Sexually Transmitted Diseases and Infections (STDs and STIs) and HIV/AIDS Research
The NICHD funds and conducts research on many STDs and STIs and on how they affect women. A large portion of this research examines the impact of HIV/AIDS in female populations. Through these research efforts, the NICHD has made great progress in understanding these diseases and the unique needs of the women who have them.
General Information about STDs and STIs
STDs and STIs are diseases that you get by having intimate sexual contact, including having sex (vaginal, oral, or anal intercourse) with someone who already has the disease. Every year, STDs affect more than 13 million people.
Researchers have identified more than 20 different kinds of STDs, which can fall into two main groups:
STDs caused by bacteria--These diseases can be treated and often cured with antibiotics. Some bacterial STDs include: chlamydia, gonorrhea, trichomoniasis, and syphilis.
STDs caused by viruses--These diseases can be controlled, but not cured. If you get a viral STD, you will always have it. Some viral STDs include: HIV/AIDS, genital herpes, genital warts, human papilloma virus (HPV), hepatitis B virus, and cytomegalovirus.
The best way to deal with STDs is to avoid getting one in the first place. The only way to ensure that you won't get infected is to not have sex. This means avoiding all types of intimate sexual contact.
If you are sexually active, you can reduce your risk of getting STDs by practicing "safe sex." This means:
Using a condom and an approved microbicide for vaginal, oral, and anal intercourse
Knowing your partner and his/her STD status and health
Having regular medical check-ups, especially if you have more than one sexual partner
You can find out more about STDs, their symptoms, and their treatments by contacting the
, supported by the Centers for Disease Control and Prevention (CDC). You can also call the Hotline at 1-800-227-8922. The CDC also supports the
, which offers information on STDs.
(Above text adapted from
, DHHS, 1999.)
NICHD Research on STDs and STIs
The NICHD focuses a great deal of its research on preventing STDs through methods that reduce risky behaviors, which are actions that can lead to the spread of STDs, in various populations. For instance, through its Demographic and Behavioral Sciences Branch (DBSB), the NICHD has supported the
since the early 1990s. The Add Health Study strives to understand the factors influence health and health-related behaviors, including sexual activity and STD prevention, among adolescents. The Institute has also created several intervention programs that strive to understand the things that influence teens' decisions in regard to behaviors that may put them at risk for STDs, including HIV. Among these programs is the NICHD-sponsored
for HIV/AIDS interventions, which conducts research, often in collaboration with other networks, on different ways to prevent HIV transmission among at-risk adolescents and on treatment for HIV-infected youth.
The Institute also conducts research on trends related to risky behaviors. For instance, some NICHD research revealed that teens who are infected with HIV/AIDS are more likely to also have another STD, such as gonorrhea. In one study, 77 percent of HIV-positive women also had HPV, and 15 percent of HIV-positive females also had hepatitis B virus. The NICHD currently co-funds the
, the largest and longest ongoing study of HIV-infected women. WIHS data are providing a great deal of information about STDs and the nature of risky sexual behaviors in this population.
Since 1987, the Institute has supported research and training activities that have helped to establish and define the field of contraceptive microbicides, products meant to prevent pregnancy and the transmission of STDs, including HIV. The NICHD's Contraceptive and Reproductive Health Branch oversees much of this research, including managing the Contraceptive Clinical Trials Network. Contraceptive Microbicide Research and Development: A Vision for the Future is a scientific report that summarizes the many projects and accomplishments of this research program.
In addition, the
and the NICHD jointly sponsor a series of program projects on microbicide development. This series currently involves more than 200 investigators, in national and international settings, who are working on different approaches to preventing the spread of HIV using new or different compounds.
NICHD-supported researchers are also trying to understand the best ways to communicate with people about STDs and preventing STDs. Some of this research includes studying attitudes, perception, and knowledge of STDs and how to prevent them; understanding the use, misuse, and misinformation that surround contraception as a way to prevent STDs; and identifying the best settings for providing STD and prevention information.
Clinical Trials on STDs and STIs
Preventing and treating STDs is a major research aim for the NIH. The
is the main NIH Institute conducting and supporting such research. The NIAID is currently conducting a number of
, both as the sole sponsor and in conjunction with other NIH Institutes.
