West Nile Virus: What you need to know to protect your family

The nation's first human case of West Nile Virus (WNV) in 2003 was confirmed in South Carolina, July 8, 2003 by the Centers for Disease Control and Prevention (CDC). WNV, a seasonal infection transmitted by mosquitoes, grew from an initial U.S. outbreak of 62 disease cases in 1999 to 4,156 reported cases, including 284 deaths, in 2002.

State and local health departments have reported 4,325 cases of illness related to WNV this year and 81 deaths. (September 18, 2003)

"It is impossible to predict what this year's season will hold; however, the recurrence of WNV in humans is a compelling reminder of the importance of individual preparedness in preventing disease," said Dr. Julie Gerberding, CDC Director. "Knowing how rapidly WNV spread last year, we urge everyone who spends time outdoors to take steps to protect themselves from mosquito bites."

How is WNV Transmitted?
Infected mosquitoes can transmit WNV to humans and animals. The virus is located in the mosquito's salivary glands and may be injected into the animal or human, where it can multiply, possibly causing illness.

In a very small number of cases, WNV has also spread through blood transfusions, organ transplants, breastfeeding and even during pregnancy from mother to baby.

West Nile virus is not transmitted from person-to-person. For example, you cannot get WNV from touching or kissing a person who has the disease, or from a health care worker who has treated someone with the disease.

Who is Most at Risk?
For most, the risk is low. Less than one percent of people who are bitten by mosquitoes develop any symptoms of the disease and relatively few mosquitoes actually carry WNV. There is a greater risk for those who spend a lot of time outdoors, Also, people over 50 are more likely to develop serious symptoms of WNV if they do get sick and should take special care to avoid mosquito bites. The risk of getting WNV through medical procedures, such as blood transfusions and organ transplants is low.

Pregnancy and Breastfeeding
Pregnancy and nursing do not increase the risk of becoming infected with WNV. There is also no documented evidence that a pregnancy is at risk due to infection with WNV. There are no reported adverse events following use of insect repellents containing DEET in pregnant or breastfeeding women.

It appears that WNV can be transmitted through breast milk. A new mother in Michigan contracted WNV from a blood transfusion shortly after giving birth. Laboratory analysis showed evidence of WNV in her breast milk. She breastfed her infant, and three weeks later, her baby's blood tested positive for WNV. The child is healthy, and does not have symptoms of West Nile virus.

Because the health benefits of breastfeeding are well established, and the risk for WNV transmission through breastfeeding is unknown, the new findings do not suggest a change in breastfeeding recommendations. The American Academy of Pediatrics and the American Academy of Family Physicians recommend that infants be breastfed for at least the first year of life.

Babies and Young Children
West Nile virus illnesses in children younger than one year old are infrequent. During 1999-2001, no cases in children younger than one year of age were reported to the Centers for Disease Control and Prevention. Of the over 2,500 total WNV cases in 2002, only four were less than one year of age.

Page Two: Find out how to protect your family

Page Three: Learn the symptoms to watch for and how West Nile Virus is diagnosed and treated

What You Can Do to Protect Your Family