Module 1. Introduction to HIV/AIDS

Transcription

1 Module 1 Introduction to HIV/AIDS

2 Module Objectives At the end of this module participants will be able to; Describe the global effects of HIV/AIDS. Describe the effects of the national HIV/AIDS epidemic. Explain the difference between HIV and AIDS. Describe the transmission and natural history of HIV infection. Explain the WHO clinical staging system and how it would apply in a clinical setting. 2

3 Unit 1: Overview of the HIV Pandemic Zanzibar National PMTCT Training Module 1: January

4 Unit 1 Objectives At the end of this unit participants will be able to; Discuss the global impact of HIV/AIDS. Describe the effect of the HIV epidemic at the community, family and individual levels. Zanzibar National PMTCT Training Module 1: January

5 Adults and Children Estimated to be Living with HIV in 2009 (Source: UNAIDS, 2009) 5 5

6 Global Overview of HIV Rates Worldwide Percentage of PLHIV stabilized since 2000 while overall number of PLHIV increases due to new infections outnumbering AIDS deaths. HIV is leading cause of mortality among women of reproductive age worldwide Sub-Saharan Africa 22.4 million adults and children infected with HIV Represent 66% of all people living with HIV/AIDS worldwide In 2008, only 2.9 of 6.7 million people enrolled at care and treatment centres received ARV therapy TraTanzania National PMTCT ining Module 1: January

7 HIV in women and children By million women were living with HIV globally Women accounted for 60% of adults living with HIV in sub-saharan Africa Children accounted for 6% of all people living with HIV More than 90% of children living with HIV are infected through mother to child transmission during pregnancy, birth or breast feeding. 7

8 Mother-to-Child Transmission (MTCT) of HIV Responsible for more than 90% of childhood HIV infections worldwide 20 45% risk of HIV transmission from infected mothers to newborns Prevention efforts, including ARV medication, can drastically reduce chances of MTCT of HIV. 8 8

9 Access to Services to Prevent MTCT MTCT has been significantly reduced in countries with universal access to PMTCT services Universal access is an achievable goal The number of pregnant women living with HIV in low-income countries who received ARVs to prevent MTCT has steadily grown. 9

10 Global Effects of HIV Economic burden Overwhelmed healthcare systems Reduced life expectancy Reduced child survival rates Increased number of orphans 10 10

11 Human Impact of HIV Individuals Illness and suffering, loss of work and income, barriers to health care resulting from stigma and discrimination Families Poverty, weakened integrity and support structure of family unit, death of a parent, orphans Children Often orphaned; lack of parental care, child-headed families 11 11

12 Unit 2 Scope of the National HIV/AIDS Epidemic 12

13 Unit 2 Objective At the end of this unit participants will be able to; Describe the effects of the national HIV/AIDS epidemic. 13

14 HIV/AIDS Situation in Tanzania First cases reported in Kagera region in 1983 In 2012, HIV prevalence among adults was estimated at 5.1% (1.8 million PLWHA) Concentrated in urban settings (7.2% vs. 4.3% in rural areas) More than 100,000 children below 15 years are living with HIV, 90% of whom may have acquired infection through MTCT 14

15 Tanzania HIV Map 2011/

16 HIV/AIDS Situation in Tanzania HIV/AIDS recognized as one of nation s greatest development challenges The Health Sector HIV/AIDS Strategic Plan and National Multisectoral Strategic Framework intended to consolidate interventions to prevent infections and reduce vulnerability High prevalence of HIV among TB clients (40.8%) 16

17 HIV Prevalence among ANC Attendees in Tanzania HIV Prevalence (%) Dar es Salaam HIV prevalence data of ANC surveillance studies by region and residence, 2003/2004 Dodoma Kagera Kilimanjaro Mbeya Mtwara Kigoma Lindi Morogoro Tanga Urban Roadside Rural Source: Ministry of Health/Tanzania Mainland: National AIDS Control Programme, HIV/AIDS/STI Surveillance Report, January- December 2004, Report Number 19, Issued October