The NICHD also supports basic and social science studies, as well as studies of interventions that focus on preventing STD and HIV infection, including:
Developing network models, mathematical models of interpersonal relationships, to learn more about the characteristics of diseases spread through intimate sexual contact
Creating and improving methods for tracing sexual contacts and notifying partners of STD/HIV infection
Understanding the factors that influence the consistent and correct use of: condoms for preventing STDs; microbicides to prevent HIV; and dual-use methods of contraception, which involve using one form of highly effective contraception (such as oral contraceptives) and condoms at the same time, to prevent pregnancy
Factoring the effects of relationship dynamics, cultural and gender norms, and other social standards on managing HIV risk
The DBSB, within the NICHD Center for Population Research manages much of this research, both nationally and internationally. For example, the Branch is coordinating eight research grants, collectively called Partnerships for HIV/AIDS Research in African Populations. These projects pair organizations in the United States and Africa to build local research resources, train new researchers, and conduct preliminary studies on behavioral and social aspects of HIV prevention and care.
Research on HIV/AIDS in Female Populations
Overview of HIV/AIDS in Women
According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), 19.2 million women are living with HIV/AIDS throughout the world. In many countries, the rate of HIV infection in women is rising faster than in any other group. At the end of 2002, women made up 58 percent of the total number of people living with HIV in sub-Saharan Africa, where more than 70 percent of all the HIV-infected persons in the world live. And, in the world's countries that have been hardest-hit by HIV/AIDS, young women ages 15 to 24 were up to three times more likely to be HIV infected than young men of the same age.
Worldwide, more than 80 percent of HIV infections are spread by heterosexual sex (vaginal intercourse); women are particularly at risk of contracting HIV through this type of contact.
In the United States, for the year 2001, 26 percent of those diagnosed with AIDS (the most advanced stage of HIV infection) were women. In 1986, women made up only 7 percent of those diagnosed with AIDS. Among those diagnosed with HIV infection in 2001, women made up 32 percent of the total. And, among adolescents ages 13 to 19 in the United States, nearly 50 percent of new HIV infections are among young women.
The most dramatic increases in the epidemic have occurred among women of color. More than 77 percent of the AIDS cases reported to date in women in the United States occur in African American and Hispanic women, even though these groups, combined, represent less than one-fourth of all the women in this country.
Treatment advances have improved the survival rates and decreased progression of HIV disease for women and men with HIV infection and AIDS in developed countries like the United States, where antiretroviral drugs are available. The NICHD and other governmental and non-governmental organizations, are exploring ways to improve the availability of treatment in areas where it is currently not available or not reliably available.
However, women have complex family issues and multiple life problems that they often put before their own HIV treatment. Because women are often the primary caregivers for the family, HIV infection and its associated problems affect not only the lives of women infected with HIV, but also the lives of their children and other family members, some of whom might also be infected with HIV. HIV-infected women may be poor, may lack social support, and may have difficulty accessing health care, which makes helping these women deal with societal pressures, as well as caring for those who are HIV positive more complex.
NICHD Research on HIV/AIDS in Female Populations
Women-focused research forms an important component of the HIV/AIDS research funded by the NICHD. Although most of the signs and symptoms of HIV infection are similar in men and women, some are more female-specific. For example:
Vaginal yeast infections may be chronic, more severe, and difficult to treat in women with HIV infection than in women who are uninfected.
Pelvic inflammatory disease, an infection of the female reproductive organs, may also be more frequent and severe in women with HIV infection.
Human papillomavirus (HPV) infections, which cause genital warts, may occur more frequently in HIV-infected women, and can lead to pre-cancerous lesions of the
(called cervical dysplasia, pronounced diss-PLAY-see-uh), or cancer of the cervix.
Societal norms and gender inequities may multiply a woman's risk of exposure to HIV. In some cultures, women are less likely to be able to control their sexual activity or to insist upon protection from disease.
