HSV-2 prevalence, stigma among topics covered at major STD research meeting

Studies that focused on the clinical and emotional aspects of herpes were among those featured at the 19th meeting of the International Society for STD Research, held this past July in Quebec City. This conference, which occurs every other year, brings together delegates from around the world and highlights cutting-edge findings from international sexual health and STD researchers.

Abstracts that provide an overview of each meeting presentation are available as a supplement to the journal Sexually Transmitted Infections online.

Below is a summary of selected HSV studies presented in Quebec:

• Data from the National Health and Nutrition Examination Surveys (NHANES) indicates approximately 16% of those in the U.S. between the ages of 14-49 have HSV-2 infection, which in the vast majority of cases is associated with genital herpes (even though most don’t have recognizable symptoms and are undiagnosed). Using modeling, a study presented at the conference estimated the number of new cases of HSV-2 in the U.S. between 1988 and 2008 based on the rates of current infections, and suggests that risk for the infection is skewed by gender, age, and ethnicity.
  
  HSV-2 rates in the U.S. were estimated to be highest among those ages 25-35 across all ethnic groups (with the exception of Mexican-American men), with a large portion of new HSV-2 infections (45%) occurring in those under age 25. In the two decades covered by the analysis, age-adjusted rates showed little variation. The model indicated stark racial disparities exist; African-Americans bore the brunt of a disproportionate number of HSV-2 infections. As a snapshot of just how common herpes is, the model indicates in 2007-2008 African-Americans, whites, and Mexican-Americans ages 14-49 combined for 750,000 new HSV-2 infections.
  
  The author says understanding how HSV-2 is distributed in the population is important as new interventions are developed. Research with an African cohort found suppressive therapy with the drug acyclovir is not protective against HSV-2 acquisition in couples discordant for HIV-1 and HSV-2.
• Research with an African cohort found suppressive therapy with the drug acyclovir is not protective against HSV-2 acquisition in couples discordant for HIV-1 and HSV-2. In previous research with HSV-2 discordant heterosexual couples – where one partner has the virus and the other does not- a daily dose of the drug valacyclovir reduced transmission of the virus by nearly half. (Valacyclovir is a prodrug that converts to acyclovir as the body absorbs it.) These studies involved healthy couples, though, leaving unanswered questions as to the impact on transmission of a suppressive regimen among those with HIV.
  
  To evaluate the effect of suppressive therapy in discordant couples where the partner with HSV-2 is also HIV-positive, researchers followed such 911 couples for approximately 18 months. With a median follow-up of 18 months, the investigators observed 40 new cases of HSV-2 (confirmed by antibody detection through blood tests) in the acyclovir group, compared to only 28 cases of HSV-2 among those receiving placebo. Factors associated with HSV-2 acquisition among women included use of hormonal contraceptives and having an uncircumcised male partner. Among the men, younger age was the only variable strongly associated with an incident HSV-2 infection.
• Most cases of HSV-2 are unrecognized and undetected, and the stigma surrounding genital herpes gives pause to some health care providers who might consider testing for the virus. There’s some pushback on this, though, given that knowledge of one’s HSV status opens the door to safer sex practices, including treatment regimens that can reduce HSV-2 transmission rates.
  
  So just how upsetting is a positive herpes blood test? Researchers from the University of Washington in Seattle examined this by pouring through studies that used type-specific HSV blood tests in those without a history of genital herpes and also evaluated the emotional state of patients following diagnosis. Looking at nine studies from the U.S., Australia, and the U.K. that involved over 1,300 subjects (341 of whom had no history of genital symptoms but were diagnosed with HSV-2) the investigators found positive herpes tests had no long-term emotional impact on the majority of asymptomatic patients. The authors conclude that worries over emotional stress should not deter clinicians from using HSV tests in patients without symptoms.

References
Gerver S. Incidence rate of Herpes Simplex Virus type 2 (HSV-2) in the USA, 1988–2008. Sex Transm Infect 2011; 87:A108.

Mujugira A, Margaret A, Celum C, Lingappa J, Baeten J, Wald A, et al.Acyclovir and transmission of HSV-2 from HSV-2/HIV-1 dually infected persons. Sex Transm Infect 2011;87:A185. Ross K, Wald A, Johnston C. HSV-2 serologic testing and psychosocial harm: a systematic review. Sex Transm Infect 2011;87:A239-A240.