Cytomegalovirus (CMV) is a type of herpes virus that’s extremely common worldwide.

In the United States alone, it’s estimated that between 50 and 80 percent of people have a CMV-related infection by age 40, and 1 in 3 children experience these infections by age 5.

Due to such a high prevalence, you may be wondering about the potential dangers and risks associated with CMV. Read on to learn more about this virus, as well as the similarities and differences between other herpes viruses.

CMV is a highly contagious virus that’s spread through body fluids, such as saliva, blood, and urine. The virus is rarely spread through blood and organ donations, due to modern preventive and treatment measures.

It may be CMV is a common virus that’s related to the same viruses that lead to mononucleosis and chickenpox. Most people will encounter CMV during their lifetimes, but the majority will experience mild symptoms only.

However, CMV can cause more severe infections if you have a weakened immune system or if you’ve recently had an organ transplant.

Additionally, newborn babies who contract CMV from their mothers during pregnancy or through nursing may also be at risk of developmental issues.

It’s estimated that about 1 percent of babies in the United States contract CMV before birth. This is also called congenital CMV.

Once you have CMV, it stays in your body for the rest of your life. It may go through cycles of dormancy, where you may experience periodic active infections.

In most cases, you don’t need any treatment unless you have a weak immune system and require antiviral medications.

CMV belongs to the herpes virus family. Aside from CMV, this group includes:

The main similarity between all viruses in the herpes virus family is that they have a lifelong latency. This means that each one may persist in your body, creating active infections on a periodic basis only and that it may persist without causing any symptoms at all.

However, CMV doesn’t cause any cold sores or external ulcers seen with the herpes simplex virus, or the blister-like rashes seen in chickenpox.

While all members of the herpes virus family are contagious, CMV isn’t considered a sexually transmitted infection (STI) like certain forms of herpes simplex are.

Additionally, CMV is considered the only member of the herpes virus family to spread directly from mother to child through the placenta during pregnancy.

Below is a brief look at the primary similarities and differences between the main types of herpes viruses:

Similarities and differences between types of herpes viruses

CMVHerpes SimplexEpstein-BarrVaricella-zoster
May cause flu-like symptomsXXX
Causes skin lesions or blistersXX
May cause unintentional weight lossX
May spread through sexual contactXXX
May spread to an unborn baby during pregnancyX
May cause severe illness in immunocompromised individualsXXXX
May stay dormant in the body and
cause reinfection

While CMV is transmitted via body fluids, including semen, it’s not considered an STI.

Herpes simplex 2, on the other hand, is considered an STI because it’s primarily transmitted through sex.

Both types of herpes simplex may be spread through contact with herpetic lesions, either by oral or genital contact.

While part of the same family, CMV won’t result in a positive herpes test.

The exception is if CMV testing is ordered as a part of a TORCH panel. Mostly used during pregnancy and the newborn period, TORCH includes tests for:

Also, when considering testing, a CMV result may be positive for life, whether your infection is active or dormant.

In most people, CMV causes mild illness only. However, if you’re immunocompromised, the virus may cause problems with your:

  • eyes
  • esophagus
  • stomach
  • intestines
  • lungs

Also, while not common, CMV may lead to liver inflammation (hepatitis) or mononucleosis.

Babies who are born with CMV may also experience growth and developmental issues. Hearing loss is the most common related complication.

Is CMV treatable?

Yes. While most people with CMV don’t require treatment, your doctor may prescribe antiviral medications if you’re immunocompromised. Antiviral treatments may also be recommended for newborns to help prevent complications.

Does CMV cause cold sores?

Unlike herpes, CMV doesn’t cause cold sores. Most people with CMV may exhibit symptoms of a mild illness, such as fever, swollen lymph nodes, fatigue, and sore throat, while others may not have any symptoms at all.

Can you have herpes and CMV?

It’s considered rare to have both herpes and CMV at the same time. However, your risk of coinfection may be higher if you have a weakened immune system.

Can you give other people CMV if you have it?

Yes. CMV is spread through body fluids, such as blood, urine, saliva, and semen. It may also be passed during pregnancy to a fetus, as well as through breast milk to babies.

Is CMV dangerous?

While CMV is harmless in most people, you may be at a higher risk for related complications if you have a weakened immune system. It may also be more dangerous in babies, as well as in fetuses.

How can I get tested for CMV?

If you’re displaying symptoms of an active infection, your doctor can order a blood test to check for CMV. Urine and saliva testing is used for infants.

CMV is a member of the herpes virus family and is primarily spread through body fluids. While this is a highly contagious and common virus, only newborns and immunocompromised people experience serious illness.

If you have concerns about CMV active infections or reinfections, talk with your doctor about the next steps. While treatment isn’t usually required, antiviral medications may be needed in some cases.