Hornok S, Heijmans J F, Békési L, Peek H W, Dobos-Kovács M, Drén C N, Varga I
Department of Parasitology and Zoology, University of Veterinary Science, Budapest, Hungary.
Vet Parasitol. 1998 Mar 31;76(1-2):43-55. doi: 10.1016/s0304-4017(97)00046-0.
The natural occurrence of concomitant chicken anaemia virus (CAV) and Cryptosporidium baileyi infection was described earlier. In this experiment, 1-day-old chickens were infected with CAV alone (anaemia virus infected, AI) or followed by inoculation with 8 x 10(5) C. baileyi oocysts orally at 1 wk of age (anaemia virus and Cryptosporidium infected, ACI). Another group of chickens received the same dose of C. baileyi oocysts without previous virus infection (Cryptosporidium infected, CI), and two groups of uninfected chickens served as controls. Except one group (uninfected control, UC), all groups -- including the other control group (challenged control, CC) -- were challenged with an oral inoculum of 8 x 10(5) C. baileyi oocysts at the age of 4 wk. Haematological, serological, immunohistochemical and pathological findings confirmed the effect of the virus agent. The individual C. baileyi oocyst shedding did not show significant difference between group CI and ACI, however, after challenge infection the AI chickens shed approximately three times more C. baileyi oocysts than those in group CC. Mortality and the percentage of birds that developed anaemia was significantly higher among ACI than AI chickens, while haematocrit values at 2 wk of age and relative bursal weights at 4 wk of age were moderately lower in the ACI group. The results presented here suggest that concurrent CAV infection increases the reproductive potential of C. baileyi in chickens, and both pathogens have synergistic effect on each other.
鸡贫血病毒（CAV）与贝氏隐孢子虫感染的自然共发情况已在早期有所描述。在本实验中，1日龄雏鸡单独感染CAV（感染贫血病毒，AI），或在1周龄时口服接种8×10⁵个贝氏隐孢子虫卵囊（感染贫血病毒和隐孢子虫，ACI）。另一组雏鸡在未预先感染病毒的情况下接受相同剂量的贝氏隐孢子虫卵囊（感染隐孢子虫，CI），两组未感染的雏鸡作为对照。除一组（未感染对照，UC）外，所有组——包括另一对照组（攻毒对照，CC）——在4周龄时口服接种8×10⁵个贝氏隐孢子虫卵囊进行攻毒。血液学、血清学、免疫组化和病理学结果证实了病毒因子的作用。CI组和ACI组之间单个贝氏隐孢子虫卵囊排出量未显示出显著差异，然而，攻毒感染后，AI组雏鸡排出的贝氏隐孢子虫卵囊比CC组雏鸡多约三倍。ACI组的死亡率和出现贫血的鸡的百分比显著高于AI组雏鸡，而ACI组在2周龄时的血细胞比容值和4周龄时的法氏囊相对重量适度较低。此处呈现的结果表明，CAV并发感染增加了鸡体内贝氏隐孢子虫的繁殖潜能，且两种病原体之间具有协同作用。
