Cytomegalovirus (CMV) Avidity, IgG

Cytomegalovirus (CMV) is a common virus that belongs to the herpes family. On average, every person gets infected by this virus at least once by the time they reach 40 years of age. This virus can remain dormant in your body for a long time. It is also possible that you can catch the infection during childhood, teenage, or even during adulthood with no distinct symptoms. In most cases, the virus remains inactive and causes symptoms only when it experiences stress in the immune system.

In such a scenario, the CMV avidity test is essential to detect the presence of cytomegalovirus. This is because the virus can quickly spread through the saliva of one person and can cause cold sores. The cytomegalovirus test is essential for people with a weak immune system as they may suffer from severe symptoms of the infection.

Different types of CMV infections can affect an individual at various stages:

• Congenital: This infection is usually inherited from maternal blood and affects a baby before it is born.
• Primary: It is the first infection from CMV that an individual suffers at any point in their lifespan. Usually, it seems like mononucleosis due to its symptoms.
• Reactivation: A reactivation of CMV is a secondary infection where the virus activates itself after remaining dormant for a period. These infections can also result from HIV infection, cancer treatment, and organ transplantation.

Apollo 24|7 offers a panel for CMV avidity test to detect the presence of the infection. Some of the symptoms to notice before going for a CMV IgG test are:

• Feeling constant fatigue
• Swelling in glands
• Consistent relapse of fever
• Sore throat 
• Ache in the muscle

Some rare symptoms to also look for before opting for a CMV avidity test include:

• Changes in personality that may seem like mood swings
• Constant headache or heaviness in the head
• Breathing difficulty
• Dry cough after soreness of the throat
• Difficulty in concentrating on tasks

If it is congenital, one can look for these symptoms in their new-born and order a cytomegalovirus test:

• Premature birth
• Low birth weight
• Bruise-like rashes all over the body
• Jaundice
• Microencephaly, i.e., small-sized head
• Loss of hearing
• Pneumonia
• Seizure s
• Hepatitis or liver inflammation

The CMV test is also necessary after an organ transplant. 
 

Medically reviewed by Dr. Surya Narayan Mohanty, Obstetrics and Gynaecology, Apollo Hospitals Old Sainik School Road, Bhubaneswar

Frequently asked questions

What is the CMV avidity test?

The term avidity stands for the ability of antibodies to aggregate around the antigen. The CMV IgG test detects IgG, the antibody produced after primary CMV infection. Usually, low avidity indicates a recent infection, whereas a high avidity indicates an infection of high intensity.

Why should one go for a cytomegalovirus test?

A CMV avidity test helps differentiate a recent infection from a secondary infection or an infection that occurred in the past. For instance, if a woman catches a CMV infection after pregnancy, she is more likely to pass it on to the foetus than a woman who already had the infection before conceiving. The CMV test thus identifies the timeline of a CMV infection.

Is the intermediate result in the CMV avidity test dangerous for the foetus?

The intermediate avidity result for a cytomegalovirus test depends on the stage of pregnancy. An intermediate avidity during the first trimester is expected to be high, whereas the results in the second or third trimester are expected to be low.

How is CMV transmitted from one person to another?

Usually, the mode of transmission of a CMV is through saliva, semen, vaginal fluid, breast milk, urine, and blood. One can also catch an infection by touching an infected person’s eyes, nose, or mouth.

What are some ways to recover from a severe cytomegalovirus infection?

A robust antiviral therapy for a couple of weeks may help manage the condition. However, a CMV IgG test will be able to identify the intensity of the infection. This can help your physician decide on the right therapy for your condition and choose between drugs such as foscarnet, maribavir, ganciclovir, or cidofovir.