Cytomegalovirus: What the CDC wants you to know during the holiday

Cytomegalovirus, it causes a mononucleosis syndrome. Image produced from an image taken with transmission electron microscopy. Viral diameter around 200 nm. (Photo by: BSIP/Universal Images Group via Getty Images)

The U.S. Centers for Disease Control and Prevention is issuing an alert about cytomegalovirus, or CMV, during the holiday. 

"Sharing is caring during the holidays, but sharing cups, water bottles, & other items with saliva on them can spread cytomegalovirus #CMV," the agency tweeted Wednesday. "Drink only from your cup to help protect you & others from getting infected."

According to the CDC, cytomegalovirus is a common virus that can affect people of all ages. Symptoms include fever, sore throat, fatigue and swollen glands. The virus can even cause mononucleosis or hepatitis. Some cases are asymptomatic. 

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However, health officials said a healthy immune system usually prevents the virus from causing an illness. 

The CDC said infected people may pass the virus "in body fluids, such as saliva, urine, blood, tears, semen, and breast milk."

It can be transmitted:

  • From direct contact with saliva or urine, especially from babies and young children
  • Through sexual contact
  • From breast milk to nursing infants
  • Through transplanted organs and blood transfusions

Health officials said a blood test usually confirms the diagnosis and it usually doesn't require medical treatment. 

According to the CDC, nearly one in three children in the U.S. are already infected with CMV by age five. Over half of adults have been infected with CMV by age 40. Once CMV is in a person’s body, it stays there for life and can reactivate. 

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A person can also be re-infected with a different strain of the virus, according to the agency. 

The chances of getting infected while pregnant are small, and the chances of passing along the virus in utero are even smaller. Of about 4 million annual U.S. births, about 30,000 babies - less than 1 percent - are born with a CMV infection. About 5,000 of those babies will have CMV-related permanent problems.

The Associated Press contributed to this report. This story was reported from Los Angeles.