- [Voiceover] Bacterial vaginosis is a disease
that's caused by the overgrowth
of a type of bacteria
that's called Gardnerella vaginalis,
Gardnerella vaginalis.
And as the name might suggest,
this is the most common vaginal infection.
Now I wanna put these really big quotes
around the term infection
because the thing that's interesting
about Gardnerella vaginalis
is that it's a bacteria that's naturally found
in the vagina.
Now some may consider this to be
a sexually transmitted infection,
which is interesting because it doesn't cause
any problems until there's too much of it there.
So when we look to the causes
of bacterial vaginosis,
they are all things that change
the vaginal environment.
That can include acts like douching,
so douching, or rinsing of the vagina.
The other is having new or multiple sex partners.
And finally, another known cause
is the use of antibiotics.
This could be in the case of somebody
that has a throat infection
or a pneumonia that's on antibiotics
which will then attack the bacteria that exists
within the vagina and allow Gardnerella vaginalis
to overgrow and cause bacterial vaginosis.
So we've touched a little bit on it here,
but I wanna draw it out.
So when we talk about the pathophysiology
of a disease, we're talking about the mechanism
by which that disease occurs.
So in order to understand the pathophysiology
of bacterial vaginosis, we need to take
a look at a sample of bacteria
that exists in the vagina.
So I'll draw out some Gardnerella vaginalis bacteria,
and so I'll put this up in our key.
This is the symbol for Gardnerella vaginalis.
And I'll draw a few of them around here,
but I also wanna show that there are
a lot of other bacteria that exist in this sample.
So if you really look at it here,
the Gardnerella vaginalis is the vast minority
of bacteria that are present in this sample
of vaginal bacteria.
So what happens over here,
let's say our patient is somebody
that's recently been treated
for a throat infection,
and so they're taking an antibiotic.
What happens is that antibiotic kills off some
of the bacteria that exists in the vagina
as well as elsewhere in the body.
As you can see now,
the majority of bacteria that exists
are the Gardnerella vaginalis bacteria.
So they'll reproduce and overgrow,
and if they do so,
you're going to end up having bacterial vaginosis.
So the key here is that you have an increase
in the population of your Gardnerella vaginalis bacteria,
and that leads to your symptoms.
So what symptoms can you have
with bacterial vaginosis?
One of the main features associated
with bacterial vaginosis, or BV,
are copious, or a lot, of vaginal discharge.
This discharge also characteristically
has a fishy odor to it as well,
and perhaps one of the most dangerous
symptoms or effects that can occur
is that pregnant women can deliver
their babies early, and this is referred to
as preterm labor before the baby has
enough time to properly mature in the uterus.
So it's important then to talk about how
we can diagnose bacterial vaginosis.
This is mainly done by using what's called
a wet mount.
So a wet mount.
That's where you take a swab
or a sample from the vagina,
so this swab has taken a sample from the vagina,
and you add this onto a microscopic slide,
so right here, and when you take a look
at this under a microscope,
what you'll see is this.
Now you've got these two simple squamous cells.
So I'll label that.
These are vaginal epithelial cells,
both of these guys.
What I'm hoping you can see littered all
over these cells are just
these bacterial organisms.
There's just so many of them
just kind of outlining them.
They're just littered with them all over the place.
So this is actually a clue.
In fact, these are referred to as clue cells.
If you find these under a wet mount,
that indicates that your patient has bacterial vaginosis.
Okay, so now that we've made our diagnosis,
the next step, of course, would be treatment,
and because Gardnerella vaginalis is a bacterium,
you would treat it with antibiotics
to decrease the amount of Gardnerella vaginalis
that exists in the vagina to return to the normal
demographic, or population, of bacteria
we should have there.
So the next question you can ask
would be how do you prevent BV
from happening in the first place?
And that's a tougher question to answer
because some of these things that cause BV,
like using antibiotics to treat pneumonia,
well we have to use antibiotics
to treat pneumonia.
So the only thing that's recommended
to prevent when having new or multiple
sex partners, use condoms.
Beyond that, what doctors usually do
when a patient becomes symptomatic
is just to treat with antibiotics.