2009 Influenza A (H1N1) Virus

Updated November 18, 2009

The information provided is offered as a resource for Wisconsin Laboratories, Testing Sites, and Health Care Facilities. Guidance documents will be updated to reflect changes in the situation and/or available information.

Respiratory Virus Activity, Statewide  NEW 10/21/09

Nomenclature: To be consistent with CDC and the WI Division of Public Health, we will now refer to this virus as "2009 influenza A (H1N1) virus" or "2009 H1N1 influenza virus."

NEW 11/18/09
CHANGE IN FEE EXEMPT TESTING CRITERIA AT WSLH: The WSLH will discontinue fee-exempt testing of patients in the classifications of healthcare workers and less than 2 years of age, effective Monday, November 23, 2009.  This change was instituted in collaboration with Wisconsin Division of Public Health to be consistent with state and national guidelines for patient management and infection control.  Fee-exempt testing will continue for cases involving pregnancy, hospitalization, death, resident or staff of longterm care facility or correctional facility, and public health department approval.  An updated requisition form is available at the WSLH website under “Forms and Instructions” at http://www.slh.wisc.edu/comdis/swineflu.dot 

WSLH THANKSGIVING DAY & WEEKEND SCHEDULE

Testing for 2009 Influenza A (H1N1) at the WSLH:  The WSLH has discontinued confirmatory testing of influenza A positives by rapid tests in all regions of Wisconsin.

• Rapid testing sites in all counties should not send influenza A positives to WSLH for confirmatory testing.  However, specimens that meet fee-exempt criteria may be submitted with the fee-exempt requisition form, regardless of whether rapid testing was performed.
• Specimens that are positive for influenza A by rapid tests in all regions of Wisconsin can be presumed to be a true positive until the level of influenza activity declines. 
• The WSLH has implemented this change in testing to conserve reagents and supplies. 
• We thank the rapid test sites that provided specimens.
  

Please continue to send the following specimens to the WSLH:

• Rapid testing sites in all counties should continue to send all influenza B positives to the WSLH for confirmatory testing.   
• Rapid testing sites that are enrolled to submit their first ten weekly specimens should continue to do so. 
• WSLH testing of specimens that meet fee-exempt criteria will continue.  The criteria for fee-exempt testing are being reviewed and may be modified.

Other Changes in WSLH Testing

• Influenza A Subtyping of Fee Exempt Specimens:  Specimens that meet fee-exempt criteria will be tested for influenza A at the WSLH. At this time, subtyping is being performed on influenza A-positives in cases of pregnancy, hospitalization or death.    

Surveillance for Other Viruses

• Influenza B and Other Respiratory Viruses:  WSLH will perform testing for influenza B and other respiratory viruses on selected subsets of surveillance specimens and on rapid test samples that are submitted as positive for influenza B.  
  • Graphs of estimated positivity of respiratory viruses according to WSLH statewide surveillance testing will be posted each week; see “Respiratory Virus Activity” above on this page.  

Fee-for-service testing at the WSLH :  The WSLH discontinued fee-for-service testing for 2009 influenza A (H1N1) virus, as of October 1, 2009, to focus on surveillance responsibilities.

Testing for influenza by PCR is available at a number of clinical laboratories and may become available at additional laboratories. Healthcare facilities/providers and clinical laboratories should inquire with their reference laboratory about test availability. See below for a listing of Wisconsin clinical laboratories where testing may be available.

Fee-Exempt testing for 2009 Influenza A (H1N1) at the WSLH

• Fee-exempt testing for 2009 Influenza A (H1N1) virus is available at the WSLH only for specimens that meet the fee-exempt criteria OR the surveillance criteria listed below.



• Fee-Exempt Specimens:  Specimens submitted to the WSLH for fee-exempt testing for 2009 influenza A (H1N1) must be submitted to the WSLH with a WSLH Fee-Exempt 2009 H1N1 Influenza Requisition Form indicating clinician suspicion of influenza and/or febrile respiratory illness and at least one of the following criteria:
  
  
  • Pregnancy
  
  
  
  • Death
  
  
  
  • Resident or Staff of Residential or Correctional Facility (Note: Once the presence of influenza has been established within a facility, testing additional patients is not necessary.)
  
