WNV Specimen Collection and Submission

Testing for patients with clinical symptoms suggesting WNV encephalitis/meningitis/fever can be obtained through submission of specimens by laboratories or physician offices to MDCH.  Kits for submission of human specimens for arbovirus panel (unit # 8) can be requested from MDCH by faxing a request to 517-335-9039 or by calling 517-335-9867. Testing request forms are included in the collection kits or can be printed off the web site.

How are specimens submitted?

1. Collection of samples

• CSF: at least 1.5 ml should be submitted in sterile, plastic tubes.  Hold CSF at 2-8^oC until shipped. Note: the tubes included in the collection kit #8 are non-sterile. Kindly replace with a sterile one.

• Serum:  All serum samples submitted for arbovirus testing must be approved by the Virology Section Manager (517-335-8099).  CSF is the specimen of choice however, under special circumstances, serum testing may be approved.  To differentiate recent exposure acute and convalescent (drawn at least 22 days post onset) specimens must be tested in parallel.  If IgM antibody is not detected in the convalescent specimen, no further testing will be performed.  If IgM is detected, plaque reduction neutralization testing (PRNT) will be performed on both the acute and convalescent specimen.  Turnaround time for PRNT is approximately 2-3 weeks.  Refer to MDCH/BOL Lab Services website   http://www.michigan.gov/mdch/1,1607,7-132-2945_5103---,00.html A-Z test listing.

Complete the MDCH Test Requisition Form and provide the following information on this form only:

• Date of onset of disease

• Date of sample collection

• Travel history within past 30 days

• History of vaccinations (e.g. Yellow Fever vaccination, Japanese Encephalitis virus vaccination - can lead to cross-reactions with arboviral agents)

• Clinical symptoms that suggest encephalitis

• Previous testing done for WNV and results if available

For serum samples, submit a completed CDC test request form.

3. Shipping

• Place no more than two labeled tubes, wrapped in absorbent material such as paper towel or tissue, into aluminum screw-capped can and tighten the cap.  Specimens may be shipped at ambient temperatures provided there are no anticipated delays in transport beyond 48 hours.  If transport of > 48 hours are expected, please ship the specimens in ice packs.

• Place aluminum can with completed test requisition(s) and additional information into screw-capped cardboard container and secure tightly with cap.

• Complete and apply return orange address and clinical specimen label to cardboard container and ship by the most rapid and convenient means available (e.g. First Class, Priority or US Mail and Express Mail with O/N delivery, etc.) to the BOL at MDCH.

Reporting by Physicians and Non-Public Health Laboratorians

We appreciate the collaboration with our clinical colleagues that allowed MDCH to respond to WNV as it emerged as a threat in Michigan and provide robust surveillance data to our Bureau of Epidemiology and CDC.   The elimination of Arbovirus IgG testing at MDCH will mean a greater dependence upon reporting of positive serum antibody tests by clinical laboratories and physicians.   More than ever, we will be relying upon our clinical partners to assist in the surveillance for human arboviral illness in the state.  Please continue to report all positive arbovirus IgG results to your local health jurisdiction.