Transcript AIDS

Development Issues in Africa
Spring 2007
4. HIV/AIDS in Africa
Takashi Yamano
FASID
Contents
HIV/AIDS in Africa
– How HIV works
– Prevalence
– Preventions
– Treatments
FASID
Understanding HIV and AIDS
1981 Reported in The Morbidity and
Mortality Weekly Report, CDC
1983 The 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
FASID
FASID
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.
FASID
FASID
Barnett and Whiteside (2002) AIDS in the 21st century
Probability of HIV-1 infection per exposure
Female-to-Male, unprotected sex
Infection per
1000 exposure
0.33 – 1.0
Male-to-female, unprotected sex
1–2
Male-to-male, unprotected anal sex
5 – 30
Needle stick
3
Mother-to-child transmission
Exposure to contaminated blood products
FASID
130 – 480
900 – 1,000
World Bank (1997) Confronting AIDS
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.
FASID
FASID
Barnett and Whiteside (2002) AIDS in the 21st century
FASID
Source: UNAIDS (2006) 2006 Report on the global AIDS Epidemic
FASID
Prevalence: A Global Overview
Region
Number of adults
(15+) living with
HIV (millions)
24.5
0.4
8.3
HIV prevalence
rate among
adults (15-49)
6.1
0.2
0.4
Oceania
Latin America
Caribbean
0.8
1.6
0.3
0.3
0.5
1.6
E. Europe and C. Asia
Others
Total
1.5
2.0
38.6
0.8
0.5
1.0
Sub-Saharan Africa
N. Africa & Middle East
Asia
FASID
Source: UNAIDS (2006) 2006 Report on the global AIDS Epidemic
FASID
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
FASID
FASID
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.
FASID
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.
FASID
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
FASID
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
FASID
FASID
Males
Females
FASID
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
FASID
FASID
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.
FASID
FASID
FASID
FASID
Source: UNAIDS (2004) Report on the global AIDS Epidemic
FASID