Of the approximately 33 million people worldwide infected with HIV, more than half are women. In sub-Saharan Africa, women account for a striking 60 percent of HIV cases. The World Health Organization reported in 2009 that HIV/AIDS is the leading cause of death globally among women of reproductive age. The Centers for Disease Control and Prevention (CDC) reports that women accounted for 25 percent of all HIV cases in the United States in 2006.
Biologically, women are more vulnerable than men to HIV infection from heterosexual intercourse because of their substantial mucosal exposure to seminal fluids. Women's risk is increased by other factors, such as non-consensual sex, sex without condoms, and the unknown or high-risk behaviors of their partners—all of which, in many parts of the world, are out of a woman’s control.
Once infected with HIV, women can face obstacles in seeking and getting treatment. Frequently, they have difficulty accessing health care. They often lack social support and face other challenges that may impede their ability to stick to treatment, such as caring for children or other family members stricken with HIV/AIDS. If they do follow through with treatment, studies have shown that women differ from men in the way they metabolize drugs, which could result in unexpected responses to antiretroviral therapy and an increase in adverse reactions to the drugs.
Women also suffer gender-specific consequences of HIV, including recurrent vaginal yeast infections, pelvic inflammatory disease (PID), genital ulcer disease, severe herpes infections, abnormalities related to infection with human papillomavirus (HPV), and vulvar and vaginal carcinomas.
STDs, such as HPV, trichomoniasis, genital herpes, and chlamydia, disproportionately affect women and infants globally and can increase the risk of HIV infection. CDC reported in 2009 that about 19 million new STDs occur in the United States each year at a cost of nearly $16.4 billion, with a particular burden of diseases on women.
In addition to being at higher risk than men of transmitting some STDs, women face particular health challenges as a result of contracting an STD. Women face infertility, cancer, and chronic conditions like PID, especially when STDs go untreated. They also risk passing on the infection during pregnancy or breastfeeding.
Autoimmune diseases are a group of more than 80 chronic and often disabling illnesses that develop when underlying defects in the immune system lead the body to attack its own organs, tissues, and cells. They affect approximately 8 percent of the U.S. population, but nearly 80 percent of those affected are women. They are among the leading causes of death for young and middle-aged women.
Learn how NIAID works to prevent, diagnose, and treat infectious and autoimmune diseases that disproportionately affect women.
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Last Updated June 14, 2012
Last Reviewed June 14, 2012