LETTERS Recurring Influenza B Virus Infections

• Main Author: In Seals
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Phoca vitulina
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.307.5223; http://wwwnc.cdc.gov/eid/article/19/3/pdfs/12-0965.pdf

influenza B virus was considered to infect humans only. However, more recent data proved that harbor seals (Phoca vitulina) and gray seals (Halichoerus grypus) also can be infected (1). Since the identification of seals as a novel host, antibodies against human influenza B viruses have been detected in some additional otarid and phocid species in a few relatively small studies (2,3). It has been speculated that seals may be an animal reservoir for human influenza B viruses, although whether influenza B viruses continues to circulate among pinnipeds is unknown. To investigate whether influenza B viruses had continued to circulate in seals, we analyzed serum samples from 615 seals (548 harbor seals [Phoca vitulina] and 67 gray seals [Halichoerus grypus]). The samples had been collected upon the animal’s admission to the Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, the Netherlands, from seals living in Dutch coastal waters during 2002–2012. We tested these samples for influenza B virus–specific antibodies with a previously described hemagglutination inhbition (HI) assay, using the following influenza B virus strains as