Presentation on theme: "Sexually Transmitted And Sexually Related Diseases."— Presentation transcript:
Sexually Transmitted And Sexually Related Diseases
What Are They, And Who Gets Them? Bacteria- Small, single-celled organisms that lack a nuclear membrane, but have all the genetic material (RNA and DNA) to reproduce themselves. Virus- A protein shell around a nucleic acid core. Viruses have either RNA or DNA, but not both, and thus cannot reproduce themselves. They invade host cells that provide the material to manufacture new virus particles.
Venereal diseases- Term originally used to refer to gonorrhea, syphilis, and three other diseases that are spread almost exclusively by sexual contact. Sexually transmitted diseases (STDs)- Diseases that can be, but are not necessarily always transmitted by sexual contact. This term is generally preferred to the term venereal diseases. Today, the description sexually transmitted diseases (STDs) is generally preferred and refers to these diseases plus other infectious diseases that can be, but are not always, transmitted by sexual contact.
Where Did They Come From? AIDS originated in monkeys, but it was probably transmitted to humans by contact with blood, not by sex. Although where and how STDs originated remain unknown, some of these sexually transmitted diseases have been around for at least a few thousand years, as many famous Greeks, Romans, and Egyptians were described as having the symptoms.
1. Discovery of penicillin and other antibiotics made people less fearful about contracting an STD. 2. A large drop between the end of World War II and 1955 in the amount of federal funds available for STD prevention. 3. New sexual freedom from birth control pill. 4. The shift from use of the condom to use of the birth control pill. 5. A lack of education, or just plain ignorance.
Gonorrhea Its symptoms are described in Leviticus in the Old Testament, which dates back to about 1500 B.C., and were also described in detail by Greek physicians. The number of reported cases of gonorrhea declined by 72% from the mid-1970s to the mid- 1990s, but began to rise again in the late 1990s. The rate of infection is considerably higher among African Americans than it is among Latinos or whites and is 6 times more likely among teens aged 15 to 19 than among the general population.
Symptoms and Complications Gonorrhea is caused by a bacterium. It lives on warm, moist mucous membranes in the urethra, vagina, rectum, mouth ad throat, and eyes. A person gets gonorrhea by having his or her mucous membranes come into contact with another person’s infected membranes. A mans risk of infection during intercourse with an infected woman is about 30 to 50%, whereas a woman has about a 50 to 60% chance of catching it the first time she has intercourse with an infected man.
Most women show no symptoms during the early stages. They are often unaware of their infection unless told about it by an infected male partner, and thus can unknowingly pass gonorrhea on to new partners.
Diagnosis and Treatment Most individual with symptoms of gonorrhea will seek treatment immediately. However, many people—particularly women—have no early symptoms. Fortunately, penicillin was discovered around the time of WWII and proved to be highly effective.
Unfortunately, the bacterium developed resistance to penicillin over time. A dosage of 150,000 units was given to people for gonorrhea in the 1940s, but by the 1980s the standard dosage was nearly 5 million units, and there were some strains that could not be destroyed with any dose. Today, most physicians treat gonorrhea with a drug called ceftriaxone. However, in 2000 the Centers for Disease Control and Prevention announced that gonorrhea is becoming resistant to many currently used drugs as well.
Symptoms and Complacations Chlamydia is spread when the infected membranes of one person come into contact with the membranes of another person. If left untreated, chlamydia spreads thought the reproductive system, which in men can cause infection of the prostate and epididymis and possibly sterility. In women the spread of chlamydia can cause pelvic inflammatory disease, which can leave the Fallopian tubes scarred and result in sterility or increased risk of tubal pregnancy.
Diagnosis and Treatment If chlamydia is confirmed, it is usually treated with tetracycline, doxycycline, or erythromycin.
Syphilis Worldwide, there are about 12 million cases of syphilis per year. Most cases are in Southeast Asia and Africa. In the US, the disease last peaked in 1990, when 50,578 cases were reported. In the US, the disease is found mainly in southern states and large urban areas and is 30 to 40 times more common among African Americans than whites.
