Health Update
INFLUENZA TESTING
SEPTEMBER, 2009

The Delaware Public Health Laboratory (DPHL) is now offering the FDA approved Real Time Reverse Transcriptase Polymerase Chain Reaction (CDC rRT-PCR Flu Panel) method for detection of influenza virus nucleic acids. This method has the ability to detect non-viable viral particles and provides optimal sensitivity and specificity for identification of influenza. It can also distinguish the common seasonal human strains of influenza virus (H1, H3) from uncommon strains (H5 and H7) and from the Novel 2009 H1N1 (swine-like) strain. This testing service is conducted for public health surveillance purposes to help determine what influenza viral types are circulating in Delaware. Specimens for submission to DPHL should be from:

• Hospitalized patients with screen positive or culture confirmed results, including ante mortem specimens from patients who have died from influenza like illness
• Sentinel providers who are part of the established influenza surveillance program
• Individuals with influenza-like illness who are a part of a public health outbreak investigation
• Public health clinics

Providers are reminded that testing does not need to be done on all patients with symptoms of influenza. The Centers for Disease Control and Prevention (CDC) recommend testing for individuals at high risk of complications related to influenza. Once influenza activity has been documented in the community or geographic area, a clinical diagnosis can be made for patients with signs and symptoms consistent with influenza. This will avoid treatment delays inherent in waiting for test results.

Test results will be available within 48 to 72 hours from time of receipt, depending on the number of specimens received. Laboratory couriers will pick up specimens daily from our regular pick-up locations. For pick-up sites see the DPHL web site:   http://www.dhss.delaware.gov/dhss/dph/lab/courierroutes.html.

To receive a supply of collection kits please contact the laboratory kit room by calling (302) 223-1520 or e-mailing labsupplies@delaware.gov. Sentinel physicians are asked to use one of our regular pick-up locations for pick up of supplies and drop off of specimens. If this is not practical, please call the laboratory kit room to make alternate arrangements. Use the influenza virus detection kit for collection and transport of specimens for identification of influenza types A and B. Instructions are included in the kit and are also printed below. If rapid testing has been performed, please provide the results on the requisition form.

The testing algorithm that has been used by DPHL from May 1 to October 3, 2009 detects only influenza A and subtypes for only the Novel 2009 H1N1 (swine-like) strain. This algorithm was implemented to help the Centers for Disease Control and Prevention (CDC) conserve reagents. However, in order to provide more complete surveillance data, effective October 5, 2009, the beginning of the 2009-2010 influenza season, the testing algorithm used will detect both influenza A and B as well as subtype both A and B strains. DPHL may adapt this algorithm during the influenza season to suit detection demands and the predominant influenza strain in circulation. If this occurs, DPHL will notify specimen submitters.

We encourage health care providers who submit influenza specimens to DPHL to be on the laboratory’s information management system (LIMS). This system will provide real time electronic access to test results. Public Health clinics are already on LIMS, but hospitals and sentinel physicians may not be. To gain access to LIMS you will need to sign a Memorandum of Understanding and receive 1-2 hours of training. To initiate the process, please call Kathy Gray, DPHL LIMS Administrator, at (302) 223-1520.

We ask that health care providers be prepared to reduce the number of specimens sent to the DPHL at the peak of the season, traditionally in mid to late February. This will only be necessary if we exceed our capacity for testing or reagent supplies are low. Should either of these conditions occur, we will send out an e-mail giving instructions on numbers and types of specimens to submit – for example submit a specimen from one in every fifth patient.

For Private Physicians (not sentinel physicians):

Most commercial laboratories have developed assays that will detect the Novel 2009 H1N1 (swine-like) influenza strain. Therefore, physicians are encouraged to use their usual contract laboratory for testing for influenza. Commercial laboratories will collaborate with DPH to refer specimens that they are unable to subtype to the DPHL and to report positive results. Commercial labs will also provide guidance on collection of specimens and acceptable specimen types to submit for testing. Do not send patients to emergency rooms for testing. If you are interested in becoming a sentinel physician for public health surveillance please call the influenza epidemiologist at (302) 744-1154.

Large Group Settings:

For nursing homes, schools, colleges and universities, Department of Corrections, etc. the DPHL will perform testing until 5-10 positive specimens have been reported. Once the virus is identified and subtyped and it has been established that influenza virus is circulating in the institution, only testing for individuals at high risk of complications related to influenza will be performed by DPHL. Testing for large institutions should be done in consultation with the DPH Bureau of Epidemiology at 888-295-5156 who will assist in identifying and controlling outbreaks and determining specimens to be tested.

For the latest CDC guidance on the use of rapid antigen detection tests for influenza see: http://www.cdc.gov/h1n1flu/guidance/rapid_testing.htm

INFLUENZA Virus Detection Kit - Instructions

Use this kit for collection and transport of nasopharyngeal (NP) specimens. Collect specimens as soon as possible after onset of symptoms. Other types of specimens may be tested, but negative results will indicate the specimen was not the recommended type. For collection of NP specimens see the DPHL web site at http://www.dhss.delaware.gov/dhss/dph/lab/labs.html.

1. Kit contains:  1 requisition form
                          1 screw-capped tube with 2ml of sterile transport media
                          1 flexible slender nasopharyngeal swab
2. Fill in patient name and date collected on tube.
3. Complete requisition form. Failure to fill out all the requested information may result in delayed testing or specimen rejection.
4. For collection of nasopharyngeal specimen insert the swab into the posterior nasopharynx and rotate it gently. Contact time should be 10 seconds or at least until the patient coughs.
5. Place the swab into the screw-capped tube containing transport medium.
6. Place collected specimens along with requisition slip back into original biohazard specimen bag.
   Immediately place in a refrigerator (2-8 C). DO NOT FREEZE.
7. Arrange for transportation of specimen at 4 C (on ice or in cool van) to Virus Diagnostic Laboratory within 24 hours after collection. Courier specimen pick up locations can be found at the following web address: http://www.dhss.delaware.gov/dhss/dph/lab/courierroutes.html

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