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ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS)

ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS). EPIDEMIOLOGY By Emmanuel E Nkwogu Liberty University Online, Lynchburg, Virginia USA. DEFINITIONS. AIDS (Acquired immune deficiency syndrome) diagnosis;── stage 3 HIV infection

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ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS)

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  1. ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS) EPIDEMIOLOGY By Emmanuel E Nkwogu Liberty University Online, Lynchburg, Virginia USA

  2. DEFINITIONS • AIDS (Acquired immune deficiency syndrome) diagnosis;── stage 3 HIV infection • HIV (Human immunodeficiency virus) infection; ranges from asymptomatic to advanced disease • Two types of HIV: (a) HIV-1; major cause of HIV infection worldwide (b) HIV-2; less virulent and mainly in West Africa

  3. Etiology • HIV/AIDS─ of zoonotic origin1 • Switched from primates to humans • Switched from chimpanzees and gorillas from West Central Africa • HIV -1 identified in a serum from 1959 and a biopsy from 1960 in Democratic Republic of Congo (DRC)

  4. Transmission/Spread • One of the most serious health problems f the 21st century • Globally, major source of spread are heterosexual (>75%), and mother to child (5%-10%) • HIV present in blood, semen and breast milk • Course of infection defined by changes in the CD4+ T-Lymphocyte (helper T-cells) • CD8 Cytotoxic T cell lymphocytes most important for recognizing and lysing of CD4 cells • Exact mechanism not fully understood.

  5. The Phylogenetic Relationships of Lentiviruses The phylogenetic relation of lentiviruses in man and non-human primates Adapted from Simon V.,Ho DD., and Karim QA. HIV/AIDS epidemiology, pathogenesis, prevention and treatment. The Lancet, Volume 368, issue 9534 2005 489-504 http://dx.doi.org/10.1016/so140-6736(06)69157-5

  6. The Course of HIV-1 Infection The course of HIV-1 infection defined by the level of viral replication, Plasma viraemia (top) And dynamic changes of the CD4+ T-Lymphocyte components (bottom. Primary infection charcterized by high plasma viraemia (red line top), Low CD4… Adapted from Simon V.,Ho DD., and Karim QA. HIV/AIDS epidemiology, pathogenesis, prevention and treatment. The Lancet, Volume 368, issue 9534 2005 489-504 http://dx.doi.org/10.1016/so140-6736(06)69157-5

  7. Worldwide Prevalence and Incidence • A Modern Day Plague: A global security threat3 • First recognized in 1981 • AIDS takes about 2-15 years to develop • 34.2 million people living with HIV/AIDS worldwide • 2.5 million New cases (including 330,000 children ) in 2011 • More than 25 million people have died from HIV/AIDS

  8. Worldwide Distribution of HIV-1 Infection Adapted from Simon V., Ho DD., and Karim QA. HIV/AIDS epidemiology, pathogenesis, prevention and treatment. The Lancet, Volume 368, issue 9534 2005 489-504 http://dx.doi.org/10.1016/so140-6736(06)69157-5 Worldwide distribution of HIV-1 infections, modes of transmission, and HIV-1 subtypes. HS=Heterosexual, MSM= Men who have sex with men, IDU= Injection drug users. Based on Joint UNAIDS and WHO AIDS epidemic update, December 2005

  9. Deaths from AIDS in 2005 totaled 2.3 million3 Source: UNAIDS Report on the Global AIDS Epidemic, 2012

  10. HIV/AIDS Timeline • 1981- a new syndrome AIDS was discovered among homosexuals in the United States of America. • 1983 – HIV identified as the etiologic agent for AIDS. • By mid-1980’s it was discovered that the virus had spread unknowingly throughout most of the world. • HIV/AIDS pandemic consists of separate epidemics • Separate in terms of geography, specific populations affected, different risk behaviors and practices • Sub-Saharan Africa most affected • Most explosive epidemic in Southern Africa 2 • Botswana and Swaziland have the highest prevalence level

  11. HIV among Pregnant women in Developing Countries Source: UNAIDS_WHOPaper 2: Workshop on HIV/AIDS and adult mortality In Developing Countries ─September 2003

