H3N8 in Greyhounds in Northeast a Recombinant / Reassortant?
Recombinomics Commentary
May 13, 2005
>> "We think what we've seen is what began in Florida in December. It's almost certainly an influenza virus. The greyhounds are vaccinated, but not for this strain……
"We're catching up with it. When we started, the critically ill dogs passed away. But the less ill dogs have responded great to the medicine and the trainers are being made aware of what to do. We veterinarians don't call this `kennel cough.' We have to be careful when we try to identify what it is. I can tell you that what they had in Florida has been identified as a strain of influenza, and what the dogs have had up here is very similar." <<
The initial H3N8 isolate from Florida, A/canine/Florida/43/04(H3N8) was isolated in early 2004. The above comments indicate the outbreak in Florida for this season was also influenza, suggesting it also is H3N8. The isolate from last season was 96-99% homologous with equine influenza in all eight genes.
This season the number of greyhound fatalities is markedly higher, suggesting the virus may have changed. The number of fatalities is highest in New England where human flu was widespread. A second wave of influenza infections caused by the virulent California/7 H3N2 strain was in the northeast, raising the possibility that the latest outbreak of fatal infections may be an H3N8 that has recombined or reassorted with California/7 H3N2.
Having two H3 viruses co-circulating creates additional opportunities for emerging viruses. This may have contributed to the unprecedented number of fatalities among greyhounds in the northeast.
Atypical influenza outbreaks in the spring of 1918 preceded the deadly pandemic outbreak in the fall. The signs of unusual spring influenza activity appear to be erupting worldwide in the northern hemisphere. More information on the serotype of the influenza infecting greyhounds in the northeast would be useful, along with sequence information on isolates from this season as well as last season. The most recent H3N8 isolate from the United States at GenBank is A/equine/Kentucky/5/02(H3N8).
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