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Background: Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are common infections with serious sequelae. HSV-1 is an increasingly important cause of genital herpes in industrialized countries., Methods: Using nationally representative data from the National Health and Nutrition Examination Survey (NHANES), we examined HSV-1 and HSV-2 seroprevalence among 14- to 49-year-olds in the United States. We estimated seroprevalence in 1999-2004 and 2005-2010, stratified by sociodemographic characteristics and sexual behaviors. We also reviewed HSV-1 and HSV-2 seroprevalence from 1976-1980 to 2005-2010., Results: In 2005-2010, the seroprevalence of HSV-1 was 53.9%, and the seroprevalence of HSV-2 was 15.7%. From 1999-2004 to 2005-2010, HSV-1 seroprevalence declined by nearly 7% (P < .01), but HSV-2 seroprevalence did not change significantly. The largest decline in HSV-1 seroprevalence from 1999-2004 to 2005-2010 was observed among adolescents aged 14-19 years, among whom seroprevalence declined by nearly 23%, from 39.0% to 30.1% (P < .01). In this age group, HSV-1 seroprevalence declined >29% from 1976-1980 to 2005-2010 (P < .01)., Conclusions: An increasing number of adolescents lack HSV-1 antibodies at sexual debut. In the absence of declines in HSV-2 infections, the prevalence of genital herpes may increase.

Background: In 2006, the largest mumps outbreak in the United States in 20 years occurred. To understand prior mumps seroprevalence and factors associated with the presence of antibody to mumps virus, data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) were analyzed., Methods: A mumps virus-specific enzyme immunoassay was used to measure the seroprevalence of serum immunoglobulin G (IgG) antibody among NHANES participants aged 6-49 years. Participants were grouped on the basis of 10-year birth cohorts, 95% confidence intervals (CIs) were calculated using SUDAAN software, and logistic regression was used to identify independent predictors., Results: The overall age-adjusted seroprevalence of IgG antibody to mumps virus during 1999-2004 was 90.0% (95% CI, 88.8%-91.1%). Seroprevalence was higher among US-born non-Hispanic blacks (96.4% [95% CI, 95.5%-97.2%]) and non-US-born Mexican Americans (93.7% [95% CI, 92.0%-95.2%]). Seroprevalence was significantly lower in the 1967-1976 birth cohort (85.7% [95% CI, 83.5%-87.8%]). The variables sex, education, and race/ethnicity/birthplace were independent predictors in at least 1 of the birth cohorts., Conclusions: The overall estimate of 90.0% is at the lower end of the estimated population immunity (90%-92%) needed to achieve herd immunity. Lower seroprevalence among groups suggest that they represent populations at an increased risk. For mumps control, high vaccine coverage and high population immunity must be achieved and maintained.

Background: Hepatitis E virus (HEV) is prevalent and causes disease worldwide, but its epidemiological profile is only partially understood., Methods: We used an enzyme immunoassay to measure anti-HEV immunoglobulin G antibodies in 18,695 serum samples collected in the Third National Health and Nutrition Examination Survey. We calculated estimates of HEV seroprevalence and examined associations with putative risk factors., Results: The seroprevalence of HEV in the civilian noninstitutionalized United States (US) population during the period from 1988 through 1994 was 21.0% (95% confidence interval [CI], 19.0%-22.9%). Among US-born individuals, males, non-Hispanic whites, and individuals residing in the Midwest and/or in metropolitan areas had the highest seroprevalence estimates. Having a pet in the home (odds ratio [OR], 1.19 [95% CI, 1.01-1.40]) and consuming liver or other organ meats more than once per month (OR, 1.38 [95% CI, 1.01-1.88]) were significantly associated with increased odds of HEV seropositivity., Conclusions: Exposure to HEV is common in the US population, although hepatitis E is rarely reported. Having pets and consuming organ meats may play a role in HEV transmission in the United States, but other mechanisms of transmission may also exist. HEV may be considered a possible etiologic agent of acute and chronic hepatitis in US patients reporting no travel history.