The NICHD, along with other Institutes, supports studies to determine what aspects of HIV are specific to women and how to best treat these factors. Some of this research includes the following studies:
. This study, which is co-sponsored by the NICHD and four other NIH Institutes, is the largest and longest ongoing study of HIV-infected women. The NICHD's Pediatric, Adolescent, and Maternal AIDS (PAMA) Branch has been funding one of the six clinical sites for the WIHS since 1993. WIHS has enrolled more than 2,700 HIV-infected women and about 1,000 uninfected women. This study is trying to understand the unique ways HIV/AIDS affects women, the ways successful treatments for HIV/AIDS affect women, the relationship between HIV/AIDS and other diseases, such as hepatitis C virus infection, and the impact of hormonal factors on HIV disease. Most of the women enrolled in WIHS are women of color. Examples of WIHS research findings include:
As women infected with HIV have increased their use of a combination treatment, called highly active antiretroviral therapy (HAART), WIHS researchers have seen a decrease in development of AIDS, and in the number of deaths. This research showed that the treatment benefits seen in HIV-infected, mostly white men, also occur in a mostly minority and disadvantaged group of HIV-infected women.
WIHS researchers found that initial levels of the HIV virus in women's blood tended to be lower than levels in the blood of infected men. But, the study showed no real difference between women and men in the development of AIDS.
WIHS researchers found that levels of HIV in the genital tracts (which includes the vagina and the cervix) of infected women vary over the course of the menstrual cycle. These changes were not seen in the blood of these women. The highest viral levels in the genital tract were found during menses; the lowest levels were found immediately thereafter. These findings suggest that female hormones may influence how HIV multiplies in the female genital tract.
. This study, which is co-sponsored by the NICHD's PAMA Branch, ongoing since 1988, is one of the longest study of HIV-infected pregnant women and their children in the United States to date. As of 2002, six sites in the United States and Puerto Rico had enrolled 2,872 women, and 2,396 infants born to these women into the study. The results from this study will help health care providers figure out if the course of HIV/AIDS is different in pregnant women, and, if so, why. The study will also examine the relationship between HIV and other diseases, such as hepatitis C infection, in pregnant women; the long-term effects of antiretroviral therapy on pregnant women and their infants; effects of following treatment regimens and developing resistance to treatment drugs on the risk of mother-to-child transmission; and factors that may lead to higher rates of transmission. Examples of WITS research findings include:
WITS researchers found that pregnancy was not associated with an increase in progression of HIV disease.
WITS researchers showed that using antiretroviral drugs during pregnancy was not associated with an increased risk of drug toxicity in the woman, or of problems with her pregnancy.
Researchers showed that women infected with both HIV and hepatitis C had a higher rate of mother-to-child transmission of HIV than women infected only with HIV.
Researchers from WITS demonstrated that the level of HIV in the blood and in the genital tract were associated with risk of mother-to-child transmission.
Women's HIV Interdisciplinary Network (WHIN). This group of multidisciplinary studies focuses on understanding the unique biological differences between HIV/AIDS in women versus men. The studies are fully funded by the NICHD, through its Contraception and Reproductive Health Branch. For more information, read the Institute's news release about the WHIN.
Reducing Mother-to-Child Transmission of HIV
Mother-to-child HIV transmission is the major source of HIV infection in children. Without any type of intervention, mother-to-child transmission rates range from 15 percent to 30 percent (without breastfeeding), and can reach 30 percent to 45 percent if a woman breastfeeds for a long time. Studies have shown that mother-to-child transmission can occur:
During pregnancy and delivery. But, many researchers believe that most of the transmission during this time occurs in late pregnancy and during the birth process.
From a mother to her breastfeeding child.
Much of the NICHD's research efforts in HIV/AIDS focus on developing ways to prevent HIV transmission, both through medical interventions with pregnant women, and by helping women avoid pregnancy. Through its research, the NICHD has helped make great progress in reducing the spread of HIV in these situations. In the United States, these rates dropped from 25 percent to under 2 percent as a result of discoveries made by NICHD researchers and their colleagues in medical and academic communities, and through the work of other NIH Institutes.
Reducing Transmission during Pregnancy and Delivery
Research conducted by NICHD researchers found that the risk of mother-to-child HIV transmission is higher in pregnant HIV-infected women who had: high amounts of the HIV virus in their blood, low levels of a specific type of immune cell (the CD4 lymphocyte, which is the target for HIV infection), or advanced HIV disease. This research suggested that treating infected pregnant women with antiretroviral drugs that could lower viral levels, improve immune status, and reduce progression of HIV disease, might also reduce mother-to-child HIV transmission.
In 1994, a landmark study conducted by NICHD- and NIAID-funded researchers in the
showed that giving a specific regimen of zidovudine (AZT) to an HIV-infected pregnant woman during pregnancy and delivery, as well as to her infant for six weeks after birth reduced transmission from 25 percent to 8 percent.
