Human Immunodeficiency Virus

Transcription

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2 Human Immunodeficiency Virus Isolated in 1983 by Luc Montagnier & Robert Gallo, separately. Genetic material is RNA Carries reverse transcriptase, an enzyme that makes DNA out of RNA in the host cell

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4 Cells of the Immune System Recall: Lymphocytes (B & T cells) are grown in bone marrow and enter the blood stream as white blood cells (WBC). Some WBC are involved in general non-specific immunity- neutrophils, & who else? Lymphocytes are involved in specific immunity Only 20% of all the body s lymphocytes are in blood at any time

5 Lymphocytes

6 Types of Lymphocytes 2 main types: T-cells and B-cells Have different membrane proteins (id tags & binding sites) T-cells can kill cells which have been invaded by viruses B-cells make antibodies to tag cells or neutralize bacteria and other invaders

7 White Blood Cells

8 Infection cycle 1. Virus attaches: Proteins on HIV virus "dock" with CD4 receptors on host cell 2. Genes copied: HIV virus makes a copy of its own genetic material 3. Replication: Virus inserts this copy into host cell s DNA. When host cell replicates, it manufactures the parts of the HIV virus 4. Release: Parts are assembled and form a "bud", which emerges as a new HIV virus

9 HIV IS present in the saliva of infected persons, but: not in quantities sufficient to transmit infection. Once infected fluids dry, risk of them transmitting the virus is effectively 0. HIV is present in blood, sexual fluids and breast milk of infected persons. The inoculum depends on the viral load the person is currently suffering. The viral load depends on the stage of disease and the presence or absence of effective treatment with antiretroviral drugs.

10 HIV attacking a lymphocyte

11 Infection time course

12 Pneumocystis pneumonia (PCP): PCP is an opportunistic infection which causes pneumonia. It usually targets the lungs but can also affect the lymph nodes, spleen, liver or bone marrow. Historically it has been a major killer of HIV patients, but can now be prevented and treated with drugs. It occurs mostly in people with CD4+ cell counts below 200.

13 Tuberculosis (TB): Leading cause of AIDS-related deaths worldwide Many countries face parallel epidemics of HIV and TB. Caused by a bacteria which many people carry, but which only causes disease in some. TB carriers with HIV are 30 times more likely to develop the disease than those without. TB attacks the lungs first, but can spread to the lymph nodes and brain.

14 Antiretroviral mechnisms Entry inhibitors bind to proteins on the HIV virus and stop it from entering the target cell Nucleoside reverse transcriptase inhibitors prevent HIV from copying its genes into the cell. Nucleosides = building block for genes. The drugs supply faulty versions of these building blocks Non-nucleoside reverse transcriptase inhibitors also block the gene-copying process. They disable the enzyme that controls it Protease inhibitors disable protease, an enzyme which plays a key role in the formation of the new virus

15 Retroviruses mutate faster Retroviruses copy their genes into target cell DNA with a high level of error (mutations). In combination with HIV's high replication rate, this means the virus mutates quickly as it spreads.

16 Global Burden of AIDS

17 Condom use by women Territory size shows the proportion of all girls and women aged years old worldwide who used a condom last time they had high-risk sex.

18 Condom Use by Men Territory size shows the proportion of all boys and men aged years old worldwide who used a condom last time they had high-risk sex. High-risk sex is defined as sex with someone who men are not living with or married to.

19 HIV Prevalence 2003 Territory size shows the proportion of all people aged with HIV (Human Immunodeficiency Virus) worldwide, living there.

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24 YLL for some countries

25 Regional HIV and AIDS statistics and features, 2007 Sub-Saharan Africa Middle East & North Africa South and South-East Asia East Asia Latin America Caribbean Eastern Europe & Central Asia Western & Central Europe North America Oceania TOTAL Adults & children living with HIV 22.0 million [ million] [ ] 4.2 million [ million] [ million] 1.7 million [ million] [ ] 1.5 million [ million] [ million] 1.2 million [ million] [ ] 33 million [30 36 million] Adults & children newly infected with HIV 1.9 million [ million] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] 2.7 million [ million] Adult prevalence (15 49) [%] 5.0% [4.6% 5.4%] 0.3% [0.2% 0.4%] 0.3% [0.2% 0.4%] 0.1% [<0.1% 0.2%] 0.5% [0.4% 0.6%] 1.1% [1.0% 1.2%] 0.8% [0.6% 1.1%] 0.3% [0.2% 0.4%] 0.6% [0.4% 1.0%] 0.4% [0.3% 0.5%] 0.8% [0.7% - 0.9%] Adult & child deaths due to AIDS 1.5 million [ million] [ ] [ ] [ ] [ ] [ ] [ ] 8000 [ ] [ ] 1000 [< ] 2.0 million [ million] The ranges around the estimates in this table define the boundaries within which the actual numbers lie, based on the best available information.