Background: Endemic measles transmission was declared eliminated in the United States in 2000. To ensure that elimination can be maintained, high population immunity must be sustained and monitored. Testing for measles antibody was included in the National Health and Nutrition Examination Survey (NHANES), a nationally representative survey, conducted during 1999-2004., Methods: A measles-specific immunoassay was used to measure the seroprevalence of measles antibody in NHANES participants 6-49 years of age. For analysis, participants were grouped by birth cohort., Results: During 1999-2004, the rate of measles seropositivity in the population overall was 95.9% (95% confidence interval [CI], 95.1%-96.5%). The highest seroprevalence of measles antibody was in non-Hispanic blacks (98.6% [95% CI, 98.0%-99.1%]). Those born during 1967-1976 had significantly lower levels of measles antibody (92.4% [95% CI, 90.8%-93.9%]) than did the other birth cohorts. Independent predictors of measles seropositivity in the 1967-1976 birth cohort were non-Hispanic/black race/ethnicity, more than a high school education, having health insurance, and birth outside the United States., Conclusions: Measles seropositivity was uniformly high in the US population during 1999-2004. Nearly all population subgroups had evidence of measles seropositivity levels greater than the estimated threshold necessary to sustain measles elimination. Non-Hispanic whites and Mexican Americans born during 1967-1976 had the lowest measles seropositivity levels and represent populations that might be at increased risk for measles disease if the virus were reintroduced into the United States.

Background: Human herpesvirus 8 (HHV-8) causes Kaposi sarcoma. In the United States, transmission routes for HHV-8 are uncertain., Methods: The National Health and Nutrition Examination Survey III sampled individuals from the US general population (1988-1994). We used enzyme immunoassays (EIAs) to measure HHV-8 antibodies (K8.1 and open reading frame [ORF] 73 antigens) in 13,894 surveyed adults. HHV-8 seroprevalence was examined according to sexual history and viral coinfection markers., Results: Overall, seroprevalence was low when a highly specific cutoff was used (K8.1, 1.6%; ORF73, 1.5%) but was higher when a less-specific cutoff was used (K8.1, 7.1%; ORF73, 7.4%). When the more-specific approach was used, K8.1 seroprevalence was similar in men and women. Men who have sex with men (MSM) had a higher K8.1 seroprevalence (8.2%). Among other men, K8.1 seroprevalence was marginally associated with duration of heterosexual activity (P=.1) and was positively associated with the lifetime number of sex partners (P=.04) and with coinfections with hepatitis B virus (6.1% vs. 1.2% without coinfection; P<.001) and herpes simplex virus 2 (2.7% vs. 1.0%; P=.003). Among women, K8.1 seroprevalence was not significantly related to duration of sexual activity, the lifetime number of sex partners, or viral coinfections. The ORF73 EIA revealed similar but less clear-cut patterns., Conclusions: Among men, HHV-8 transmission may occur through sexual activity, particularly sex with other men. No evidence was observed for heterosexual transmission to women.

After the 1989-1991 rubella resurgence, rubella vaccination efforts targeted children and women of childbearing age. Utilizing National Health and Nutrition Examination Survey data collected during 1988-1994 and 1999-2004, we assessed whether US levels of rubella seropositivity are consistent with rubella elimination and whether changes are consistent with immunization efforts. Serum samples with rubella antibody levels > or =10 IU tested by rubella immunoglobulin G enzyme immunoassay were considered to be positive. In 1999-2004, the overall age-adjusted rubella seropositivity level was 91.3% (95% confidence interval [CI], 90.5%-92.1%), a significant increase from 88.1% (95% CI, 86.9%-89.1%) in 1988-1994 (P<.001). Among children, seropositivity was highest in children 6-11 years of age (96.2%), followed by adolescents 12-19 years of age (93.7%). Both groups showed significant increases in immunity levels, in comparison with those in 1988-1994 (P<.001). Among adults, seropositivity among women increased (from 88.9% to 91.5%; P=.015), and there was no change among men (from 87.8% to 88.0%; P=.84). In 1999-2004, population rubella immunity levels were at or above the modeled threshold for elimination of rubella virus transmission. Increases in immunity levels are consistent with vaccination efforts.

Infection with human papillomavirus (HPV) type 16 accounts for about half of cervical cancers worldwide. This study investigated the seroepidemiology of HPV-16 infection in the United States by using a population-based survey. Serum samples and questionnaire data were collected from 1991 to 1994 for the National Health and Nutrition Examination Surveys. HPV-16-specific IgG antibody was detected by use of an HPV-16 virus-like particle ELISA. HPV-16 seropositivity in the US population aged 12-59 years was 13.0% (95% confidence interval, 11.5%-14.7%). Seroprevalence was higher in women (17.9%) than in men (7.9%). Age, race/ethnicity, and number of lifetime sex partners were associated with HPV seropositivity in women. Race/ethnicity, age at first intercourse, urban/nonurban residence, years of sexual activity, and having had sex with a man were associated with HPV seropositivity in men. Information on HPV-16 seroepidemiology will be important for designing prevention efforts including vaccine programs.