Prevalence of Herpes Simplex Virus Type 1 and Type 2 in Persons Aged 14-49: United States, 2015–2016

February 7, 2018

Geraldine McQuillan, Ph.D., Infectious Disease Epidemiologist

Questions for Geraldine McQuillan, Ph.D., Infectious Disease Epidemiologist and Lead Author of “Prevalence of Herpes Simplex Virus Type 1 and Type 2 in Persons Aged 14-49: United States, 2015–2016

Q: In the first bullet in the key findings section of your new report, 47.8% is listed for 2015-2016 herpes simplex type 1 prevalence and 11.9% is listed for type 2. Yet in the last bullet there, it reads that prevalence is 48.1% and 12.1%. Why are these estimates different?

GM: This report offers two statistical estimates – a crude rate, or “real” prevalence estimate, and an age-adjusted one. If you look at the data table for Figure 1, you can see that the unadjusted prevalence — or the true prevalence for herpes simplex virus type 1 (HSV-1) — is 47.8% in the U.S population. In order to compare across subgroups that have differing age distributions, we need to age-adjust the data to allow for a more accurate comparison among groups. The age-adjusted prevalence for the total population is 48.1%. Crude rates are influenced by the underlying age distribution of a population, and age-adjusting the rates assures that differences are not due to the age distribution of the populations being compared.

Q:  What made you decide to focus on the prevalence of the herpes simplex virus for the subject of your new report?

GQ: Our main motivation for conducting this study is to offer a current assessment of herpes prevalence in the United States. Though we have included HSV-1 and -2 testing in the National Health and Nutrition Examination Survey (NHANES) since 1999, we have not looked at the data since 2010 (Bradley et al. Seroprevalence of herpes simplex virus type 1 and 2 – United States, 1999-2010. JID 2014:209; 325-333). With the addition of six more years of data and a sufficient amount of years to look at trends over time, we decided it was time to re-look at the prevalence of these common viruses in the United States.

Q:  Was there a result in your study that you had not expected and that really surprised you?

GQ: The decline in herpes simplex virus type 2 (HSV-2) across all race and ethnic groups was quite striking. The linear decline in prevalence was seen in the previous study for HSV-1 that used data from 1999-2010. There was no decline with the prevalence of HSV-2 at that time. With the addition of six more years of data, we now also see a linear downward trend for HSV-2 and again for HSV-1. We did not expect to see the decline of HSV-2 in all race and ethnic subgroups.

Q:  What differences or similarities did you see among race and ethnic groups, and various demographics, in this analysis?

GQ: The difference by race and ethnic subgroups in herpes simplex virus prevalence did not differ from previous reports even with the declines in prevalence in both viruses. Mexican-Americans still have the highest prevalence of HSV-1, and non-Hispanic whites have the lowest. The prevalence of HSV-2 is highest in the non-Hispanic black population and lowest in the non-Hispanic Asian population. Non-Hispanic whites and Mexican- Americans have a similar prevalence. All these race/ethnic differences have been seen in many of our infectious diseases especially those that are transmitted sexually.

Q: What is the take-home message of this report?

GQ: This is a good news data report. I think its take-home message is that two of our most prevalent viruses, HSV-1 and HSV-2, are steadily declining in the U.S population. Though NHANES provides prevalence estimates (new and old infections), once a person is infected with a herpes virus they are infected for life. The only way we see a decline is if there is a drop in new infections or a decrease in the incidence of both HSV-1 and HSV-2. While this report is a presentation of data findings, and did not go into an analysis of risk factors to determine why we are seeing this decline, other industrialized countries have observed declines in HSV-1 during the past two decades. Improvements in living conditions, better hygiene and less crowding likely explain these declines. Other countries who also have seen a decline in HSV-2 in their populations, suggest that the increase in safe-sex practices in the post-AIDS pandemic may contribute to the decline.


Condom Use During Sexual Intercourse Among Women and Men Aged 15-44 in the United States: 2011-2015 National Survey of Family Growth

August 10, 2017

Questions for Casey Copen, Ph.D., M.P.H., Statistician and Author of “Condom use during sexual intercourse among women and men aged 15-44 in the United States: 2011-2015 National Survey of Family Growth

Q: Why did you decide to examine condom use in this report?

