Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States.
BACKGROUND
Herpes simplex virus type 1 (HSV-1) and type 2 are common infections worldwide. Herpes simplex virus type 2 (HSV-2) is the cause of most genital herpes and is almost always sexually transmitted. In contrast, HSV-1 is usually transmitted during childhood via nonsexual contacts. Preexisting HSV-1 antibodies can alleviate clinical manifestations of subsequently acquired HSV-2. Furthermore, HSV-1 has become an important cause of genital herpes in some developed countries.


OBJECTIVE
To examine trends in HSV-1 and HSV-2 seroprevalence in the United States in 1999-2004 compared with 1988-1994.


METHODS
Cross-sectional, nationally representative surveys (US National Health and Nutrition Examination Surveys [NHANES]), were used to compare national seroprevalence estimates from 1999-2004 with those from 1988-1994, and changes in HSV-1 and HSV-2 seroprevalence since 1976-1980 were reviewed. Persons aged 14 to 49 years were included in these analyses.


METHODS
Seroprevalence of HSV-1 and HSV-2 antibodies based on results from type-specific immunodot assays; diagnosis of genital herpes.


RESULTS
The overall age-adjusted HSV-2 seroprevalence was 17.0% (95% confidence interval [CI], 15.8%-18.3%) in 1999-2004 and 21.0% (95% CI, 19.1%-23.1%) in 1988-1994, a relative decrease of 19.0% between the 2 surveys (95% CI, -28.6% to -9.5%; P<.001). Decreases in HSV-2 seroprevalence were especially concentrated in persons aged 14 to 19 years between 1988 and 2004. In adolescents aged 17 to 19 years and young adults, the decreases in HSV-2 seroprevalence were significant even after adjusting for changes in sexual behaviors. Among those infected with HSV-2, the percentage who reported having been diagnosed with genital herpes was statistically different (14.3% in 1999-2004 and 9.9% in 1988-1994; P = .02). Seroprevalence of HSV-1 decreased from 62.0% (95% CI, 59.6%-64.6%) in 1988-1994 to 57.7% (95% CI, 55.9%-59.5%) in 1999-2004, a relative decrease of 6.9% between the 2 surveys (95% CI, -11.6% to -2.3%; P = .006). Among persons infected with HSV-1 but not with HSV-2, a higher percentage reported having been diagnosed with genital herpes in 1999-2004 compared with 1988-1994 (1.8% vs 0.4%, respectively; P<.001).


CONCLUSIONS
These data show declines in HSV-2 seroprevalence, suggesting that the trajectory of increasing HSV-2 seroprevalence in the United States has been reversed. Seroprevalence of HSV-1 decreased but the incidence of genital herpes caused by HSV-1 may be increasing.
Xu
Fujie
F
Centers for Disease Control and Prevention, Atlanta, Ga 30333, USA. fax1@cdc.gov
Sternberg
Maya R
MR
Kottiri
Benny J
BJ
McQuillan
Geraldine M
GM
Lee
Francis K
FK
Nahmias
Andre J
AJ
Berman
Stuart M
SM
Markowitz
Lauri E
LE
D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006561:Herpes Simplex / Q000453:epidemiology* / Q000821:virology; D018259:Herpesvirus 1, Human / Q000276:immunology*; D018258:Herpesvirus 2, Human / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016036:Seroepidemiologic Studies; D014481:United States / Q000453:epidemiology