Cytomegalovirus (HHV-5): symptoms, diagnosis, and prevention

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Jefferson Chen, MD 

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Jefferson Chen, MD 

last updated: Oct 30, 2019

4 min read

Cytomegalovirus (CMV) is a virus in the herpesvirus family. It can also be called human herpesvirus 5 (HHV-5). Other members of the herpesvirus family cause infectious mononucleosis, chickenpox, shingles, cold sores, and genital herpes. It infects people of all ages and is very common—according to the Centers for Disease Control and Prevention (CDC) one in three children will be infected by age 5, and over 50% of adults have been infected (CDC, 2019).


Improve and support your health from the comfort of home

What are the symptoms of a cytomegalovirus infection?

The good news is that in most healthy people, CMV infections will be asymptomatic. If you are unfortunate enough to get symptoms from CMV, it will most likely manifest just like infectious mononucleosis (mono). Mono is typically caused by Epstein-Barr virus (EBV), another member of the herpesvirus family. If you’ve never had mono before, the symptoms are typically fevers, fatigue, sore throat, lymph node swelling, and possibly a rash. Like other members of the herpes virus family, CMV hides away and goes into latency after the initial infection. It has the chance to recur later on, especially if your immune system weakens.

Rarely, more serious complications can develop in adults, even if you are healthy. In certain cases, CMV infections can damage the liver, colon, brain, nervous system, eyes, and heart. More commonly, these problems develop in people that have a weak immune system, including people with human immunodeficiency virus (HIV), people on immunosuppressive medications like organ transplant recipients, and people with cancer on chemotherapy. In fact, cytomegalovirus retinitis, in which part of the eye is infected, is considered an AIDS-defining illness—a person with HIV is considered to have progressed to AIDS after getting CMV retinitis. These infections can be life-threatening and require treatment with antiviral medications.

Cytomegalovirus in pregnancy

Another extremely serious consequence of CMV is when infants are infected during pregnancy, also called congenital CMV infections. Congenital cytomegalovirus infections affect approximately 1 in every 200 babies born in the United States (Schleiss, 2016). The risk of transmitting CMV is much higher if the mother has never been infected with CMV before, around 30-40% in the first and second trimester, and 40-70% in the third trimester (CDC, 2019). The risk of transmitting CMV is around 3% from reactivation of the CMV virus. Congenital CMV infections can be life-threatening and can cause permanent brain damage, hearing loss, vision loss, epilepsy, premature birth, low birth weight, cerebral palsy, loss of coordination, among other disorders.

So how can we avoid these unfortunate conditions? First, women who are pregnant should practice good hygiene, especially around young children. Second, attend your prenatal visits. If you get a mono-like illness during your pregnancy, your healthcare provider may test you for CMV. Also, getting your prenatal ultrasounds to check up on your baby is very important. If there’s something abnormal on these ultrasounds, you and your baby may need testing for CMV. Finally, it’s important to take your baby regularly to your healthcare provider after delivery, even if they appear healthy. Screening for hearing loss and other signs of CMV can help diagnose CMV infections. Treatment with antiviral medications can help prevent hearing loss and intellectual disability from developing (Kimberlin, 2003).

How is CMV transmitted?

CMV is transmitted from person to person via contact with infected body fluids. This includes urine, saliva, blood, tears, semen, and breast milk. CMV can be transmitted through sexual contact or through other close contact. CMV has also been known to be transmitted through organ transplantation or blood transfusion.

How is CMV diagnosed?

If your healthcare provider suspects that you have been newly infected with CMV, they can test you by using what’s called a serologic test, in which a sample of your blood is tested for antibodies against CMV. In people with weakened immune systems and in infants, a polymerase chain reaction (PCR) might be performed. PCR tests for the level of viral DNA. In infants, this PCR test is done on the saliva. In adults with poor immunity, this is a blood test.

How can you prevent and treat CMV?

Preventing CMV is challenging because it’s a very common virus, and there’s currently no vaccine to protect people at high risk. The best way we have to prevent CMV is to practice good hygiene. The CDC published a guide to preventing CMV, which is especially important for pregnant women.

They recommend:

  • Washing your hands often with soap and water for 15-20 seconds, especially after changing diapers, feeding young children, wiping a young child’s nose or drool, or handling children’s toys

  • Not sharing food, drinks, or eating utensils used by young children

  • Not putting pacifiers in your mouth

  • Not sharing a toothbrush with a young child

  • Avoiding contact with saliva when kissing a child

  • Cleaning toys, countertops, and all other surfaces that come into contact with urine or saliva from children

Most of these recommendations are targeted towards handling young children, who have especially high rates of CMV because they can easily spread it to one another in daycare.

Treating CMV is usually unnecessary in healthy adults or healthy children. In infants with congenital CMV, IV antiviral medications like valganciclovir (brand name Valcyte) or ganciclovir (brand name Zirgan) can help prevent long-term hearing loss and intellectual disability. In immunocompromised adults, CMV infection or reactivation with treatment can be life-threatening. In these patients, IV antiviral medications are also used.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

  • Centers for Disease Control and Prevention. (2019, May 31). Cytomegalovirus (CMV) and Congenital CMV Infection: Clinical Overview. Retrieved from

  • Centers for Disease Control and Prevention. (2019, May 31). Cytomegalovirus (CMV) and Congenital CMV Infection: Congenital CMV Infection. Retrieved from

  • Kimberlin, D. W., Lin, C.-Y., Sánchez, P. J., Demmler, G. J., Dankner, W., Shelton, M., et al. (2003). Effect of ganciclovir therapy on hearing in symptomatic congenital cytomegalovirus disease involving the central nervous system: a randomized, controlled trial. The Journal of Pediatrics , 143 (1), 16–25. doi: 10.1016/s0022-3476(03)00192-6. Retrieved from

  • Schleiss, M. R. (2016). Preventing Congenital Cytomegalovirus Infection: Protection to a ‘T.’ Trends in Microbiology , 24 (3), 170–172. doi: 10.1016/j.tim.2016.01.007. Retrieved from

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

October 30, 2019

Written by

Jefferson Chen, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewer

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.