An outbreak of cryptosporidiosis among veterinary students performing fetotomy exercises on euthanized calves took place in September 2018 in Denmark. A prospective cohort investigation was performed to identify risk factors and provide guidance for preventing outbreaks of cryptosporidiosis in this setting. Ninety-seven students attended the fetotomy exercises and completed a questionnaire about symptoms and potential risk behavior. Real-time PCR was used to detect Cryptosporidium spp. in stool samples from students and to quantify the fecal parasite load in the calves used for the exercises. gp60 subtyping was carried out for the Cryptosporidium-positive samples. Our case definition was based on participation in a fetotomy exercise, reported symptoms, and laboratory results. Eleven laboratory-confirmed or probable cases (11%) were identified in two outbreaks during the prospective study period, with attack rates of 4/10 (40%) and 7/9 (78%), respectively. The risk factors for cryptosporidiosis we identified were performing the exercise on a diarrheic calf, reporting visible fecal contamination on the personal protective equipment (PPE), and reporting problems with PPE during the exercise. Cryptosporidium parvum IIaA15G2R1 was detected in both cases and calves. A significantly higher proportion of the calves aged 7 days old and above were positive compared with younger calves. Furthermore, a high fecal Cryptosporidium load in a calf was associated with a higher probability of an outbreak among the students. Based on our results, using noninfected calves for the exercises, appropriate use of PPE, and thorough hand hygiene are recommended to reduce the risk of contracting cryptosporidiosis in connection with fetotomy exercises.

中文翻译：

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当使用高粪便隐孢子虫负荷量的犊牛进行截肢术时，兽医学生患隐孢子虫病的风险较高。

2018年9月在丹麦发生了在安乐死的小牛上进行截骨术练习的兽医学生中的隐孢子虫病暴发。进行了一项前瞻性队列研究，以识别危险因素并为在这种情况下预防隐孢子虫病暴发提供指导。九十七名学生参加了成骨术，并完成了有关症状和潜在危险行为的问卷调查。使用实时PCR检测隐孢子虫。从学生的粪便样本中提取，并量化用于锻炼的小牛粪便中的寄生虫负荷。对隐孢子虫进行了gp60亚型分析阳性样本。我们的病例定义基于参加假肢切除术运动，报告的症状和实验室结果。在前瞻性研究期间，在两次暴发中确定了11例实验室确认或可能的病例（11％），发作率分别为4/10（40％）和7/9（78％）。我们确定的隐孢子虫病的危险因素是在腹泻小腿上进行锻炼，报告个人防护设备（PPE）上可见的粪便污染以及在锻炼期间报告PPE存在问题。在这两种情况和小牛中均检测到小隐孢子虫IIaA15G2R1。与年轻的犊牛相比，年龄在7天及以上的犊牛阳性的比例明显更高。此外，高粪隐孢子虫小牛的负重与学生中爆发疾病的可能性较高相关。根据我们的研究结果，建议使用未感染的小牛进行锻炼，适当使用PPE以及彻底的手部卫生，以减少在进行整形术锻炼时患隐孢子虫病的风险。