Herpes in a baby (neonatal herpes)

About neonatal herpes

Herpes can be very serious for a young baby whose immune system won't have fully developed to fight off the virus.

Neonatal herpes is rare in Northern Ireland. It can be prevented by following some simple advice, (see preventing neonatal herpes section below).

Symptoms and signs of herpes infection in babies

Because newborn babies have underdeveloped immune systems, they can quickly become seriously ill after catching the virus.

Call your GP or your health visitor straight away if your baby:

• is lethargic or irritable
• isn't feeding
• has a high temperature (fever) – find out how to take your baby's temperature
• has a rash or sores on the skin, eye and inside the mouth

These are early warning signs that your baby may be unwell.

Call 999 immediately if your baby:

• is lacking in energy (listless)
• is becoming floppy and unresponsive
• is difficult to wake up from sleep
• has difficulty breathing or starts grunting
• breathes rapidly
• has a blue tongue and skin (cyanosis)

Very often the baby won't have any specific herpes symptoms, such as a rash. But they can become unwell very quickly, so you need to act fast.

How a newborn baby catches herpes

During pregnancy and labour

A newborn baby is at risk of catching herpes if the mother had genital herpes for the first time within the last 6 weeks of her pregnancy.

There's a risk the mother will have passed the infection on to her baby if she had a vaginal delivery. 

This risk is much lower if the mother has had genital herpes before.

• Learn more about the risks of genital herpes and pregnancy.

After birth

The herpes simplex virus can also be passed on to a newborn baby if:

• a person has a cold sore and kisses the baby
• the mother breastfeeds her baby with herpes sores on her breast – these can develop after touching her cold sore and then her breast

Cold sores are at their most contagious when they burst (rupture). They will stay contagious until completely healed.

Treating neonatal herpes

Neonatal herpes is usually treated with antiviral drugs given directly into the baby's vein (intravenously). This treatment may be needed for several weeks.

Any related complications, such as fits (seizures), will also need to be treated.

The baby can be breastfed while receiving treatment, unless the mother has herpes sores around her nipples.

If the mother is taking antiviral treatment too, this can be excreted in her breast milk but isn't thought to cause any harm to the baby.

Sometimes neonatal herpes will only affect the baby's eyes, mouth or skin. In these cases, most babies will make a complete recovery with antiviral treatment.

But the condition is much more serious if it's spread to the baby's organs. Nearly a third of infants with this type of neonatal herpes will die, even after they have been treated. 

If widespread herpes isn't treated immediately, there's a high chance the baby will die.

Preventing neonatal herpes

If you're pregnant and have a history of genital herpes, tell your doctor or midwife. 

You may need to take medication during the last month of pregnancy to prevent an outbreak of vaginal sores during labour.

Delivery by caesarean section is recommended if the genital herpes has occurred for the first time in the last 6 weeks of your pregnancy.

If you develop a cold sore or think you're coming down with a herpes infection, take these precautions:

• do not kiss any babies
• wash your hands before contact with a baby
• wash your hands before breastfeeding and cover up any cold sores to avoid accidentally touching your mouth and then breast – this is enough to transfer the virus

More useful links

• How to use your health services
• Sands