AIDS Overview and Statistics

Questions and Answers

What characterizes the symptomatic stage of AIDS?

CD4 levels below 200 cells/μL (correct)

Presence of opportunistic organisms (correct)

Transient symptoms lasting less than a week

High levels of CD4 cells

Which of the following symptoms is NOT typically associated with AIDS-related complex (ARC)?

Fever

Diarrhea

Confusion (correct)

Night sweats

What is the most common malignant cancer associated with AIDS?

Melanoma

Leukemia

Lymphoma

Kaposi’s sarcoma (correct)

Which method is primarily used for the laboratory diagnosis of HIV?

Enzyme immunoassay (EIA) Signup and view all the answers

What leads to the development of wasting syndrome in patients with AIDS?

Marked weight loss and anorexia Signup and view all the answers

Which of the following is a transmission route for the HIV virus?

Contact with contaminated body fluids Signup and view all the answers

Which statement about breast-feeding and HIV is accurate?

HIV appears in breast milk and breast-feeding is not recommended. Signup and view all the answers

What must occur after a positive enzyme immunoassay (EIA) result for HIV?

Confirmation by a Western blot or immunofluorescence assay Signup and view all the answers

What is the purpose of polymerase chain reaction (PCR) in the context of HIV?

To assess viral load by measuring HIV DNA levels Signup and view all the answers

What is the primary rationale for starting HIV treatment immediately upon diagnosis?

To halt viral replication regardless of CD4 counts Signup and view all the answers

Which of the following statements about highly active antiretroviral therapy (HAART) is correct?

It combines three different antiretroviral drugs from at least two classes Signup and view all the answers

What is an important component of HIV treatment besides medication?

Prophylactic treatment for all opportunistic infections Signup and view all the answers

Which of the following reflects the current research direction in HIV treatment?

Creating a vaccine to protect against HIV infection post-exposure Signup and view all the answers

How is the effectiveness of HIV antiretroviral therapy determined?

Through the assessment of CD4 counts and plasma HIV RNA Signup and view all the answers

What year was AIDS first identified?

1981 Signup and view all the answers

What percentage of individuals infected with HIV globally are receiving antiretroviral therapy?

46% Signup and view all the answers

Which enzyme is crucial for the replication of retroviruses like HIV?

Reverse transcriptase Signup and view all the answers

What is the primary function of gp120 in the HIV structure?

Acting as a binding site for CD4 Signup and view all the answers

What is the outermost layer of the HIV virus called?

Lipid bilayer Signup and view all the answers

Which of the following describes the composition of the HIV genome?

Single-stranded RNA Signup and view all the answers

From where does the lipid envelope of HIV originate?

Host cell membranes Signup and view all the answers

What role does HIV protease play in the lifecycle of the virus?

Processing viral proteins Signup and view all the answers

What is a primary reason for the development of numerous resistant HIV variants?

Low fidelity of reverse transcriptase coupled with high rates of HIV replication Signup and view all the answers

Which benefit is provided by using HIV drug cocktails?

They help offset the problem of drug resistance Signup and view all the answers

How does genotypic resistance testing differ from phenotypic resistance testing?

It focuses on specific resistant mutations in HIV Signup and view all the answers

What is one limitation of genotypic resistance testing?

It may not detect new mutations that have arisen Signup and view all the answers

Why might phenotypic resistance testing be considered more challenging than genotypic testing?

It is more expensive and technically difficult Signup and view all the answers

Which statement is true regarding drug-resistant HIV mutants?

More than 100 drug-resistant HIV mutants have been identified Signup and view all the answers

What is the primary type of cell that has the highest concentration of CD4 proteins?

Helper T-cells Signup and view all the answers

Which glycoprotein on the HIV peplomer first binds to the CD4 site on the host cell?

gp120 Signup and view all the answers

What is required for effective HIV binding to CD4 cells in addition to CD4 proteins?

Chemokine receptors Signup and view all the answers

During which step does the HIV RNA get converted into a DNA/RNA hybrid molecule?

Reverse transcription Signup and view all the answers

What is the role of the HIV integrase enzyme in the viral lifecycle?

To embed viral DNA into host DNA Signup and view all the answers

What occurs to newly formed HIV viruses before they can become fully functional?

