Field detection of avian influenza virus in wild birds: Evaluation of a portable rRT-PCR system and freeze-dried reagents

John Y. Takekawa, Samuel A. Iverson, Annie K. Schultz, Nichola J. Hill, Carol J. Cardona, Walter M. Boyce, Joseph P. Dudley

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Wild birds have been implicated in the spread of highly pathogenic avian influenza (HPAIV) of the H5N1 subtype, prompting surveillance along migratory flyways. Sampling of wild birds is often conducted in remote regions, but results are often delayed because of limited local analytical capabilities, difficulties with sample transportation and permitting, or problems keeping samples cold in the field. In response to these challenges, the performance of a portable real-time, reverse transcriptase-polymerase chain reaction (rRT-PCR) unit (RAPID®, Idaho Technologies, Salt Lake City, UT) that employed lyophilized reagents (Influenza A Target 1 Taqman; ASAY-ASY-0109, Idaho Technologies) was compared to virus isolation combined with real-time RT-PCR conducted in a laboratory. This study included both field- and experimental-based sampling. Field samples were collected from migratory shorebirds captured in northern California, while experimental samples were prepared by spiking fecal material with an H6N2 AIV isolate. Results indicated that the portable rRT-PCR unit had equivalent specificity to virus isolation with no false positives, but sensitivity was compromised at low viral titers. Use of portable rRT-PCR with lyophilized reagents may expedite surveillance results, paving the way to a better understanding of wild bird involvement in HPAIV H5N1 transmission.

Original languageEnglish (US)
Pages (from-to)92-97
Number of pages6
JournalJournal of Virological Methods
Issue number1-2
StatePublished - Jun 2010

Bibliographical note

Funding Information:
We appreciate the help and co-operation of San Pablo Bay National Wildlife Refuge and California Department of Fish and Game for use of habitat for shorebird capture. Thanks to those who provided invaluable assistance with capture including L. Lieu, K. Henderson, S. Moskal, B. Hattenbach, E. Palm, B. Stieg, N. Warnock, B. Hill and L. Dembosz. We are grateful to UCD staff including G. Lee for co-ordinating sample media and supplies and N. Anchell, N. Dao and J. Anunciacion for their expert technical assistance in conducting confirmation lab testing. We are grateful to J. Yee of the U.S. Geological Survey for statistical advice. Finally we wish to thank M. Scullion and R. Crisp of Idaho Technologies for technical support. This research was performed under the auspices of the Center for Innovative Technology – Institute for Defense and Homeland Security ( ), in support of the Department of Defense and Air Force Research Laboratory. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. government.


  • Active surveillance
  • Avian influenza
  • HPAI H5N1
  • Migratory birds
  • Rapid diagnosis


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