West Nile Virus Egg Donor Screening

West Nile Virus (WNV) is an arbovirus spread principally by Culex mosquitos that occur widely in the continental US. Mosquitos pick up the virus from infected birds and transmit it to other birds, mainly in the summer.

After being bitten by an infected mosquito, most people with West Nile Virus are asymptomatic or mildly symptomatic with a flu-like illness with or without a rash (West Nile fever). However, encephalitis (WNE) or meningitis (WNM) may follow infection, with significant morbidity and mortality rates. A US outbreak in 2012 caused 286 deaths. Recovery from even milder cases may be lengthy with physical and cognitive/mental symptoms.

First noted in Uganda in 1937, and highly prevalent with serologic testing in Africa and India, the disease was detected in North America in 1999. Human-to-human transmission through transfusion was noted and US blood banks began testing in 2003.

Under the guidance of the US Food and Drug Administration (FDA), “establishments must perform donor testing to adequately and appropriately reduce the risk of transmission of relevant communicable disease agents and diseases.”

Although donation of human oocytes has never been shown to cause infectious disease, oocytes fall under FDA jurisdiction under Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps) regulations. West Nile virus was added to the list of recommended screening within the last year.

Oocyte donor testing involves a questionnaire regarding blood transfusion, rashes and febrile illnesses as well as testing a donor’s blood at specific intervals before oocyte retrieval. Nucleic acid testing (NAT) has higher sensitivity and specificity for most viruses than antibody tests that may be easier to implement for screening large populations. The FDA has authorized specific NAT assays that are now widely commercially available.

The World Egg Bank stays current with all suggested and recommended FDA protocols and has implemented WNV testing, along with HIV, Hepatitis B & C, and other infectious disease testing such as Chlamydia. We have undergone frequent inspections by the FDA and have had no major citations.

Clinics which do not perform oocyte or sperm donor screening and stimulation are exempt from FDA inspections. The onus of regulation and inspection falls upon the organizations, such as The World Egg Bank, doing the donor screening and testing.