Cytomegalovirus (CMV) is a very common virus in the herpes virus group. As much of 80% of some populations are infected with cytomegalovirus, and for the most part, infections are silent, meaning that no symptoms appear, although people with silent infections are still carriers. Some people are at risk of developing symptoms from cytomegalovirus infection, including people with compromised immune systems and infants, because infants have poorly developed immunities.
There are several species in the CMV genus, some of which infect non-human primates in addition to people. Cytomegalovirus attacks the epithelial cells in the top layer of the skin, causing them to swell and fill with fluid. It tends to appear in the viscera and internal organs, and it also infamously attacks the eyes, causing vision impairment and sometimes blindness. If a doctor suspects a cytomegalovirus infection, a culture can be performed to test for the presence of the virus.
Because the infection rate of this virus is so high, there is a reasonable chance that you have it, but your body has kept it at bay. Cytomegalovirus first began to be recognized as a medical problem in the 1980s, when patients turned up with a number of bizarre infections with viruses and bacteria which normally did not manifest symptoms in healthy people. These opportunistic infections ended up being a key piece of the puzzle in the discovery of HIV/AIDS, and to this day, cytomegalovirus is regarded as an “indicator infection” suggesting the presence of HIV or AIDS.
In addition to HIV/AIDS patients, this virus can also appear in people taking immunosuppressive drugs to prepare for organ transplant, and in cancer patients undergoing chemotherapy and radiation. Cytomegalovirus infection can also be an issue in pregnant women, since the virus can cause neurological deficits, hearing issues, and vision problems in unborn children.
Some silent carriers experience vague symptoms, like fatigue, swollen lymph nodes, and an enlarged liver or spleen. Often, these symptoms are so low-grade that the patient never seeks treatment, but in some cases, a flareup due to a temporarily weakened immune system may lead someone to go to the doctor, in which case cytomegalovirus may be diagnosed.
There is no cure for cytomegalovirus, although antiviral drugs can sometimes be used to control it and reduce the symptoms. In people with a severe infection, intravenous drugs may be administered to get the infection under control, followed by oral antivirals at home. Patients who are at risk for cytomegalovirus infection may also be given prophylactic drugs to suppress the virus or prevent infection, and encouraged to use good personal hygiene to reduce the risk of transmission.
The symptoms of cytomegalovirus (CMV) differ depending on whether you have:
primary CMV - where someone develops a CMV infection for the first time
re-infection with CMV - an infection with a different strain of virus
reoccurring CMV - a previously inactive CMV infection is reactivated, often because the immune system (the body’s natural defence against infection and illness) is weakened
congenital CMV - a CMV infection develops when a woman is pregnant and infects the unborn baby
Most cases of primary CMV cause no noticeable symptoms. If you do experience symptoms, they will be similar to flu symptoms and can include:
a high temperature of 38C (100.4F) or above
extreme tiredness
sore throat
swollen glands
muscle and joint pain
loss of appetite
These symptoms should only last for a couple of weeks.
If you are re-infected with a different strain of the CMV virus, you may not have any symptoms, or you may have symptoms that are similar to a primary CMV infection (see above).
If CMV reoccurs in healthy people, including during pregnancy, it will cause few if any symptoms.
A CMV infection that reoccurs due to a weakened immune system can cause a wide range of symptoms. This is because the virus can quickly spread throughout the body, causing damage to one or more of your organs. In particular, damage can be done to the digestive system, lungs and eyes.
Symptoms of reoccurring CMV include:
a high temperature of 38C (100.4F) or above
diarrhoea
shortness of breath
large painful ulcers in your mouth and oesophagus (gullet)
visual disturbances, such as blind spots, blurring and floaters (a black spot or "web" that appears to be floating in your field of vision)
pneumonia - inflammation (swelling) of the tissue in your lungs
retinitis - inflammation of the retina, the light-sensitive tissue that lines the back of your eyes
hepatitis - inflammation of the liver
If you have a weakened immune system and have one or more of the symptoms above, contact your GP or treatment team immediately.
Around 9 out of 10 babies born with congenital CMV experience no symptoms at birth. This is known as an asymptomatic congenital CMV infection.
A small number of babies with asymptomatic congenital CMV may develop some degree of hearing loss over their first few years of life. Loss of hearing can range from mild to total.
The hearing problems can affect just one ear (unilateral hearing loss) or can cause problems in both ears (bilateral hearing loss). Children with bilateral hearing loss are likely to experience difficulties with speech and communication as they get older.
One in 10 babies born with congenital CMV have symptoms at birth, including:
jaundice - yellow-coloured skin and yellowing of the whites of the eyes
pneumonia
a rash of small, purplish spots
an enlarged liver and spleen
low birth weight
seizures (fits)
While some of these symptoms can be treated, some babies will develop long-term conditions as a result of the infection. Up to 9 out of 10 babies born with congenital CMV who have symptoms at birth will develop one or more physical or mental disabilities. These include:
hearing loss
visual impairment
blindness
learning difficulties
lack of physical co-ordination
epilepsy - a condition that affects the brain and causes repeated seizures