CMV - Preventing cytomegalovirus (CMV)

It's not always possible to prevent a cytomegalovirus (CMV) infection, but there are steps you can take to reduce the risk.

Most people don't worry about preventing CMV, because it doesn't often cause symptoms. However, you should be careful if you're at increased risk of developing more serious problems or if you're planning a pregnancy.

Newborn babies, pregnant women, people receiving an organ transplant and people with a weakened immune system have an increased risk of developing serious problems.

A person donating an organ will be screened for CMV before or at the time of the organ transplant.

Good hygiene

Maintaining high levels of hygiene is a simple measure that may help prevent a CMV infection spreading. For example, always wash your hands with soap and warm water:

• before preparing, serving or eating food
• after going to the toilet
• after changing a baby’s nappy
• after coming into contact with bodily fluids, such as semen or urine

You should clean any surfaces that have come into contact with bodily fluids, and wear disposable gloves while doing this.

Pregnant women

CMV infections are common in young children. If you're pregnant, you can reduce your risk of becoming infected by taking some simple measures, such as:

• regularly washing your hands with soap and hot water, particularly if you've been changing nappies, or you work in a nursery or day care centre
• not kissing young children on the face; it's better to kiss them on the head or give them a hug
• not sharing food or eating utensils with young children, or drinking from the same glass as them

These precautions are particularly important if your job brings you into close contact with young children. If it does, you can have a blood test to find out whether you've previously been infected with CMV.

CMV is particularly dangerous to the baby if the pregnant mother hasn't had a previous CMV infection. However, all pregnant women should follow the hygiene precautions above to reduce their risk of infection, even if they've had CMV before, because they could be infected with a different strain of the virus.

Organ transplants

CMV used to be one of the main causes of illness and death during the first six months after having an organ transplant. However, antiviral medicines have proved very effective in preventing CMV infections in people who've received transplants.

Therefore, it's likely that you'll be given antiviral medicines to help prevent a CMV infection developing into a problem if you're having an organ transplant.

Weakened immune system 

Your immune system may be weakened if you have HIV, or you're taking medication to prevent a transplanted organ being rejected. The immune system is the body's natural defence against illness and infection. If it's weakened, you'll be more vulnerable to infections, including CMV.

As well as maintaining a high level of hygiene, you can help prevent infections developing by:

• having daily showers or baths, and washing your clothes, towels and bed linen regularly 
• avoiding contact with people who have serious infections, such as chickenpox or flu
• taking extra care not to cut or graze your skin (if you do, clean the area thoroughly with warm water, dry it and cover it with a sterile dressing)
• eating a healthy, balanced diet that includes plenty of fresh fruit and vegetables
• resting when you need to
• asking your friends and relatives to make sure their flu vaccines, MMR vaccines and chickenpox vaccines are up-to-date before they visit you 

Contact your GP if you have a weakened immune system and you think you may have an infection – for example, if you have a high temperature of 38C (100.4F) or above.

Vaccination

Research is currently underway to find vaccines for CMV. 

One possible vaccine is aimed at young women. The theory is that vaccinating women before they become pregnant could reduce the risk of congenital CMV.

Another possible vaccine is aimed at toddlers. By reducing their chance of getting active CMV, their mothers may be protected from CMV during pregnancy.

A third possible vaccine is aimed at people having organ transplants. The aim is to prevent the donated organ causing a new CMV infection or reactivating an existing CMV infection in the person receiving the transplant.

However, because of the stringent safety checks that all new medicines and vaccinations have to go through, it's likely to be several years before routine vaccinations against CMV are available.