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Antiretroviral%20therapy%20for%20hiv-infected%20adults Signs and Symptoms
Introduction
- Human immunodeficiency virus (HIV) is a single-stranded ribonucleic acid (RNA) virus recognized as the causative agent of acquired immunodeficiency syndrome (AIDS)
- Types of HIV epidemics:
- Low-level epidemic is when HIV may have existed for many years but has never spread to significant levels in any sub-population; recorded infection is largely confined to high-risk individuals (eg drug injectors, sex workers, men having sex with other men [MSM]); HIV prevalence has not consistently exceeded 5% in any sub-population
- Concentrated HIV epidemics is when HIV has spread rapidly in a defined sub-population but is not well established in the general population; HIV prevalence is consistently >5% in at least one sub-population but is <1% in pregnant women in urban areas
- Generalized HIV epidemic is when HIV is firmly established in the general population; HIV prevalence is consistently >1% in pregnant women
Epidemiology
- Globally, as of 2021, reported cases to the World Health Organization (WHO) were approximately 38.4 million (33.9–43.8 million), with an estimated 3.8 million people coming from South-East Asia
- There have been 40.1 million deaths reported to the WHO globally as of 2021, with 650,000 (510,000-860,000) deaths due to HIV-related causes
- In the Philippines, people living with HIV were estimated at 140,000 in 2021, at 520,000 in Thailand in 2021, at 540,000 in Indonesia in 2021, and at 87,581 (77,910-98,007) in Malaysia in 2019
- A cumulative total of 10,785 HIV cases in Hong Kong have been recorded in 2020, with the median age of 37 years (30-39 years old in males; 40-49 years old in females) and are mostly male (83%)
Pathophysiology
- The outer viral membrane which contains HIV-specific glycoproteins (gp) including gp120 and gp41, facilitates attachment and entry of HIV into the host's CD4+ cells
- CD4+ T cell destruction is the hallmark of HIV infection
- Viral replication progresses with the presence of 2 key enzymes: Reverse transcriptase and integrase
- Reverse transcriptase: Forms viral RNA to viral DNA
- Integrase: Transports viral DNA into the nucleus to integrate with human chromosomal DNA
- B cell proliferation and abnormal antibody production impairs humoral immunity
- Ongoing viremia with pro-inflammatory cytokines, B cell proliferation, and hypergammaglobulinemia leads to a chronic inflammatory state that contributes to cardiovascular disease, cancer, and other chronic diseases
