BACKGROUND: HIV antibody testing has been included in the National Health and Nutrition Examination Survey, for ages 18-49 since 1999 and for ages 18-59 years since 2009 enabling estimation of trends in HIV prevalence as part of national surveillance in the U.S. household population. Self-reported HIV testing and antiretroviral (ARV) use was also included in the survey since 1999. SETTING: A continuous household-based probability sample of the U.S. population. METHODS: From 1999-2018, 29,020 participants age 18-49 years were tested for HIV antibody and 34,092 participants age 18-59 years were asked about self-report of any previous HIV testing. RESULTS: HIV prevalence was 0.41% among those aged 18-59 in 2009-2018 with a non-significant trend over time among those aged 18-49 years from 1999-2002 to 2015-2018. However, significant declines in prevalence were seen among those aged 18-39 years (0.37% to 0.11%), women (0.22% to 0.06%) and non-Hispanic black persons (2.14% to 0.80%). Participants age aged 18-39 self-reported a decline in HIV testing while those aged 40-49 and 50-59 years, non-Hispanic black persons and women reported an increase in getting a HIV test. Prevalence of infection and self-reported history of HIV testing varied by demographic and risk groups. HIV testing among HIV positive persons was 83.9%. ARV therapy among those HIV positive was under 50%. CONCLUSION: Though total HIV prevalence and previous self-reported HIV testing remained stable for the last 20 years, there were significant declines in age and demographic subgroups. Prevalence for both outcomes varied by demographic and risk variables.

Toxoplasma gondii can cause severe neurologic and ocular disease when transmitted congenitally and in immunosuppressed persons. Sera collected in the National Health and Nutrition Examination Survey 2011 through 2014 in 13,507 persons >/= 6 years old were tested for T. gondii immunoglobulin (Ig) G and IgM antibodies, and in those both IgG and IgM antibody positive, for IgG avidity. Overall, 11.14% (95% confidence limits [CL] 9.88%, 12.51%) were seropositive for T. gondii IgG antibody (age-adjusted seroprevalence 10.42% [95% CL 9.19%, 11.76%]); in women aged 15-44 years, the age-adjusted T. gondii IgG seroprevalence was 7.50% (95% CL 6.00%, 9.25%). In multivariable analysis, risk for IgG seropositivity increased with age and was higher in males; persons living below the poverty level; persons with </= a high school education compared with those with > a high school education; and non-Hispanic black, Mexican American, and foreign born non-Hispanic white persons compared with U.S.-born non-Hispanic white persons. Overall, 1.16% (95% CL 0.94%, 1.42%) were T. gondii IgM antibody positive and 0.71%, (95% CL 0.54%, 0.92%) were both IgM and IgG antibody positive. In multivariable analysis, the significant risk factors for being both IgM and IgG positive were age, crowding, and non-U.S. birth origin compared with U.S.-born persons. Among those positive for both IgM and IgG antibody, almost all had high avidity (all women aged 15-44 years had high avidity). Toxoplasma gondii antibody prevalence remains relatively low in the United States, although it is higher in non-U.S.-born persons, males, and some minority and socioeconomically disadvantaged groups.

BACKGROUND: Knowledge of the number of persons with chronic hepatitis C virus (HCV) infection in the United States is critical for public health and policy planning. OBJECTIVE: To estimate the prevalence of chronic HCV infection between 2003 and 2010 and to identify factors associated with this condition. DESIGN: Nationally representative household survey. SETTING: U.S. noninstitutionalized civilian population. PARTICIPANTS: 30 074 NHANES (National Health and Nutrition Examination Survey) participants between 2003 and 2010. MEASUREMENTS: Interviews to ascertain demographic characteristics and possible risks and exposures for HCV infection. Serum samples from participants aged 6 years or older were tested for antibody to HCV; if results were positive or indeterminate, the samples were tested for HCV RNA, which indicates current chronic infection. RESULTS: Based on 273 participants who tested positive for HCV RNA, the estimated prevalence of HCV infection was 1.0% (95% CI, 0.8% to 1.2%), corresponding to 2.7 million chronically infected persons (CI, 2.2 to 3.2 million persons) in the U. S. noninstitutionalized civilian population. Infected persons were more likely to be aged 40 to 59 years, male, and non-Hispanic black and to have less education and lower family income. Factors significantly associated with chronic HCV infection were illicit drug use (including injection drugs) and receipt of a blood transfusion before 1992; 49% of persons with HCV infection did not report either risk factor. LIMITATION: Incarcerated and homeless persons were not surveyed. CONCLUSION: This analysis estimated that approximately 2.7 million U. S. residents in the population sampled by NHANES have chronic HCV infection, about 500 000 fewer than estimated in a similar analysis between 1999 and 2002. These data underscore the urgency of identifying the millions of persons who remain infected and linking them to appropriate care and treatment.

