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!

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References:

Centers for Disease Control and Prevention. (2020). Cytomegalovirus and Congenital CMV Infection. Retrieved from https://www.cdc.gov/cmv/index.html 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.