CMV: The Most Common Virus You Never Heard About

When I was pregnant with my son Logan, my obstetrician advised me not to attend a close friend’s wedding in St. Lucia due to the Zika virus outbreak. Of course, I listened- I wouldn’t do anything that would put my unborn child in any danger. Ironically, my child was still infected with a virus that caused him to be born three months early and to lose his life four months later to an infection that can cause very similar congenital disabilities, including microcephaly. I didn’t have to travel to another country to get this virus; it’s here in the United States and all over the world. Not once had I ever heard of it. This virus was, of course, cytomegalovirus (CMV). 

You may be wondering to yourself, “How common can CMV be if I am just learning about it?” The statistics below may surprise you.

In the United States

  • 50-80% of the U.S. population has had a CMV infection by 40 years old (CDC, 2020). 
  • Nearly 1 in 3 children are infected by age 5 (CDC, 2020), putting pregnant women who have young children in the home or workplace at higher risk for contracting CMV.
  • The prevalence of CMV infection is higher among non-Hispanic Blacks and Mexican Americans, as well as among those of low-income households (Colugnati et al., 2007). 

Around the world

  • CMV prevalence ranges significantly around the world, with prevalence in women of reproductive age ranging between 45-100% (Cannon et al., 2010).
  • The prevalence of CMV is higher in developing countries and “resource-poor” communities in industrialized countries, due to crowded living conditions (Manicklal et al., 2013). 
  • The prevalence of CMV among people of color tends to be 20–30 percentage points higher than that of Caucasians (Cannon et al., 2010). 
  • CMV prevalence is highest in South America, Africa, and Asia and lowest in Western Europe and the United States (Cannon et al., 2010).

The Connection Between CMV and Congenital CMV

Congenital CMV is when a baby is born with a CMV infection, which they acquired while in utero. The higher the prevalence of CMV in a particular area, the higher the prevalence of congenital CMV. In developing countries, congenital CMV infection affects as many as 1-5% of births (Manicklal et al., 2013). In the United States, 1 in 200 babies are born with congenital CMV, and 1 in 5 of these children will go on to have long-term health problems, including hearing loss, visual impairment, and intellectual disability (CDC, 2020).

Why is awareness of CMV so low?

CMV is described as a “silent” virus for many reasons (Manicklal et al., 2013). First, people with CMV infections often don’t have any symptoms, including pregnant mothers. Only 10% of newborns with CMV have symptoms at birth; of the 90% of infected newborns that don’t have symptoms, 10-15% of them develop symptoms months or even years later (Colugnati et al., 2007). If a baby is not tested for congenital CMV within their first three weeks of life, this diagnosis cannot be made, leaving those with delayed symptoms without answers. 


In Summary

Traveling to another country is not the only time to worry about contracting a virus that could affect your unborn child. CMV is the LEADING cause of congenital infections here in the United States, as well as around the world (Manicklal et al., 2013). It causes more severe disabilities in children than many more well-known conditions, including fetal alcohol syndrome and the Zika virus (Colugnati et al., 2007; Schleiss, 2018). Furthermore, you may be at a higher risk of contracting CMV, depending on the population of your community and whether or not you are in frequent contact with young children. Fortunately, there are ways to lower your risk for contracting CMV during pregnancy, and we can all make a massive difference by empowering ourselves with this life-changing knowledge. 

In the next couple of weeks, we will be wrapping up our first topic, “What is CMV?,” by looking more deeply at how CMV is transmitted and what are its signs and symptoms. If you are learning a lot and want to keep receiving these posts, please consider subscribing below! 

Follow the MCC Blog:

Centers for Disease Control and Prevention. (2020). Cytomegalovirus and Congenital CMV Infection. Retrieved from on 8/16/20.
Cannon, M. Schmid S., & Hyde T. Review of Cytomegalovirus Seroprevalence and Demographic Characteristics Associated with Infection. Rev Med Virol 2010; 20:202. 
Colugnati, F., Staras, S., Dollard, S., & Cannon, M. Incidence of Cytomegalovirus Infection Among the General Population and Pregnant Women in the United States. BMC Infectious Diseases 2007, 7:71.
Demmler-Harrison, G. (2020), Congenital cytomegalovirus infection: Clinical features and diagnosis. Retrieved from Up to Date on 8/17/20.
Manicklal, S. Emery, V., Lazzarotto, T., Boppana S., Gupta, R., The “Silent” Global Burden of Congenital Cytomegalovirus. Clinical Microbiology Reviews 2013, 26;1.
Schleiss, M. Congenital Cytomegalovirus: Impact on Child Health. Contemporary Pediatrics 2018, 35; 7.