Multiple myeloma (MM) incidence is markedly higher in blacks compared with whites, which may be related to a higher prevalence of monoclonal gammopathy of undetermined significance (MGUS). Our objective was to define the prevalence and risk factors of MGUS in a large cohort representative of the United States (U.S.) population. Stored serum samples from National Health and Nutritional Examination Survey (NHANES) III or NHANES 1999-2004 were available for 12 482 persons age ≥50 years (2331 'black', 2475 Hispanics, 7051 'white', and 625 'others') on which agarose-gel electrophoresis, serum protein immunofixation, serum free light-chain assay, and M-protein typing were performed. MGUS was identified in 365 participants (2.4%). Adjusted prevalence of MGUS was significantly higher (P<0.001) in blacks (3.7%) compared with whites (2.3%) (P=0.001) or Hispanics (1.8%), as were characteristics that posed a greater risk of progression to MM. The adjusted prevalence of MGUS was 3.1% and 2.1% for the North/Midwest versus South/West regions of the U.S., respectively (P=0.052). MGUS is significantly more common in blacks, and more often has features associated with higher risk of progression to MM. A strong geographic disparity in prevalence of MGUS between the North/Midwest versus the South/West regions of the U.S. was found, which has etiologic implications.

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.

Many persons infected with hepatitis C virus (HCV) are unknown to the healthcare system because they may be asymptomatic for years, have not been tested for HCV infection, and only seek medical care when they develop liver-related complications. We analyzed data from persons who tested positive for past or current HCV infection during participation in the National Health and Nutrition Examination Survey (NHANES) from 2001 through 2008. A follow-up survey was conducted 6 months after examination to determine (1) how many participants testing positive for HCV infection were aware of their HCV status before being notified by NHANES, (2) what actions participants took after becoming aware of their first positive test, and (3) participants' knowledge about hepatitis C. Of 30,140 participants tested, 393 (1.3%) had evidence of past or current HCV infection and 170 (43%) could be contacted during the follow-up survey and interviewed. Only 49.7% were aware of their positive HCV infection status before being notified by NHANES, and only 3.7% of these respondents reported that they had first been tested for HCV because they or their doctor thought they were at risk for infection. Overall, 85.4% had heard of hepatitis C; correct responses to questions about hepatitis C were higher among persons 40-59 years of age, white non-Hispanics, and respondents who saw a physician after their first positive HCV test. Eighty percent of respondents indicated they had seen a doctor about their first positive HCV test result. CONCLUSION: These data indicate that fewer than half of those infected with HCV may be aware of their infection. The findings suggest that more intensive efforts are needed to identify and test persons at risk for HCV infection. (HEPATOLOGY 2012;55:1652-1661).

OBJECTIVES: Depression has been linked to risky sexual behaviours in adolescents, but there is little research among adults. The goal of this analysis was to examine the associations between current depression and self-reported risky sexual behaviours in a nationally representative sample of US adults aged 20-59 years. The authors also examined the association between depression and infection with herpes simplex virus type 2 (HSV-2), a biological marker of risky sexual behaviours. METHODS: The authors used data from the 2005-2008 National Health and Nutrition Examination Surveys. Current depression was measured by the Patient Health Questionnaire-9. Antibodies to HSV-2 were tested using the enzymatic immunodot assay. The authors used logistic regression to examine the associations controlling for socio-demographic variables. RESULTS: Among 5273 adults aged 20-59 years, 7% had depression, 36% reported 10 or more lifetime sex partners, 15% had two or more past-year sex partners and 13% had first sex before 15 years of age. Persons with each of the risky sexual behaviours were more likely to have depression than those without. In stratified analyses, risky sexual behaviours were associated with depression in women but not in men. Among 3940 adults aged 20-49 years, 19% had HSV-2 infection. Persons with HSV-2 infection were more likely to have depression (OR 2.1, 95% CI 1.5 to 2.9). CONCLUSIONS: Risky sexual behaviour is related to current depression in adult women. Healthcare providers should be aware of this association and its potential implications in order to deliver better care for patients with depression or sexually transmitted infections.

