Presentation on theme: "HIV & AIDS RCS 6080 10/24/06. Some Terms Virus: Any large group of submicroscopic agents capable of infecting plants, animals and bacteria. They are characterized."— Presentation transcript:
HIV & AIDS RCS /24/06
Some Terms Virus: Any large group of submicroscopic agents capable of infecting plants, animals and bacteria. They are characterized by a total dependence on living cells for reproduction and by a lack of independent metabolism. HIV: Human Immunodeficiency Virus. AIDS: Acquired Immune Deficiency Syndrome
More Terms Antibody: A protein (immunoglobulin) that is secreted and produced by B lymphocytes when it finds an antigen. Antibodies can bind to and, in turn, destroy certain antigens. When you test positive for HIV, they are actually testing for antibodies. Antigen: A substance that is recognized as foreign by the immune system. Antigens are either whole microorganisms, or they can be a portion of an organism or virus. See the handout for a more complete glossary of AID related terms
History AIDS was first recognized a new disease in First report in the medical literature was concerning 5 young, homosexual men living in the Los Angeles area that had Pneumocystis carinii pneumonia and Kaposi's sarcoma. A few weeks later there was a report from San Francisco and New York about 26 young homosexual men with the same conditions. This was followed by reports of individuals who had injected drugs with similar conditions. All of these individuals had profound immunodeficiency suggesting a depletion of CD4-positive, or T-helper, lymphocytes.
History continued With the prominence of homosexual men and intravenous drug users in the early cases it was originally speculated that these individuals became immunosuppresed because of a history of drug use or because of multiple sexually transmitted diseases. HIV was 1 st identified in a lab in France. Strong evidence did not show up until 1984 when 4 papers were published in one issue of Science. Several variants of the HIV were discovered during this time.
Transmission HIV does not survive well in the environment. HIV is found in varying concentrations or amounts in blood, semen, vaginal fluid, breast milk, saliva, and tears. There have been rare occurrences of transmission between family members in households: usually resulting from contact between skin or mucous membranes and infected blood.
Some Recommended Precautions (from the CDC) for health professionals and care givers Gloves should be worn during contact with blood or other body fluids that could possibly contain visible blood, such as urine, feces, or vomit. Cuts, sores, or breaks on both the care giver’s and patient’s exposed skin should be covered with bandages. Hands and other parts of the body should be washed immediately after contact with blood or other body fluids, and surfaces soiled with blood should be disinfected appropriately. Practices that increase the likelihood of blood contact, such as sharing of razors and toothbrushes, should be avoided. Needles and other sharp instruments should be used only when medically necessary and handled according to recommendations for health-care settings. (Do not put caps back on needles by hand or remove needles from syringes. Dispose of needles in puncture-proof containers out of the reach of children and visitors.)
Other environments CDC has only found one case of HIV transmission from open mouth kissing HIV might be able to be transmitted by biting due to trauma and blood interaction Contact with saliva, tears, or sweat has never been shown to result in transmission of HIV. Studies conducted by researchers at CDC and elsewhere have shown no evidence of HIV transmission through insects--even in areas where there are many cases of AIDS and large populations of insects such as mosquitoes.
Condom use Numerous studies among sexually active people have demonstrated that a properly used latex condom provides a high degree of protection against a variety of sexually transmitted diseases, including HIV infection.
Acute Retroviral Syndrome Not all become acutely ill Flu-like illness Very contagious
HIV Antibodies Develop after infection (varies) Seropositive (Enzyme immunoassay followed by Western Blot or other tests Clinic or home testing Lymph node biopsy Antigen detection (viral load)
Immunodeficiency Begins immediately after infection Kills CD4+ T-lymphocyte cells Category 1 >500 cells Category cells Category 3 <200 cells CD8 lymphocytes attack HIV Triple drug therapy makes a difference!!!!
