Serological evidence of transmission of human influenza A and B viruses to Caspian seals (Phoca caspica)

• Published in: Microbiology and immunology Vol. 46; no. 9; p. 639
• Main Authors: Ohishi, Kazue, Ninomiya, Ai, Kida, Hiroshi, Park, Chun-Ho, Maruyama, Tadashi, Arai, Takaomi, Katsumata, Etsuko, Tobayama, Teruo, Boltunov, Andrei N, Khuraskin, Lev S, Miyazaki, Nobuyuki
• Format: Journal Article
• Language: English
• Published: Australia 01.01.2002
• Subjects: Animals; Antibodies, Viral - blood; Enzyme-Linked Immunosorbent Assay; Female; Hemagglutination Inhibition Tests - methods; Hemagglutinin Glycoproteins, Influenza Virus - genetics; Humans; Influenza A virus - classification; Influenza A virus - genetics; Influenza A virus - immunology; Influenza B virus - classification; Influenza B virus - genetics; Influenza B virus - immunology; Influenza, Human - immunology; Influenza, Human - transmission; Influenza, Human - veterinary; Male; Oceans and Seas; Seals, Earless - virology
• ISSN: 0385-5600
• DOI: 10.1111/j.1348-0421.2002.tb02746.x

Seroepidemiological surveillance of influenza in Caspian seals (Phoca caspica) was conducted. Antibodies to influenza A virus were detected in 54% (7/13), 57% (4/7), 40% (6/15) and 26% (11/42) of the serum samples collected in 1993, 1997, 1998 and 2000 by enzyme-linked immunosorbent assay (ELISA). In an hemagglutination-inhibition (HI) test using H1-H15 reference influenza A viruses as antigens, more than half of the examined ELISA-positive sera reacted with an H3N2 prototype strain A/Aichi/2/68. These sera were then examined by HI test with a series of naturally occurring antigenic variants of human H3N2 virus, and H3 viruses of swine, duck, and equine origin. The sera reacted strongly with the A/Bangkok/1/79 (H3N2) strain, which was prevalent in humans in 1979-1981. The present results indicate that human A/Bangkok/1/79-like virus was transmitted to Caspian seals probably in the early 1980s, and was circulated in the population. Antibodies to influenza B virus were detected by ELISA in 14% (1/7) and 10% (4/42) serum samples collected from Caspian seals in 1997 and 2000, respectively. Our findings indicate that seal might be a reservoir of both influenza A and B viruses originated from humans.