Previous studies suggest that male testosterone concentrations have declined over time. To explore this in a large US population, we examined testosterone and free testosterone concentrations in National Health and Nutrition Examination Surveys (NHANES) from 1988-1991 and 1999-2004. We also examined sex hormone-binding globulin (SHBG), estradiol, and androstanediol glucuronide (3alpha-diol-G) over the same period. Non-Hispanic white, non-Hispanic black, and Mexican-American men from 1988-1991 and 1999-2004 NHANES surveys who were ≥20 years old and had serum from morning blood draws were included in this analysis (1988-1991: N = 1,413; 1999-2004: N = 902). Testosterone, estradiol and SHBG were measured by competitive electrochemiluminescence immunoassays and 3alpha-diol-G was measured by enzyme immunoassay. Free testosterone was calculated using testosterone and SHBG values. Adjusted mean hormone concentrations were estimated using linear regression, accounting for NHANES sampling weights and design, age, race/ethnicity, body mass index, waist circumference, alcohol use and smoking. Differences in adjusted mean concentrations (Delta) and two-sided p-values were calculated; p < 0.05 was statistically significant. Overall, 3alpha-diol-G and estradiol declined between 1988-1991 and 1999-2004, but there was little change in testosterone, free testosterone, or SHBG (Delta: 3alpha-diol-G = -1.83 ng/mL, p < 0.01; estradiol = -6.07 pg/mL, p < 0.01; testosterone = -0.03 ng/mL, p = 0.75; free testosterone = -0.001 ng/mL, p = 0.67; SHBG = -1.17 nmol/L, p = 0.19). Stratification by age and race revealed that SHBG and 3alpha-diol-G declined among whites 20-44 years old (Delta: SHBG = -5.14 nmol/L, p < 0.01; 3alpha-diol-G = -2.89 ng/mL, p < 0.01) and free testosterone increased among blacks 20-44 years old (Delta: 0.014 ng/mL, p = 0.03). Estradiol declined among all ages of whites and Mexican-Americans. In conclusion, there was no evidence for testosterone decline between 1988-1991 and 1999-2004 in the US general population. Subgroup analyses suggest that SHBG and 3alpha-diol-G declined in young white men, estradiol declined in white and Mexican-American men, and free testosterone increased in young black men. These changes may be related to the increasing prevalence of reproductive disorders in young men.

OBJECTIVES: We described seroprevalence of antibody to hepatitis A virus (anti-HAV) in the United States during 1999-2006 and compared it with seroprevalence before the availability of vaccine. METHODS: We analyzed data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (NHANES) to obtain estimates of anti-HAV seroprevalence for the U.S. household population. We grouped region of residence based on the 1999 Advisory Committee on Immunization Practices recommendations into 17 states with any recommendation (vaccinating) and 33 states without any recommendation (non-vaccinating). RESULTS: During 1999-2006, the overall seroprevalence of anti-HAV was 34.9% (95% confidence interval [CI] 33.1, 36.7). During 1999-2006, U.S.-born children living in vaccinating states (33.8%, 95% CI 26.2, 42.2) had a higher seroprevalence than children in non-vaccinating states (11.0%, 95% CI 9.4, 12.8; p < 0.001). Seroprevalence among children increased from 8.0% (95% CI 6.3, 10.1) during 1988-1994 to 20.2% (95% CI 16.0, 24.8) during 1999-2006 (p < 0.001). For U.S.-born children aged 6-19 years, the strongest factor associated with seroprevalence was residence in vaccinating states. Among U.S.-born adults aged > 19 years, the overall age-adjusted seroprevalence of anti-HAV was 29.9% (95% CI 28.3, 31.5) during 1999-2006, which was not significantly different from the seroprevalence during 1988-1994 (32.2%, 95% CI 30.1, 34.4). CONCLUSIONS: Increases in seroprevalence among children in vaccinating states suggest a positive effect of the 1999 vaccination recommendations.

The National Health and Nutrition Examination Survey (NHANES) is a program of studies conducted since the 1960s by the National Center for Health Statistics of the U.S. Centers for Disease Control and Prevention. Its purpose is to obtain information on the health and nutritional status of the U.S. population. The survey involves interviews and physical examinations of a nationally representative sample of civilian and noninstitutionalized adults and children. From 1999-2002, and again from 2007-2008, biospecimens (blood, urine, and DNA samples) were collected from NHANES participants. In 2006, we reported on the NHANES experience with obtaining consent for the storage and use of biospecimens for data years 1999-2002. (1) In this report, we provide an update on the NHANES experience regarding consent for collecting biospecimens for data years 2007-2008 (DNA samples were not collected from 2003-2006).

