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4. HIV/AIDS in Africa Takashi Yamano Development Issues in Africa Spring 2007.

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Presentation on theme: "4. HIV/AIDS in Africa Takashi Yamano Development Issues in Africa Spring 2007."— Presentation transcript:

1 4. HIV/AIDS in Africa Takashi Yamano Development Issues in Africa Spring 2007

2 Contents HIV/AIDS in Africa –How HIV works –Prevalence –Preventions –Treatments

3 Understanding HIV and AIDS 1981Reported in The Morbidity and Mortality Weekly Report, CDC 1983The HIV is identified by Luc Montagnier, followed by Robert Gallo (for details see And the Band Played On by Randy Shilts or video) 2006 25 years after the first report about AIDS HIV: Human Immunodeficiency Virus AIDS: Acquired Immunodeficiency Syndrome


5 How the virus Works: Infection HIV attacks a particular set of sells in the human immune system known as CD4 cells. CD4 cells organize the body’s overall immune response, and engulf foreign invaders and ensure that the body’s immune system will recognize them. HIV enters CD4 cells and makes copies of themselves, destroying the CD4 cells. At infection, the immune system responses and the vital load is high, “the window period.” A person is highly infectious and can not be detected for HIV because of high levels of CD4 cells. >> The more people there are in the early stage of infection, the greater the chance of effective transmission between people.

6 Barnett and Whiteside (2002) AIDS in the 21 st century

7 Probability of HIV-1 infection per exposure Infection per 1000 exposure Female-to-Male, unprotected sex0.33 – 1.0 Male-to-female, unprotected sex1 – 2 Male-to-male, unprotected anal sex5 – 30 Needle stick3 Mother-to-child transmission130 – 480 Exposure to contaminated blood products900 – 1,000 World Bank (1997) Confronting AIDS

8 Epidemiology 101 An Epidemic is a rate of disease that reaches unexpectedly high levels, affecting a large number of people in a relatively short time. A disease is considered as Endemic if it is continuously present in a population (e.g., malaria). A pandemic describes epidemics of world wide proportions (e.g., influenza in 1918 or HIV/AIDS). Incidence is the number of new infections which occur over a time period. Prevalence is the absolute number of infected people in a population.

9 Barnett and Whiteside (2002) AIDS in the 21st century

10 Source: UNAIDS (2006) 2006 Report on the global AIDS Epidemic


12 Prevalence: A Global Overview RegionNumber of adults (15+) living with HIV (millions) HIV prevalence rate among adults (15-49) Sub-Saharan Africa24.56.1 N. Africa & Middle East0.40.2 Asia8.30.4 Oceania0.80.3 Latin America1.60.5 Caribbean0.31.6 E. Europe and C. Asia1.50.8 Others2.00.5 Total38.61.0 Source: UNAIDS (2006) 2006 Report on the global AIDS Epidemic


14 Why in Africa? –Largely unknown –Known or the conventional hypothesis It originated from Central Africa Poor health care systems exaggerated the epidemic Sexually Transmitted Infections increase infections per exposure Economic development and globalization helped: the virus spreads because people spread Examples: Drivers, Migration workers, prostitutes More than 90% of adult HIV infection is due to (hetero-) sexual transmission


16 Prevention Target Groups In low-prevalence settings: target key population groups (e.g., sex workers and clients, injecting drug users, men who have sex with men) In high-prevalence settings: key groups and the total population Prevention efforts should be accompanied with universal access to treatment, impact and vulnerability-reduction measures.

17 Prevention ABCs in HIV preventions A means Abstinence: not engaging in sexual intercourse or delaying sexual initiation. B means Being Faithful: being faithful to one’s partner or reducing the number of sexual partners. C means Condom use: condoms reduce the risk of HIV transmission.

18 Prevention Projects AIDS education and awareness Behavior change programs Condom promotion Voluntary counsel and testing Preventing and treating STDs Prevent mother-to-child transmission Harm reduction programs for drug users Safe blood supply Infection control in health care settings

19 The Success Story: Uganda The national HIV prevalence rate declined from 15% in 199a to 5% in 2001 Why? – High-level political support –Behavior Change Communication (BCC) interventions reached the general population and key target groups –Early and significant mobilization of Ugandan religious leaders –A decrease in multiple sexual partnerships –Use of condoms Source: Hogle, et al., USAID, 2002


21 Males Females

22 Impacts of HIV/AIS Because HIV spreads through heterosexual transmission, adults in their prime ages get infected Many HIV positive people and AIDS patients are important income earners to their families and productive members of societies They are also parents; thus they leave many AIDS orphans behind when they die Orphans’ education is the next week’s presentation topic HIV/AIDS epidemic is different on these aspects from other infectious diseases that affect mostly children and elderly


24 Treatment Five to six million people in low-and middle-income countries need antiretroviral treatment immediately. But only 0.4 million (7%) in 2003 receive it (WHO). The price has come down from over $10,000 to $300 per person per year. The 3 by 5 Initiative: Treating 3 million people by 2005 (WHO) –This initiative did not achieve the target (3 million) but helped the triple the number of people with access to drugs from 0.4 to 1.3 million people in just two years.



27 Source: UNAIDS (2004) Report on the global AIDS Epidemic


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