  12. Strategies for Surviving HIV/AIDS epidemic7 Source: Mutangadura, et al., 1999:17

  13. HIV/AIDS epidemic in Addis Ababa, Africa2 Source: SimonV, Ho DD, Karim QA. HIV/AIDS epidemiology… The Lancet Vollume 368, issue 9534

  14. HIV/AIDS IN THE USA • Dr D Gallo and co-workers discovered HTLV-1 and HTLV-2 between 1976 and 1982 • Initially referred to the disease as GRID (Gay-related immune deficiency) • Later known as Acquired immune deficiency syndrome (AIDS)

  15. HIV/AIDS in the USA, cont’d STATISTICAL OVERVIEW: • At the end of 2009 1,148,200 persons living with HIV/AIDS6 • 207,600 (18.1%) undiagnosed • In 2010 incidence of HIV=47,500 • Two-thirds of these were in gay and bisexual men • Blacks/ African American men and women had HIV incidence 8 times that of whites • In 2010, number of deaths from AIDS=15529 • Cumulative AIDS diagnoses through 2010=636,048 • In 2011 HIV incidence: 49,273 (men-38,825,Women=10257

  16. HIV/AIDS in the USA cont’d Diagnoses OF HIV INFECTION BY AGE Data Source: Center for Disease Control and Prevention (CDC)-Statistical Overview

  17. HIV/AIDS in the USA cont’d DIAGNOSES OF HIV INFECTION , BY RACE/ETHNICITY Data Source: Center for Disease Control and Prevention (CDC)- Statistical Overview

  18. HIV/AIDS in the USA cont’d HIV DIAGNOSES, BY TOP 10 STATES/DEPENDENT AREAS Data Source: Center for disease Control and Prevention (CDC)- Statistical Overview

  19. Core Indicators of Global AIDS Response • Reducing sexual transmission of HIV by 50% by 2015 • Eliminate new HIV infections among children by 2015 and substantially reduce AIDS-related maternal deaths. • Reducing transmission of HIV among people who inject drug by 50% by 2015 • Reach 15 million people living with HIV with lifesaving antiretroviral treatment by2015. • Reduce tuberculosis deaths in people living with HIV by 50% by 2015. • Close the global AIDS resource gap by 2015 and reach annual global investment of US$ 22$ billion in low- and middle income countries. • Eliminating gender inequalities, stigma and discrimination and travel restriction • Strengthening HIV integration.

  20. Some AIDS-defining Diagnoses Kaposi sarcoma Pneumocystis Jirovecii pneumonia Source: Lewthwaite p and Wilkins E. Natural History of HIV/AIDS Herpes simplex

  21. Current Hypotheses RISK FACTORS • Risky Sexual behavior • Unsafe blood transfusion, • High prevalence of STD, • Absence of circumcision, • Use of non sterile needles, • Human density in forest areas, • Increasing transport between urban and rural areas, • Human migration, • Increase in commercial sex

  22. Gaps in Knowledge Mode of Transmission Mechanism of destruction of CD4 • Many people do not know the mode of transmission of HIV/AIDS; and thus are uncomfortable associating with people with HIV/AIDS. • The exact mechanism of the destruction of CD4 lymphocytes is not well understood yet. Viral load/CD4 Changes over time following HIV infection Source: Natural History and Clinical features by Lewthwait P, & Wilkins E. 2009 Elsevier Ltd.

  23. Further Epidemiologic Research Focus on understanding the: Exact mechanism of the destruction of CD4 lymphocytes All that is involved in the transmission of the HIV/AIDS. With a fuller understanding of the mode and mechanism of transmission, there will be hope that a vaccine would be developed against HIV/AIDS. Although the current Antiretroviral drugs are active in reducing the effects of HIV/AIDS Research into development of new drugs is still important as the HIV is known to have a high capacity to mutate. Source: UNAIDS Report on the Global AIDS Epidemic,2012

