- [Instructor] Now with immune system,
sometimes there's special case.
AIDS is one of those cases.
AIDS, or Acquired Immune Deficiency Syndrome,
is caused when a person is infected with the HIV.
HIV is Human Immunodeficiency Virus.
The name right there, immunodeficiency.
The immune system will not function properly.
The HIV is so potent because it targets
the helper T cells.
Now if you remember, the helper T cells
are one of the main cells that will
activate your immune response, so if you don't
have these helper T cells you really can't
activate your immune response efficiently.
Now HIV can be transmitted through any body fluid.
We're talking blood, semen, breast milk, vaginal secretions.
The idea is though, blood probably is
one of the more potent ways, but usually
semen, vaginal secretions, breast milk,
all have high enough concentrations.
Here's how HIV works.
HIV is a retrovirus, so when it's in your body
it will find a cell to bind to.
It will then insert the viral DNA.
The viral DNA will use your own cell's machinery
to make a single-stranded DNA.
Well, DNA is our genetic code.
That single-stranded DNA becomes a double-stranded DNA
just like our DNA.
It will head into the nucleus
and in the nucleus it will be reproduced,
copied, and read just like any other bit of DNA.
When the double-stranded DNA from the retrovirus is read
it will make viral codes.
It will make proteins which can make up
the virus itself.
That means that this viral RNA that was inserted
into a cell uses your cell's machinery
to make more of that virus.
That just keeps on going and going and going.
So now, in AIDS, there's several different phases.
Phase one, if you know it's going to take
a few weeks to a few years.
There is no one set time frame.
Everyone progresses at different rates.
You'll have these flu-like symptoms,
swollen lymph nodes, chill, fever, fatigue, body aches
but if the doctor does a test for the flu
it will come back negative.
At this point, the retrovirus is just getting going.
It's invading the cells, creating more retroviruses,
and spreading throughout your body.
You body's aware there's a problem
so it's trying to attack it.
It's acting like you have a flu
but the problem is a lot of people don't
exhibit symptoms.
It just occurs in their body without any clue
because it's happening so gradually
but that virus is multiplying.
Antibodies are made.
The problem is, the antibodies you're making
really aren't working very well.
They can get rid of parts of the virus.
It might get rid of some of the aspects here or there
but it does not clear the entire virus out.
Now those antibodies you're making,
they might not be good in six months
or a year from that point because the HIV virus
is constantly changing.
It's one of the biggest problems of why
medicine cannot find a cure or a vaccine.
The virus just changes too frequently
for anything to keep current.
Once that phase is gone then you get to phase two.
It can occur about six months to anywhere to 10 years.
This has a problem because now
it's opportunistic infections.
Opportunistic infections are any infection
that in a healthy person you probably could fight off
but with your immune system being compromised now
these infections can take set
and cause some major problems, and the reason here,
the helper T cells.
All the helper T cells are becoming infected,
they're becoming destroyed.
The numbers are slowly dwindling down.
The fewer and fewer helper T cells,
the slower and slower and weaker the immune response is.
If untreated, this phase two will go into the next phase,
the phase of AIDS.
So phase three, full-blown AIDS.
Now AIDS is diagnosed when the helper T cells
fall below 200 cells per cubic millimeter.
That means your body just cannot adequately fight infections
because the cells that activate the immune response
just aren't there.
So phase three, this is what typically is called AIDS,
is when the helper T cells are below
that 200 cell per cubic millimeter count.
Tuberculosis, pneumonia, mengitis, encephalitis,
Kaposi's sarcoma, non-Hodgkins lymphoma, cancers,
all these opportunistic infections will now
come into the system and try to take over.
Now any one of these is quite problematic.
More often than not a healthy individual
with a fully functional immune system
will not have any of these be able to take hold.
Well if you're thinking, hold on, I had pneumonia
or hey, I had meningitis,
these can take hold but usually they take hold
while you're already sick with something else.
For instance, I've had pneumonia.
Not the end of the world.
I was down and out for about a week or two,
but the pneumonia was only able to take hold
because I was already sick with a head cold
and upper respiratory infection.
That infection allowed the pneumonia infection to come in
because it's opportunistic.
If I didn't have that head cold and chest infection
pneumonia would not have a had a chance,
so that's that idea of opportunistic.
Something must be affecting your immune system
for these to come in and take hold.
Now, if there's no treatment at this point,
it's pretty much always fatal
because any one of these opportunistic infections
could be deadly, so treatment is pretty much
essential to try to help combat
these opportunistic infections.
So here's a graph showing your T cell count,
your antibodies, HIV in the blood,
all things mixed together.
