HIV in Women: A Global View of the HIV Epidemic

Transcription

1 Training Course in Reproductive Health / Sexual Health Research Geneva 2006 HIV in Women: A Global View of the HIV Epidemic George Schmid, M.D., M.Sc. Department of HIV/AIDS World Health Organization Geneva, Switzerland Schmidg@who.int

2 The Problem of the HIV Epidemic Why Is it Occurring? What Can We Do About the It?

3 Global estimates for adults and children end 2002 People living with HIV/AIDS New HIV infections in 2002 Deaths due to HIV/AIDS in million 5 million 3.1 million

4 About new HIV infections a day in 2002 More than 95% are in developing countries 2000 are in children under 15 years of age About are in persons aged 15 to 49 years, of whom: almost 50% are women about 50% are year olds

5 Regional HIV/AIDS statistics and features, end of 2002 Epidemic started Adults & children living with HIV/AIDS Adults & children newly infected with HIV Adult prevalence rate * % of HIVpositive adults who are women Main mode(s) of transmission for those living with HIV/AIDS ** Sub-Saharan Africa North Africa & Middle East late 70s early 80s late 80s 29.4 million million % 0.3% 58% 55% Hetero Hetero, IDU South and South-East Asia late 80s 6.0 million % 36% Hetero, IDU East Asia & Pacific late 80s 1.2 million % 24% IDU, Hetero, MSM Latin America Caribbean Eastern Europe & Central Asia late 70s early 80s late 70s early 80s early 90s 1.5 million million % 2.4% 0.6% 30% 50% 27% MSM, IDU, Hetero Hetero, MSM IDU Western Europe North America Australia & New Zealand TOTAL late 70s early 80s late 70s early 80s late 70s early 80s million million 0.3% 0.6% 0.1% 1.2% 25% 20% 7% 50% MSM, IDU MSM, IDU, Hetero MSM * The proportion of adults (15 to 49 years of age) living with HIV/AIDS in 2002, using 2002 population numbers ** Hetero: heterosexual transmission IDU: transmission through injecting drug use MSM: sexual transmission among men who have sex with men

6 The global view of HIV, end Recent trends in HIV infection, % of all persons living with HIV/AIDS are in developing countries % + 20% + 20% + 100% + 160% + 40% + 60% HIV prevalence in adults, end % 5 15% 1 5% % % % not available + 30% In 7 countries, >20% of all adults are infected with HIV + 20% Source: UNAIDS/WHO July 2002

7 11.8 million young people (aged 15 24) living with HIV/AIDS 7.3 million young women and 4.5 million young men Latin America & Caribbean 560,000 Industrialized countries 240,000 Central and Eastern Europe, Commonwealth of Independent States and Middle East & North Africa 160,000 Baltic States 430,000 South Asia 1.1 million East Asia & Pacific 740,000 ource: UNICEF/UNAIDS/WHO, Sub-Saharan Africa 8.6 million

8 HIV prevalence rate among teenagers by age in Kisumu,, Kenya HIV prevalence (%) Age in years boys girls Source: National AIDS Programme, Kenya, and Population Council, 1999

9 The Impact of HIV/AIDS

10 Changes in life expectancy in African countries with high and low HIV prevalence: Life expectancy (years) with high HIV prevalence: Zimbabwe South Africa Botswana with low HIV prevalence: Madagascar Senegal Mali Source: UN Department of Economic and Social Affairs (2001) World Population Prospects, the 2000 Revision.

11 Leading causes of death in Africa, % of Total HIV/AIDS Malaria Perinatal conditions Tuber culosis Cerebro vascular disease Lower respiratory infections Diarrhoeal disease Measles Ischaemic Heart disease Maternal conditions Source: The World Health Report 2001, WHO

12 Lifetime risk of AIDS death for 15-year year-old boys, assuming unchanged or halved risk of becoming infected with HIV, selected countries Risk of dying of AIDS 100% 80% 60% 40% 20% 0% Cambodia Burkina Faso risk halved over next 15 years Côte d Ivoire Kenya Cambodia Burkina Faso South Africa Zambia Kenya Côte d Ivoire Zimbabwe Zimbabwe South Africa Zambia Botswana Botswana 0% 5% 10% 15% 20% 25% 30% 35% 40% Current adult HIV prevalence rate current level of risk maintained Source: Zaba B, 2000 (unpublished data)

13 Why Is the HIV Epidemic Occurring?

14 Risk Factors (for Women) Unsafe transfusion Unsafe injection practices Unsafe injection drug use Unsafe sex

15 Distribution of AIDS cases by the route of transmission Eastern Europe 100% 80% 60% 40% 20% 0% < MSM IDU Homo/Bisexual Haemophilia Transfusion Heterosexual Other/including MTCT

16 Concept of Bridging Populations in HIV Transmission Concentrated epidemics Generalized epidemics Core (risk) group Bridging population General population IDUs, sex workers, MSMs Sex partners of IDUs, sex workers, MSMs 1. Sexual norms 2. STIs

