Decreasing seroprevalence of herpes simplex virus type 1 and type 2 in Germany leaves many people susceptible to genital infection: time to raise awareness and enhance control

BACKGROUND Herpes simplex infections (HSV1/2) are characterized by recurrent symptoms, a risk of neonatal herpes, and the facilitation of HIV transmission. In Germany, HSV1/2 infections are not notifiable and data are scarce. A previous study found higher HSV1/2 seroprevalences in women in East Germany than in women in West Germany. We assessed changes in the HSV1/2 seroprevalences over time and investigated determinants associated with HSV1/2 seropositivity to guide prevention and control. METHODS The study was based on the German Health Interview and Examination Survey for Adults (DEGS; 2008-2011) and the German National Health Interview and Examination Survey (GNHIES; 1997-1999). We tested serum samples from DEGS participants for HSV1 and HSV2 immunoglobulin G. We used Pearson's χ2 test to compare the HSV1/HSV2 seroprevalences in terms of sex, age, and region of residence (East/West Germany) and investigated potential determinants by calculating prevalence ratios (PR) with log-binomial regression. All statistical analyses included survey weights. RESULTS In total, 6627 DEGS participants were tested for HSV1, and 5013 were also tested for HSV2. Overall, HSV1 seroprevalence decreased significantly from 1997-1999 (82.1%; 95%CI 80.6-83.6) to 2008-2011 (78.4%; 95%CI 77.8-79.7). In the same period, overall HSV2 seroprevalence decreased significantly from 13.3% (95%CI 11.9-14.9) to 9.6% (95%CI 8.6-10.8), notably in 18-24-year-old men (10.4 to 0%) in East Germany. Women were more likely than men to be seropositive for HSV1 (PR 1.1) or HSV2 (PR 1.6). A lower level of education, smoking, and not speaking German were associated with HSV1 in both sexes. Women of older age, who smoked, or had a history of abortion and men of older age or who had not attended a nursery school during childhood were more often seropositive for HSV2. CONCLUSION The reduced seroprevalences of HSV1 and HSV2 leave more people susceptible to genital HSV1/2 infections. Practitioners should be aware of HSV infection as a differential diagnosis for genital ulcers. We recommend educational interventions to raise awareness of the sexual transmission route of HSV1/2, possible consequences, and prevention. Interventions should especially target pregnant women, their partners, and people at risk of HIV.