  
  
  • Hospitalization (provide name and city of hospital)
  
  
  
  • Public Health Department Approval (provide name and agency of approval)

Note:  Fee-exempt testing of children 2 years of age or less and healthcare workers is being discontinued at the WSLH, effective November 23, 2009.  

• Fee-Exempt Laboratory-Based Influenza Surveillance during 2009-2010: 
  
  
  • Specimens that are submitted by "sentinel submitters" - healthcare providers and/or sites that are specifically enrolled by the WSLH.  Forms are available by request of enrolled providers through our Clinical Orders Department (608-265-2966 or 800-862-1088).
  
  
  
  • Specimens that are submitted as the first 10 specimens (or first 5 specimens, depending on influenza activity) each week with a WSLH Influenza Surveillance Requisition Form.  These sites are specifically recruited and enrolled.  Forms are available by email request of enrolled sites to WCLN@mail.slh.wisc.edu.
  
  
  
  • Specimens that are submitted for confirmatory testing of influenza-positive rapid test results, with a WSLH Virology Confirmation Requisition Form.  Fee-exempt testing of these specimens by the WSLH has been discontinued.  Depending on influenza activity, fee-exempt testing may be re-instituted at another time. 


• Note:  When submitting specimens that meet fee-exempt criteria AND one of the surveillance categories, please use the WSLH Fee-Exempt 2009 H1N1 Influenza Requisition Form.

These fee-exempt guidelines refer to fee-exempt testing for cases of public health interest for surveillance purposes and should not be construed as guidance for clinical management of individual patients.

If you have questions, please email WSLH staff.

Wisconsin Laboratories At Which Influenza PCR Testing May Be Available

(The list below may not be all-inclusive and does not imply endorsement.)

• ACL Laboratories, West Allis
• Childrens Hospital of Wisconsin, Milwaukee 
• Dean Health System, Madison
• Dynacare Laboratories, Milwaukee
• Gundersen Lutheran Medical Center, LaCrosse
• Marshfield Labs, Marshfield
• Meriter Laboratories, Madison
• Midwest Respiratory Virus Program Laboratory, Milwaukee
• Milwaukee Health Department Laboratory, Milwaukee
• Prodesse Clinical Reference Laboratory, Waukesha
• ProHealth Laboratories, Waukesha
• University of Wisconsin Hospital & Clinics, Madison

Nationally, PCR testing (including subtyping) for 2009 influenza A (H1N1) virus is available through Quest Laboratories or Focus Diagnostics, California, and other laboratories.

WSLH Response Activities

The WSLH has provided laboratory support in the form of testing, specimen collection and packaging supplies, specimen transport arrangements, consultation, facilitating outbreak testing at other Wisconsin laboratories, etc. to Wisconsin public health agencies and to our clinical laboratory partners during the 2009 influenza A (H1N1) outbreak.

The WSLH also conducted teleconferences and provided email and fax laboratory messages for the clinical laboratories in Wisconsin as needed and provided guidance to laboratories and public health on specimen collection, transport and testing.

Below is a brief update of WSLH activities:

• Between 4/25/09 and 11/14/09, the WSLH tested more than 16,500 patient specimens for H1N1 2009 H1N1 influenza testing.



• WSLH has validated and performs the CDC 2009 H1N1 influenza virus test on-site. In addition, the WSLH is partnering with other Wisconsin laboratories to enhance testing capacity in Wisconsin.



• The Milwaukee Health Department Laboratory (MHDL) performs the same test as the WSLH. Contact MHDL at 414-286-3526 to register your facility, order forms, receive information on couriers, etc.

WSLH Contacts

• Telephone Inquiries: WSLH Customer Service at 608-262-6386 or 800-862-1013

• Specimen Collection & Shipping Supplies Ordering: WSLH Clinical Orders at 608-265-2966 or 800-862-1088

• Emergency Answering Service: 608-263-3280

Forms and Instructions

WSLH Fee-Exempt 2009 H1N1 Influenza Requisition Form Please be sure to provide your institution/agency name and address in the "submitter" space.

WSLH Virology Confirmation Requisition Forms are available to testing sites that wish to submit their influenza-positive specimens for confirmatory testing, based on current WSLH recommendations. Please complete the submitting agency information before printing. The WSLH is not currently accepting specimens that are positive for influenza A by rapid tests, but is accepting specimens that are positive for influenza B.

