The History of HIV/AIDS

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Questions and Answers

What is the primary purpose of Highly Active Anti-Retroviral Treatment (HAART) in HIV management?

To boost the immune system without targeting HIV

To reduce the viral load to undetectable levels only

To completely eliminate HIV from the body

To inhibit multiple steps of the HIV replication cycle (correct)

Which component of the HIV virion is primarily targeted by diagnostic tests?

Protease

Envelope glycoproteins (correct)

Integrase

Reverse transcriptase

What is a major challenge in developing an effective HIV vaccine?

The variability of the HIV virus (correct)

The lack of knowledge about HIV structures

The availability of funding for research

The ability to eliminate immune memory of HIV

During the immune response to HIV infection, which lymphocyte count is often observed to be extremely low?

T cells Signup and view all the answers

What was a significant finding related to the first reports of an unknown disease linked to HIV in the early 1980s?

A rise in unexplained pneumonia cases among homosexual men Signup and view all the answers

What is the principal cause of the AIDS pandemic?

HIV-1 group M Signup and view all the answers

Which enzyme is essential for the replication of HIV, allowing it to convert its RNA into DNA?

Reverse transcriptase Signup and view all the answers

What significant impact does HIV have on the immune system?

Destroys CD4+ T cells Signup and view all the answers

Which method is primarily used to diagnose HIV infection?

Serology tests for p24 antigen Signup and view all the answers

What is a key challenge in developing an effective HIV vaccine?

High mutation rate of the virus Signup and view all the answers

In Highly Active Anti-Retroviral Treatment (HAART), which of the following classes of drugs is NOT typically included?

Antifungal agents Signup and view all the answers

What facilitates the entry of HIV into CD4+ T cells?

Glycoproteins gp120 and gp41 Signup and view all the answers

Which of the following is a structural gene encoded by the HIV genome?

Gag Signup and view all the answers

What is the role of CD4 T cells during advanced stages of HIV infection?

They decline and no longer stimulate B cells. Signup and view all the answers

Why are HIV vaccines particularly challenging to develop?

HIV creates a large pool of diverse viral variants. Signup and view all the answers

What is the impact of adhering to antiretroviral therapy (ART)?

Decreases the risk of transmission and increases life expectancy. Signup and view all the answers

What is a common characteristic of individuals classified as elite controllers in HIV infection?

They maintain suppressed viral levels without HIV treatment. Signup and view all the answers

What type of test is essential for diagnosing HIV infection?

Antigen/Antibody test. Signup and view all the answers

What is one major hurdle in HIV vaccine development post-integration into host DNA?

HIV persists in a pool of hard-to-eliminate reservoirs. Signup and view all the answers

Which class of drugs is NOT a target for existing HIV treatments?

Viral protein synthesis enhancers. Signup and view all the answers

What percentage of HIV transmissions occurs in individuals unaware of their HIV-positive status?

40% Signup and view all the answers

Which of the following best describes the longevity of clinical latency in untreated asymptomatic HIV patients?

7-11 years. Signup and view all the answers

Study Notes

The Silent Spread of an Unknown Disease

A Danish surgeon working in the Democratic Republic of the Congo in the 1960s developed symptoms including diarrhea, swollen lymph nodes, weight loss, and fatigue
In 1977, the surgeon returned to Copenhagen in respiratory distress, with low T-cell counts and was diagnosed with Staphylococcus aureus, candidiasis, and pneumonia from Pneumocystis jirovecii.
The surgeon died and the cause of death was unexplained at the time
Her stored blood was tested positive for HIV.

Not so Silent Spread of an Unknown Disease

1981: the Centers for Disease Control (CDC) reported a cluster of cases of Kaposi's Sarcoma and Pneumocystis pneumonia among homosexual men in New York City and California.
A viral sequence from a man residing in the Congo taken in 1959 was found positive for HIV, identifying it as the oldest known case

Zoonotic Origins of HIV/AIDS

Human Immunodeficiency Virus (HIV) originated from simian immunodeficiency viruses (SIVs) that infect African primates
A transmission event around 1911, involving SIVcpz from chimpanzees in southeastern Cameroon, gave rise to HIV-1 group M
HIV-1 group M is the primary cause of the global AIDS pandemic
HIV-1 group M likely transferred from chimpanzees to human hunters via blood-borne transmission
Currently, approximately 40 million people are living with HIV/AIDS worldwide

Discovery of a Novel Human Herpesvirus

Kaposi's Sarcoma (KS) was a highly stigmatized sign of HIV infection during the peak of the AIDS pandemic.
In 1994, DNA sequences from skin biopsies of AIDS-KS patients revealed a new human herpesvirus known as Kaposi's Sarcoma-associated herpesvirus (KSHV or HHV-8)

HIV Virology: Structure

HIV is a single-stranded, positive polarity, RNA virus enveloped in a membrane
HIV replicates by producing DNA from RNA via reverse transcriptase, classifying it as a retrovirus (Group VI).
Viral DNA integrates into the host's DNA

HIV Virology: Genome

Three structural genes encode the following:
- Gag: internal proteins including p24 used for serological testing
- Pol: reverse transcriptase, protease and integrase
- Env: gp120/gp41 (attachment)
Six regulatory genes including Tat, which reduces HLA class I molecules

HIV Virology: Tropism

HIV glycoproteins gp120 and gp41 interact with the CD4 molecule, leading to infection of CD4+ T cells.
This results in loss of cellular immunity which leads to opportunistic infections (e.g. Pneumocystis pneumonia).

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Description

Explore the timeline and origins of HIV/AIDS, from its silent spread in the 1960s to the identification of the oldest known case in 1959. This quiz dives into the significant events that shaped the understanding of this epidemic and its zoonotic origins. Test your knowledge on how this global health crisis emerged and evolved over the decades.