Now the bottom of the graph is years.
You can see within the first year, HIV in the blood spikes
and gets knocked down.
That's because your antibodies are fighting it.
So phase one basically means the HIV has spiked,
antibodies are trying to catch up.
Phase two you can see, well, HIV in
the blood's pretty low.
The antibodies do a good a job
but they're not getting rid of everything
and the biggest problem is,
look what's happening in phase two.
The T cells are plummeting.
So even though the antibodies are pretty efficient here,
they're not 100% and the ones that are being missed,
those HIV virus particles that are still going,
they're killing and destroying
more and more and more T cells.
Eventually, you'll end up at a point
where there's more HIV in the blood
than there are T cells.
It's that point that typically is where
you say now it's full-blown AIDS.
Now any of these behaviors can increase
your chance of getting AIDS.
Now these are worldwide numbers.
Males, usually about 3/4 of new cases.
So it's going to be sex, man with man.
It can be sharing needles during
intravenous drug use.
Heterosexual with an HIV-infected female.
What all three of these share in common
is in exchanging bodily fluid.
In the first two, it could be exchanging blood.
In the first and third it could be exchanging
semen or vaginal fluids in the female.
Females, only about 1/4 of new cases, again worldwide.
If a female has sex with an HIV-infected male
or sharing drug needles.
Now the idea of safe sex.
Well, you hear all over the place,
abstinence is the only way perfectly to be safe.
That because it's the only 100% way.
Anything beyond that, you never get more than
a 99 point some percent chance.
Even tube-tying, vasectomy, you name
the different types of contraception,
every one of them, even the best ones,
are only at 99 point seven or eight percent.
There's no 100% method out there,
so that's why they say abstinence is the safest.
Well, if that's not the choice, reduce
the number of sexual partners.
The fewer people you're close with,
the less chance of having an infection.
Low-risk behavior.
Individuals that are engaging in drug use
a lot of times have a higher risk because of
the intravenous needle potential
or someone that is constantly being with
other individuals, having different partners.
The idea of avoiding high-risk sexual practices.
Anal-genital is a very high risk,
one of the reasons being that a lot of times
this will cause tearing of the anal
or the rectal tissue.
That tearing will be bleeding.
Blood carries virus particles.
Latex, polyurethane condoms, barriers
are ways of helping prevent the passage of fluids
but it's one of those things where
even then they're not 100%.
There could be a rip, there could be a tear.
If anyone thinks they're exposed,
thinks there might have been a risk factor,
might have been an issue, get tested.
It's better to catch it early because
today's modern medicines, it might be
a lot of medicine to take but a lot of times
HIV can be put into a remissive state.
There are people that have had the HIV virus
for 15, 25 years at this point
living a relatively normal life,
just having to take an increased amount of medication
to try to keep the HIV infection in check
so getting tested will help answer the questions.
It will help answer are you or are you not infected.
It also could help catch it at an earlier stage.
The key thing though is just be safe.
Be smart about choices.
Today's treatments, those drugs I was talking about.
One of the HIV drugs is AZT,
reverse transcriptase inhibitor.
If you're saying, what the heck is
a reverse transcriptase inhibitor,
it's the way it works when your RNA
from the virus is made back into DNA.
The term transcription is when DNA is made
into RNA, so reverse, go the other way, RNA to DNA.
If you can stop the HIV virus from creating
new virus particles, you can help keep the virus in check.
That's AZT.
Protease inhibitors, well these things are
meant again to prohibit a certain pathway
within the viral production.
Then we have Maraviroc.
It's a newer drug on the market
but it helps to protect the T cells specifically.
It does not allow HIV to actually enter
into the T cell and destroy the T cell.
The whole thing though is early treatment.
The only way for early treatment is
early detection to get tested.
With all these drugs, people are living
longer and more normal lives once they've been infected.
The best thing to do obviously is
don't get infected, practice safe practices
but if it unfortunately occurs, click it, seek help.
Go over basically to come clinic and get tested.
Figure out what's going on earlier rather than later.
Now they're working on a vaccine.
The problem is, they can't quite pin it down.
They've been working on a vaccine for
the past decade or two almost.
The vaccine is constantly under development
but every time they identify a unique feature to target,
the virus mutates.
It changes.
That's one of the biggest problems with HIV
is how often this virus is changing.
The only way a vaccine can be efficient
is if what the vaccine is presenting
is matched exactly with a future virus.
If a virus changes, the vaccine is useless
and sometimes the HIV virus is changing
as frequently as every six months.
So vaccines, they're trying to figure it out
but so far they haven't found one thing
that stays consistent.