Health Update
PUBLIC HEALTH LABORATORY TESTING FOR SWINE FLU

This is a Delaware Division of Public Health (DPH) Health Update. The Delaware Public Health Laboratory (DPHL) is requesting specimens from suspect Influenza-like illness cases with a history of travel to Mexico or exposure to known or suspected cases of Swine Flu.

The U.S. Centers for Disease Control and Prevention (CDC) has announced over 20 cases of swine influenza A (H1N1) have occurred recently in the United States. The U.S. cases have had self-limited febrile respiratory illness and were seen on an out-patient basis only. None had any exposure to swine and all had viruses with identical genetic sequences that contain a unique combination of gene segments previously not seen in humans or swine in the United States. The viruses that were tested were resistant to amantadine and rimandatine, and sensitive to oseltamivir and zanamivir.

INFORMATION FOR CLINICIANS

DPH requests that clinicians consider the possibility of swine influenza virus infections in patients presenting with febrile respiratory illness who

1. Live in Mexico or have recently traveled to Mexico; or
2. Have been in contact with known or suspected cases of Swine Flu within 7 days prior to their illness onset.

If swine flu is suspected, clinicians should obtain a respiratory swab for swine influenza testing and place it in a refrigerator (not a freezer). Once collected, the clinician should call the DPH Bureau of Epidemiology (302) 744-4541 to make laboratory transport arrangements.

INFORMATION FOR LABORATORIANS

Due to the recent cases of a novel swine influenza as noted above, please send positive influenza samples to DPHL. DPHL needs your help to assess the influenza subtype(s) that may be present in our communities. Therefore, when your laboratory obtains a positive rapid A influenza result, including PCR (or culture-positive), please send an appropriate sample to DPHL Appropriate sample types are listed below.

What sample type to submit to DPHL

• Preferred specimen is a combination throat/nasal pharyngeal swab or oral pharyngeal swab; most other routine respiratory specimens will be acceptable.
• When influenza is detected in your laboratory by RAPID TESTING methods, please send an aliquot (1-2 ml) of the original suspension (not exposed to test kit reagents) in viral transport media or sterile diluent; or if an additional original specimen is available, that is preferable.
• When influenza is detected in your laboratory by VIRAL CULTURE, please send the actively growing viral culture tube with 2 ml of viral maintenance media.
• If you have questions regarding specimen collection, please call Rebekah Parsons at (302) 223-1520.

ADDITIONAL INFORMATION

• DPH Laboratory:  (302) 223-1520
• DPH Bureau of Epidemiology (302) 744-4541
• CDC Website: http://www.cdc.gov/swineflu/investigation.htm