Asymptomatic HIV Infection Herpes zoster (“shingles”) Goal of antiretrovial therapy is to reduce viral load to undetectable
Early HIV Category A: lymph node swelling, acute infection Category B: Candidiasis (oral or vaginal), peripheral neuropathy, herpes zoster, fatigue, low energy Catergory C: 23 qualifying infections e.g. pneumocystis carinni (pneumonia) or kaposi’s sarcoma
Conditions Associated with AIDS 27 clinical conditions can be used in diagnosing AIDS along with HIV + status Include the presence of “opportunistic infections” that take advantage of weakened immune system Also include cancer, clinical conditions, and other infections
Conditions Associated with AIDS Opportunistic infections: Often caused by common bacteria present in healthy people; immune suppression makes people with AIDS vulnerable Pneumocystis carinii pneumonia (PCP) Common organism multiplies in lungs Fluid accumulates (pneumonia) Mycobacterium avium intracellulare Most common tuberculosis in people with AIDS, may affect many organs Resistant to most antibiotics
Conditions Associated with AIDS Mycobacterium tuberculosis Occurs in lungs Infectious, but treatable with antibiotics Bacterial pneumonia Caused by several common bacteria Patient may have many episodes Toxoplasmosis Disease of brain and central nervous system (spinal cord) Caused by parasite found in cat feces
Conditions Associated with AIDS Cancers: Kaposi’s sarcoma Cancer of the blood vessels Red/purple splotches under skin Lymphomas Cancer of the lymphatic system/brain Invasive cervical cancer Can lead to uterine cancer if untreated
Clinical Conditions Associated with AIDS Wasting syndrome severe weight loss, with weakness and diarrhea HIV encephalopathy/ AIDS dementia Direct infection of the brain Impairment of mental functioning, changes in mood Other infections Candidiasis or “Thrush”: yeast infection of mouth Herpes simplex: persistent lesions of mouth, lungs, esophagus Cytomegalovirus: infects brain, retina, lungs
Symptoms of HIV Infection and AIDS Unexplained persistent fatigue Fever, chills, night sweats Unexplained weight loss Swollen lymph nodes Pink, red, purple, or brown blotches Persistent dry cough Persistent, fuzzy, white spots in mouth, tongue, or throat Memory loss or depression Abnormal pap smears Persistent vaginal candidiasis Abdominal cramping (due to Pelvic inflammatory Disease) Persistent Diarrhea
The Immune System and HIV Leukocytes – white blood cells Macrophages Engulf foreign particles Antigens Stimulate immune system, react with antibodies Antibodies Inactivate antigens, mark them for destruction B cells and T cells
Treatment AZT (zidovudine) Protease inhibitors HAART (highly active anti-retroviral therapy) Fatality rate dropped from 90% to 5% in US Secondary treatment of infections & tumors
AIDS and Its Treatments
Phases of Infection Time from HIV infection to AIDS variable Ranges from few months to 17 years Early phase flu-like symptoms Intermediate phase T cells decrease to /milliliter of blood Advanced phase T cells drop to under 200, virus is detectable in blood Person with AIDS dies from opportunistic disease
Phases of Infection
Epidemiology of HIV Epidemic: rapid and wide spreading of a contagious disease Worldwide, over 36 million people have been infected with HIV 29 million people in sub-Saharan Africa Five million people newly HIV infected each year In the U.S., 816,000 people are infected About 40,000 people a year are infected with HIV in the U.S.
