Smith C D, Furcolow M L, Hulker P
Am J Epidemiol. 1976 Sep;104(3):299-305. doi: 10.1093/oxfordjournals.aje.a112303.
Observation of 33 dogs exposed to Blastomyces dermatitidis over a 2 1/2 year period is reported. During the first 1 1/2 years six dogs died and 23 (77%) developed skin lesions. Clinical evidence of disease in all the animals then subsided and remained so through another year of observation. Nine animals were sacrificed after 120 weeks and several tissues were cultured from each one. The remaining 18 were given immunosuppressants--azathioprine, prednisone, and cyclophosphamide--for eight weeks prior to autopsy. About one-half of the dogs were found to be infected with Histoplasma capsulatum and all were negative for B. dermatitidis by culture. The dogs were thought to have been inadvertently exposed to H. capsulatum during the first eight weeks of observation from a nearby soil plot before being moved to a more remote shelter. Skin testing with histoplasmin and blastomycin and complement-fixation (CF) tests, performed at various intervals after exposure to B. dermatitidis, appeared to reflect the course of disease with the number of reactors to the H. capsulatum antigens remaining relatively high while the number of reactors to B. dermatitidis antigens fell with the passage of time. The blastomycin skin test results in these dogs, however, persisted far longer than positive Blastomyces CF results. These data suggest that most dogs exposed to B. dermatitidis exhibit clinical symptoms of disease after about 12 weeks, persisting for about one year. The majority of animals recover spontaneously and completely. With H. capsulatum, however, the infection can be subclinical for at least a two-year period.
报告了在2年半时间内对33只暴露于皮炎芽生菌的犬的观察情况。在最初的1年半中，6只犬死亡，23只（77%）出现皮肤病变。所有动物的疾病临床证据随后消退，并在接下来的1年观察期内一直保持。120周后处死了9只动物，每只动物取多个组织进行培养。其余18只在尸检前8周给予免疫抑制剂——硫唑嘌呤、泼尼松和环磷酰胺。约一半的犬被发现感染了荚膜组织胞浆菌，通过培养所有犬对皮炎芽生菌均为阴性。这些犬被认为在观察的前8周从附近的一块土壤中无意中暴露于荚膜组织胞浆菌，之后被转移到更偏远的庇护所。在暴露于皮炎芽生菌后的不同时间间隔进行组织胞浆菌素和芽生菌素皮肤试验以及补体结合（CF）试验，似乎反映了疾病进程，对荚膜组织胞浆菌抗原产生反应的动物数量相对较高，而对皮炎芽生菌抗原产生反应的动物数量随时间下降。然而，这些犬的芽生菌素皮肤试验结果持续的时间远长于阳性的皮炎芽生菌CF结果。这些数据表明，大多数暴露于皮炎芽生菌的犬在约12周后出现疾病临床症状，持续约1年。大多数动物可自发且完全康复。然而，对于荚膜组织胞浆菌，感染至少在两年内可能为亚临床状态。
