The herpesviruses constitute
a large number of viruses,
and we'll go through them by name
and number just very shortly,
but all of them contain a large enveloped,
They all have an icosadeltahedral capsid.
But important to remember in terms
of both clinical use and testing
is that the herpesviruses have a double-
stranded DNA genome which is linear.
They, like many other viruses,
are able to create a lytic,
but also latent infection cycle.
So, infection with any of the herpesviruses
means that you have it for life.
In some part or some reservoir
in the human body
or the human immune system,
there will be one of the herpesviruses
living in a latent situation.
The treatment for when one is ready
to treat the herpesviruses
are these drugs here: acyclovir,
valacyclovir, ganciclovir, and valganciclovir.
Each of these might have efficacy
against all other herpesviruses.
But of these, acyclovir and ganciclovir
are the most commonly used
primarily to treat herpes 1 and 2
and then cytomegalovirus.
So, let's now look at the different types
of herpesviruses and we start with
herpes simplex 1 or herpesvirus 1.
This is the herpes that we all
know and love, or not,
as it is the source of oral herpes,
those cold sores which
recur, which everybody is
quite familiar with.
But herpes I also can cause
an adult or even child onset encephalitis
called sporadic encephalitis,
which affects the lobar, or the temporal
lobar part of the brain
and is quite devastating.
One can also have a much more
mild disease with conjunctivitis,
and importantly, herpes simplex type 1
and herpes simplex type 2 can both cross-
contaminate and cause each other's illness.
So, via self-inoculation, and I'll leave it to
your imagination for how that might occur,
one can get herpes 2 mostly
in the genital region,
up to the eyes, up to the mouth.
Herpes simplex type 2 or herpes type 2
is primarily the cause of anything
related to genital herpes.
This means that babies born to
mothers with genital herpes
will be exposed to and can develop
infection with herpes as well causing
neonatal herpes disease.
Both adults and infants can develop
herpes type 2 meningitis,
which behaves like a very simple
or benign aseptic meningitis,
but they also can develop herpes type 2
encephalitis, which again, is a far
more serious disease.
And once again,
herpes simplex virus type 1
from the face region can transmit
down via self-inoculation
to the genital region.
Herpes type 3
is named varicella-zoster virus, VZV,
or sometimes just varicella virus.
This is the cause of shingles
and chicken pox.
is named Epstein-Barr virus.
Most often you'll hear us say EBV,
and this is the lovely cause of infectious
many adults and adolescents
but it also can be the cause of
some malignant diseases.
Hairy oral leukoplakia, which
can be pre-malignant,
Burkitt's lymphoma, and also
Herpesvirus 5 is named cytomegalovirus, CMV,
and this is the cause of another
milder form of infectious mononucleosis
in adults or children,
but even more importantly, is a significant
cause of congenital infection.
Mothers who are infected primarily
with CMV during their pregnancy
can transmit symptomatic congenital
CMV to their infants.
And those infants can have hepatitis,
retinitis, you name it.
Herpesviruses 6 and 7 are
and these both can cause exanthema subitum,
which is the lovely Latin name,
which to us is the disease, roseola,
a very common childhood illness,
and we'll show pictures of this
coming up very shortly.
There's a whole list of other possibilities
that can be caused by these viruses,
but especially human herpesvirus 7
an cause pityriasis rosea,
hypersensitivity syndrome, encephalopathy,
the whole 9 yards.
It's quite rare, but when it happens,
it's quite significant.
And then finally, herpesvirus 8 is named
Kaposi's sarcoma-associated herpesvirus,
or many times just Kaposi's virus.
And this is, of course, by its name,
the cause of Kaposi's sarcoma.