Neonatal herpes (herpes in a baby)

Neonatal herpes is infection of a newborn with the herpes simplex virus — the same virus that in adults causes a cold sore on the lip or sores on the genitals. In an adult it lives in the body for years and causes little trouble; in a baby only weeks old it behaves quite differently, because the immune defences are not yet working at full strength: within days the infection spreads through the blood and reaches the liver, the lungs and the brain. The illness is rare, but in it time decides everything. And almost all of it is preventable, because a baby catches it from adults.

How the virus reaches the baby

Most often during birth, passing through the birth canal, if the mother has genital herpes at that moment. The danger is greatest when a woman catches it for the first time in the last weeks of pregnancy: her antibodies have not yet had time to form and cross the placenta, the virus is shed in large amounts, and the risk becomes high. If the herpes is long-standing and flares only occasionally, the baby receives those antibodies in advance and the chance of infection is small.

One detail throws many families off: in most mothers of affected babies genital herpes was never diagnosed, because it ran without visible sores. So the sentence "I have never had herpes" guarantees nothing, and the rules for looking after a newborn are the same for everybody.

The second route comes after birth and lies entirely in adult hands. The virus is brought by someone with a cold sore who kisses the baby or licks its dummy or spoon. It is brought by someone with blisters on a finger — herpetic whitlow, an inflamed finger with clear blisters. And it is brought by a mother who has developed blisters on the breast or nipple, because then both the feed and milk expressed from that breast pass it on. Very rarely the virus reaches the baby before birth, and those babies are born already with skin scarring and damage to the eyes and brain.

How to protect a newborn

The most delicate stretch is the first six weeks or so. The rules are simple, but they need saying out loud to everyone who comes into the house.

• Wash hands before picking the baby up. Everyone, every time, no exceptions.
• Do not kiss the baby on the face. The safe place for a kiss is the top of the head; the area around the mouth, nose and eyes is out.
• Anyone with a cold sore now, or who has had one in recent days, does not kiss the baby at all and where possible does not hold the baby either. If it is the mother and there is no way round it: washed hands, a face mask, the sore covered, and no kisses.
• Do not suck a dummy, spoon or bottle teat to "test" or "clean" it.
• Blisters on a finger are covered with a dressing, and meanwhile it is better for another adult to handle the baby.
• If blisters appear on a breast, do not feed from that breast, and milk expressed from it is thrown away until everything has healed. The other breast carries on as normal.
• Any skin lesions on those caring for the baby are covered with clothing or a dressing.

Three forms of the illness, and why everything depends on them

Neonatal herpes follows one of three scripts, and which one it is decides both the severity and what to expect afterwards.

• Skin, eyes and mouth. The virus has gone no further than the surface: blisters on the skin, a red watering eye, ulcers inside the mouth. This is the most favourable form, and with treatment started in time babies recover, though the blisters may come back over the first few years. Its danger is that untreated it moves fairly easily into the next two.
• Brain involvement. It usually appears in the second or third week of life: the baby is listless, feeds poorly, has a temperature, seizures, or odd repeated jerks and blank staring spells. There may be no blisters on the skin at all.
• Disseminated disease. The virus takes hold of the liver, the lungs and the clotting system; it starts most often in the first week and looks like a severe general illness — listlessness, jaundice, laboured breathing, bleeding. This is the form that threatens life most.

One thing is worth holding on to: in a substantial proportion of affected babies no blisters appear at all, and that is what most often delays the diagnosis. Waiting for a rash to "be sure" is not an option — what is watched is the baby's general condition. Early treatment has changed the outlook of this illness beyond recognition, but after brain involvement and disseminated disease seizures, developmental delay and loss of hearing or sight are possible, which is why those children are followed up for years.

What should alert parents

The early signs do not look like herpes. They look like "the baby is not himself today" — and doctors take that impression from parents seriously.

• The baby is listless and drowsy and hard to rouse, or the opposite: unsettled and soothed by nothing.
• Takes the breast or bottle less well, or refuses feeds.
• A temperature of 38C or above. In a baby under three months this alone is a reason to seek help the same day, whatever the cause. The reverse is worrying too: a temperature below normal along with cold hands and feet.
• Clear blisters the size of a pinhead have appeared on reddened skin, singly or in clusters. They often break out where the skin has been rubbed: on the head, where a sensor sat, or in a skin fold.
• An eye is red and watering, the lids stick together, the baby screws the eyes up against the light.
• The skin has turned yellow, the tummy has become swollen, or bruises and pinpoint red spots have appeared.