18 Gender and HIV/AIDS in Tanzania HIV prevalence in women is 6.2% as compared to 3.8% in males. Women are more vulnerable to HIV due to: Inability to negotiate safer sex Unsafe practices of male partner who may have multiple partners Trauma, bleeding caused by sexual intercourse at early age Rape, sexual abuse Economic pressure to exchange sex for money/goods Socio-cultural factors such as polygamy, wife inheritance, female genital mutilation, and early marriage Lack of access to appropriate information on STIs & HIV/AIDS 18

19 Gender and HIV/AIDS in Tanzania Socio-cultural factors that increase HIV risk factors for men: Failure to seek proper care for HIV and STIs Cultural acceptance of having multiple sexual partners Unsafe sex due to drug and alcohol abuse or peer pressure to display manhood 19

20 Youth and HIV/AIDS in Tanzania Youth are more vulnerable to HIV due to: Lack of information on sexuality and development Inability to delay first sexual experience, reduce sexual partners, use condoms correctly, and avoid substance abuse Limited access to health services, counselling and testing and risk reduction centres Parents not readily addressing issues of sexuality with their children 20

21 Reducing HIV Inequalities Ways to reduce gender and agerelated inequalities: Ensure access to HIV-related information for women and girls Develop community-based initiatives to involve couples/partners Empower women to make health decisions Introduce communication interventions for men 21

22 Unit 3 Basic Facts about HIV/AIDS 22

23 Unit 3 Objective At the end of this unit participants should be able to; Explain the difference between HIV and AIDS. 23

24 Understanding HIV Basics What is HIV? How do you get it? How don t you get it? What is the difference between HIV and AIDS? 24

25 What is HIV? H: Human I: Immunodeficiency V: Virus 25

26 What is HIV? HIV is a virus that damages the immune system of people it infects The virus replicates and continues to weaken the body s immune system by infecting its protectors (white blood cells) When the immune system is weakened by HIV, illness progresses to AIDS HIV is the virus that causes AIDS Tanzania National PMTCT Training Module 1: May

27 What is AIDS? A: Acquired I: Immune D: Deficiency S: Syndrome AIDS is: A diagnosis based on a group of symptoms or illnesses that occur when HIV has damaged the immune system Most advanced stage of HIV infection Tanzania National PMTCT Training Module 1: May

28 What is AIDS? AIDS is characterized by certain infections that take advantage of the body s weakened immune system A diagnosis of AIDS is made by healthcare workers (HCWs) based on clinical symptoms or specific blood or laboratory test results Progression from initial infection with HIV to advanced AIDS varies among people and can take several months to up to 10 years or more Tanzania National PMTCT Training Module 1: May

29 Difference Between HIV and AIDS If HIV is not treated, it will weaken the immune system until a person is vulnerable to life-threatening diseases that don t normally affect a healthy person. This stage of HIV infection is referred to as AIDS. Tanzania National PMTCT Training Module 1: May

30 HIV-1 and HIV-2 HIV-1 and HIV-2 Transmitted through the same routes Associated with similar opportunistic infections HIV-1 is more common worldwide HIV-2: Found primarily in West Africa, Angola, and Mozambique Less easily transmitted Develops more slowly MTCT relatively rare with HIV-2 Tanzania National PMTCT Training Module 1: May

31 Unit 4 Transmission and Natural History of HIV 31

32 Unit 4 Objectives At the end of this unit participants should be able to; Describe transmission and natural history of HIV infection. Explain the WHO staging system of HIV/AIDS and how it applies in a clinical setting. 32

33 How is HIV Transmitted? Sexual contact Unprotected vaginal, anal, or oral sex HIV-infected body fluids like semen, vaginal and cervical secretions Drug use Infected needles or syringes Blood-to-blood Transfusions Direct contact Reuse of infected sharps Occupational exposure Mother-to-child Pregnancy, labour and delivery, or breastfeeding In Tanzania, the most common route of HIV transmission is through sexual contact, especially unprotected heterosexual intercourse. 33