WSLH Influenza Surveillance Requisition Forms are available to testing sites that are enrolled as "structured submitters".

WSLH Viral Monitoring Requisition Forms are available to healthcare providers that are enrolled as "sentinel submitters".  

NOTE: Please provide the patient address and telephone number when completing requisition forms and when providing reportable disease reports to public health. Including this information allows a more rapid public health response and minimizes disruptions to the laboratory for information requests.

Shipping Instructions

FAX Authorization Form Complete form and FAX it to 608-890-2548 to authorize FAX reporting of WSLH results for your facility.  Please contact the WSLH Customer Service group at 608-262-6386 or 800-862-1013 for additional information.

Specimen Collection & Transport Information

The information below provides Wisconsin-specific guidance to submit specimens and receive result reports for 2009 Influenza A (H1N1).

• Specimen Collection:  According to the current recommendation from CDC, the preferred respiratory specimens for 2009 influenza A (H1N1) testing are nasopharyngeal swab, nasal aspirate or a combined nasopharyngeal swab with oropharyngeal swab. If these specimens cannot be collected, a nasal swab or oropharyngeal swab is acceptable. An endotracheal aspirate should also be collected from intubated patients. Bronchoalveolar lavage (BAL) and sputum specimens are also acceptable. 
  
  Following is additional information about proper specimen collection for 2009 influenza A (H1N1) 
  
  
  • Collect specimens as soon as possible after onset.
  
  
  
  • Collect using swabs with synthetic tips (e.g., polyester, Dacron) with wire or plastic shafts; flocked swabs are also acceptable.  Swabs with cotton tips and wooden shafts are not recommended; swabs made of calcium alginate are not acceptable.
  
  
  
  • Place specimens in 1-3 ml. of viral transport medium (VTM).  Any commercially available viral transport medium may be used.
    
    If viral transport medium is unavailable (VTM, UTM, M4), WSLH will accept swab specimens transported in sterile, screw-cap tubes containing 3-5 ml. of sterile 0.85% saline or sterile phosphate buffered saline (ph 6.8-7.6) for PCR testing only.
    
    Swabs that are not submitted in viral transport medium, saline, or PBS will not be tested, due to regulatory compliance requirements.    
  
  
  
  • Store and transport all specimens at refrigerator temperatures.
  
  
  
  • Follow infection control guidance during collection and handling of specimens.



• Instructions to Transport Specimens to the WSLH
  
  
  • Store and transport all specimens at refrigerator temperatures. 
  
  
  
  • Specimens for 2009 influenza A (H1N1) testing should be transported to the WSLH as soon as possible, but specimens are stable at refrigerator temperatures and will still be tested if transport takes more than 24 hours. The WSLH has validated the PCR test for specimens up to 7 days after collection.   
    
    
  • Specimen transport supplies can be requested through the WSLH Clinical Orders group at 608-265-2966 or 800-862-1088.  Shippers from other sources are also acceptable, as long as refrigerator temperatures are maintained.
  
  
  
  • Refer to specific instructions for shipment of specimens to the Wisconsin State Laboratory of Hygiene for Enhanced Viral Surveillance.  

Test Results Reporting

• Result Notification:  Results of influenza testing are NOT telephoned to submitters.
  
  
  • Written results are transmitted by FAX to those institutions that have authorized FAX reporting.
  
  
  
  • Written reports are provided by postal mail for those institutions that have not authorized FAX reporting.
  
  
  
  • We encourage institutions to authorize FAX reporting, to ensure rapid receipt of result reports.
    
    
    • Complete and return by FAX the FAX Authorization Form to FAX number 608-890-2548 to authorize FAX reporting of WSLH results for your facility.  Please contact the WSLH Customer Service group at 608-262-6386 or 800-862-1013 for additional information. 



• Result Terminology:  Below are explanations of the terminology that is currently used in WSLH result reports.     
  
  
  • No Influenza A Virus RNA detected. 
    
    
    • This result indicates that testing was not able to detect influenza A virus genetic material in the specimen.  The influenza A genetic material that is detected in this test is considered to be universal for all influenza A viruses, regardless of whether they are swine, avian or human origin viruses.  This specimen is considered "negative" for influenza A viruses, including 2009 influenza A (H1N1).
  
