Smith H J, Snowdon K E, Finlay R C
Agriculture Canada, Health of Animals Laboratory, Sackville, New Brunswick.
Can J Vet Res. 1991 Jul;55(3):274-6.
Taenia saginata infections were established in four groups of calves by administering doses of 10, 10(2), 10(3) and 10(4) infective eggs respectively by gavage. A fifth group remained as uninfected controls. Sera were collected from all calves over a period of 210 days. The sera were examined by an enzyme-linked immunosorbent assay (ELISA) with a fraction of larval Taenia hydatigena cyst fluid as antigen for the presence of anti-T. saginata IgG antibodies. At slaughter, the tongue, masseter, diaphragm and cardiac muscles and liver were examined for cysticerci. The higher dose rates of T. saginata eggs were reflected in higher numbers of cysticerci found in the calves at necropsy. There was also a correlation between higher levels of antibodies produced as measured by the ELISA and the numbers of eggs given. Sero-conversion was first detected about 25 days postinfection in heavy infections and later in the lighter infections. Maximal levels of antibody occurred between 40 and 60 days postinfection, followed by a gradual decrease in levels of antibody. A secondary increase in antibody occurred between 160 and 200 days postinfection which might have been due to release of antigen after death of the cysticerci. The low level of circulating antibodies in light infections may result in false positive or false negative diagnoses depending upon the selection of the cut-off point.
通过分别经口灌服10、10²、10³和10⁴个感染性虫卵，在四组小牛中建立牛带绦虫感染。第五组作为未感染对照。在210天的时间里从所有小牛采集血清。用酶联免疫吸附测定（ELISA），以泡状带绦虫幼虫囊液的一部分作为抗原，检测血清中抗牛带绦虫IgG抗体的存在情况。屠宰时，检查舌、咬肌、膈肌、心肌和肝脏是否有囊尾蚴。尸检时在小牛中发现的囊尾蚴数量较多反映了牛带绦虫虫卵的较高剂量率。通过ELISA检测到的产生的抗体水平较高与给予的虫卵数量之间也存在相关性。在重度感染中，感染后约25天首次检测到血清转化，轻度感染中则较晚出现。抗体的最高水平出现在感染后40至60天，随后抗体水平逐渐下降。感染后160至200天抗体出现二次升高，这可能是由于囊尾蚴死亡后抗原释放所致。轻度感染中循环抗体水平较低可能导致根据临界值的选择出现假阳性或假阴性诊断。
