Hi. My name is Eithne MacMahon.

I work at Guy's and St Thomas' Hospital,

where I'm a consultant
specialising in virology

in the directorate of infection.

The main cause of glandular fever

is a first infection
of the Epstein-Barr virus.

Now, the thing about Epstein-Barr virus

is that everybody gets that infection
in this country.

90 per cent or more of adults
have already had infection.

The thing about it is,
once you get the virus

it stays in your body,
it doesn't go away.

And in fact it doesn't cause
any significant damage at all

to the vast majority of people.

But because you have it in your body,

when you're intimate with
other individuals you can spread it.

If you get the infection
for the first time in childhood,

usually there aren't any symptoms.

If you don't, however, contract your
first infection of Epstein-Barr virus

until you're a teenager
or a young adult,

you have about a 50 per cent
to two thirds chance

of actually getting the symptoms
of glandular fever first infection.

How that is manifested typically
is with a fever

and with a sore throat
and with swollen glands,

swollen lymph nodes, as they're called.

When a young person gets glandular fever
they can feel pretty wiped out by it.

The duration of the symptoms
is fairly variable,

so whereas some will be better
in a matter of a week or two,

others can feel quite poorly

for quite a long length of time,
for weeks or months.

In terms of treatment,

there are antiviral agents
that are active against the virus,

but what we understand now
is that the symptoms of glandular fever

are actually due more
to your immune response to the virus

rather than to the virus itself,

and that explains
why the antiviral therapy

doesn't really make any difference
to the symptoms.

Very occasionally, on rare occasions,

a very small percentage of people
get quite bad swelling in their neck

that might threaten
their ability to breathe,

and in those rare circumstances

it may be appropriate for your doctor
to prescribe steroids,

but in general there is no treatment,

it's just a matter
of staying comfortable and resting

and not taking any more activity
than you're able to during it.

During glandular fever,
something that happens very often

is that the spleen and also the liver
swell a bit.

Usually that doesn't give rise
to any specific symptoms

but there is a risk
during contact sports

that if there's any trauma
to the abdomen,

the spleen can rupture,
which is quite serious.

So for that reason it's very important
that anyone who's got glandular fever

avoids contact sports
for at least a month.

It's quite difficult to avoid glandular
fever if you live in the world.

Children who acquire it
in the course of family contact,

a little bit difficult to avoid,

and in terms of adolescents and adults,
the only way really to avoid it

would be to avoid intimate contact,
including kissing.

Perhaps that might be good advice
if you have a major exam coming up.