Later studies conducted by NICHD researchers and their colleagues showed that, when HIV-infected women received combination antiretroviral therapy, particularly HAART, during pregnancy, transmission could fall to as low as 1 percent. Further studies have shown that the use of HAART was not associated with an increase in birth complications, such as premature delivery; thus the benefits of taking HAART during pregnancy are greater than the risks.
Events that occur during labor can also affect the rate of mother-to-child HIV transmission during the birth process. NICHD-supported researchers found that HIV-infected women whose labor moved slowly, that is, there was a long time between when their membranes ruptured (sometimes referred to as when a woman's "water breaks") and when they delivered their babies, were more likely to transmit HIV to their infants. Building on these findings, researchers found that elective cesarean section, a surgical way to deliver a baby, cut transmission rates in half when the surgery was done before the woman's water broke and before she went into labor. Elective cesarean delivery also reduced transmission among women receiving AZT.
Based on these studies and on other research conducted by the NICHD and colleagues, the
for all HIV-infected women whose blood viral levels are above 1,000 copies/mL.
Women with very low viral levels, such as those on HAART, have a very low rate of transmission to their infants. For this reason, the risks of a surgical delivery may outweigh the small benefits of elective cesarean delivery in reducing mother-to-child transmission in these women.
NICHD-supported researchers and their colleagues are working to uncover whether shorter, cheaper, and more practical antiretroviral treatments can reduce transmission, so that women in developing countries might benefit from treatment advances. Research has identified several different treatments, of a shorter duration, that can reduce transmission. These shorter treatments are now being used in many developing countries.
Visit the UNAIDS Web site for more
; or visit the World Health Organization (WHO) for more
.
Reducing Transmission from a Mother to Her Breastfeeding Infant
In most cases breastfeeding is good for both mother and baby. The benefits of breastfeeding include protecting the infant against common childhood diseases, such as diarrhea and respiratory infections, and lowering the risk of infant death by decreasing infections and providing the best possible nutrition to the infant. Breastfeeding also offers emotional and psychosocial benefits to the infant and the mother. According to the
, women who don't have certain health problems, such as HIV, should exclusively breastfeed their infants for at least the first six months of life.
But, for women who are infected with HIV, breastfeeding can transmit HIV to the infection. In its
, AAP recommends that, in countries like the United States, where infant formula is safe and is often available and affordable, HIV-infected women should feed their infants commercially available formula instead of breastfeeding.
However, on a global basis, the choice between breastfeeding and infant formula is more difficult. In many developing countries, HIV-infected mothers can't afford infant formula. In other cases, infant formula may not be reliably available, or clean water for mixing formula safely is not available. Even if infant formula is available, not breastfeeding may leave many infants in developing countries at greater risk for digestive problems and infections that can be fatal. And, in areas where there is a stigma associated with being HIV positive, feeding infant formula may be viewed as a signal that a mother is infected, which can lead to societal problems for the family. So these women face a tough choice.
Currently, the UNAIDS recommends that HIV-infected women in developing countries be educated and counseled so they can make an informed choice about how best to feed their children, and that when feeding infant formula is not available, affordable, acceptable or safe, women should exclusively breastfeed their infant for the first three to six months of life. For more information, read the
.
NICHD researchers have been working to understand the risks and benefits of breastfeeding and infant formula use in developing country settings. In one study, breastfeeding nearly doubled the rate of HIV transmission in an area of Nairobi, Kenya, where clean water was available and infant formula was provided free of charge as part of the study. Most transmissions occurred during the first six months of the baby's life. The breastfed infants were better off nutritionally than the formula-fed infants during the first six months of life, but the number of infants affected by diarrhea, pneumonia, and other diseases, and the number of deaths among these infants were similar for both groups.
The study also showed that death rates were higher among women who breastfed, which may mean that the breastfeeding process takes a high toll on an HIV-infected woman. These findings suggest that, for HIV-infected mothers in certain settings (such as those in developing countries where formula is provided free and clean water is available), feeding infant formula instead of breastfeeding may be better for both the baby and the mother.