  24. Appraisal of the data as a whole: • According to CDC and from the data as a whole, the battle against HIV/AIDS is yielding to science and worldwide commitment. • This is also illustrated below by UNAIDS 2012 report. • Progress in Fighting the Epidemic: • 50% reduction in New HIV infections between 2001 and 2011 in 25 countries

  25. Appraisal of the Data as a Whole, cont’d • 43% decline in new HIV infections in children from 2003 to 2011, with over half of that decline occurring within the last two years • 50% or greater drop in HIV/AIDS-related deaths between 2005 and 2011 in 14 countries, with another 29 countries achieving a reduction of 25-49% • 25% decline in TB-related deaths worldwide and 28% decline in sub-Saharan Africa between 2004 and2011. • The progress is reflected in terms of longer life span due to antiretroviral treatment. The progress is illustrated in the figures below.

  26. Cumulative Life-Years Gained from Antiretroviral Drugs, 1996-2011 Source: UNAIDS World AIDS Day Report, 2012

  27. HIV/AIDS Programmatic Tipping Point in 2011 Source: UNAIDS World AIDS Day Report, 2012

  28. References 1 1. Martine P., Steve AM., Eitel MN., Eric D. Origin of HIV and risk for ongoing zoonotic transmissions from nonhuman primates to humans. July 2010: P.387: http://dx doi.org. Epoxy.liberty.edu. 2048/102217/hiv10332. 2. Simon V., Ho DD., Karim QA. HIV/AIDS epidemiology, pathogenesis, prevention and treatment. The Lancet, Aug 5-Aug 11, 2006; 368, 9534 ProQuest Central P.489. Accessed from www.ncbi.nlm.nih.gov on June 3, 2013. 3. WHO Global AIDS Response 2013. 2011 UN Political Declaration on HIV/AIDS. www.who.int/hiv/pub/progress_report 2011 4. A History of the HIV/AIDS Epidemic with Emphasis on Africa. UNAIDS and WHO www.un.org/esa/population/publications...UNAIDS. 5. Tekoa F. The economic impacts of HIV/AIDS morbidity and mortality on households in Addis Ababa, Ethiopia. AIDS care, Volume 20 issue 8 doi. 10.108/09540120701777256 P.995 6. CDC’s HIV Surveillance Report: Diagnosis of HIV Infection and AIDS in the United States and Dependent areas 2011. Centers for Disease Control and Prevention. Statistics Review. (/ hiv/library/report/surveillance/2011/Surveillance Report vol. 23.html) vol.23 retrieved from 7. Naidu V., Harris G. The Impact of HIV/AIDS on morbidity and mortality on households. A review of household studies. South African Journal of Economics Vol. 73 2005, Special issue on HIV/AIDS. Doi: 10.11 11/saje.2005.73.issue-s1/issue toc, www.demographic research.org /volume/vol. 27

  29. References 2 8. CDC and the fight against Global HIV/AIDS. Accessed on June 3, 2013 from www.cdc.gov/globalaids/publications/CDC-Global-HIV-Update-2013.pdf 9. Fauci AS, Kasper DL, Long DL, Hauser S, Jameson J, Lascalzo J. HIV Infection and AIDS. Harrison’s Principles of Internal Medicine, 18th ed., McGraw-Hall, Health Professions Division, New York.2011. 10. Guyton, A.C., Hall, J. E. (2001). Resistance of the body to Infection: Immunity and Allergy. Text Book of Medical Physiology, 10th ed., W.B. Saunders Company, A Harcourt Health Sciences Company, The Curtis Center, Independence Square West, Philadelphia, Pennsylvania 19106, 2010 11. Jacques Initiative; Institute of Human Virology, University of Maryland School of Medicine. Accessed from www.jacques.umaryland.edu 12. Sullivan LM. Essentials of Biostatistics in Public Health, 2nd ed. Burlington, Massachusetts, MA; Jones and Bartlett Learning, LLC: 20128. 13. Friis RH, Seller AT. Epidemiology for Public Health Practice, 4th ed. Sudbury, Massachusetts, MA; 14. Lewthwaite P and Wilkins E. Natural History Clinical features of HIV/AIDS , Elsevier Ltd.,2009.

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