CC: There are about 20 million new sexually transmitted infections (STI) in the United States each year. These infections can lead to long-term health consequences, such as infertility. Condoms can provide protection against most STIs but are often used incorrectly and inconsistently. Similarly, condoms can reduce the risk of pregnancy but have one of the highest rates of contraceptive failure of any contraceptive method.

The purpose of this report was to examine recent trends in condom use during vaginal (sexual) intercourse and measure the prevalence of condom use, alone or in combination with another contraceptive method. This information can be used to plan health services and educational programs in the U.S.

Q: Has the data in this report been previously published?

CC: Data on condom use has been collected for women since 1973 and for men, since 2002. Starting in 2013, questions on problems with condom use were asked of women aged 15-44 who used a condom during intercourse in the past 4 weeks. Periodically, the National Survey of Family Growth (NSFG) publishes reports on current contraceptive use, which includes condoms, to measure how contraceptive use among women has changed over time.

Last month, NSFG released a report on contraceptive use among female and male teens aged 15-19 that included information on condom use at first and most recent intercourse ( However, the data on condom use problems have not been previously published.

Q: What do you think were the main findings of your report?

CC: In 2011-2015, 23.8% of women and 33.7% of men aged 15–44 used a condom at last sexual intercourse in the past 12 months. Among condom users aged 15-44, the majority of women and men used only a condom and no other method during last intercourse in the past 12 months (59.9% of women and 56.4% of men); another 25.0% of women and 33.2% of men used condoms plus hormonal methods; and 15.1% of women and 10.5% of men used condoms plus non-hormonal methods. Almost 7% of women aged 15–44 who used a condom in the past four weeks said the condom broke or completely fell off during intercourse or withdrawal and 25.8% said the condom was used for only part of the time during intercourse.

Q: How has the percentage of condom use in the U.S. during sexual intercourse changed since 2002?

CC: The percentages of women aged 15-44 who used condoms at last sexual intercourse in the past 12 months were similar from 2002 to 2011-2015, but for men aged 15–44, the percentages increased from 29.5% in 2002 to 33.7% in 2011–2015. Percentages of female and male condom users aged 15–44 who used condoms only at last intercourse in the past 12 months decreased from 67.9% of women and 63.0% of men in 2002 to 59.9% and 56.4% in 2011-2015. Alongside this decline, percentages of female condom users aged 15–44 who used condoms plus non-hormonal methods at last intercourse increased from 11.9% in 2006–2010 to 15.1% in 2011–2015.

Q: What is the take-home message of your report?

CC: This report showed that the majority of women and men aged 15-44 in each NSFG survey period did not use a condom at all during last sexual intercourse. It is important to note that there are many factors associated with condom nonuse, such as being in a monogamous relationship, using hormonal or other methods to prevent pregnancy or trying to get pregnant. Although this report could not address each of these factors directly, these findings indicate there are differences in condom use by age, education, Hispanic origin and race, relationship at last sexual intercourse and number of sexual partners in the past 12 months. About one-quarter of women aged 15-44 who used a condom during intercourse in the past 4 weeks reported that the condom was used for only part of the time during intercourse (25.8%), suggesting that condoms are often used inconsistently.

Sexual Activity and Contraceptive Use Among Teenagers in the United States: 2011-2015

June 22, 2017

Questions for Joyce Abma, Ph.D., Social Scientist and Lead Author on “Sexual Activity and Contraceptive Use Among Teenagers in the United States: 2011-2015

Q: Is the bottom line here in this study that teens are less sexually active than in the past?

JA: Yes. Although this has changed very gradually, fewer teens have ever had sex than was the case three decades ago. In the late 1980s, just over half of female teens and 61% of male teens had had sex, and the most recent data through 2015 show this percent is well under half: 42% for females and 44% for males.- So males have had a particularly large decrease in the percent who have ever had sex during the teen years.

Over the past 3 decades, since 1988, the percent of teens who had ever had sex has been declining gradually. (decreasing from over half – 51% for females and 60% for males, to under half – 42% for females and 44% for males in 2011-15). Since 2002, however, the decline slowed and there has been no significant change for female or male teens. And this plateau continued through the most recent time period, 2011-2015.

Q: Are the teens of today also more likely to use contraception than past generations?

