Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about Hepatitis B in children.

And if you want to follow along with written notes on this topic,

you can follow along at zero tofinals.com slash hepb or in the infectious diseases section

of the Zero to Finals Pediatrics book. So let's get

straight into it. Hepatitis B is a DNA virus. It's transmitted by direct contact with blood

or bodily fluids, and this may occur during sexual intercourse or when sharing needles,

for example amongst ivy drug users or people getting

tattoos. It can also be passed through sharing contaminated household products such as toothbrushes

or contact between minor cuts or abrasions. It can also be passed from mother to child during

pregnancy and delivery and this is known as vertical transmission.

Most children fully recover from the infection within two months, however, a portion will go on to become chronic hepatitis B carriers.

In these patients, the viral DNA has integrated into their own DNA, and they continue to produce

the viral proteins. The risk of developing chronic hepatitis B after exposure is 90% for neonates,

30% for children under five years, and 10% for adolescents.

Most children with chronic hepatitis B are asymptomatic with normal growth and development and normal liver function tests.

Less than 5% of children will develop liver cirrhosis and less than 0.05% will develop hepatocelular carcinoma

before adulthood. These risks will increase once they enter adulthood. Let's talk about

viral markers. Remember that antibodies are produced by the immune system against pathogen proteins.

Antigens are proteins that are targeted by antibodies.

In this scenario, the antigens are parts of the hepatitis B virus.

It can be quite tricky to understand the different serological tests for hepatitis B.

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