Seroprevalence of Herpes Simplex Virus Type 2 Among Persons Aged 14--49 Years --- United States, 2005--2008

Seroprevalence of Herpes Simplex Virus Type 2 Among Persons Aged 14--49 Years --- United States, 2005--2008
Weekly
April 23, 2010 / 59(15);456-459


Herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections worldwide and the primary cause of genital and neonatal herpes and genital ulcer disease (1). Multiple studies have shown that HSV-2 infection increases the risk for human immunodeficiency virus (HIV) infection by at least twofold (2). HSV-2 infection is lifelong, and serologic testing provides the best method to estimate HSV-2 prevalence. Since 1976, CDC has monitored HSV-2 seroprevalence in the United States through the National Health and Nutrition Examination Survey (NHANES). After increasing from 1976--1980 (NHANES II) to 1988--1994 (NHANES III), HSV-2 seroprevalence decreased, from 21.0% in 1988--1994 to 17.0% in NHANES 1999--2004 (1). To determine whether HSV-2 seroprevalence in the United States has changed since 1999--2004 and to estimate HSV-2 seroprevalence by age, race/ethnicity, and reported lifetime number of sex partners, CDC analyzed serologic test results from persons aged 14--49 years who participated in NHANES 2005--2008. The results indicated that HSV-2 seroprevalence was 16.2% overall, not statistically different from the seroprevalence in 1999--2004. Seroprevalence was highest among women (20.9%) and non-Hispanic blacks (39.2%). Of those infected with HSV-2, 81.1% had not received a diagnosis. Clinicians, health departments, health-care organizations, and community groups should promote measures that prevent HSV-2 transmission, including minimizing the number of sex partners, avoiding concurrent sexual partnerships, and using condoms consistently and correctly. Patients with known HSV-2 infection should be tested for HIV.

NHANES surveys are cross-sectional surveys designed to compile nationally representative statistics on the health of the U.S. civilian, noninstitutionalized population through complex, multistage probability sampling. During NHANES 2005--2008, a total of 8,283 persons aged 14--49 years were interviewed. Of these, 8,002 had a medical examination; sera were collected from 7,293 participants (88% of those interviewed) for testing of HSV-2 antibodies using a type-specific immunodot assay. Seroprevalence was analyzed by sex, age group, number of lifetime sex partners, and three racial/ethnic categories (non-Hispanic white, non-Hispanic black, and Mexican American). Participants also were asked, "Has a doctor or other health-care professional ever told you that you had genital herpes?" Statistical software was used to generate seroprevalence estimates and 95% confidence intervals. All seroprevalence estimates were weighted using medical examination weights of the survey to represent the U.S. civilian, noninstitutionalized population, accounting for survey participants' unequal probabilities of selection and adjustments for nonresponse. Differences in seroprevalence among categories of participants (e.g., sex or age group) were assessed using the Wald chi-square test.

Overall HSV-2 seroprevalence from NHANES 2005--2008 was 16.2%, not statistically different from the 17.0% seroprevalence in NHANES 1999--2004 (p = 0.34). Of those testing positive for HSV-2 infection, 81.1% said they had never been told by a doctor or health-care professional that they had genital herpes. Seroprevalence increased with age, ranging from 1.4% among those aged 14--19 years to 26.1% among those aged 40--49 years (p<0.001) (Table). HSV-2 seroprevalence was greater among women (20.9%) than men (11.5%) (p<0.001).

By race/ethnicity, HSV-2 seroprevalence was approximately three times greater among non-Hispanic blacks (39.2%) as among non-Hispanic whites (12.3%) (p<0.001). Seroprevalence was greatest among non-Hispanic blacks in the 30--39 years (56.2%) and 40--49 years (56.0%) age groups (Figure 1). In contrast, seroprevalence was 20.8% for non-Hispanic whites aged 40--49 years, and 20.4% for Mexican Americans aged 40--49 years. For all three racial/ethnic groups, HSV-2 seroprevalence generally was greater among those with more lifetime sex partners (Figure 2). For example, among persons with two to four lifetime sex partners, seroprevalence was 9.1% for non-Hispanic whites, 34.3% for non-Hispanic blacks, and 13.0% for Mexican Americans. Among persons with 10 or more lifetime sex partners, seroprevalence was 22.7% for non-Hispanic whites, 49.9% for non-Hispanic blacks, and 17.1% for Mexican Americans. (Figure 2).

Reported by
F Xu, MD, PhD, MR Sternberg, PhD, SL Gottlieb, MD, SM Berman, MD, LE Markowitz, MD, Div of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention; SE Forhan, MD, LD Taylor, DrPH, EIS officers, CDC.

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Seroprevalence of Herpes Simplex Virus Type 2 Among Persons Aged 14--49 Years --- United States, 2005--2008