Moss D M, Bennett S N, Arrowood M J, Wahlquist S P, Lammie P J
Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Am J Trop Med Hyg. 1998 Jan;58(1):110-8. doi: 10.4269/ajtmh.1998.58.110.
Symptoms consistent with an outbreak of cryptosporidiosis (diarrhea, vomiting, nausea, and abdominal cramps) occurred on a U.S. Coast Guard cutter within 0-18 days after the cutter filled its tanks with Milwaukee, Wisconsin city water in March 1993. At three-weeks postdocking (PD), the suspected water was removed, and serum samples and stool specimens were collected from 47 of the 58 crew members, as well as questionnaire data on their water consumption and symptoms aboard the cutter. At 10-weeks PD and/or at 28-weeks PD, additional serum specimens were collected. Intensitometric data from enzyme-linked immunoelectrotransfer blot (EITB) were obtained on IgA responses to a 17-kD antigen group, IgM responses to a 27-kD antigen group, and IgG responses to 27-, 17-, and 15-kD antigen groups extracted from oocysts. In addition, IgG responses to crude oocyst antigens were obtained by ELISA. Based on reported symptoms, EITB results, and stool examination, the crew members were classified as confirmed (10), probable (10), suspected (22), and noncases (16). Of the 10 confirmed cases (all symptomatic) and the 10 probable cases (eight symptomatic) whose stools were positive and negative, respectively, for Cryptosporidium oocysts by microscopy, all showed changes in EITB intensities to the antigen groups and were considered EITB positive. The remaining 38 crew members, 22 suspected cases (all symptomatic), and 16 noncases (all asymptomatic), if tested, had negative stool examinations and were considered EITB negative. Of the 10 confirmed cases, only four showed a significant change in IgG responses (P < 0.05) between three-weeks PD and follow-up serum specimens by ELISA. Crew members considered confirmed cases consumed significantly more water (P < or = 0.005) aboard the cutter than noncases. Crew members considered EITB positive consumed more water (P < or = 0.04) than crew members considered EITB negative while there was no significant difference in water consumption (P > or = 0.19) between crew members considered ELISA positive and ELISA negative. Using the EITB, the observation of changes in intensity of IgA responses to the 17-kD antigen group, IgM responses to the 27-kD antigen group, and IgG responses to the 27- 17-, and 15-kD antigen groups from C. parvum oocysts between acute and convalescent serum specimens appears useful for immunodiagnosis of Cryptosporidium infection and for prospective epidemiologic studies designed to monitor infection risk.
1993年3月，美国海岸警卫队的一艘快艇用威斯康星州密尔沃基市的水装满水箱后，0至18天内出现了与隐孢子虫病暴发相符的症状（腹泻、呕吐、恶心和腹部绞痛）。停靠三周后，将可疑水源移除，并从58名船员中的47人采集了血清样本和粪便标本，以及他们在快艇上的用水情况和症状的问卷调查数据。在停靠10周和/或28周时，又采集了额外的血清标本。通过酶联免疫电转移印迹法（EITB）获得了对从卵囊中提取的17-kD抗原组的IgA反应、对27-kD抗原组的IgM反应以及对27-、17-和15-kD抗原组的IgG反应的光密度测定数据。此外，通过ELISA获得了对粗卵囊抗原的IgG反应。根据报告的症状、EITB结果和粪便检查，将船员分为确诊病例（10例）、疑似病例（10例）、可能病例（22例）和非病例（16例）。在10例确诊病例（均有症状）和10例可能病例（8例有症状）中，通过显微镜检查，其粪便中隐孢子虫卵囊分别为阳性和阴性，所有病例对抗原组的EITB强度均有变化，被认为EITB阳性。其余38名船员，22例疑似病例（均有症状）和16例非病例（均无症状），如果进行检测，粪便检查为阴性，被认为EITB阴性。在10例确诊病例中，只有4例通过ELISA检测，在停靠三周后的血清标本和随访血清标本之间，IgG反应有显著变化（P<0.05）。被认为是确诊病例的船员在快艇上的饮水量明显多于非病例（P≤0.005）。被认为EITB阳性的船员比被认为EITB阴性的船员饮水量更多（P≤0.04），而被认为ELISA阳性和ELISA阴性的船员之间饮水量没有显著差异（P≥0.19）。使用EITB，观察急性和恢复期血清标本之间对微小隐孢子虫卵囊的17-kD抗原组的IgA反应强度变化、对27-kD抗原组的IgM反应以及对27-、17-和15-kD抗原组的IgG反应，似乎有助于隐孢子虫感染的免疫诊断以及用于监测感染风险的前瞻性流行病学研究。
