Clinical Utility of A Quantitative Rose Bengal Slide Agglutination Test in the Diagnosis of Human Brucellosis in an Endemic Region
Clinical Utility of A Quantitative Rose Bengal Slide Agglutination Test in the Diagnosis of Human Brucellosis in an Endemic Region
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DOI：
10.7754/clin.lab.2013.121120
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发表时间：
2014-01-01
影响因子：
0.7
通讯作者：
Desai, Arun S.
中科院分区：
文献类型：
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作者：
Mantur, Basappa G.;Amarnath, Satish K.;Desai, Arun S.
背景：布鲁氏菌病目前被列为世界上最重要的人畜共患疾病。布鲁氏菌病很难诊断，因为患者经常出现非特异性临床症状，这些症状可归因于该地区流行的多种疾病病原体。因此，这使得临床医生必须依赖微生物学确认，通常通过血清诊断方法。如果特定的抗生素治疗要对患者有效，早期、准确地检测布鲁氏菌病非常重要。使用 REST 作为定性诊断手段非常常见。然而，迄今为止，医学文献中应用REST作为定量诊断方法的报道屈指可数。定量孟加拉红玻片凝集试验 (REST) 对疑似布鲁氏菌病的潜在有用性被评估为一种简单、廉价的诊断工具，可用于流行地区的临床实践。方法：对 2009 年 6 月至 2011 年 12 月期间向卡纳塔克邦贝尔高姆贝尔高姆医学科学研究所 (BIMS) 医院报告的 200 名连续患者进行了研究。对所有患者进行标准REST、定量REST、标准管凝集试验（SAT）、2-巯基乙醇试验（2-ME）和血培养。如果其中任何一项检测呈阳性，则病例被确认为布鲁氏菌病阳性，并将数据与定量 REST 进行比较，考虑血培养结果作为金标准。结果：本研究中仅 28% 的患者培养了羊种布鲁氏菌。对于血培养阴性的患者，使用血清学进行诊断。灵敏度为 88.9%（标准 REST）、92.6%（SAT）和 57.4%（2ME）。特异性为 87.7%（标准 REST）、86.2%（SAT）和 95.7%（2ME）。大多数经细菌学证实患有布鲁氏菌病的患者 (50, 74%) 检测到 REST 滴度 >= 1:8，从而指导临床医生及时治疗。在 4 名患者中观察到的前带反应与 REST 是一个有趣的发现，这 4 名真实病例仅根据定性/标准 REST 可能会被诊断不足并被拒绝治疗。通过测试多种稀释度，可以避免具有高 REST 抗体滴度的患者血清中出现前带的可能性。结论：该技术具有巨大的价值，特别是在农村地区资源匮乏的环境中使用。它可以在 10 分钟内向临床医生提供明确的诊断，从而可以尽早开始特定的治疗，因此可以作为床边方法应用。它在技术上要求不高且易于解释，不涉及大量资本支出或训练有素的人员，因此在资源匮乏的实验室，特别是在发展中地区可能有用。此外，定量 REST 表现出与 SAT 相同的灵敏度和特异性。它可以很容易地扩展到筛查大量血液样本，特别是在布鲁氏菌病高流行的地区。定量 REST 和 2ME 在治疗监测中具有重要价值。我们的数据表明，REST 滴度在 1:8 和 1:16 范围内，结合居住在该疾病流行地区的患者的临床和流行病学证据，无疑可以被视为布鲁氏菌病的诊断。因此，建议在临床微生物学实验室中常规使用定量 REST，作为一种准确、快速的诊断测定方法。
Background: Brucellosis currently ranks as the most important zoonotic disease in the world. Brucellosis is difficult to diagnose because patients often have nonspecific clinical symptoms that can be attributed to a number of disease agents prevalent in the area. Thus, this has necessitated the dependency of clinicians on microbiological confirmation, very often by sero diagnostic methods. Early and accurate detection of brucellosis is important if specific antibiotic treatment is to be effective for the patients. The use of REST as a qualitative means of diagnosis is quiet common. However, to date, there are only a handful of reports of the application of REST as a quantitative diagnostic method in medical literature. The potential usefulness of quantitative Rose Bengal slide agglutination test (REST) for suspected brucellosis was evaluated as a simple, inexpensive diagnostic tool to be used in clinical practice in an endemic region.Methods: 200 consecutive patients who reported to Belgaum Institute of Medical Sciences (BIMS) Hospital, Belgaum, Karnataka (India) between June 2009 and December 2011 were studied. Standard REST, quantitative REST, standard tube agglutination test (SAT), 2-mercaptoethanol test (2-ME), and blood cultures were carried out on all patients. The case was confirmed as positive for brucellosis if any one of the tests was positive and the data was compared to the quantitative REST considering blood culture result as gold standard.Results: B. melitensis was cultured in only 28% of the patients in this study. In patients with negative blood cultures, serology was used for diagnosis. The sensitivities were 88.9% (standard REST), 92.6% (SAT), and 57.4% (2ME). The specificities were found to be 87.7% (standard REST), 86.2% (SAT), and 95.7% (2ME). REST titers >= 1:8 were detected in a majority of patients (50, 74%) with bacteriologically proven brucellosis thereby guiding clinician for prompt therapy. Prozone reaction with REST observed in 4 patients was an interesting finding and these four true cases would have been underdiagnosed and denied therapy on the basis of qualitative/standard REST alone. The possibility of prozone in patient's serum with high REST antibody titers can be avoided by testing several dilutions.Conclusions: This technique has an immense value particularly for use in resource poor settings seen in rural areas. It can deliver definitive diagnosis in < 10 minutes to the clinician, which may in turn result in the early initiation of specific treatment and could be applied thus as a bedside methodology. It is not technically demanding and easy to interpret, does not involve heavy capital outlay, or trained personnel and, thus, is potentially useful in resource poor laboratories, particularly in developing regions. In addition, quantitative REST demonstrates sensitivity and specificity equivalent to that achievable by performing SAT. It can readily be extended to screen a vast number of blood samples particularly in areas where brucellosis is hyperendemic. Quantitative REST and 2ME have been noted to be of great value in therapeutic monitoring. Our data suggest that REST titers in a range of 1:8 and 1:16 can undoubtedly be considered diagnostic of brucellosis in conjunction with compatible clinical and epidemiological evidence for the patients residing in areas endemic for the disease. Quantitative REST is, therefore, recommended for routine use in clinical microbiology laboratories as an accurate and speedy diagnostic assay.