Symptoms and Complications The spirochete that causes syphilis can also pass directly though any little cut or scrape of the skin into the bloodstreams. If a person has been infected by the spirochete, the first symptoms generally appear 2 to 4 weeks later. If many bacteria are transmitted, the incubation period can be as short as 10 days; but if only a few are transmitted, the sores can take as long as 90 days to appear.
The symptoms of syphilis generally occur in four stages. The primary stage begins with the appearance of a very ugly ulcerlike (raised edges with a crater) sore called a chancre at the site where the spirochete entered the body.
Herpes Before all the attention given to AIDS, herpes was the media’s favorite STD, appearing on the covers of the “Time” and “Newsweek” and even the subject of a feature article in “Rolling Stone” magazine. Herpes (from a Greek word meaning “to creep”) has been around for a long time. It is spread by direct skin-to-skin contact.
Herpes was finally identified as a virus in the 1940s, with two different types of the virus identified in the mid-1960s. They type 1 virus is much more common than type 2, with two thirds of Americans older than 12 infected. Not only can a person with blisters on the mouth transfer the virus to another person’s genitals, and vice versa, but a person with herpes can transfer it by touch to other parts of his or her own body— including the eyes—as well.
Symptoms—Primary Attack Symptoms of the initial herpes attack normally appear about 2 to 20 days after contact with an infected person, with an average of 6 days. The symptoms occur in three stages. In stage one, the prodromal stage, the person feels a tingling, burning, itching, or anesthetic-like sensation on the skin surface where he or she came into contact with the virus.
These symptoms mark the second, or vesicle stage, which can last from 2 to 3 weeks. The first, or primary, herpes attack includes more than just painful blisters, however. The person often has flulike symptoms, suffering muscle aches and pains, headache, fever, and swollen lymph glands. The sores eventually begin to develop scales and form scabs. This is the third, or crusting-over stage. Concomitant bacterial infection of the sore sometimes occurs during this stage, but the lesions eventually heal without leaving scars. The average duration of a primary attack is about 16 days.
Recurrent Attacks About one third of those who have suffered primary herpes symptoms never again have another attack, but he remaining cases are evenly divided between those who suffer occasional attacks and those who suffer regular recurrent attacks. Recurrent attacks are usually less severe than the primary attack and generally last only from 5 to 10 days.
Serious Complications We generally think of herpes blisters as occurring only on the mouth and the genital or anal area, but the blisters may appear on any part of the body. The virus can be spread to the eyes, resulting in herpes keratitis, or ocular herpes. This is the leading cause of blindness resulting from infection in the US today.
Diagnosis and Treatment As yet, there is no cure for herpes. Although there is no known cure for herpes, antiviral drugs are available that relieve symptoms and speed up the healing process during the primary attack.
Hepatitis Hepatitis A (infectious hepatitis) is caused by a small virus that is spread by direct or indirect oral contact with contaminated feces. The Centers for Disease Control and Prevention recommends routine vaccination of children to reduce the prevalence of this disease. Hepatitis B (serum hepatitis) is caused by a different, larger virus and is transmitted by infected blood or body fluids such as saliva, semen, and vaginal secretions.
Hepatitis C, which is caused by still another virus, was not identified as a specific virus until About one-fifth will develop cirrhosis of the liver and/or liver cancer, resulting in about 10,000 deaths a year. The number of deaths is expected to double or triple over the next 10 to 20 years.
Human papillomaviruses infect epithelial cells (the covering of internal and external surfaces of the body). Over 100 different types have been identified, of which about 30 can infect a woman’s cervical mucosa. We can separate clinical HPV cases into three broad categories: (1) those that cause a rare skin condition that appears as reddish plaques, (2) those that cause nongenital warts, and (3) those that cause warts in the genital and anal area. For those people who develop genital (venereal) warts, the first symptoms generally appear anywhere from 3 weeks to 8 months after contact with an infected person. The warts can cause itching, irritation, or bleeding. In men, the warts generally appear on the penis, scrotum, and/or anus, but they can also grow within the urethra.