26 HIV prevalence (%) among years old, by sex, selected countries, Swaziland South Africa Zimbabwe Central African Republic Uganda Female Chad Côte d'ivoire Male Sierra Leone Rwanda Haiti Guinea Ethiopia Benin Mali DR Congo Niger Dominican Republic Senegal Cambodia India % HIV prevalence

27 HIV prevalence through time

28 Distribution of Infection

29 HIV prevalence (%) among pregnant women attending antenatal clinics in Sub-Saharan Africa, Southern Africa Median HIV prevalence (%) Eastern Africa Botswana Lesotho Mozambique Namibia South Africa Swaziland Zimbabwe West Africa NOTE: Analysis restricted to consistent surveillance sites for all countries except South Africa (by province) and Swaziland (by region) Median HIV prevalence (%) Ethiopia 10 5 Kenya Median HIV prevalence (%) Burkina Faso Côte d'ivoire Ghana Senegal

30 Percentage of most-at-risk populations reached with HIV prevention programmes, % Median %* (39 countries) Sex workers 46.1%** (15 countries) 40.1%* (27 countries) Injecting drug users Men having sex with men * Percentage of sex workers and men having sex with men reported knowing where they can receive an HIV test and that they were given condoms. ** Percentage of injecting drug users who reported knowing where they could receive an HIV test and be provided with condoms and sterile injecting needles and syringes. Source: UNGASS Country Progress Reports 2008

31 Condom use is increasing Prevention & education programs are reaching their audience

32 I have come to the conclusion that HIV/AIDS is not entirely about death. People die and will continue to die for one reason or the other. AIDS is also about the living. Kiiza Ngonzi, 2004

33 HIV in the USA Who is infected? The changing face of HIV/AIDS Number of new infections each year is stable. The face of infections is not--some populations have always been at risk; in others, the risk is increasing. Men who have Sex with Men (MSM) & Injection Drug Users (IDU) are still the largest proportion of new HIV infections and AIDS cases each year. At increasing risk are women, young people, & people of color. Approximately 5 million Americans are considered to be at high risk for HIV infection.

34 Women Women make up nearly one-third of new HIV infections. In 1992, women accounted for 13.8% of people living with AIDS; by the end of 2001, that percentage had increased to 21%. Among women, sexual contact accounts for 75% of infections.» Data from the CDC, 2006

35 Paula Peterson When I first learned that I had full-blown AIDS, I thought I was going to die the next day. I felt like my future had been cut off. That was nine or ten months ago. Time now is broken up into "before the diagnosis" and "after the diagnosis." Every day is really weighty. Rather than months, I feel it in days. It just feels like every hour, every minute counts. It's not that I feel that I don't have a future exactly. It's just very uncertain. But I no longer wake up and think I am going to die that day.

36 Young People Half of all new HIV infections are believed to occur in people age 25. More than 50% of new HIV infections among young people age 25 are the result of heterosexual contact. Heterosexual contact accounts for at least 45% of new HIV infections among women under the age of 25. Among men age 25, 49% of all AIDS cases reported in 2000 were among men who have sex with men (MSM).» Data from the CDC, 2006

37 "I look at the pills and think, 'Yeah, these pills -- this fistful of pills -- are what's keeping me alive [laughter].' It's hard to describe. It was hard watching my mom die of the disease that I had, that I knew I had. I knew I could end up like her. It's hard having that realization at such a young age. Alara, age 15

38 People of Color In 2000, the rate of reported AIDS cases among African Americans was eight times the rate for whites. African Americans represent 12% of the U.S. population, yet make up more than half of new HIV infections. In 2000, almost two-thirds of all women reported with AIDS were African American. African American children make up two-thirds of new pediatric AIDS cases. African American and Hispanic women together represent less than one-quarter of all U.S. women, yet they account for more than threequarters of AIDS cases among women. Hispanics, who represent 13% of the population, account for about 19% of new AIDS cases. Although African Americans and Hispanics combined represent about one-quarter of the United States population, they account for more than two-thirds of both new HIV infections and new AIDS cases. Data from the CDC,2006

39 I live in Brooklyn's Fort Greene neighborhood. It's a tight-knit community, within walking distance of my church and the Farragut housing projects where I grew up and where my mother still lives. My block has all nationalities, religions and races -- it's a nice place to live. I am an artist and an AIDS activist. I sculpt, paint, speak and write about living with HIV and coordinate the AIDS ministry at my church, The Church of the Open Door. My sculptures have been exhibited throughout the world, from Brooklyn to Uganda in East Africa, where slides of my work were displayed to HIV-positive artists. I've also shown my work in women's shelters, churches and hospitals and done presentations in churches. I've been on TV and in POZ, Our Time Press, the Daily News and Amsterdam News. Joyce McDonald Age: 55 Home: Brooklyn, New York Diagnosed: 1995

40 HIV/AIDS in the World Adults and children living with HIV Number of women living with HIV Adults and children newly infected with HIV 40.3 million 17.5 million 4.9 million AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics

41 A global view of HIV infection 33 million people [30 36 million] living with HIV, 2007

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43 Prevalence in Africa

44 Half of all new HIV infections worldwide are in young people aged 15-24