17 Sexual Transmission of STIs, Including HIV 1 R o =β c D R o = reproductive rate β =transmission efficiency C=rate of partner change D=duration of infectiousness 1 among people having sex Anderson and May

18 Male to Female Transmission Efficiency Study Per 1000 acts Padian et al (1987) Peterman et al (1988) Wiley et al (1989) Duerr et al (1994) Downs et al (1996) Leynaert et al (1998) Shiboski et al (1998) Gray et al (2001) Combined male to female with female to male

19 ß (Transmission efficiency) Cofactors Cofactor effect of STIs Cofactor effect of young age Cofactor effect of hormonal contraceptives Negative cofactor effects of condom use Negative cofactor effect of microbicides (we hope!) Negative cofactor effect of circumcision (we think!)

20 ß (Transmission efficiency) Model Concentration of virus in seminal secretions 1 Viral phenotype Number of receptors for HIV in endocervix 1 Chakraborty H et al. AIDS 2001;15:621

21 Seminal Fluid Characteristics, 132 Samples CD4 count Semen volume (ml) Median 2.4 Minimum 0.1 Maximum 7.3 NSI HIV-1 RNA count per sample Median 4,904 Mean 522,656 Minimum 42 Maximum 27,870,835 Chakraborty H et al. AIDS 2001;15:621

22 CCR5 Receptor Cell Count, Endocervix Median 184/mm 3 Mean 176/mm 3 Minimum 13/mm 3 Maximum 450/mm 3 Chakraborty H et al. AIDS 2001;15:621

23 Probability of Transmission by Seminal Viral Load, Number of Receptor Cells, or Proportion of HIV Virions that are NSI Transmission Probability % NSI or many receptor cells 50% NSI or few receptor cells Seminal viral load, log 10 Chakraborty H et al. AIDS 2001;15:621

24 ß (Transmission efficiency) Cofactors again Amount of seminal secretions Young age STIs, Etc. Review! Coombs RW et al. AIDS 2003;17:455

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30 Presence of HIV in Ulcer Secretions Disease PCR for HIV (Pos./Tested) Chancroid 2 6/7 (86%) Chancroid 3 2/6 (33%) Syphilis 1/2 (50%) Unknown 2/3 (67%) Genital herpes 1/3 (33%) Genital herpes 4 25/26 (96%) 1 Kreiss J et al. J Infect Dis 1989;160:380 2 Plummer FA et al. J Infect Dis 1990;161:810 3 Mertz KJ et al. J Infect Dis 1998;178:1795 Schacker T et al. JAMA 1998;280:61

31 HIV prevalence rate and frequency of sexually transmitted infection (STI) episodes, Carletonville miners, South Africa, HIV prevalence (%) Number of STI episodes Source: Ballard R, 2000 (unpublished data).

32 Probability of Transmission by Seminal Viral Load, Number of Receptor Cells, or Proportion of HIV Virions that are NSI Transmission Probability % NSI or many receptor cells 50% NSI or few receptor cells Seminal viral load, log 10 Chakraborty H et al. AIDS 2001;15:621

33 If These Transmission Efficiencies are so Low, Why is there an HIV Epidemic?

34 Cohort study, Nairobi 73 HIV-negative men with an STD All men had had one act of sexual intercourse with a prostitute The men were counseled, given condoms, told to avoid sex with prostitutes, and followed every 2 weeks for three months for HIV seroconversion 85% of prostitutes were HIV-positive Cameron WD et al. Lancet 1989;2:403 Cameron D et al. Lancet 1989;2:403

35 Proportion of Men Developing HIV Infection After a Single Act of Sexual Intercourse Circumcised Uncircumcised Unstratified Urethritis Ulcer Urethritis Ulcer 13% 0% 7% (6*) 0% 43% (15) Standard Error Attributable risk due to lack of circumcision and genital ulcer=98% Cameron WD et al. Lancet 1989;2:403

36 An Outbreak of HIV Infection, United States Of 42 teenaged girls having only vaginal sex with one teenaged boy, 13 (31%) became infected Of 15 girls with a brief time period of sexual activity, seven (47%) became infected. Infected girls, compared to uninfected girls, had more exposures: Partners Infected Uninfected Median 3 1 Range MMWR 1999;48:413

37 Sexual Transmission of STIs, Including HIV 1 R o =β c D R o = reproductive rate β =transmission efficiency C=rate of partner change D=duration of infectiousness 1 among people having sex Anderson and May

38 Alternately, Maybe Something Else is Going On?

39 Unsafe Injections in the Developing World WHO estimates that 5% of all infections, worldwide, are from unsafe injections (2.5% in sub- Saharan Africa)

40 Injections Given with Sterile and Unsafe Equipment Worldwide Global Burden of Disease, 2000 South America Central Europe West Africa China and Pacific South East Asia East and Southern Africa Eastern Europe and Central Asia South Asia Injections given with equipment re-used in the absence of sterilization Injections given with sterile equipment Middle East Crescent Number of injections per person and per year

