Fujii Kei, Kakumoto Chiharu, Kobayashi Mari, Saito Sachiko, Kariya Tatsuya, Watanabe Yukiko, Sakoda Yoshihiro, Kida Hiroshi, Suzuki Masatsugu
Laboratory of Wildlife Biology, Graduate School of Veterinary Medicine, Hokkaido University, Japan.
J Vet Med Sci. 2007 Mar;69(3):259-63. doi: 10.1292/jvms.69.259.
For proper management and conservation of the Kuril harbor seal (Phoca vitulina stejnegeri) through disease control, serological analysis was performed for influenza A virus infection in free-ranging seals in Hokkaido, Japan. Serum samples were collected from seals at Nosappu (231 seals), Akkeshi (16) and Erimo (75), between 1998 and 2005, and were analyzed by ELISA. Antibodies to the influenza A virus were detected only in seals from Nosappu. The incidences were 11% (1/9), 3% (2/66), 12% (7/59) and 6% (5/77) in 1998, 2003, 2004 and 2005, respectively. These suggest sporadic infection. Because antibody-positive seals included juvenile seals in each year, the infections were considered to have been circulated since no later than the late 1990s until recent years. ELISA-positive sera were analyzed by hemagglutination inhibition (HI) tests to determine the subtypes. Antibodies to the H3 and H6 subtypes were detected in 10 and 2 sera, respectively. Two of the sera that had antibodies to the H6 subtype also had antibodies to the H3 subtype. These two seals were considered to have been infected with both the H3 and H6 subtypes. This is the first investigation to find antibodies to the H6 subtype in seals. Although the H6 subtype had been isolated only from avians, genetic analysis had suggested that the H6 subtype could become a novel mammalian pathogen. For definitive diagnosis, detection of the virus from the tissue or mucus of seals is required.
为通过疾病控制对千岛港海豹（Phoca vitulina stejnegeri）进行妥善管理和保护，对日本北海道自由放养海豹的甲型流感病毒感染情况进行了血清学分析。1998年至2005年间，从诺萨普（231只海豹）、厚岸（16只）和襟裳（75只）的海豹身上采集血清样本，并通过酶联免疫吸附测定（ELISA）进行分析。仅在来自诺萨普的海豹中检测到甲型流感病毒抗体。1998年、2003年、2004年和2005年的感染率分别为11%（1/9）、3%（2/66）、12%（7/59）和6%（5/77）。这些表明是散发性感染。由于每年抗体呈阳性的海豹中都包括幼年海豹，因此认为这种感染至少从20世纪90年代末一直持续到近年来。对ELISA呈阳性的血清进行血凝抑制（HI）试验以确定亚型。分别在10份和2份血清中检测到针对H3和H6亚型的抗体。两份针对H6亚型有抗体的血清也针对H3亚型有抗体。这两只海豹被认为感染了H3和H6两种亚型。这是首次在海豹中发现针对H6亚型抗体的调查。尽管H6亚型仅从禽类中分离出来，但基因分析表明H6亚型可能成为一种新型的哺乳动物病原体。为进行确诊，需要从海豹的组织或黏液中检测到病毒。
