ADDL Fiscal Year 2016 Annual Report
HPAI Outbreak
By: Dr. Craig Bowen, Velina Lindley, Angie Chan and Liam Fitzgerald
2016 began with a diagnosis of highly pathogenic Avian Influenza (HPAI), the second year in a row for Indiana. A commercial turkey flock in southwest Indiana suffered a major increase in mortality, and ADDL sister lab, the Heeke Laboratory of Southern Indiana Purdue Agricultural Center, confirmed farmers’ fears with a positive diagnosis for Avian Influenza Virus. This was the first of a total of ten locations confirmed positive over the next several days. Diagnoses were confirmed by the ADDL laboratory and the National Veterinary Services Laboratory for nine of those locations.
The first diagnosis was made on January 14th, immediately initiating a multi-agency effort to prevent the disease from spreading that would last until April 21st. Those involved included the Indiana State Board of Animal Health, the United States Department of Agriculture Veterinary Services, the Indiana Department of Homeland Security, and the Indiana State Poultry Association. Throughout the episode, the Indiana Animal Disease Diagnostic Laboratory at Purdue served as the primary location for testing, and the Molecular Diagnostics staff worked long hours to provide reliable results quickly.
Veterinarians, representatives from state agencies, and local farmers collected swabs from birds at commercial poultry companies, backyard/small flocks and wild birds, sending all samples to the ADDL. Extreme caution and biosecurity were used to prevent contamination and exposure.
The Molecular Diagnostics section tested samples using Polymerase Chain Reactions (PCR). To perform a PCR, genetic material (DNA or RNA) is extracted from a sample. Using a controlled combination of primers and enzymes, technicians initiate a reaction that replicates DNA or RNA, but only DNA or RNA that targets the agent interest, in this case influenza A virus. By repeating the process of replication over and over, the targeted sequence is amplified to a level which can be detected and measured. In this case, ADDL targeted a genetic segment found only in the RNA of the Influenza A Virus.
State animal health officials initiated quarantines and movement restrictions. All commercial poultry operations and backyard flocks within ten kilometers of the infected premises were tested. Throughout the three months, ADDL provided diagnoses for over four thousand eight hundred samples. Quick turnaround was critical in keeping the Influenza contained, and maintaining necessary poultry operations.
Positive results were sent to NVSL for confirmation and characterization. The initial positive was identified as highly pathogenic H7N8. Eight of the additional nine positives were identified as low pathogenic H7N8, with the tenth positive deemed a suspect. As the episode progressed, ADDL continued to test samples not only for initial diagnosis but also for surveillance, movement, environment, post cleaning and disinfection. It is in no small part thanks to the exceptional work of the ADDL staff that this Influenza episode was contained.
This Highly Pathogenic Avian Influenza episode occurred on a much larger scale than that of 2015. It was through review of the 2015 incident and evolution of ADDL’s process that the laboratory was prepared to handle the large demand of the 2016 episode. The Molecular Diagnostics section entered 2016 with the materials and strategy to handle four hundred cases a day for ten days straight, which is the amount of time necessary to receive supplies for the next ten days. This worst-case scenario strategy was nearly stretched to capacity in the 2016 episode. ADDLs crucial role in containing this outbreak reaffirms the relationships, communication, and inter-agency teamwork that are vital to the future of animal health in the state of Indiana.
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