Women with HPV infections have a greatly increased risk of developing cervical and/or vulvar cancer. In fact, nearly all women with cervical cancer are found to have HPV infections. The latency period between infection with HPV and detection of cancer is 5 to 25 years. About 15 kinds of human papillomaviruses are found in cervical cancers, most commonly HPV 31, HPV 33, HPV 45, HPV 18, and in particular, HPV 16.
Hiv Infection And Aids More and more cases of depressed immune systems began to appear, but it was not until 1982 that the new disease was given a a name: acquired immundodeficiency syndrome (AIDS). It was not until 1984 that the cause of AIDS was identified as a virus, named human immunodeficiency virus, or HIV. To date, researchers have identified 11 major HIV-1 subtypes (classified as group M subtypes A, B, C, D, F, G, H, K and at least 11 recombinat forms) and two very aberrant subtypes (groups N and O).
HIV and the Body’s Immune System The immune system is that part of your body that defends against bacteria, viruses, fungi, and cancerous cells. White blood cells, or lymphocytes, are the main line of defense in this system.
This is called primary HIV infection and can last for several weeks. A normal, healthy person has between 1,000 and 1,200 CD4+ cells per cubic millimeter of blood. Infected persons generally start to show symptoms of a weakened immune system when their CD4+ cell count falls below 500 per cubic millimeter of blood. HIV infection is not called AIDS until it has become life-threatening. As the CD4+ cell count approaches 200 per cubic millimeter of blood, infected person’s immune systems have become so weakened that they fall prey to what are referred to as opportunistic infections.
Several studies have shown that the best single predictor for progression to AIDS is not an individual’s CD4+ cell count but his or her plasma HIV RNA levels, which show the amount of virus in the blood. This is called the viral load. The higher the viral load, the sooner the person will develop AIDS. Without medication, the survival time is only about 1 year. However, new drug therapies have allowed many HIV and AIDS patients to live longer, productive lives.
How is HIV Spread? There is no need for panic—HIV is not spread by casual contact. There are three main ways in which HIV is transmitted: (1) sexual contact with an infected person; (2) exposure to infected blood (mainly needle sharing among intravenous drug users); and (3) mother-to-infant transmission.
Who Has HIV/AIDS? Currently, worldwide there are about 14,000 new infections a day and about 34 to 46 million people currently living with HIV. At present, 90% of persons infected with HIV live in developing countries. More than two-thirds of the world’s cases are in sub-Saharan Africa, where HIV originated; countries such as Uganda, Zambia, and Rwanda have been devastated. The UN expects that China will have 10 million HIV-infected people by 2010.
India is another country where HIV has reached epidemic proportions. In fact, while Africa is bearing the burden of the epidemic now, experts believe that because of the dense populations and sexual practices, Southeast Asia and the Indian subcontinent will be hit the hardest during this century.
Testing for HIV The standard tests for HIV do not test for the virus directly, but instead detect antibodies to the virus that are produced by an infected person’s immune system.
Many drugs have been approved for treating patients with HIV. One group of antiretroviral drugs is technically called nucleoside reverse transcriptase inhibitors. They slow the progression of HIV infection by blocking an essential enzyme needed for the virus to replicate itself. A second group is called non-nucleoside reverse transcriptase inhibitors. These drugs block the same enzymes as the nucleoside drugs, but in a different manner. Protease inhibitors block an enzyme called protease that is critical to the last stages of HIV replication.
A newer drug, nevirapine, reduces the transmission rate even further, and a transmission rate of less than 2% can be achieved if the mother uses the HIV drugs and has a cesarean delivery. Nevirapine is so cheap compared to AZT and other drugs that is hoped it can be used effectively in Africa. Because of these successes, the Centers for Disease Control and Prevention has recommended that all pregnant women be tested for HIV.
The most exciting advance in the treatment of HIV has been use of a drug “cocktail”—the use of several drugs in combination. This is commonly called highly active antiretroviral therapy (HAART). As a result of this new combination drug therapy, deaths from AIDS in the US have dropped dramatically since 1996.
First, it will be difficult to develop a vaccine that is effective against all the different genetic subtypes of HIV. Second, because the virus continues to mutate, a vaccine developed today may become ineffective over time. The best hope presently is that one of the vaccines undergoing testing might prove to be 85% accurate.