CMV is a Herpes Virus but it isn’t what You’re Thinking…

What is CMV?

Cyto-megalo-what?! If you are reading this post, you probably already know that CMV is the name of a virus. For those of you hearing about it for the first time, here’s what you need to know: 

  • CMV stands for cytomegalovirus. 
  • It is extremely common.
  • It’s the #1 infectious cause of birth defects in the nation and most women have never heard about it (Doutre, et. al, 2016).
  • It is a type of herpesvirus. 

Wait, I have Herpes? (It’s not what you’re thinking…)

If you were just diagnosed with a CMV infection, your first response might be- I DON’T have herpes!!! The herpesvirus STD, which causes genital blisters or lesions, is actually one of 130 herpesviruses strains, 8 of which are known to infect humans (Ada, 2019). And you are likely to have had more than one of them…

The Herpesvirus Family:

  1. Herpes Simplex Virus (HSV-1): Have you ever had a cold sore? Well, then you have had HSV-1, as have about 48% of individuals in the U.S. who are between the ages of 14-49 (Infectious Disease Advisor, 2018). 
  1. Herpes Simplex Virus (HSV-2): This is the sexually transmitted strain that causes genital blisters or lesions. About 12% of people in the U.S. between the ages of 14-49 carry this virus (Infectious Disease Advisor, 2018). 
Note: Both HSV-1 and HSV-2 can cause neonatal herpes. Neonatal herpes is rare (10/100,000 births globally), but can cause neurologic disability or death (World Health Organization, 2020). Neonatal herpes is NOT the same thing as CMV.
  1. Varicella Zoster Virus (VZV): This strain causes chickenpox, a common childhood disease. When it is reactivated in adults later in life, it causes shingles (Ada, 2019). 
  1.  Epstein-Barr Virus (EBV): 90% of the world’s population carries this virus and its symptoms are mostly mild. If infected as an adolescent or in early adulthood, one can develop infectious mononucleosis or what is commonly known as “mono” (Ada, 2019).
  1. Cytomegalovirus (CMV): CMV is a very common virus that over half of adults are infected with by age 40 (CDC, 2020). It is often harmless to healthy people- many are even asymptomatic- but it can be very serious when contracted during pregnancy or for people with compromised immune systems. 
  1. Human Herpesvirus 6 (HHV-6): A common strain that most people get by age 3. It is often harmless but can cause the common childhood condition called Roseola Infantum. It is most harmful to people with weakened immune systems (Ada, 2019).
  1. Human Herpesvirus 7 (HHV-7): Another common strain often acquired in childhood that is often harmless, but can also reactivate in people with weakened immune systems (Ada, 2019).
  1. Human Herpesvirus 8: Kaposi’s Sarcoma-associated Herpesvirus (KSHV): Kaposi’s Sarcoma is a much less common strain of the herpes virus, affecting less than 5% of the U.S. population (Ada, 2019). 

In Summary…

Well, there you have it. CMV is 1 of 8 human herpesviruses. And it is NOT the same as having genital herpes, nor is it the same as the dangerous, but rare, neonatal herpes. CMV is very common among the general public and serious for babies infected in the womb and for those who have weakened immune systems. Over the next few weeks, we will continue to explore more about CMV, such as its level of incidence in different populations, how it is transmitted, and signs of infection. After that, we will dive into other topics, including congenital CMV and its effects on babies, prevention, and treatment. Thank you for reading and stay tuned!

Follow the MCC Blog:

Ada’s Medical Knowledge Team. (2019). Human Herpesvirus (HHV). Retrieved from
Centers for Disease Control and Prevention. (2020). CMV; Clinical Features for Healthcare Providers. Retrieved from
Doutre S., et. al. (2016). Losing Ground: Awareness of Congenital Cytomegalovirus in the United States. Retrieved from
Infectious Disease Advisor. (2018). CDC Reports on Latest Estimates of HSV-1, HSV-2 Prevalence in the United States. Retrieved from

World Health Organization. (2020). Herpes Simplex Virus. Retrieved from