Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Baby

Font Size

West Nile Virus May Infect Breast Milk

Parts of Virus Found In Milk of Nursing Mother
WebMD Health News

West Nile virus giving birth breast breast

"The infant is doing well clinically. We are testing the infant now," CDC West Nile virus expert Lyle Petersen, MD, MPH, said at a news conference. "We have only detected viral genetic material [parts of the virus] in the breast milk. We do not know if this represents live virus [that can cause infection] or not."

Results from the child's blood tests won't be known for several days. The CDC is trying to determine whether there is live virus in the woman's breast milk. Those tests have run into problems and won't be finished for several days at least.

Even if breast milk does carry West Nile virus, it does not seem to be a very big problem. Very few of the 2,206 cases of West Nile fever reported this year have been seen in infants.

"The risk of West Nile virus infection due to breast milk among infants is going to be low -- if there is any risk at all," Petersen says. We do not know if there is live virus in these milk samples. However, we would expect the virus would be present in the breast milk for a very short period of time. If there was a risk, it would become negligible in a very short time."

So what should women do? The CDC recommends that nursing mothers who think they may have West Nile virus infection should see their doctors and get tested. If they do test positive, they should consult with their doctor about whether to continue to breastfeed.

"We do not have sufficient information to determine whether West Nile virus can be transmitted by breast milk," Petersen says. Therefore, other factors must be taken into consideration. These factors would include, for example, illness in the woman. "If the woman has severe disease and cannot breastfeed easily, we certainly recommend supplemental feeding. On the other hand, breastfeeding has many beneficial effects. The decision whether to continue breastfeeding is a big one and must be taken seriously."

The 40-year-old woman gave birth on Sept. 2. That day she got a transfusion of a single unit of blood and got a second unit the next day. While she was in the hospital she had a fever, but she went home on Sept. 4. However, the woman did not feel well and on Sept. 17 went back to the hospital with fever and headache. A spinal tap on Sept. 18 showed that she had West Nile virus infection.

Baby's First Year Newsletter

Because every week matters, get expert advice and facts on what to expect in your baby's first year.

Today on WebMD

mother on phone holding baby
When you should call 911.
parents and baby
Unexpected ways your life will change.
baby acne
What’s normal – and what’s not.
baby asleep on moms shoulder
Help your baby get the sleep he needs.

mother holding baby at night
mother with sick child
Chinese mother breast feeding newborn baby girl
Track Your Babys Vaccines
Baby Napping 10 Dos And Donts
Woman holding feet up to camera
Father kissing newborn baby
baby gear slideshow