  
  
  • Influenza A Virus RNA detected.  
    
    
    • This result indicates that testing was able to detect influenza A virus genetic material in the specimen.  The influenza A genetic material that is detected in this test is considered to be universal for all influenza A viruses, regardless of whether they are swine, avian or human origin viruses.  This specimen is considered “positive” for influenza A, but the subtype has not been defined. The report may include a separate result that identifies the subtype or may include a comment that only selected positives will be subtyped.
      
  
  
  
  • 2009 Influenza A (H1N1) Virus RNA detected.
    
    
    • This result indicates that testing has detected influenza A virus, and has detected the 2009 H1N1 subtype of influenza A virus.  This specimen is positive for influenza A virus, and is positive for 2009 influenza A (H1N1).
  
  
  
  • Influenza A Virus RNA detected; NOT 2009 Influenza A (H1N1) Virus.
    
    
    • This result indicates that testing has detected influenza A virus, but has not detected the 2009 H1N1 subtype of influenza A virus.  The virus may be one of the “seasonal” subtypes of influenza A.  This specimen is positive for influenza A virus, but is negative for 2009 influenza A (H1N1). 
  
  
  
  • Influenza A Virus RNA detected; equivocal for 2009 Influenza A (H1N1) Virus.
    
    
    • This result indicates that testing has detected influenza A virus, but has not definitively detected the 2009 H1N1 subtype of influenza A virus. The RT-PCR for 2009 influenza A (H1N1) virus includes tests for three genetic targets; all three must be positive for the test result to be reported as positive, according to CDC protocol.  If the universal influenza A virus target is detected, and only one of the two targets for influenza A (H1N1) virus is detected, the specimen is considered positive for influenza A virus, but equivocal for 2009 influenza A (H1N1) virus.    
      
      
      
  • Influenza A Virus RNA detected; unable to subtype as 2009 Influenza A (H1N1) Virus.
    
    
    • This result indicates that testing has detected influenza A virus, but cannot confirm that it as the 2009 H1N1 subtype of influenza A virus, due to low concentration of virus in the specimen.
      
      
      
  • Indeterminate:
    
    
    • An RNase P (“RNP”) gene detection reaction is included for each specimen tested in the RT-PCR test for influenza as a measure of specimen quality and to detect the presence of PCR inhibitors.  Detection of the RNP is an indicator of the presence of sufficient human cellular material, and therefore, a satisfactory specimen.  If insufficient RNP is detected, the specimen is considered to be indeterminate, as there are likely very low levels of human cellular material or inhibitors of the PCR reaction in the specimen. This specimen is indeterminate in testing for influenza viruses due to low levels of human cellular material or presence of inhibitors. 
      
      
      
  • A negative result does not rule out infection with influenza A virus:
    
    
    • This statement is included as a reminder that these test results should be considered with clinical and epidemiological information to establish a diagnosis for the patient.  A negative test result by itself does not eliminate the possibility of infection.   
      

Resources

Webcast: Laboratory Testing Plans and Recommendations for Upcoming Influenza Season (9/2/09)

Specimen Collection, Processing, and Testing
CDC: Interim Guidance on Specimen Collection, Processing and Testing for Patients with Suspected Novel Influenza A (H1N1) Virus Infection

Recommendations for Clinical Use of Influenza Diagnostic Tests  NEW!

Rapid Influenza Tests
CDC: Interim Guidance for the Detection of Novel Influenza A Virus Using Rapid Influenza Diagnostic Tests

Infection Control Measures for 2009 H1N1 Influenza in Healthcare Settings, Including Protection of Healthcare Personnel  NEW!

Biosafety
CDC: H1N1 Influenza Virus Biosafety Guidelines for Laboratory Workers

Testing Guidance
Wisconsin DHS: Wisconsin Testing Guidance for Clincians

Other CDC Guidance Documents

Other Wisconsin DHS Guidance Documents

Other Links

• Wisconsin Department of Health Services



• CDC (Centers for Disease Control and Prevention)



• Flu.gov 



• WHO (World Health Organization)



• University of Wisconsin-Madison H1N1 web page