JA: Yes. Although even about 3 decades ago, in the late 1980s, contraceptive use was common among teens – for example 84% of males used a method at last sex in 1988 – they have become increasingly more likely since then. In the most recent data, 2011-2015, 95% of males used a contraceptive method at last sex. Related to this increase among females is another big change across the time period: the development and availability of a wider variety of contraceptives for females. These include Depo-Provera injectable, implants, emergency contraception, the patch, and more recently, the IUD has been re-designed and recommended for teens. These newer hormonal methods are starting to be used more commonly, but use of the pill remains common as well among female teens.

Q: With such a sensitive topic, do you meet with a lot of resistance in trying to collect this data?

JA Actually, the response rate for the survey is 70%, meaning of the people eligible for the survey, 70% agree to participate and complete it. Generally, people recognize the importance, validity and value of the survey. Those who participate tend to find it an interesting and positive experience. And many topics are covered, including some questions about education, health services, attitudes and opinions, questions about children, and relationships.

Q: Do these findings include teens with same-sex partners?

JA: No, this report covers only sexual intercourse with opposite-sex partners. The purpose of the report is primarily to understand risk behaviors for pregnancy among teens, thus the focus is only on opposite sex sexual activity.

Q: Any other important points of note?

JA: There are several interesting findings in this report, both in terms of sexual activity as well as contraceptive use among teens. For example, teens who had not yet had sex – which is over half of all teens — were asked to identify the main reason they hadn’t yet had sex, from 5 possible reasons. Female and male teens were very similar in the reasons they chose. Female and male teens both chose “against religion or morals”, followed by “don’t want to get (a female) pregnant”, and “haven’t found the right person yet” as the most common reasons. So female and male teens seem to be thinking along the same lines when considering the issue of not being sexually active.

As for contraceptive use, recently the IUD and contraceptive implants have been re-designed and are recommended by reproductive health professionals for teens to reduce the chances of pregnancy. These methods, referred to as “LARC” – for “long-acting reversible contraception”– are important because they offer protection for multiple years, they don’t require regular action on the part of the teen, and their failure rates are extremely low. These methods are still relatively rarely used among teens but are being used more often: 6% of teens had ever used either of these two methods as of the 2011-15 data.

Prevalence of HPV in Adults Aged 18–69: United States, 2011–2014

April 6, 2017

Questions for Geraldine McQuillan, Ph.D., Statistician, and Lead Author of “Prevalence of HPV in Adults Aged 18–69: United States, 2011–2014”

Q:  Are these the first HPV estimates you’ve released?  If not, how has this problem changed over time?

GQ:  In this report we do not examine changes over time. But based on a report authored by one of our Co-authors, Dr. Markowitz, analyzing previously released NHANES data, since the highly efficaciously vaccine against HPV 6,11 and 18 was introduced in 2006, the prevalence of high risk HPV in female adolescents has decreased by 64% and among females age 20-24 years by 34%.

Q:  What do you think is the most striking finding in your report?

GQ:  That over 20% of the adult population of the US have high risk HPV detected with significant race/ethnic differences.

Q:  What are we to make of the relatively low HPV prevalence numbers among Asians?  Are they less promiscuous/sexually active?

GQ:  This is a brief report that provides estimates on HPV prevalence overall and by race/ethnic differences.  We did not further examine the characteristics of these individuals and cannot speculate on why the prevalence may be lower among Asian adults.

Q: Your report talks about people with “high risk” HPV being at a higher risk for cancer – but what is the difference between low risk HPV and high risk HPV?  How is that determined medically?

GQ:  It is not determined medically but by a laboratory test looking at subtypes that are associated with cancer. High risk subtypes have been associated with oral, genital and anal cancers, while low risk types have been associated with warts.

Q: Are people with genital HPV at a higher risk to contract other STIs, including HIV?

GQ:  We again did not examine this in the current report, but based on prior research, we know that men who have HIV and men who have sex with men are at particular risk for anal, penile and throat cancers due to persistent HPV infection.

Q: What are the current recommendations for HPV vaccine?

