Ek-Kommonen C, Sihvonen L, Pekkanen K, Rikula U, Nuotio L
Department of Virology and Epidemiology, National Veterinary and Food Research Institute, Helsinki, Finland.
Vet Rec. 1997 Oct 11;141(15):380-3. doi: 10.1136/vr.141.15.380.
Canine distemper reappeared in dogs in Finland in 1990 after a 16-year absence. In 1994 to 1995 an outbreak occurred in areas with a high density dog population which involved dogs vaccinated against distemper. The estimated total number of cases was at least 5000, and 865 cases were confirmed by indirect fluorescent antibody testing of 3649 epithelial cell samples. The signs recorded by veterinary clinicians ranged from conjunctivitis, pyrexia and anorexia to signs of respiratory and gastrointestinal illness, with an estimated mortality of 30 per cent. Of the confirmed cases 631 (73 per cent) were between three and 24 months of age; 487 of these had been vaccinated at least once and 351 (41 per cent) had a complete vaccination history. Of these 351 fully vaccinated animals the proportion of dogs vaccinated with the most popular vaccine was significantly higher than would have been expected by its market share. In total, 4676 serum samples were collected from healthy vaccinated dogs during the peak and decline of the outbreak and tested for the presence of virus neutralising antibodies. The decrease in the proportion of young dogs with antibody titres < 1/8 coincided with the decline and end of the outbreak during the spring and summer of 1995. It was concluded that a critical decrease in the population's immunity during 1990 to 1994 was a major reason for the outbreak in the summer of 1994 and that the ultimate test for vaccines is an outbreak of disease.
犬瘟热在芬兰消失16年后，于1990年在犬类中再度出现。1994年至1995年，在犬只高密度分布的地区爆发了疫情，其中涉及已接种犬瘟热疫苗的犬只。估计病例总数至少为5000例，通过对3649份上皮细胞样本进行间接荧光抗体检测，确诊了865例。兽医临床医生记录的症状范围从结膜炎、发热和厌食到呼吸道和胃肠道疾病症状，估计死亡率为30%。在确诊病例中，631例（73%）年龄在3至24个月之间；其中487例至少接种过一次疫苗，351例（41%）有完整的疫苗接种史。在这351只完全接种疫苗的动物中，接种最流行疫苗的犬只比例明显高于其市场份额所预期的比例。在疫情高峰期和衰退期，共从健康接种疫苗的犬只中采集了4676份血清样本，检测其中是否存在病毒中和抗体。抗体滴度<1/8的幼犬比例下降与1995年春夏疫情的衰退和结束相吻合。得出的结论是，1990年至1994年期间人群免疫力的严重下降是1994年夏季疫情爆发的主要原因，并且疫苗的最终检验是疾病的爆发。
