Did you read the previous part: CMV Infection Risks and Transmission?
Article updated : September, 2023.
How do you know if you’re already infected with cytomegalovirus?
Unfortunately, no very precise screening tests for the true presence of the infection exist. We don’t have clear recommendations about what you can do. Currently, recognised effective ways to treat this infection don’t exist. This is why public health officials don’t recommend systematic screening of CMV before or during pregnancy. However, doctors can ask for targeted monitoring for a pregnant woman, like they do when they have flu symptoms. A follow-up ultrasound can also examine the baby’s proper growth and the placental development in these circumstances. The SOGC criteria also suggest screening pregnant women for CMV if ultrasound scans show a possible problem in the fetal central nervous system with calcifications, or in the heart and/or abdomen.
A diagnosis of cytomegalovirus infection is possible, but limited, using blood tests (serology) to detect specific “anti-CMV” antibodies. This indicates a previous or new infection.
This analysis is more frequent for pregnant women and added to the doctor’s clinical exam and data collection.
Even if the symptoms are similar to mononucleosis, healthy subjects don’t have a sore throat when they are infected with cytomegalovirus, which differentiates the two infections.
Other more sophisticated ways to diagnose and screen for a previous or recent CMV infection exist, but they’re infrequent and variable from one country to another. At 21 weeks of pregnancy, some pregnant women can have an amniocentesis to take a sample of the amniotic fluid. This will check to see if the baby was infected in utero.
Newborn infection can occur in their mother’s uterus during any trimester of pregnancy. From 0.2% to 2.4% of babies will be infected congenitally. The CMV infection can also occur after birth through neonatal infection.
Most of the time the baby’s diagnosed with a urine or saliva test. These look for the presence of bacteria, germs and other agents possibly responsible for the infection. A saliva test is quicker, but if the baby has their mother’s milk in their mouth, she might be screened (through her milk) rather than her baby. For this reason, urine testing is still the most specific and sensitive method of screening newborns. Early diagnosis of CMV infection in newborns is very important, as treatment needs to be administered very quickly, within the first few weeks of life (ideally before 14 to 21 days), and for 6 months thereafter.
Cytomegalovirus Infection Symptoms
As I said earlier, 90% of infected healthy adults and children won’t have specific symptoms. This is why it’s a “silent” infection. But they may also have innocuous signs that aren’t specific to the infection. It might look like viral influenza, with some fever, headaches, general muscle and joint pain, general fatigue and swelling of certain lymph nodes noted during a clinical exam, similar to mononucleosis. In babies, there may be problems with eye or hearing tests, or evidence of neurological damage on postnatal assessment (e.g. microcephaly, convulsions). 5 to 15% of newborns may have sequelae of congenital CMV infection.
Continue reading with Cytomegalovirus during Pregnancy.
Photo credit: Jarun Ontakrai