Salim S. Abdool Karim, MBChB, PhDand

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.

• PrevalencePrevalence- How much disease at a point in time- How much disease at a point in time- Existing infected people- Existing infected people

• Implications for health impactImplications for health impact• Indicates the need for health careIndicates the need for health care

• Incidence rateIncidence rate- New infections in those without the infection- New infections in those without the infection- Rate at which new infections are acquired - Rate at which new infections are acquired

over a period of timeover a period of time• More sensitive for assessing growth of epidemicMore sensitive for assessing growth of epidemic• Sensitive marker of effect of interventionsSensitive marker of effect of interventions

Source: Abdool Karim Q, Abdool Karim SS. South Africa: Host to a new and emerging HIV epidemic. Sex Trasm Inf 1999; 75: 139-140Abdool Karim Q, Abdool Karim SS. Epidemiology of HIV infection in South Africa. AIDS 1999; 13: S4 - S7.

• About 10% of global burden of infectionAbout 10% of global burden of infection

• Major and Minor epidemicMajor and Minor epidemic

• Distinctive features of major epidemicDistinctive features of major epidemic- - Prior to 1987 HIV infection rare in general popPrior to 1987 HIV infection rare in general pop- High prevalence- High prevalence- Highest rates of infection in young women- Highest rates of infection in young women- Predominantly subtype C- Predominantly subtype C

Source: National Department of Health, Pretoria, South Africa

0

10

20

30

40

1988 1990 1992 1994 1996 1998 2000 2002

HIV

pre

vale

nce

(%

)

• 1982 – First reported cases of AIDS 1982 – First reported cases of AIDS

• Epidemic largely limited to:Epidemic largely limited to:- - Men who have sex with menMen who have sex with men

- Transfusion recipients and- Transfusion recipients and- Haemophiliacs- Haemophiliacs

• Clade BClade B

Year Province Group N %

1985 KwaZulu Natal Rural community 441 0

1986 Transvaal Miners 17 021 0.01

Transvaal Sex workers 1 200 0

1987 KwaZulu Natal Antenatal women 500 0

Outpatient 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: 609-611Dusheiko 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.

Source: Department of Health

0

10

20

30

40

1988 1990 1992 1994 1996 1998 2000 2002

HIV

pre

vale

nce

(%

)

00

<9<9 10-1410-14

JUN/JUL 1992JUN/JUL 1992

Pre

vale

nce (

%)

Pre

vale

nce (

%)

15-1915-19 20-2420-24 25-2925-29 30-3930-39 40-4940-49

22

44

66

88

1010

FemaleFemaleMaleMale

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

Source: Department of Health

0

10

20

30

40

1988 1990 1992 1994 1996 1998 2000 2002

HIV

pre

vale

nce

(%)

YearPerson-months

of follow-upIncidence Rate (%);

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

Source: Williams BG, Gouws E, Wilkinson D, Abdool Karim SS. Estimating HIV from Age Prevalence data e epidemic situation. Statistic in Medicine 2000.Source: Williams BG, Gouws E, Wilkinson D, Abdool Karim SS. Estimating HIV from Age Prevalence data e epidemic situation. Statistic in Medicine 2000.

Year N Prev(%)(95% CI) Incidence %

1992 884 4.2 (3.0-5.7) 2.0

1993 709 7.9 (6.0-10.1) 3.3

1995 314 14.0 (10.4-18.4) 7.1

1997 4731 27.2 (25.9-28.5) 10.2

1998 3166 29.9 (28.4-31.6) 10.5

1999 3001 34.0 (32.5-35.7) 10.3

2001 906 36.1 (32.9-39.2) 10.2

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

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: Department of Health

0

10

20

30

40

1988 1990 1992 1994 1996 1998 2000 2002

HIV

pre

vale

nce

(%)

Source: Dept. Health – 12th National HIV and Syphilis Sero-prevalence survey of women attending public antenatal clinics in South Africa 2001

0

10

20

30

40

Kw

aZul

u- N

ata

l

Mpu

mal

anga

Gau

ten

g

Fre

e S

tate

Nor

th W

est

Eas

t C

ape

Lim

popo

Nor

ther

n C

ape

Wes

tern

Cap

e

Province

Pre

vale

nce

(%

)

1999

2000

2001

Source: Hlabisa Hospital Records

0

500

1000

1500

2000

2500

3000

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

Year

Nu

mb

er o

f T

B c

ases

0

5

10

15

20

25

30

35

40

HIV

Pre

vale

nce

(%

)

• 54% of Medical in-patients were HIV+54% of Medical in-patients were HIV+

• 84% of HIV+ met WHO AIDS case criteria84% of HIV+ met WHO AIDS case criteria

• 56% HIV+ co-infected with tuberculosis56% HIV+ co-infected with tuberculosis

• Case fatality rates: HIV+ = 22% vs HIV- = 9%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

15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69

1996-1998

1999-2000

AGE

0

50

100

150

200

250

300

350

PE

RC

EN

TA

GE

OF

19

85-1

990

AV

ER

AG

E

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

0.000

0.500

1.000

1.500

2.000

2.500

3.000

3.500

15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64

Age

Rat

io

1994

1996

1997/8

1998/99

1999/2000

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:Current epidemic phase has 5 parallel effects:- - Continuing large numbers of new HIV infectionsContinuing large numbers of new HIV infections- Ongoing high mother-to-child transmission rates- Ongoing high mother-to-child transmission rates- Rising morbidity and its impact on health - Rising morbidity and its impact on health

servicesservices- Rapidly rising deaths- Rapidly rising deaths- Increase in numbers of orphans- Increase in numbers of orphans

• Essential to intervene with:Essential to intervene with:- - Prevention of new infectionsPrevention of new infections- PMTCT programmes- PMTCT programmes- Care including OI prophylaxis and ARV treatment- Care including OI prophylaxis and ARV treatment- Social services for families impacted by AIDS - Social services for families impacted by AIDS

deathsdeaths- Programs and social services for orphans- Programs and social services for orphans

• HIV affecting mainly young women in SA, HIV affecting mainly young women in SA, highlighting the importance of:highlighting the importance of:

- interventions targeting youth- interventions targeting youth- addressing gender inequity- addressing gender inequity- greater involvement of men in prevention - greater involvement of men in prevention

programsprograms

• South Africa is experiencing a devastating South Africa is experiencing a devastating epidemicepidemic

• Sources of DataSources of Data - National Department of Health, Pretoria, South Africa- National Department of Health, Pretoria, South Africa- Debbie Bradshaw, South African Medical Research - Debbie Bradshaw, South African Medical Research Council Council - Rob Dorrington, University of Cape Town- Rob Dorrington, University of Cape Town- Brian Williams, WHO, GenevaBrian Williams, WHO, Geneva- Eleanor Gouws, WHO, GenevaEleanor Gouws, WHO, Geneva- Cheryl Baxter, CAPRISACheryl Baxter, CAPRISA