Serologic evidence of influenza A infection in marine mammals of Arctic Canada

A serologic survey of influenza A antibodies was undertaken on 1,611 blood samples from five species of marine mammals collected from Arctic Canada fr om 1984-98. Sampling was done in 24 locations throughout the Canadian Arcti c encompassing Sachs Harbor (72 degreesN, 125 degreesW), Northwest Territor ies in the west to Loks Land (63 degreesN, 64 degreesW), Nunavut in the eas t, to Eureka (80 degreesN, 86 degreesW), Nunavut in the north to Sanikiluaq (56 degreesN, 79 degreesW), Nunavut in the south. A competitive ELISA usin g a monoclonal antibody (Mab) against influenza A nucleoprotein (NP) was us ed. Five of 418 (1.2%) belugas (Delphinapterus leucas) and 23 of 903 (2.5%) ringed seals (Phoca hispida) were serologically positive. None of the 210 walruses (Odobenus rosmarus rosmarus), 76 narwhals (Monodon monoceros) and four bowhead whales (Balaena mysticetus) had detectable antibodies to influ enza A. Positive belugas were identified from communities on southeast Baff in Island while positive ringed seals came from communities in the eastern, western and high Arctic. Virus isolation attempts on lung, tissue from a s eropositive beluga were unsuccessful. We believe that influenza A infection in marine mammals is sporadic, the infection is probably self-limiting, an d it may not be able to be maintained in these animals. Although the predom inant hemagglutinin (H) type was not determined and therefore the pathogeni city of the strains to humans is unknown, the hunting and consumption of ma rine mammals by the Inuit may put them at risk for influenza, infection.