Current diagnostic techniques in genital herpes: their role in controlling the epidemic

Abstract

Genital herpes continues to be a public health problem in both developed and developing countries. Laboratory confirmation of clinical diagnosis is important, particularly as there are other conditions which present similarly to genital herpes, while atypical presentations of genital herpes also occur. Herpes simplex virus type 2 (HSV-2) is the most common cause of genital herpes globally, although HSV-1 genital herpes infections occur also. Type-specific serology has overcome the technical problems posed by earlier cross-reactive HSV serological assays, hence HSV-2 specific antibodies can be identified using both in-house and commercial assays. All HSV-2 serological assays require an appropriately thorough validation, and here an understanding of the natural history of genital HSV infection is important. Validated HSV-2 specific antibody assays have featured in seroepidemiological studies which have emphasised the largely asymptomatic nature of this infection. Subsequent seroepidemiological studies have included a sexual lifestyle questionnaire to identify risk factors for genital HSV-2 infection. This has given rise to serological screening proposals which, it is argued, may arrest the spread of genital herpes in the general population. However, counter arguments to such proposals are important to consider. As regards diagnosis and management of genital herpes in individual patients, situations have been identified where type-specific serology may be of benefit. PCR has become the method of laboratory diagnosis for HSV encephalitis over the past decade, but its role in the diagnosis of genital herpes has been addressed only in recent years. Evaluation of HSV PCR on specimens from genital herpes cases has shown PCR to be more sensitive than virus culture, the traditional "gold standard" of HSV identification. However, questions remain regarding the acceptance of HSV into routine diagnostic settings, particularly concerning sample preparation, although automation and the ability to include diagnosis of other genital infections in a multiplex PCR is an advantage. Such developments should enhance the role of PCR in genital herpes diagnosis and ultimately reduce costs relative to traditional methods such as culture and HSV antigen detection. Finally, the use of type-specific serology and HSV PCR in genital herpes research is noted.