Download HIV & AIDS

HIV & AIDS
IB Topic 6.3
Turn and Talk

What do you know or think of HIV &
AIDS?
Talking Point

http://www.nytimes.com/1987/09/01/o
pinion/on-my-mind-our-house-inarcadia.html
Introduction

Human immunodeficiency virus (HIV)
is the virus that eventually results in a
set of symptoms collectively called
acquired immune deficiency
syndrome (AIDS)
Some background
information

1981

U.S. healthcare workers noticed an increase
in the number of cases of Kaposi’s sarcoma
& pneumonia
• Kaposi’s sarcoma: cancer; red/purple lesions on
the skin, mouth, nose, throat & other organs


These observations led to what came to be
known as acquired immunodeficiency
syndrome (AIDS)
1983

The retrovirus human immunodeficiency
virus (HIV) was discovered as the cause of
AIDS
Where did HIV come from?
A lot of different theories & conspiracy
theories
 Molecular studies of HIV reveal the
virus probably evolved from another
HIV-like virus in chimpanzees in
central Africa


Believed to have appeared in humans
between 1915-1940
• Unrecognized
HIV

There are two strains of HIV
HIV-1 & HIV-2
 HIV-1 is more widely distributed and
virulent

How HIV damages the
immune system

All viruses must find a type of cell in
the body that matches their own
proteins

This is why only certain body cells are
damaged by certain viruses reflected
in the symptoms associated with the
particular infection
• Ex: a cold virus locates the proteins on
the mucus membrane cells in your nasal
region and danger those cells
• Results in swelling of the area and excessive
mucus production
How HIV damages the
immune system
The same is true for HIV
 Only certain cells in the body have the
protein in their membranes that HIV
recognizes
 One of those cells …


Is the helper T cell
• More specifically, CD4 receptors

This is the cell HIV infects
HIV is a retrovirus
HIV-RNA is reverse transcribed
 The product DNA is integrated into the
host genome



Directs the production of new virus
particles
Because the virus exists within the
infected cell, the immune system fails
to eradicate it
How this affects the immune
system




Helper T cells communicate which cells
need to undergo the cloning process and
begin antibody production
If these cells die, the communication no
longer exists
Antibodies do not get produced
At this stage, the individual can no longer
fight off pathogens

Secondary infections ultimately take the life
of someone with AIDS
Other facts/challenges

Accumulation of mutations from viral
replication


Difficult to develop a vaccine or cure
HIV has a latency period
Infection occurs, but cells remain alive
 Usually years after HIV infection
before the symptoms of AIDS
develops

The stages of HIV infection
Immune response diminishes viral
load; however, HIV continues to
replicate
 Viral load rises
 T cells decrease
 Extensive loss of cell-mediated
immunity

HIV tests

Detection of HIV-1 antibodies
Appear in the blood about 1-12
months after infection
 Called an ELISA

• Enzyme linked immunosorbent assay
Symptoms/Stages
Often asymptomatic
 Initial infection (primary or acute)

Feels like the flu
 Fever, headache, nausea


Chronic infection

Swollen lymph nodes
(Some) Symptoms of AIDS
Weight loss
 Reoccurring respiratory tract infection
 Skin rashes/ulcers
 Opportunistic infections

Pneumonia
 Cancers (Kaposi’s sarcoma)
 Herpes

No cure


HIV cannot be cured & progression to AIDS
cannot be prevented
Drugs can slow the process
• Slow viral replication
• HAART (highly active antiretroviral treatment)
• May also be administered to people who have
been exposed – take for 28 days
• Also given to newborns for ~ 1 week if mother is
infected


Expensive
Need to be taken properly (if not, mutation
can occur)
Statistics (2010; UNAIDS,
WHO, UNICEF)

~35 million people living with AIDS today



~1 million in North America
Fasted growth rate: Russia, Eastern Europe
& Central Asia



~70% (23 million) live in Sub Saharan Africa
Since 2001, HIV prevalence has increased
by 250%
Intravenous drug use (opium/heroin);
commercial sex workers
Prevalence in Sub Saharan Africa has
stabilized (but obviously still a problem)
Transmission






Bodily fluids
 Semen, pre-ejaculate, vaginal fluid, breast milk, blood
Unprotected sex
 Vaginal, oral, anal
Drug use
 Sharing needles
Breast feeding
Birth (parinatal transmission)
Blood transfusions
 Not the case anymore – all donated blood is screened
for HIV
 However, this was not the case until the mid-1990s
• Numerous cases of people contracting HIV from blood
transfusion
Misconceptions/Stereotypes/
Stigma

Originally labeled as a disease
affecting homosexuals & drug abusers
Back to the group of people in 1980
 This initially led to some reluctance in
allocated $ for HIV research
 Rumored that Earvin Magic Johnson
was homosexual …


AIDS is rapidly spreading among
heterosexuals
Turn and talk

Should criminalization of HIV
transmission be enforced?



Meaning, should a person be tried and/or
punished by the court of law for having
unprotected sex without disclosing to his/her
partner that he/she is HIV positive?
In some countries, the intentional or
reckless transmission of HIV is a crime
Countries that have some law include:
Australia, UK, Canada, Russia, Scotland,
Germany, Finland, and the US
• 35 US states have prosecuted HIV positive
individuals for exposing another person to HIV
(Illinois is one of them)
Turn and talk

Discuss the social, emotional, political
and financial issues related to AIDS
Issues related to AIDS
Education
 Access to health care
 Stereotypes
 Employment
 Finances