34 How HIV is NOT Transmitted? HIV cannot be transmitted by: Coughing, sneezing Shaking hands Insect bites Touching, hugging Water, food Kissing Public baths/pools Work or school contact Telephones Cups, glasses, plates, or other utensils Other items touched by PLWHAs Toilets 34

35 Natural Course of HIV Infection Organs of the Immune System Source: US Dept. of Health & Human Services, National Institutes of Health, Understanding the Immune System: How it Works, NIH Sept. 2003, P. 4, available at: The immune system protects the body by recognizing and destroying infectious agents. HIV infects the immune system s CD4 cells. Once in the cell, HIV produces new copies of itself, which can then go on to infect other cells. As HIV infection progresses: Viral load (amount of HIV in blood) increases CD4 count (number of CD4 cells in blood) decreases CD4 cells can no longer help fight off other infections. 35

36 HIV Life Cycle Free Virus Binding and Fusion Infection Budding Reverse Transcription Integration Transcription Assembly Breaking -free Maturation 36

37 Measuring HIV Progression CD4 count: number of CD4 cells in blood Normal for healthy adult is 600 1,200 cells/mm 3 Below 200 cells/mm 3 indicates high risk of opportunistic infections Viral load: amount of HIV in the blood, usually measured by HIV-RNA PCR As HIV infection progresses, viral load increases 37

38 Natural History of HIV Infection Characteristic viral load and CD4 cell count changes over time Source: Pantaleo, G, C Graziosi and A S Fauci The immunopathogenesis of human immunodeficiency virus infection. New England Journal of Medicine, 328(5):

39 Understanding Viral Load Viral load depends on How fast the virus is reproducing (water drips) How well the immune system controls the virus (drain) 39

40 Summary of Natural History of HIV HIV multiplies inside CD4 cells, destroying them. As CD4 cell count decreases and viral load increases, the immune system becomes weak. Opportunistic Infection (OI): An illness caused by an organism that might not cause illness in a healthy person, but will cause illness in a person who has a weakened immune system. People infected with HIV become vulnerable to opportunistic infections. Without ARV treatment, HIV progresses to symptomatic disease and AIDS. 40

41 HIV Infection HIV-infected: HIV has entered the body HIV-positive: A blood test has determined that an individual is infected with the HIV virus The window period is the period of time between when a person is infected with HIV and when the antibody test result is positive. A test may not detect HIV during this period, but the virus can still be transmitted. 41

42 Progress of HIV Infection 1. Seroconversion: HIV exposure and infection occurs, antibodies develop Some people may experience a flu-like illness with symptoms of fever, sore throat, rash, joint pains, and enlarged lymph nodes during the process of seroconversion. The collection of these symptoms is also known as Acute Retroviral Syndrome (ARS). 2. Asymptomatic: No clinical symptoms of HIV infection, viral replication controlled by immune system 42

43 Progress of HIV Infection 3. Symptomatic: Clinical symptoms of HIV infection, varying degrees of immune suppression 4. AIDS: most advanced stage of HIV infection, vulnerable to Opportunistic Infections (OIs) 43

44 Module 1: Key Points HIV/AIDS is a global pandemic. The number of people living with HIV worldwide continues to increase. HIV prevalence in Tanzania is estimated at 5.1% among adults age Women of childbearing age are at particular risk for acquiring HIV. HIV infection may be transmitted from a pregnant woman to her baby. 44

45 Module 1: Key Points Risk of mother-to-child transmission of HIV can be greatly reduced through effective PMTCT programmes. HIV is a virus that destroys the immune system, leading to opportunistic infections and AIDS. CD4 cell count and viral load are two measures that indicate the progression of HIV. Antiretrovirals (ARVs) can slow the progression of HIV to AIDS. 45

46 Module 1: Key Points Without ARV treatment, HIV progresses to symptomatic disease and AIDS. Period between HIV infection and positive antibody test result is the window period. AIDS can be diagnosed through direct observation of clinical signs and symptoms (WHO Clinical Staging System). 46