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West Nile Virus Biovigilance Network (WNV) Frequently Asked Questions (FAQ)

When can I start using the system?

The system is available now. As soon as you identify a Presumed Viremic Donation (PVD) you may enter it into the system.

What kind of test results should I report into the system?

Presumed Viremic Donations or PVDs for WNV.


Results from what kinds of donors should be included?

Results for blood donors, tissue donors, and hematopoietic progenitor cell (stem cell, or other) donors, should be included in this system. In order to distinguish between types of donors, please add a “B” for blood donor, a “T” for tissue donor, or an “H” for HPC donor to the Submission Name field for tracking purposes. You may follow that letter with the blood donor unit number or any other unique identifier that will allow you to track the PVD in your system. For example: B097FS87654 may be a blood donor PVD identifier; T1234567, a tissue sample identifier, and H0010078, an autologous HPC donor PVD identifier.

What is a PVD?

(1) A reactive sample that is repeatable by Individual (ID) NAT, i.e. repeatable NAT reactivity using the same screening test, analogous to repeat reactivity in serology, OR, if not repeating the NAT, (2) reactivity in the Procleix assay that has a signal to cutoff ratio exceeding or equal to 17.

What is a confirmed positive?

A WNV Case is considered confirmed positive if one or more of the following occur for the index and/or follow up sample:

Index Sample

Repeat NAT reactivity using the same NAT assay but an independent sample source (i.e., if the NAT repeat reactivity that qualified the donation as a PVD used the index test sample tube(s), then it is recommended that the confirmation testing use an independent sample from the retrieved frozen plasma component to exclude the possibility of source tube contamination).

Alternate NAT reactivity (from same or preferably from an independent sample, again to exclude the possibility of source tube contamination).

IgM and/or IgG reactivity (note isolated IgG reactivity at index does not exclude the possibility of prior infection or cross reactivity with a closely related flavivirus if WNV reactivity at index cannot be repeated).

Follow-up Sample

NAT reactivity using the same or alternate NAT method (within a time period from the index NAT-reactive result that excludes the possibility of a new infection; e.g., not greater than 28 days).

IgM and/or IgG reactivity (IgM reactivity should also occur within a time period from the index NAT-reactive result that excludes the possibility of a new infection; e.g., not greater than 28 days).

Do I have to enter confirmatory results and if so, when?

Yes, you should enter confirmatory test results. You can enter the confirmatory results at the time of the first entry of the PVD if they are available. If not, you can access the PVD record later and edit the Final Test Interpretation field, e.g. when a follow up sample is NAT reactive or antibody reactive.

Can I edit my results?

Yes, you can add additional test result data on the index PVD or on additional samples from the same donor at any time after the index PVD has been entered. You can also edit entries should they have changed.

Do I have to use the donation unit number as the PVD identification number?

The purpose of the donation unit number is to be able to track and access the record once it has been entered. Obviously, the easiest way is with a donation unit number. However, if there are concerns about using this number, the laboratory entering the data should choose an identifier that will allow the laboratory to identify that PVD later for editing and internal tracking.

Should autologous donors be entered into the system?


Why is AABB requesting this info?

It is intended for use by AABB’s West Nile Virus Task Force, blood centers and others to identify where and when cases of WNV are occurring. This information will be used by other labs and blood centers to assist in the decision as to when they might decide to “trigger” for ID NAT. It will serve to provide information to the CDC and the FDA, as well.

My lab tests for multiple blood centers, should I report for them?

The system is designed to have input from the testing lab.. You will need to collect some of the information from the blood centers, for example, the blood donor’s state of residence and zip code or postal code.

Is this just a U.S. based reporting system?

No, we are asking that Canadian PVDs be included in the system as well. You will notice that the system accommodates Canadian provinces and territories as well as Canadian postal codes.

Do I still need to report to state and local public health authorities?

Yes, state and local public health authorities use this information to monitor human cases of WNV in their area and to report these cases to CDC.

Who will see the data and the results that are in the system?

There are multiple layers of access to the system. Only your laboratory will have access to the actual PVD records for data entry and editing and to lab-specific reports. All users of the system will have access to the summary reports. Summary graphics and maps will be posted on AABB’s web page when data has been entered into the system.

Which reports are lab specific?

Lab specific reports are reports that include data that has been entered by the lab requesting the report. These include:

  • Lab Data by Week
  • PVDs with Incomplete Data
  • All Data for a Requested PVD.

What report should I use to see PVDs that have no final interpretation?

The report “PVDs for a requested State” can be used to see all the data in the system. Choose the report. Select “All States” and Click the View Report button.

What report should I use to find out if there are any PVDs from my lab that have not been updated with final interpretations?

Use the PVDs with Incomplete Data report. It will generate a list of all PVDs with no entry in the final interpretation field.