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Salim S. Abdool Karim, MBChB, PhD
and
Quarraisha Abdool Karim, PhD
Salim S Abdool Karim, MBChB, PhD, is a
clinical infectious diseases epidemiologist
whose current research interests are in
microbicides and vaccines to prevent HIV
infection and implementation of antiretroviral
therapy in resource constrained settings.
Quarraisha Abdool Karim, PhD, is an infectious
diseases epidemiologist whose current
research interests are in understanding the
evolving HIV epidemic in South Africa; factors
influencing acquisition of HIV infection in
adolescent girls; and sustainable strategies to
introduce HAART in resource-constrained
settings.
At the end of this lecture the student will:
• Be able to define transmission dynamics of HIV
• Have an understanding of the evolution of the HIV
epidemic in South Africa through 5 distinct periods
• Know the distinct features of the South African HIV
epidemic
• Gain knowledge of the essential interventions against
HIV/AIDS.
• Prevalence
- How much disease at a point in time
- Existing infected people
• Implications for health impact
• Indicates the need for health care
• Incidence rate
- New infections in those without the infection
- Rate at which new infections are acquired
over a period of time
• More sensitive for assessing growth of epidemic
• Sensitive marker of effect of interventions
• About 10% of global burden of infection
• Major and Minor epidemic
• Distinctive features of major epidemic
- Prior to 1987 HIV infection rare in general pop
- High prevalence
- Highest rates of infection in young women
- Predominantly subtype C
Source: Abdool Karim Q, Abdool Karim SS. South Africa: Host to a new and emerging HIV
epidemic. Sex Trasm Inf 1999; 75: 139-140
Abdool Karim Q, Abdool Karim SS. Epidemiology of HIV infection in South Africa. AIDS 1999;
13: S4 - S7.
HIV prevalence (%)
40
30
20
10
0
1988
1990
1992
1994
1996
1998
2000
Source: National Department of Health, Pretoria, South Africa
2002
• 1982 – First reported cases of AIDS
• Epidemic largely limited to:
- Men who have sex with men
- Transfusion recipients and
- Haemophiliacs
• Clade B
Year
1985
1986
1987
Province
Group
KwaZulu Natal Rural community
Transvaal
Transvaal
Miners
Sex workers
KwaZulu Natal Antenatal women
Outpatient
N
441
%
0
17 021
1 200
0.01
0
500
0
268
0
Source: Abdool Karim SS. Making AIDS a notifiable disease- is it an appropriate policy for South
Africa? S Afr Med J, 1999; 89: 609-611
Dusheiko GM. Regional prevalence of hepatitis B, delta, and human immunodeficiency virus
infection in southern Africa: a large population survey. Am J Epidemiol. 1989; 129(1):138-45.
HIV prevalence (%)
40
30
20
10
0
1988
1990
1992
1994
1996
Source: Department of Health
1998
2000
2002
10
Male
Female
JUN/JUL 1992
Prevalence (%)
8
6
4
2
0
<9
10-14
15-19
20-24
25-29
30-39
40-49
Source: Abdool Karim Q, Abdool Karim SS, Singh B, Short R, Ngxongo S. Prevalence of HIV
infection in Rural South Africa. AIDS 1992; 6: 1535 - 1539
HIV prevalence (%)
40
30
20
10
0
1988
1990
1992
1994
1996
Source: Department of Health
1998
2000
2002
Year
Person-months Incidence Rate (%);
of follow-up
95% CI
1996/97
996
16.8 (8.0-26.0)
1998
1644
18.2 (11.0-25.0)
1999
780
20.0 (9.0-31.0)
Overall (1996-99)
3420
18.2 (13.0-23.0)
Source: Abdool Karim SS, Ramjee G and Gouws E – Data from COL-1492 trial
Year
N
1992 884
1993 709
1995 314
1997 4731
1998 3166
1999 3001
2001 906
Prev(%)(95% CI)
4.2 (3.0-5.7)
7.9 (6.0-10.1)
14.0 (10.4-18.4)
27.2 (25.9-28.5)
29.9 (28.4-31.6)
34.0 (32.5-35.7)
36.1 (32.9-39.2)
Incidence %
2.0
3.3
7.1
10.2
10.5
10.3
10.2
Source: Williams BG, Gouws E, Wilkinson D, Abdool Karim SS. Estimating HIV from Age
Prevalence data e epidemic situation. Statistic in Medicine 2000.
Age Group
1992
1995
1998
2001
20-24
6.9%
21.1%
39.3%
50.8%
25-29
2.7%
18.8%
36.4%
47.2%
30-34
1.4%
15.0%
23.4%
38.4%
35-39
0.0%
3.4%
23.0%
36.4%
Source: Wilkinson D, Abdool Karim SS, Williams B, Gouws E. High HIV incidence and prevalence
among young women in rural South Africa: developing a cohort for Intervention Trials. J Acquir
Immune Defic Syndr 2000; 23: 405-409
HIV prevalence (%)
40
30
20
10
0
1988
1990
1992
1994
1996
Source: Department of Health
1998
2000
2002
40
1999
2001
30
20
Western Cape
Northern Cape
Limpopo
East Cape
North West
Mpumalanga
KwaZulu- Natal
0
Free State
10
Gauteng
Prevalence (%)
2000
Province
Source: Dept. Health – 12th National HIV and Syphilis Sero-prevalence survey of women attending
public antenatal clinics in South Africa 2001
Year
Source: Hlabisa Hospital Records
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
Number of TB cases
2500
35
30
2000
25
1500
20
1000
15
10
500
5
0
0
HIV Prevalence (%)
3000
40
• 54% of Medical in-patients were HIV+
• 84% of HIV+ met WHO AIDS case criteria
• 56% HIV+ co-infected with tuberculosis
• Case fatality rates: HIV+ = 22% vs HIV- = 9%
Source: Colvin M, Dawood S, Kleinschmidt I, Mullick S, Lalloo U. Int J STD AIDS 2001, 386-389
PERCENTAGE OF 1985-1990 AVERAGE
350
1996-1998
300
1999-2000
250
200
150
100
50
0
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
AGE
Source: Dorrington R, Bourne D, Bradshaw D, Laubscher R, Timæus IM. The Impact of HIV/AIDS
on Adult Mortality in South Africa. MRC Technical Report. 2001
3.500
3.000
2.500
Ratio
1994
1996
2.000
1997/8
1998/99
1.500
1999/2000
1.000
0.500
0.000
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
Age
Source: Dorrington R, Bourne D, Bradshaw D, Laubscher R, Timæus IM. The Impact of HIV/AIDS
on Adult Mortality in South Africa. MRC Technical Report. 2001
• Current epidemic phase has 5 parallel effects:
- Continuing large numbers of new HIV infections
- Ongoing high mother-to-child transmission rates
- Rising morbidity and its impact on health services
- Rapidly rising deaths
- Increase in numbers of orphans
• Essential to intervene with:
- Prevention of new infections
- PMTCT programmes
- Care including OI prophylaxis and ARV treatment
- Social services for families impacted by AIDS deaths
- Programs and social services for orphans
• HIV affecting mainly young women in SA,
highlighting the importance of:
- interventions targeting youth
- addressing gender inequity
- greater involvement of men in prevention programs
• South Africa is experiencing a devastating
epidemic
• Sources of Data
- National Department of Health, Pretoria, South Africa
- Debbie Bradshaw, South African Medical Research
Council
- Rob Dorrington, University of Cape Town
- Brian Williams, WHO, Geneva
- Eleanor Gouws, WHO, Geneva
- Cheryl Baxter, CAPRISA