When an ambulance is needed

Call an ambulance (in Spain, Italy, Portugal, Poland and Ukraine the single number is 112) if the baby:

• has seizures, rhythmic jerking, a fixed stare or unusual repeated movements;
• is breathing fast, grunting on breathing out, drawing in the spaces between the ribs, or pausing in breathing;
• has a blue tinge to the lips, tongue or skin;
• has pale, mottled, cold skin and is fading — floppy, not responding as usual, impossible to wake;
• cries constantly with a cry unlike the usual one that nothing will interrupt;
• refuses several feeds in a row and is wetting far fewer nappies;
• has a temperature of 38C or above and is under three months old, or a temperature below 36C at any age.

Do say to the doctor or to the call handler if anyone around the baby has had a cold sore in the past few days, or if the mother has had genital sores. That sentence speeds up everything that follows.

How the diagnosis is confirmed

The diagnosis rests on finding the virus itself, because from the outside neonatal herpes cannot be told apart from a bacterial infection of the blood.

• PCR on blood to look for viral DNA. This is the main test.
• Swabs for PCR from the blisters, the eye, the mouth and nasopharynx and the rectum.
• Lumbar puncture with examination of the spinal fluid, PCR included. It is done even when the skin is clear: brain involvement often runs without a single blister, and without the puncture it is simply missed. Its result decides how many weeks the treatment will last.
• Liver enzymes, clotting tests and a full blood count, which show whether internal organs are affected.
• An eye examination by an ophthalmologist at the least suspicion of eye involvement.

What the diagnosis is not made on. A blood test for herpes antibodies in a newborn is useless: almost all the antibodies in the baby's blood are the mother's, passed across the placenta, and say nothing about whether the illness is there or not. A negative skin swab in the first hours rules nothing out either. So where suspicion is reasonable the antiviral is started at once and the results are awaited with treatment already running.

How it is treated

Treatment is an antiviral medicine given into a vein, in hospital, over two to three weeks depending on the form; short courses and tablets instead of a drip do not work here. If the nervous system was involved, the puncture is repeated before the course ends to confirm the virus has gone from the spinal fluid.

Alongside this, whatever has already developed is treated: seizures, respiratory failure, clotting problems. If the eye is affected, antiviral eye drops and ophthalmology follow-up are added.

After discharge an oral antiviral is usually prescribed for several more months: it reduces the return of the blisters and improves later development in children who have had brain involvement. After that come planned checks of hearing, vision and development.

Breastfeeding during treatment is possible and worth continuing, provided there are no herpes sores on the breast or nipple. Antiviral medicines taken by the mother pass into the milk in minute amounts and do the baby no harm.

If you are pregnant

Tell your doctor or midwife if you have ever had genital herpes, even if the last flare was many years ago, and tell them too if your partner has it and you do not.

If painful blisters or sores appear on the genitals during pregnancy, do not put off the appointment, least of all if it is the first time in your life. A first episode in the last weeks of pregnancy is exactly the situation all of this is about: an antiviral is prescribed and caesarean birth is seriously considered, because it sharply reduces the risk to the baby. With long-standing recurrent herpes an antiviral is usually started towards the end of pregnancy and a vaginal birth is generally possible.

If your partner has herpes and you do not, use a condom in the third trimester and avoid oral sex altogether while he has a cold sore: herpes on the lip transfers to the genitals with no difficulty at all.

Online consultation with a doctor

A remote appointment works well where the situation needs sorting out and a clear plan is wanted. Before the birth: what herpes in your history means, what to do if sores appear during the pregnancy, how to discuss the mode of delivery with the obstetrician. Afterwards: how to explain the no-kissing rule to relatives, what to do if the cold sore is yours, whether you can carry on feeding, and what to cover the sore with.

The limits are worth knowing from the start. A sick newborn is not assessed through a screen: listlessness, breathing and skin colour are seen in person, and a suspicion of neonatal herpes means admission, a drip and blood tests. If the baby is floppy, refuses feeds, is struggling to breathe, or has a temperature of 38C or above in the first three months — do not write, call an ambulance.

This material is for information only and does not replace medical advice.