41 Dr Tanu Singhal, London School of Hygiene and Tropical Medicine

42 The Solution to Pollution is Dilution

43 In Addition, HIV Acts Like an STI

44 Figure 1 HIV prevalence by age and sex, Addis Ababa, Ethiopia, 1994 (ref. 52) Men Women 20 Percent infected Age group

45 Figure 2A HIV and HSV-2 2 prevalence by age and sex in Kisumu,, Kenya Percent infected Age group HIV men HSV-2 men HIV women HSV-2 women

46 Figure 4 Infection Rates, by Gender, Carletonville, South Africa

47 What Can We Do About the HIV Epidemic?

48 The HIV Epidemic Should Be Easily Controlled 1. Don t have unsafe transfusions 2. Don t have unsafe injections 3. Don t inject drugs (if you do, do it safely) 4. Don t have sex (if you do, do it safely)

49 Stopping the HIV Epidemic Personal Responsibility Giving people the means to effect personal responsibility

50 Don t have sex (if you do, do it safely) 1. Education

51 Percentage of girls who do not know that an HIV- infected person may look healthy, Central African Republic Cameroon Brazil Dominican Republic 0 Chad Niger Nepal Lesotho Madagascar Bangladesh Cambodia Mozambique Mali Benin Guatemala Papua New Guinea Percentage who do not know Mongolia South Africa Viet Nam Cape Verde Eritrea Côte d'ivoire Tanzania Romania Turkey Togo Comoros Kenya Peru Zimbabwe Malawi Haiti Uganda Zambia Sources: UNICEF, DHS surveys and other nationwide surveys,

52 Risk perception percentage of sexually active women (15-19) 19) who perceive themselves to be at no risk of getting AIDS Nicaragua Nepal Colombia Bolivia Guatemala Brazil Dominican Rep. Niger Benin Chad Mali Cameroon Togo Haiti CAR Kenya Uganda Zambia Zimbabwe HIV Prevalence (at time of survey *) Percentage of year old girls who think they are not at risk of AIDS 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% *HIV prevalence in women attending antenatal care clinics in major urban areas Sources: UNICEF, DHS surveys,

53 Percentage of men who used a condom with a recent non-regular partner, by level of formal education: None Primary 80 Secondary or more Benin Cameroon Central Arican Republic Chad Kenya Malawi Mali Niger United Republic of Tanzania Togo Uganda Zambia Zimbabwe Brazil Dominican Republic Source: Macro International ( ) Demographic and Health Surveys; UNICEF

54 Don t have sex (if you do, do it safely) 1. Education 2. Change societal norms

55 Pre-marital sex % of women (age 20-24) 24) that report pre-marital sex, various countries in Eastern Europe % Georgia (1999) Moldova (1997) Romania (1999) Ukraine (1999) Russia (1999) Czech Republic (1993)

56 Don t have sex (if you do, do it safely) 1. Education 2. Change societal norms 3. Enable safe behaviours

57 Condom gap in sub-saharan African countries in 1999 Condoms per man per year Additional condoms needed to get all countries to the level of 16.9 = 1.9 billion per year Average condom procurement of top 6 countries = 16.9 Six countries with highest condom procurement rate Countries in sub-saharan Africa, ordered by condom procurement rate Source: Shelton JD, Johnston B (2001) Condom gap in Africa: evidence from donor agencies and key infromants, British Medical Journal

58 Concept of Bridging Populations in HIV Transmission Concentrated epidemics Generalized epidemics HIV+ HIV+ HIV+ HIV- HIV- HIV- Core (risk) group Bridging population General population 1. Sexual norms 2. STIs

59 Concept of Bridging Populations in HIV Transmission Concentrated epidemics Generalized epidemics? HIV+?? Core (risk) group Bridging population General population 1. Sexual norms 2. STIs

60 Concept of Bridging Populations in HIV Transmission Testing Care HIV+??? Core (risk) group Bridging population General population 1. Sexual norms 2. STIs

61 Care Purposes (benefits) Medical, psychological, social care Altering behaviour Challenges Decreasing stigma Streamlining counseling and testing Financial Operational

62 Concept of Bridging Populations in HIV Transmission Concentrated epidemics Generalized epidemics HIV+ HIV+ HIV+ HIV- HIV- HIV- Core (risk) group Bridging population General population 1. Sexual norms 2. STIs

63 Success Story (Why?)

64 Prevalence among pregnant women in major urban areas, Uganda Prevalence Source: Uganda National AIDS Programme

65 Condom use among men with non-regular partners over time in selected sub-saharan African countries: % 40 Malawi Tanzania Uganda Zambia Source: Macro International ( ) Demographic Health Surveys; Measure Evaluation

66 Summary 1. HIV/AIDS is a HUGE problem in the world 2. Women make up ½ of cases 3. Altering the course of the epidemic is theoretically simple, but operationally difficult

67 Thank you!