They must be modified by HIV protease enzymes. Signup and view all the answers

What happens when the cellular DNA is expressed in relation to viral DNA?

Viral DNA is expressed simultaneously. Signup and view all the answers

Which of the following best describes some identified variants of the HIV virus?

Some variants progress the disease rapidly while others progress slowly. Signup and view all the answers

Study Notes

Introduction to HIV/AIDS

AIDS was first identified in 1981 among gay men in San Francisco due to uncommon opportunistic infections.
Over 1 million Americans currently live with HIV.
Between 2008 and 2014, the annual rate of HIV infections decreased by approximately 18%.
Antiretroviral therapy has significantly enhanced quality of life and life expectancy for HIV-positive patients.
Estimates indicate that 95% of people with HIV reside in developing countries.
Globally, only 46% of individuals with HIV access antiretroviral therapy.

HIV Structure and Lifecycle

HIV is an RNA virus categorized under retroviruses.
Replication of retroviruses requires reverse transcriptase to convert RNA into DNA/RNA hybrid molecules.
HIV genome includes essential enzymes: reverse transcriptase, integrase, and protease.
The structure features an inner protein core with double-stranded RNA, surrounded by a protein shell encased in a lipid bilayer.
Lipid envelope is derived from host cell membranes during viral budding.
Glycoprotein spikes (peplomers) on the lipid envelope facilitate attachment to CD4 receptors on host cells.
gp120 binds specifically to CD4 proteins, predominantly found on helper T-cells, leading to cellular fusion.
Following fusion, the viral core injects its genome into the host cell, initiating uncoating and integration into host DNA.

Symptomatic Stage of HIV/AIDS

CD4 cell levels drop below 200 cells/μL, indicating symptomatic HIV or AIDS-related complex (ARC).
Symptoms include fever, night sweats, diarrhea, and opportunistic infections.
As CD4 levels decline, viral load in the blood can increase, potentially leading to malignancies, particularly Kaposi's sarcoma.
Neurological disorders like AIDS dementia complex may arise with memory loss and motor function changes.
Wasting syndrome, characterized by severe weight loss and metabolic dysfunctions, is common in advanced stages.

Epidemiology of HIV Infection

HIV is a blood-borne pathogen transmitted through contaminated body fluids via unprotected sexual activity, needle sharing, and vertical transmission from mother to child.
HIV can appear in breast milk; breastfeeding is discouraged in HIV-positive mothers.
HIV is present in saliva, but transmission through casual contact has not been proven.

Laboratory Diagnosis of HIV

Enzyme immunoassay (EIA) detects HIV antibodies, while positive results require confirmation by Western blot or immunofluorescence assay.
p24 is the most abundant HIV core protein; others include p55, p40, gp120, and gp41.
Polymerase chain reaction (PCR) is utilized to analyze viral loads (HIV DNA levels).

Rationale for Treatment of HIV

Treatment aims to inhibit viral replication at various stages of the HIV life cycle.
Immediate treatment is recommended upon diagnosis, regardless of CD4 count.
Management includes addressing opportunistic infections and providing comprehensive support.

Treatment of HIV

Effective treatment approaches heavily rely on prevention strategies.
Ongoing research is focused on developing an HIV vaccine for post-exposure protection.
Antiretroviral therapy effectiveness is monitored via CD4 counts and plasma HIV RNA levels.
Current treatment employs highly active antiretroviral therapy (HAART), requiring a combination of three drugs from different classes.

HIV Drug Resistance

High replication rates and genetic recombination in HIV lead to numerous drug-resistant variants.
Combining multiple antiretroviral drugs can counteract resistance.
Genotypic and phenotypic testing informs clinicians about specific drug resistance for tailored treatment.

HIV Drug Resistance Testing

Genotypic resistance testing identifies specific genetic mutations linked to drug resistance; efficient but limited in mutation detection.
Phenotypic resistance testing assesses HIV's ability to replicate in the presence of drugs; it's accurate but costlier and technically complex.

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Description

This quiz covers the basics of AIDS, including its history, statistics, and impacts on those living with HIV. Understand the progression of the disease and the effectiveness of antiretroviral therapy. Test your knowledge of AIDS and its epidemiology!