative' or 'presumptive positive') on the swab within 48 h. The disadvantage is that clinic staff still have to wait for the culture result to see if the infection is HSV type 1 or type 2, as immunoassay does not differentiate between them. Since December 2007, the laboratory has processed 120 swabs that had associated culture results, the overall sensitivity and specificity being 96.3% and 92.1%, respectively.