HSC4711 Exam 3 Study Guide- Sexually Transmitted Diseases: diseases that can be transmitted by sexual contact, and some can also be transmitted by other meanso a person can be infected and able to transmit the disease, but not feel sick or show any symptomso can also be called Sexually Transmitted Infections for this reason STIs can be curedo STDs that pose a major health threat HIV/AIDS Hepatitis Gonorrhea Syphilis Chlamydia Herpes Human Papillomavirus (HPV)o these diseases are serious in themselves, cause serious complications if left untreated, and pose risks to a fetus or newborn o long-term co0nsequences chronic infertility stillbirths genital cancers deatho US has highest rate of STDs in all developed countrieso half of all young people will acquire an STD by age 25o 65 million Americans infected with an STDo 19 million Americans newly infected each year- HIV/AIDSo HIV (human immunodeficiency virus): causes HIV infection and AIDSo AIDS (acquired immunodeficiency syndrome): disease that ultimately kills most victims, especially in parts of world where treatment is not available  incurableo 65 million people infected since epidemic began (~1% world population), and tens of millions ofthose people have died alreadyo today, 33 million infected worldwide, and most of these people will die within 10 yearso disease peaked in late 1990so AIDS remains primary cause of death in Africa and continues to be a major cause of mortality worldwideo AIDS is leading cause of death worldwide for people 15-59o 1.1 million people in US have been infected with HIV and 56,000 new HIV infections reported in 2006o 550,000 Americans died from AIDS since start of epidemic in 1981, but death rate among Americans has declined; estimated 3 million infections per yearo 21-25% of infected people are unaware of their conditiono HIV Infection: chronic, progressive viral infection that damages the immune system makes an otherwise healthy person less able to resist variety of infections/disorders HIV attacks immune system, invading monocytes, macrophages, and CD4 T cells (type of white blood cell that helps coordinate activity of immune system; frontline of immune system; “helper” T-cells; primary target for HIV infection; travels in blood and lymph) HIV enters human cell and converts its own genetic material (RNA) into DNA, which is then inserted into chromosomes of host cells; viral DNA takes over CD4 cell, causing it to make new copies of HIV, as well as making the CD4 cell incapable of performing its immune functions eventually, the immune isn’t able to make enough new cells to keep up with the rapidly growing infected cells immune system destruction is signaled by loss of CD4 T cells as CD4 cells decline, a person may notice mild to moderately severe symptoms full-blown AIDS: when a person develops one of the conditions defined as a marker for AIDS or when number of CD4 T cells in blood drops below 200/µl HIV causes AIDS after an average of about 11 years people with AIDS vulnerable to serious opportunistic (secondary) infections: infectioncaused when organisms take opportunity presented by a primary (initial) infection to multiply and cause a new, different infection; TB, pneumonia  stages of infection: primary infection phase: first weeks after being infected; large amounts of HIV in blood stream, making them incredibly infections; flulike symptoms  asymptomatic (symptom-free): chronic; can last from 2-20 years (average is 11); virus progressively infects and destroys cells of immune systemo HIV is transmitted by blood, blood products, semen, vaginal secretions, cervical secretions, and breast milk lives only within cells and body fluids, not outside body can’t live in air, water, or on surfaces/objects (toilet seats, eating utensils, telephones) three main routes of transmission:  specific kinds of sexual contact direct exposure to infected blood (sharing needles, piercings)  HVI-infected woman to her fetus during pregnancy or childbirth, or to her infant during breastfeeding  more likely to be transmitted by unprotected anal or vaginal intercourse  male to female transmission more likely because female has much more surface area of mucous membranes and higher chance of tear or lesion transmission can also happen before ejaculation, because HIV has been found in preejaculatory fluid being receptive partner in unprotected anal sex is extremely risky oral-genital contact carries some risk, but less than anal or vaginal intercourse presence of lesions, blisters, or inflammation from other STDs in genital, anal, or oral areas increase likeliness for transmission 2-9 times  spermicides may also increase risk of HIV transmission risk of transmission increases during oral sex if: poor dental hygiene, oral sores, brushed/flossed before or after oral sex circumcised males have lower risk than uncircumcised males nearly 20% of all new US cases of HIV caused, indirectly or directly, by sharing drug injection equipment contaminated with HIV also transmitted in blood and blood products used in medical treatment of injuries and illnesses  14,000 cases of AIDS in US mother-to-child transmission is called vertical, or perinatal, transmission  25-30% of infants born to untreated HIV-infected mothers are also infected with viruso Populations of special concern for HIV infection most common means of HIV exposure is sexual activity between men next most common are heterosexual contact and injection drug use (IDU)  high rates of infection in certain groups tied to social, cultural, and economic factors 75% of HIV positive Americans are men, 25% women increasingly becoming a disease that affects ethnic minorities, women, and the poor African American men and women are vastly overrepresented among people newly diagnosed with AIDS also, men who have sex with men are at large risk young gay men less likely than older gay men to have experienced watching friends die from AIDS, and so are more removed from reality of disease young men may be less afraid of acquiring HIV because of advances in treatment and a false belief that cure is just around the corner men who have sex with men but still identify themselves as heterosexual just as likely to be infected with HIV, but much less likely to know HIV status and more likely to transmit it to