GQ:  According to Dr. Lauri Markowitz with the CDC’s National Center for Immunization and Respiratory Diseases, CDC recommends two doses of HPV vaccine for 11 and 12 year olds to prevent HPV cancers. Younger adolescents need fewer doses to complete the HPV vaccination series compared to older adolescents. The first dose is recommended at 11-12 years old. Vaccination can be started at age 9. The second dose of the vaccine should be administered 6 to 12 months after the first dose. Teens and young adults who start the series at ages 15 through 26 years need three doses of HPV vaccine to protect against cancer-causing HPV infections. Adolescents aged 9 through 14 years who have already received two doses of HPV vaccine less than 5 months apart, will require a third dose. Three doses are recommended for people with weakened immune systems aged 9-26 years. Here’s a link to the press release that describes the changes:

Q: What other findings in your report did you find striking?

GQ:  That among all race/ethnic groups males were significantly more likely to be infected with oral HPV except for high risk HPV among Asian adults.

Confidentiality Concerns and Sexual and Reproductive Health Care Among Adolescents and Young Adults Aged 15–25

December 16, 2016

Confidentiality concerns can impact adolescent and young adults’ access to sexual and reproductive health services. Young people who are covered by their parents’ private health insurance may be deterred from obtaining these services due to concerns that their parents might find out about it.  Similarly, confidentiality concerns may arise because youth seeking such services may not have time alone during a visit with a health care provider.

A new NCHS report describes two measures related to confidentiality concerns and sexual and reproductive health care.


  • About 7% of persons aged 15–25 would not seek sexual or reproductive health care because of concerns that their parents might find out about it.
  • For females aged 15–17 and 18–25, those who had confidentiality concerns were less likely to receive sexual and reproductive health services in the past year compared with those without these concerns.
  • Less than one-half of teenagers aged 15–17 (38.1%) spent some time alone in the past year during a visit with a doctor or other health care provider without a parent, relative, or guardian in the room.
  • Teenagers aged 15–17 who spent some time alone during a visit with a health care provider were more likely to have received sexual or reproductive health services in the past year compared with those who had not.



Trends in Attitudes About Marriage, Childbearing, and Sexual Behavior: United States

March 17, 2016

An NCHS report describes attitudes about marriage, childbearing, and sexual behavior among men and women aged 15–44 in the United States based on the 2002, 2006–2010, and 2011–2013 National Survey of Family Growth.


  • An increase in the percentage of men and women who agreed with premarital cohabitation.
  • An increase in the percentage of men and women who agreed with nonmarital childbearing.
  • An increase in the percentage of men and women who agreed with the right for gay and lesbian adults to adopt children.
  • An increase in the percentage of men and women who agreed with the right for same-sex sexual relations, as well as premarital sex for 18 year olds.
  • A decrease in the percentage who agreed with divorce.
  • No change from 2006-2010 to 2011-2013 in attitudes regarding marriage, cohabitation and the risk of divorce.
  • No change in attitudes about the necessity of having children for one’s happiness.
  • No change in attitudes about raising children in a cohabiting union.
  • No change in attitudes about premarital sex for 16 year olds.

Sexual Behavior, Sexual Attraction, and Sexual Orientation Among Adults Aged 18–44 in the United States

January 12, 2016

An NCHS report provides national estimates of sexual behavior, sexual attraction, and sexual orientation among women and men aged 18–44 in the United States, based on the 2011–2013 National Survey of Family Growth.


  • Regarding opposite-sex sexual behavior, 94.2% of women and 92% of men aged 18–44 had ever had vaginal intercourse.
  • 86.2% of women and 87.4% of men had ever had oral sex; and 35.9% of women and 42.3% of men had ever had
    anal sex.
  • Almost three times as many women (17.4%) reported any same-sex contact in their lifetime compared with men (6.2%) aged 18–44.
  • Feelings of attraction “only to the opposite sex” were more common for men (92.1%) compared with women
    (81%) aged 18–44. Among those aged 18–44, 92.3% of women and 95.1% of men said they were “heterosexual or straight”; 1.3% of women and 1.9% of men said they were “homosexual, gay, or lesbian”; 5.5% of women and 2.0% of men said they were bisexual; and 0.9% of women and 1% of men said “don’t know” or “refused” (i.e., “did not report”) on sexual orientation.
  • Sexual attraction and sexual orientation correlate closely but not completely with reports of sexual behavior. Sexual behavior, sexual attraction, and sexual orientation vary by age, marital or cohabiting status, education, and race and Hispanic origin.