But, these results may not apply to many areas of the developing world. For this reason, NICHD-sponsored research is underway to identify effective ways to reduce the risk of mother-to-child HIV transmission through breastfeeding in these other areas. NICHD researchers have identified factors that can increase the risk of HIV transmission through breast milk, including levels of HIV in the blood, levels of HIV in the breast milk, the presence of infection and inflammation of the mother's breast (called mastitis, pronounced mass-TIGHT-iss), and the presence of infections or lesions in the mouth of the breastfeeding infant.
Research sponsored by the NICHD and other Institutes is evaluating ways to prevent HIV transmission through breastfeeding for women who cannot safely feed their infants formula. For example, NICHD-sponsored efforts are underway to learn about weaning an infant safely, but earlier; giving antiretroviral drugs to breastfeeding infants or to their mothers during the period of breastfeeding; sterilizing breast milk; and possibly using HIV-preventive vaccines in the breastfeeding infant. As part of this effort, the NICHD is involved in a unique collaboration with the CDC to conduct two clinical trials on breast milk and HIV transmission.
HIV/AIDS Clinical Trials and Other Resources
The NIH is currently conducting many
.
These trials are sponsored and co-sponsored by various Institutes, including the NICHD. For information on the sponsoring Institute(s), please read the description for a specific clinical trial.
The
conducts clinical trials in children and HIV-infected pregnant women in collaboration with the NIAID-sponsored PACTG. Many sites in the NICHD Network also help enroll women into clinical trials to evaluate the treatment of female-specific HIV problems, in collaboration with the
.
The NICHD-sponsored
conducts research, often in collaboration with other networks, on various interventions to treat HIV infection and its complications in adolescents, ages 12 to 24, and interventions to prevent HIV transmission among at-risk adolescents.
The
is an international collaborative group, funded by the NIAID, with co-funding from the NICHD and other NIH Institutes that conducts clinical trials related to the prevention of HIV infection. The NICHD specifically co-funds studies that examine ways to prevent mother-to-child transmission of HIV during pregnancy, birth, and after birth; investigate the effectiveness and safety of microbicides in preventing the transmission of HIV through sexual contact; and develop ways to change behavior that may lead to the spread of HIV through sexual contact.
If you are HIV-positive, on antiretroviral therapy, and are currently pregnant, you can talk to your health care provider about being part of the
. The purpose of this registry is to identify whether any of the antiretroviral therapies taken during pregnancy increase the risk of birth defects. If you enroll in the registry, your health care provider will report on the progress of your pregnancy to the registry after your prenatal appointments. Talk to your health care provider for more information.
In addition,
, a project of the
, is the main source of information on federally approved treatment regimens and prevention guidelines for HIV infection and AIDS-related illnesses, including prevention of HIV transmission from job exposure, and from mother-to-child during pregnancy. Additionally, the AIDSinfo has a help line, at 1-800-HIV-0440 (1-800-448-0440); 301-519-0459 (International); 1-888-480-3739 (TY/TDD). This resource, open from 12:00 p.m. to 5:00 p.m. Eastern Time, Monday through Friday, is staffed by Health Information Specialists, who offer confidential responses to questions and assistance with navigating the Web site. Spanish-speaking specialists are also available. The
at the CDC also has patient information on these topics.
Please note that the resources above offer information about HIV/AIDS in all populations, not just in female populations.
For information specifically related to pregnancy and HIV/AIDS, you may find the following resources helpful:
UNAIDS provides information on
and links to other international organizations and resources.
The World Health Organization (WHO), in conjunction with UNAIDS and dozens of international contributors, maintains the
Web site. This site also provides information and links to other Web sites about HIV/AIDS.
The United Nations Population Fund hosts a Web site about
and promoting global reproductive health.
The
is a non-profit organization that serves professionals who care for children, adolescents, and families with HIV infection and AIDS. Its Web site includes information about prevention of mother-to-child HIV transmission.
The
is a national non-profit organization dedicated exclusively to supporting research for AIDS in children, and on the prevention of mother-to-child HIV transmission.
As members of the American Academy of Pediatrics Committee on Pediatric AIDS, NICHD staff wrote a committee report on the prevention of prenatal HIV transmission. This report was published in Pediatrics and is available at
. Please note that this report was intended for health care providers and contains medical terminology and scientific language.
The
program is a research project that provides access to antiretroviral drugs and other treatment to HIV-infected women, who are first diagnosed with HIV during pregnancy, as well as to their children and families. This project is led by the Mailman School of Public Health at Columbia University.
