What Does It Mean to Have CMV-Negative Blood?

Nearly everyone knows about the blood types: A+, A-, B+, B-, O+, O-, AB+ and AB-.

But did you know there’s another factor that could make your blood donation even more important to those who need it? You may be a cytomegalovirus-negative (CMV-, for short) donor and not even know it. What exactly does it mean to have CMV- blood though?


Cytomegalovirus, is a common, flu-like virus that most people encounter at some point during their lifetime. Although CMV comes from the same virus family as chickenpox, mononucleosis and herpes, it is usually harmless, and most people don’t even realize they’ve been exposed to it. In the U.S., between 50-85% of adults will contract CMV by the time they reach the age of 40.

However, CMV can be dangerous to individuals with weakened immune systems, newborns and people undergoing organ transplants. For these individuals, having a blood donor who is CMV- (someone who has never been exposed to cytomegalovirus) is very important!

How do you know if you’re a CMV- donor or not?

Blood centers run a whole battery of tests on the blood they’ve collected before it goes to the hospitals. Cytomegalovirus exposure is one of the many things for which they test. Someone who has been exposed to CMV, no matter how long ago it happened, will develop antibodies that remain in their body for the rest of their life. If a donor doesn’t have the CMV antibodies, then they are a great candidate to donate blood for babies!

The next time you come down to donate, talk to your phlebotomist. If you’ve donated before, they should be able to look at your health history to see if you’re CMV- or CMV+. A lot of donor centers have great recognition programs for their CMV- donors. And who doesn’t want to know that their blood donation was able to help a newborn who needed it!?

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Random factoid: I have CMV Negative blood | The Intrepid Wordslinger
December 19, 2013 at 7:19 am

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Carter BC Donor August 22, 2013 at 12:22 pm

I’m O+ and CMV-. Everytime I’ve gone to donate at Carter they always ask me to donate double reds. I always wondered why, and now I know. I’m interested in what I can do to prevent contracting CMV.


Dennis October 14, 2013 at 10:19 pm

O+, CMV-, they ask me to donate every two weeks. I can most of the time. I don’t understand why most people don’t donate at least three times annually. I just donated to Peninsula in San Mateo this past Saturday.
Pediatric oncology babies are especially important to me.


John November 17, 2013 at 1:13 pm

I donated blood off and on for years. Then last summer I was done very dirty by a girlfriend. After that I decided I was going to help the people that truly needed it. I don’t have much money so idecided to go donate blood. I went back a couple of months later and was told I am cmv- and that is something special. Now I go as scheduled and recently I also was tested for bone marrow donation and am now on the donater list for that as well. Am thinking about donating whole organs as well.


Jessica NC Donor January 3, 2014 at 5:09 pm

I recently went in for my first donation. Ever since I was 17 I wanted to do my part to help those in need. Unfortunately, they never allowed me to donate as I was going through treatment and needed my blood for myself. Since I was cleared a few months ago I finally got in to donate, which was when I was informed of CMV- and how that would help me reach out to more people. I was tested for it and was informed today that I’m a perfect candidate to donate platelets if I so chose! It makes me feel great to know that I not only contribute to the office I work in, on a daily basis, but in society as well. I really do enjoy what I do and donating helps me to enjoy it all the more!


Katy January 29, 2014 at 10:15 am

I am A+ CMV- and feel it an honor to donate blood to those that need it. Like many of you, I donate on a regular basis or when announcements are made in the area for blood due to a shortage. When disaster strikes, I am one of the first ones in line to donate. I love to watch the blood center put my bag of blood in a special box marked “Baby Blood”. There was one time that I went and my iron count was low and they wouldn’t take it. I left there in tears because I thought about the little babies that would need it. Over the following two weeks, I pumped up my iron count by eating a lot of iron rich foods and taking extra vitamins. I was able to donate after the two week period.


AJ March 23, 2014 at 9:09 am

They don’t check your iron. Your hemoglobin was low. To check your iron they need your serum which requires your blood to be centrifuged. They say its your iron because that’s something easy for people to understand.



Herb White March 26, 2014 at 6:13 pm


I am AB+ and do a platelet/plasma donation every 28 days or as close to it as I possibly can. Several years ago the Red Cross informed me that I am also CMV negative and I would like to know if my CMV negative status would permit me to contribute in another way as well as my platelet/plasma donations. I want to maximize my donations.

I am 69 years young and in good health.



Chelsea March 29, 2014 at 9:50 pm

During my regular blood donation visit yesterday (have been donating regularly for three years), I was told I am a double negative donor. I have O- blood and am CMV negative also. This is why my blood generally goes to newborn babies. It really feels good to give back since in 1983 I received two units of blood following the birth of my son. And I also wish more folks would donate their blood. It is so simple and quick and life affirming.


Taylor April 22, 2014 at 9:53 am

I’m O- and CMV negative. I’m thrilled I get to help save babies lives!!


tracy April 23, 2014 at 10:59 pm

i am O neg and CMV neg. My problem is low iron!! almost every time I try to donate I am turned away. What can I do?


Kimberly Wilson May 12, 2014 at 9:52 am

I am O+ and CMV- and have also had problems with low hemoglobin/iron. I was routinely turned away until I found a liquid iron supplement (prescribed by my MD). Liquid iron supplements don’t upset my stomach like the pills; however, like the pills, they can cause constipation. My doctor suggested taking a magnesium supplement and that has helped to help combat that particular problem (I take the iron in the morning and the magnesium in the evening). I hope this helps. Good luck!


Tiffany June 6, 2014 at 3:52 pm


There are different iron rich foods you can eat that will help keep your levels up. These include:
- Spinach,broccoli, sweet potatoes
- Beans (Lima beans, kidney beans, etc)
- whole wheat bread, white rice
- raisins, peaches
- nuts (especially walnuts, cashews, and almonds)
- apple juice
- shrimp, oysters, scallops
- vitamin c rich products (peppers, mango, citrus fruit)
- corn flakes

*****Be sure to have a good meal within 2-3 hours of donating and drink at least a bottle of water before the actual process. The hydration helps enlarge your veins and therefore makes it easier for the phlebotomist to access. Best of luck to you, and thank you all for donating!!

Source: I’m a phlebotomist for a local Blood Donation Center.


Tiffany June 6, 2014 at 3:56 pm

Edit: I meant Tracy!!! I saw Taylor’s reply above yours and accidentally typed her name!. My apologies!


amber July 7, 2014 at 4:55 am

I’m o- an just found out im cmv- as well! what can I do to prevent contracting the virus? (also tend to have low iron)


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