West Nile Virus Update

Oct 03 2002

Source: CDC

As of 2 October, the total number of West Nile virus cases reported to CDC reached 2,530 with 125 deaths in 32 states and Washington D.C. have reported human cases of West Nile virus in 2002.

The CDC, the Food and Drug Administration, the Health Resources and Services Administration, in collaboration with blood collection agencies and state and local health departments, continue to investigate WNV infections in recipients of blood products and organ transplantation. CDC has received reports from 10 states of 15 patients with confirmed West Nile infection diagnosed after receiving blood products within 1 month of illness onset.

It is likely that not all of the 15 patients were infected via blood products; all lived in areas with active West Nile virus activity and thus may have been infected via mosquito bites.

To recap the investigation so far, West Nile virus transmission from blood products has been confirmed in three patients. In a Mississippi investigation, West Nile virus was cultured from a blood product associated with a blood donor of one of the cases. In a Michigan investigation, two patients tested positive for WNV infection after receiving different blood products derived from a single blood donation subsequently found to have evidence of WNV.

The CDC and the Michigan Department of Community Health (MDCH) are continuing to investigate the West Nile Virus infection in a woman who received a blood transfusion who later became ill from WNV. She had been breastfeeding and her breast milk was shown to have evidence of WNV genetic material. Attempts to culture WNV from the breast milk are still underway.

Her infant has remained healthy. However, a blood sample from the infant demonstrated IgM antibodies to the WNV, indicating that the infant had been infected with the WNV.

This infant is now the youngest person reported with WNV-specific IgM since WNV was first recognized in the United States in 1999.

Because the health benefits of breast-feeding are well established and the risk for WNV transmission through breast-feeding is unknown, we do not suggest a change in breast-feeding recommendations. Women who are ill or experiencing difficulties, as always, may wish to consult with their physician about breast-feeding.

For more information on West Nile virus, the public may call the CDC hotline 1-888-246-2675.