What is genital herpes and why is testing so important?

Genital herpes is a common viral infection, caused by either herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2). It can be easily misdiagnosed and is often underdiagnosed. Clinicians can best serve their patients by using the correct laboratory test to provide a clear diagnosis along with providing education, reassurance, appropriate antiviral therapy, and resources for additional information and emotional support as needed.

Genital herpes testing is important because:

• It is very common. In the United States, more people have genital herpes than all other sexually transmitted infections combined–50 million people in total. Additionally, there are about one million new genital herpes infections each year due to HSV-2.
• It can cause significant psychosocial morbidity.
• It increases the risk of HIV acquisition three-fold.
• While rare, the effects of neonatal disease are devastating.
  While not curable, genital herpes is manageable through treatment and education.
• Using condoms and anti-viral medications reduce the risk of transmission.

Diagnosing genital herpes by history and clinical examination, without laboratory confirmation, has several serious limitations: 1) 80-90% of people who have genital herpes report no history of signs or symptoms consistent with genital herpes;^{1 2} 2) 20% of people diagnosed by clinical visual exam alone have been found in two studies to not have genital herpes³; and, 3) clinical presentations can be subtle, often without genital vesicles and ulcers, leading to misdiagnosis.

The National Health and Nutrition Examination Survey (NHANES, 1999-2004) shows that only 14.3% of those testing positive for HSV-2 are aware that they have genital herpes.

In the United States, more people have genital herpes than all other sexually transmitted infections combined–50 million people in total⁴. Additionally, there are about one million new genital herpes infections each year due to HSV-2⁵. Although the number of cases of genital herpes caused by HSV-1 is difficult to estimate, in some settings, up to half of first clinical outbreaks are due to HSV-1, usually through oral-to- genital transmission.⁶

Both HSV-1 and HSV-2 cause life-long infections; however, the natural history of genital infection is substantially different for the two types. Recurrences and asymptomatic viral shedding are much more common with HSV-2.⁷ Therefore, determining whether a patient has genital HSV-1 or genital HSV-2 infection is important as it can influence prognosis, treatment, and counseling messages. For example, the suppressive approach to treatment may be more appropriate for those with HSV-2 than for persons with HSV-1.