HIV

HIV Overview

  • Definition: Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system, specifically targeting CD4 cells, leading to a gradual deterioration of the body’s ability to fight infections.

Learning Objectives

  • Understand general concepts of the immune system.

  • Comprehend the pathology of HIV.

  • Recognize the origin of HIV.

  • Identify how HIV is transmitted.

  • Acknowledge the determinants and impacts of HIV.

Immune System Function

Physical Barriers

  • Skin, mucus, and other barriers protect against pathogens.

Innate Immune System

  • Immediate, non-specific response to pathogens.

  • Immunity present at birth.

Acquired Immune System

  • Develops over time; specific to antigens.

  • Takes several days to activate in response to pathogens.

Innate Immunity

  • Role of Phagocytes: Cells that engulf and digest pathogens that breach physical barriers.

  • Phagocytes respond to bacteria and other pathogens quickly.

Acquired Immunity

  • Activates if innate immunity fails to eliminate pathogens.

  • Key Players: Lymphocytes (e.g., T cells and B cells) play crucial roles in fighting infections.

Understanding HIV

Definition and Characteristics

  • H: Human - Only found in humans, preventable by human actions.

  • I: Immunodeficiency - The body cannot adequately defend against infections.

  • V: Virus - Lives and replicates within human cells.

HIV Structure

  • HIV is classified as a Retrovirus.

  • Contains RNA, a protein coat, and reverse transcriptase, which allows it to replicate inside host cells.

Retrovirus Functionality

  • Reverse transcription process reverses the normal flow of genetic information, using RNA as a template to create DNA.

  • This process is less stable than DNA replication, contributing to high mutation rates.

Transmission of HIV

  • Can be transmitted through:

    • Sexual contact

    • Pregnancy and childbirth

    • Breastfeeding

    • Injection drug use

    • Occupational exposure

    • Rarely through blood transfusion or organ transplant.

Body Fluids Containing HIV

  • Semen, breast milk, blood, and vaginal fluids.

Non-Transmission Sources

  • HIV is NOT transmitted through tears, saliva, sweat, or urine.

Window Period for HIV Testing

  • The window period is the time after infection when antibodies may not yet be detectable, often up to 3 months.

Historical Origin of HIV

  • Zoonosis: HIV is believed to have originated from primates infected with Simian Immunodeficiency Virus (SIV).

  • Transmission likely occurred through butchering and consumption of monkey meat.

Classification of HIV

Types of HIV

  • HIV-1: Most prevalent and responsible for the global epidemic.

  • HIV-2: Less common, primarily found in West Africa and progresses more slowly than HIV-1.

HIV Genetic Diversity

  • Subgroups and Clades: Different genetically distinct strains of HIV-1 have emerged, influencing geographical prevalence and disease impact.

Determinants of HIV Risk and Impact

Biological, Social, Environmental, and Behavioral Determinants

  • Understanding various factors (biological, social, environmental) that influence HIV prevalence and outcomes.

Disparities in HIV among Groups

  • Minority groups, particularly MSM and those with low socioeconomic status, exhibit stark disparities in HIV rates.

  • High prevalence in African American and Latino populations.

Factors Influencing Transmission in Minority Communities

  • High rates of STDs, sexual network patterns, and social determinants like poverty and healthcare access significantly increase HIV risks.

Stigma and Social Adversity

Stigmatization of HIV/AIDS

  • HIV/AIDS stigma includes societal prejudice, discrimination, and negative attitudes, impacting testing behaviors and care access.

Demographics of Late Testers

  • Common Characteristics: Black or Hispanic individuals, younger age, exposed through heterosexual contact, low educational attainment, often seek testing due to illness.

Barriers to Care for People Living with HIV/AIDS

Economic Barriers

  • Unemployment, poverty, food insecurity, lack of insurance, and transportation issues restrict access to healthcare.

Psychosocial Barriers

  • Stigma, mental health issues, and fears of disclosure hinder access to care.

Systemic Barriers

  • Limited healthcare providers, inconvenient hours, cultural insensitivity, and unwelcoming atmospheres impede service access.

Conclusion: Why HIV Rates Persist

  • Early sexual activity, inadequate sex education, multiple partners, discriminatory practices, and substance abuse contribute to ongoing HIV prevalence.