Disease Synergies and HIV Transmission Linking Millennium Development Goals and HIV

1. Disease Synergies andHIV TransmissionLinking Millennium Development Goals and HIV Eileen Stillwaggon AIDS 2006 XVI International AIDS Conference

8. What drives an epidemic to 40 % prevalencein some countriesand less than 1 % in others?

9. Median age at first intercourse (selected countries, by gender) Country Male Female United States 16 17 Great Britain 17 17 Haiti 18 19 Tanzania 18 17 Zimbabwe 19 19 Derived from Singh S, et al. 2000. “Gender Differences in the Timing of First Intercourse: Data from 14 Countries,” International Family Planning Perspectives 26(1):21–28, 43.

10. 23 % of US men report 20 or more female partners Source: John O. G. Billy, Koray Tanfer, William R. Grady, and Daniel H. Klepinger. 1993. “The Sexual Behavior of Men in the United States,” Family Planning Perspectives 25(2):52–60.

11. 41 % of US women report 4 or more male partners 23 % of US women report 6 + male partners Source: Kathryn Kost and Jacqueline Darroch Forrest. 1992. “American Women’s Sexual Behavior and Exposure to Risk of Sexually Transmitted Diseases,” Family Planning Perspectives 24(6):244–254.

12. Canada: first-year college students with more than 10 sexual partners Men: 21 % Women: 9 % Source: N. MacDonald, G. Wells, W. Fisher, et al. 1990. “High-Risk STD/HIV Behavior among College Students,” Journal of the American Medical Association 263(23):3155–3159.

13. Canada: first-year college students with 5 or more sexual partners Men: 40 % Women: 25 % Source: N. MacDonald, G. Wells, W. Fisher, et al. 1990. “High-Risk STD/HIV Behavior among College Students,” Journal of the American Medical Association 263(23):3155–3159.

14. Genital herpes simplex virus type 2 - seroprevalence, by age,(1976–80) and (1988–94) Note: Bars indicate 95% confidence intervals. *National Health and Nutrition Examination Survey

15. Immune system • Skin and mucous membranes • First line of defense • Natural Killer cells, macrophages • Non-adaptive and adaptive immunity • B cells adaptive immunity • T cells

16. Protein-energy malnutritionreduces • integrity of skin and mucous membranes • T-cell production

18. Iron-deficiency anemia reduces production of • B cells • T cells • Natural Killer (NK) cells

19. Zinc deficiencyreduces • Natural Killer cell activity • T-cell production • integrity of the skin as a barrier to infection

20. Vitamin-A deficiency • reduces production of • NK cells • T cells • B cells • reduces skin and mucosal integrity

21. Vitamin-A deficiency • reduces production of • NK cells • T cells • B cells • reduces skin and mucosal integrity • increases viral load

22. Maternal malnutritionincreasesmother-to-child transmission Anemia increases viral shedding in the birth canal

23. Global Distribution of Malaria

24. Malaria • causes chronic immune activation • depresses immune response

25. Malaria • causes chronic immune activation • depresses immune response • increases HIV replication • increases viral load in people with HIV

26. Malaria • causes chronic immune activation • depresses immune response • increases HIV replication • increases viral load in people with HIV • increases MTC transmission of HIV • increases sexual transmission of HIV

27. Malaria HIV increases malarial parasite load in the blood, increasing malaria transmission. Coinfection with malaria contributes to ARV treatment failure in malaria-endemic areas.

28. Distribution of Lymphatic Filariasis

29. Helminths (Worms) • More than 80 % of people in poor communities have at least one type of worm

30. Helminths (Worms) • More than 80 % of people in poor communities have at least one type of worm • Virtually all children in urban slums, shanty towns, and rural villages have worms

32. Helminths (Worms) • Roundworm, hookworm, whipworm • infect 25 to 35 % of world population • cause blood loss in intestines • cause anemia • cause Vitamin-A deficiency • cause loss of appetite • increase energy cost

33. Helminths (Worms) • Roundworm, hookworm, whipworm • hyperactivate the immune system • depress immune response • increase susceptibility to HIV • increase HIV viral load and • HIV transmission

37. Distribution of Schistosomiasis hematobium

38. Schistosomiasis (bilharzia) • S. hematobium (urinary schistosomiasis) infects 33 % of Africans, over 200 million people.

39. Schistosomiasis (bilharzia) • S. hematobium (urinary schistosomiasis) infects 33 % of Africans, over 200 million people. • Causes blood loss, malnutrition, anemia

40. Schistosomiasis (bilharzia) • S. hematobium (urinary schistosomiasis) infects 33 % of Africans, over 200 million people. • Causes blood loss, malnutrition, anemia • In endemic areas, 75 % of women with urinary schistosomiasis also have genital infection.

41. Schistosomiasis (bilharzia) • Worms and ova of S. hematobium infect the vagina, uterus, vulva, and cervix.

42. Schistosomiasis (bilharzia) • Worms and ova of S. hematobium infect the vagina, uterus, vulva, and cervix. • S. hematobium lesions are indistinguishable from STDs without biopsy.

43. Schistosomiasis (bilharzia) • Worms and ova of S. hematobium infect the vagina, uterus, vulva, and cervix. • S. hematobium lesions are indistinguishable from STDs without biopsy. • Lesions provide direct access to the blood stream for HIV.

44. Schistosomiasis (bilharzia) • Worms and ova of S. hematobium infect the vagina, uterus, vulva, and cervix. • S. hematobium lesions are indistinguishable from STDs without biopsy. • Lesions provide direct access to the blood stream for HIV. • Worms and ova produce inflammation, attracting CD 4+ cells to the cervix and other sites in the reproductive tract.

46. S. hematobium in Tanzania

47. S. hematobium in South Africa and Swaziland

48. What is causing the epidemic of HIV/AIDS?

49. I = N x P x Twhere I is probability of sexual infection,N is the number of partners,P is the prevalence rate in the population, and T is the per-contact transmission risk, which is assumed to be the same for every population.One risk fits all.

50. I = N x P x T • T = V – + C + (or T = V – x C +) risk of transmission = vulnerability + contagiousness • V – = f {standard risk, H, M, F, TB, STD, SCH, . . . } • C + = g {standard risk, H+, M+, F+, TB+, STD+, SCH+, . . . }