Epidemiology of HIV
Populations most affected by HIV/AIDS HIV/AIDS occurs in all population groups Four populations most affected by HIV /AIDS Men who have sex with men Injection drug users Heterosexual persons Higher rates for people who use drugs, exchange sex for drugs, have other STIs Infants whose mothers have untreated HIV infections African Americans are disproportionately affected Since the mid 1990s: more African-Americans with AIDS than white Americans in US
Populations most affected by HIV/AIDS
Modes of Transmission Vaginal or anal intercourse, oral sex without a latex or polyurethane condom or barrier Sharing needles - drug use, tattooing/piercing Passing virus from mother to fetus
Modes of Transmission Breastfeeding from HIV-positive mother Sharing sex toys Accidental contamination with infected blood Contaminated blood transfusions or organ transplants performed before April 1, 1985
Sexual Transmission Anal intercourse Vaginal intercourse Oral sex Sex toys
STIs and HIV transmission STIs increase likelihood of HIV infection two to five times An HIV-infected person also infected with STI is three to five times more likely to transmit HIV through sexual contact
Uncommon Transmission Modes Nonsexual contact Health care worker risk low with standard infection control precautions Accidents Blood transfusions and organ donations Blood has been screened for HIV since 1985 Organs, semen donations screened for HIV
U.S. AIDS Demographics People of Color Increasing infection among African Americans Gay community Men who have sex with men 55% of 2001 AIDS cases Women and HIV Risk from drug use, at-risk sex partners: 26% of cases Children and HIV Most due to exposure at birth, HIV positive mother Teens and college students Half of new infections among young people Older adults
U.S. AIDS Demographics by Infection
U.S. AIDS Demographics by Race
Poverty, Ethnicity and HIV In 2001, minorities were 68% of diagnosed AIDS cases Race and ethnicity are not risk factors: they correlate with homelessness, access to health care
Poverty, Ethnicity and HIV AIDS leading cause of death in African-American women 25-34, African-American men African-American HIV infection rate 16 times that of Non-Hispanic Whites Hispanic AIDS incidence four times that of non- Hispanic Whites Southern U.S. has disproportionate share of cases
Prevention Be aware that alcohol and drug use increases risky behaviors Develop communication skills to be able to discuss risks and prevention with partners Be aware of information on HIV testing Become familiar with condoms
Education about HIV/AIDS Prevention has reduced new infections from 150,000/year to 40,000/year Obstacles to education: blame and denial AIDS seen as disease of marginalized group, not “us” HIV/AIDS education in schools Outreach programs Heterosexual adults Men who have sex with men Youths Drug users
HIV Testing Tests should be taken 12 weeks after high-risk behavior, repeated 6 months after an uncertain result Types of tests OraQuick Rapid HIV-1 Antibody test Takes 20 minutes, 99.6% accurate ELISA - enzyme-linked immunosorbent assay Western blot –rechecks ELISA results Viral load tests measure HIV in bloodstream Notifying current and past partners
HIV Drugs Nucleoside reverse transcriptase inhibitors (RT inhibitors) Interrupt virus making copies at early stage Protease inhibitors Interrupt virus reproduction at later stage Fusion Inhibitor Block HIV before it enters the cell HAART – Highly Active Antiretroviral Therapy RT inhibitors and protease inhibitors combined Reduces HIV in blood to undetectable levels
The case of Fritz Fritz is a 43-year-old single white man that has been HIV positive for the past six years. He has been getting medical treatment at a county public health AIDS clinic and has been taking AZT for the past 5 years. Fritz has been employed full-time as a hairdresser at the same medium-sized salon for over 12 years. Lately he has been having problems with fatigue and has complained of loss of concentration and becoming forgetful. He has been occasionally forgetting what his customers tell him and has been making some mistakes while cutting and setting hair. Likewise, he has become rather tired standing all day. A friend who received vocational rehabilitation services years ago for a different condition referred Fritz to VR services. Fritz indicated that he has not told him employer that he is HIV positive, but has a good working relationship with the owner of the salon. Fritz’s physician does not think that he has the symptoms of AIDS as of yet.
Discussion on the case of Fritz What are the possible functional limitations associated with Fritz’s medical condition that would influence his rehabilitation potential? How would you explain Fritz’s disability to his employer? What vocational changes (if any) would you suggest?
Links CDC HIV transmission fact sheet: heets/transmission.htm heets/transmission.htm