Leung Alexander K C, Newman Rachel, Kumar Ashir, Davies H Dele
University of Calgary and the Alberta Children's Hospital, Department of Pediatrics, Calgary, Alberta, Canada.
Expert Rev Mol Diagn. 2006 Sep;6(5):761-6. doi: 10.1586/14737159.6.5.761.
Group A beta-hemolytic streptococcus (GABHS) is the most common bacterial cause of acute pharyngitis. Clinical criteria alone are not reliable enough to diagnose GABHS pharyngitis. Microbiological-testing is required for correct diagnosis. Although a throat swab culture remains the gold standard for documenting the presence of GABHS, a significant disadvantage of the culture is the delayed time of 1-2 days to obtain results. Most rapid antigen detection tests can provide results in less than 15 min. Rapid identification and treatment of patients with GABHS pharyngitis can reduce the risk of the spread of disease, may shorten the duration of symptoms, decrease the incidence of suppurative complications, decrease the amount of time lost from school/work, decrease the inappropriate use of antibiotics, reduce patient/parent dissatisfaction and alleviate the need for costly follow-up visits. All rapid antigen detection tests involve extraction of the group-specific carbohydrate antigen from the GABHS cell wall and identification of the antigen by an immunological reaction. There are numerous rapid antigen detection testing methods, namely latex agglutination, enzyme immunoassay, optical immunoassay, chemiluminescent DNA probes and PCR methods. Most of the rapid antigen detection tests that are currently in use have an excellent specificity of greater than 95% and a sensitivity of greater than or equal to 90%. Owing to the high specificity of the rapid antigen detection tests, a positive rapid antigen detection test is accepted as adequate for the diagnosis of GABHS pharyngitis. Conversely, confirmation of a negative antigen detection test with a throat culture result is necessary, unless the physician has ascertained in his/her practice that the sensitivity of the rapid antigen test used is comparable with that of a throat culture.
A组β溶血性链球菌（GABHS）是急性咽炎最常见的细菌病因。仅靠临床标准不足以可靠地诊断GABHS咽炎。正确诊断需要进行微生物检测。虽然咽拭子培养仍然是证明GABHS存在的金标准，但培养的一个显著缺点是需要1 - 2天才能获得结果。大多数快速抗原检测试验可在15分钟内得出结果。对GABHS咽炎患者进行快速识别和治疗可降低疾病传播风险，可能缩短症状持续时间，减少化脓性并发症的发生率，减少缺课/旷工时间，减少抗生素的不当使用，降低患者/家长的不满程度，并减少昂贵的随访需求。所有快速抗原检测试验都涉及从GABHS细胞壁提取群特异性碳水化合物抗原，并通过免疫反应鉴定该抗原。有许多快速抗原检测方法，即乳胶凝集法、酶免疫测定法、光学免疫测定法、化学发光DNA探针法和PCR法。目前使用的大多数快速抗原检测试验具有大于95%的出色特异性和大于或等于90%的灵敏度。由于快速抗原检测试验的高特异性，快速抗原检测试验呈阳性被认为足以诊断GABHS咽炎。相反，除非医生在其临床实践中确定所使用的快速抗原检测的灵敏度与咽拭子培养相当，否则需要用咽拭子培养结果来证实抗原检测试验为阴性。