OBJECTIVE: We estimated the varicella seroprevalence among the U.S. population aged 6-49 years based on retested National Health and Nutrition Examination Survey (NHANES) specimens collected between 1999 and 2004--originally tested using a method unsuitable for detecting vaccine-induced immunity--and compared it with historical estimates. METHODS: We performed a confirmatory test suitable for detecting vaccine-induced immunity on all available specimens from 6- to 19-year-olds who originally tested negative (n = 633), and on 297 randomly selected specimens that had tested positive. Retest results superseded original results for determining seroprevalence. We assessed seroprevalence for the entire sample aged 6-49 years (n = 16,050) by participant demographic characteristics and compared it with historical estimates (NHANES 1988-1994). RESULTS: The percentage of false-negative results for the original test was higher for specimens from younger children (6-11 years of age: 27.5%; 12-19 years of age: 13.3%) and for specimens collected most recently (2001-2004: 26.0%; 1999-2000: 12.6%). The age-adjusted rate of varicella seroprevalence for 1999-2004 was 93.6% for 6- to 19-year-olds and 98.0% for adults aged 20-49 years compared with 90.0% and 98.1%, respectively, for 1988-1994. We found an increase in seropositivity between the survey periods, from 93.2% to 97.2% (p < 0.001) among 12- to 19-year-olds. For children, non-Hispanic black ethnicity and younger age were associated with lower seroprevalence in both survey periods. CONCLUSIONS: Varicella seroprevalence increased with age among children and was uniformly high in the U.S. adult population between 1999 and 2004. The original testing produced false-negative seroprevalence results among children's specimens collected between 1999 and 2004 from 6- to 19-year-olds.

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.

OBJECTIVE: Most young women initiate sexual activity during adolescence; risk for sexually transmitted infections (STIs) accompanies this initiation. In this study we estimated the prevalence of the most common STIs among a representative sample of female adolescents in the United States. METHODS: Data were analyzed from 838 females who were aged 14 to 19 and participating in the nationally representative National Health and Nutrition Examination Survey 2003-2004. After interview and examination, survey participants provided biological specimens for laboratory testing. The main outcome was weighted prevalence of at least 1 of 5 STIs: Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, herpes simplex virus type 2, and human papillomavirus (HPV) (any of 23 high-risk types or type 6 or 11). RESULTS: Prevalence of any of the 5 STIs was 24.1% among all and 37.7% among sexually experienced female adolescents. HPV (23 high-risk types or type 6 or 11) was the most common STI among all female adolescents (prevalence: 18.3%), followed by C trachomatis infection (prevalence: 3.9%). Prevalence of any of the STIs was 25.6% among those whose age was the same or 1 year greater than their age at sexual initiation and 19.7% among those who reported only 1 lifetime sex partner. CONCLUSIONS: The prevalence of STIs among female adolescents is substantial, and STIs begin to be acquired soon after sexual initiation and with few sex partners. These findings support early and comprehensive sex education, routine HPV vaccination at the age of 11 to 12 years, and C trachomatis screening of sexually active female adolescents.

OBJECTIVE: To monitor trends in HIV seroprevalence in the United States, HIV testing was included in the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2006. METHODS: From 1999 to 2006, 11,928 participants aged 18-49 years were tested for HIV antibody. Prevalence estimates were weighted to account for oversampling and nonresponse. RESULTS: There were 67 HIV antibody-reactive individuals for a seroprevalence of 0.5% [95% confidence interval (CI) 0.3-0.6]. In the only age subgroup directly comparable between surveys (18-39 years), HIV seroprevalence remained constant from NHANES III (1988-1994) to NHANES 1999-2002 and 2003-2006. In NHANES 1999-2006, non-Hispanic blacks had significantly higher HIV seroprevalence (2.0%, 95% CI 1.5-2.7) compared with individuals in all other race/ethnic groups combined. Seroprevalence was also higher in each race/ethnic group among men who have sex with men (9.4% 95% CI 5.0-17.1), among persons who had detectable antibody to herpes simplex type-two (1.9% 95% CI 1.4-2.8), among those who had 50 or more lifetime sex partners (3.4%, 95% CI 1.7-6.7), and among those who never married (0.8%, 95% CI 0.5-1.3). CONCLUSIONS: In this household-based population, seroprevalence did not significantly change from NHANES III to NHANES 1999-2006. Non-Hispanic blacks had significantly higher prevalence of infection compared with other race/ethnic groups. Male-to-male sex and the presence of HSV-2 antibody were the strongest predictors of HIV infection.