FluChip May Offer Rapid Detection of Multiple Influenza Virus Strains

Researchers have developed a new diagnostic method capable of rapid identification of influenza A and B subtypes that may ultimately reduce the impact of a potential influenza pandemic. They report their finding in the August 2006 issue of the Journal of Clinical Microbiology.

Annual influenza outbreaks, and the threat of a pandemic as new strains continue to emerge and mutate, are of great worldwide concern. An estimated 36,000 people die from influenza-related illnesses each year in the United States alone and increased awareness has prompted international efforts in developing effective monitoring and preparedness measures. To date, the most reliable method for identifying influenza virus strains takes 3 to 7 days and can only test a few samples simultaneously.

In this blind study researchers used the FluChip-55 microarray to test 72 influenza virus isolates for A and B subtypes including H1N1, H3N2, as well as avian A/H5N1, which has become enzootic in poultry in certain parts of the world. In less than 12 hours, combined results provided correct types and subtypes for approximately 72% of the isolates and the correct type and partially correct subtype for 13% of the isolates. Incomplete subtyping in most cases was attributed to failure relating to nucleic acid amplification as opposed to testing limitations.

"By using the FluChip-55 microarray in conjunction with a well-established RNA amplification method, RNA from viruses of interest, including influenza viruses A/H1N1, A/H3N2, and A/H5N1 and influenza B virus, was typed and subtyped in 11 hours," the researchers said. "The ability to rapidly identify new, potentially pandemic strains of influenza virus will allow health care officials to more rapidly respond and, potentially, reduce the spread and human impact of the disease."

(M.B. Townsend, E.D. Dawson, M. Mehlmann, J.A. Smagala, D.M. Dankbar, C.L. Moore, C.B. Smith, N.J. Cox, R.D. Kuchta, K.L. Rowlen. 2006. Experimental evaluation of the FluChip diagnostic microarray for influenza virus surveillance. Journal of Clinical Microbiology, 44. 8: 2863-2871.)