UAEM-CU, Mexico, Mexico.
Transbound Emerg Dis. 2010 Apr;57(1-2):84-6. doi: 10.1111/j.1865-1682.2010.01123.x.
The objective of this study was to evaluate in native cattle the use of an in vitro derived attenuated live vaccine (Babesia bovis-Babesia bigemina). Three commercial farms located in a tropical region in Chiapas State, Mexico were included. For each ranch, 40 animals were selected as negative to Babesia spp. by using an immunofluorescent antibody test (IFAT) and PCR. Animals were distributed in four groups with 10 animals each: (i) <9 months, (ii) 9-18, (iii) 18-36 and (iv) >36 months old. From each group, two subgroups were formed with five animals each; one subgroup was vaccinated and the other served as control without vaccination. Monitoring and sampling were carried out initially at vaccination (day 0), at day 7 and then every 4 weeks for 12 months. During the study rectal temperature ( degrees C), packed cell volume (Ht %) and percentage of erythrocytes parasitized were registered, furthermore IFAT and PCR were performed. Prevalence rate at the beginning of the study was 83% by IFAT. During the survey, 26 non-vaccinated of the 120 selected animals (43%) showed clinical symptoms of babesiosis, confirmed by stained smears versus only four (6.6%) of the vaccinated ones. All Babesia-affected animals required specific treatment. Vaccinated cattle showed titres of up to 1 : 1840 and 1 : 1027 for B. bovis and B. bigemina, respectively by IFAT. Protection conferred by vaccination was about 93%. We propose that this vaccine should not only be used in cattle coming from babesiosis free zones, but also in native cattle kept in hyperendemic areas.
本研究旨在评估一种在体外衍生的减毒活疫苗（牛巴贝斯虫-双芽巴贝斯虫）在本地牛中的应用。该研究纳入了墨西哥恰帕斯州一个热带地区的三个商业农场。对于每个牧场，选择 40 头通过免疫荧光抗体试验（IFA）和 PCR 检测为巴贝斯虫阴性的动物。将动物分为四组，每组 10 头：（i）<9 个月，（ii）9-18 个月，（iii）18-36 个月和（iv）>36 个月。每组再分为两组，每组 5 头；一组接种疫苗，另一组作为未接种疫苗的对照组。监测和采样在接种（第 0 天）、第 7 天以及随后的 12 个月每 4 周进行一次。在研究期间，记录直肠温度（摄氏度）、红细胞压积（Ht%）和被寄生的红细胞百分比，此外还进行了 IFA 和 PCR。通过 IFA 检测，研究开始时的阳性率为 83%。在调查期间，120 头选定的动物中，有 26 头未接种疫苗的动物（43%）出现了巴贝斯虫病的临床症状，通过染色涂片证实，而接种疫苗的动物中只有 4 头（6.6%）出现了这种症状。所有受巴贝斯虫影响的动物都需要进行特定的治疗。通过 IFA 检测，接种疫苗的牛的牛巴贝斯虫和双芽巴贝斯虫的滴度分别高达 1:1840 和 1:1027。疫苗接种的保护率约为 93%。我们建议，这种疫苗不仅应该用于来自无巴贝斯虫病地区的牛，也应该用于在高度流行地区饲养的本地牛。
