Levine M M, Grados O, Gilman R H, Woodward W E, Solis-Plaza R, Waldman W
Am J Trop Med Hyg. 1978 Jul;27(4):795-800. doi: 10.4269/ajtmh.1978.27.795.
The usefulness of a single Widal test to diagnose typhoid fever in endemic areas was investigated. Reciprocal Salmonella typhi O and H titers greater than or equal to 40 and greater than or equal to 80, respectively, occurred in approximately 90% of 42 Mexican patients with bacteriologically-confirmed typhoid fever at the time of presentation to hospital and, by day 4 to 5 of clinical illness, in 70% of U.S. adult volunteers who developed typhoid fever in the course of vaccine efficacy trials but in only 0.7% (O) to 3% (H) of 275 healthy individuals from a non-endemic area. Healthy Peruvians from areas endemic for typhoid fever commonly had antibody which was age-related. Peak prevalence was found in 15- to 19-yr-olds in whom 29% had O titers greater than or equal to 40 and 76% had H titers greater than or equal to 80. A single Widal test in an unvaccinated individual showing elevated O and H titers is strongly suggestive of typhoid fever if the person comes from a non-endemic area or is a child less than 10 yr of age in an endemic area. Because of the high prevalence of antibody amongst healthy invididuals over 10 yr of age in endemic, areas, a single Widal test offers virtually no diagnostic assistance in adolescents and adults.
研究了单次肥达试验在伤寒流行地区诊断伤寒热的效用。在42名经细菌学确诊为伤寒热的墨西哥患者中，约90%在入院时伤寒杆菌O抗体效价和H抗体效价的倒数分别大于或等于40和大于或等于80；在疫苗效力试验过程中患伤寒热的美国成年志愿者中，到临床发病第4至5天时，70%的人出现上述情况；而在来自非流行地区的275名健康个体中，只有0.7%（O抗体）至3%（H抗体）出现上述情况。来自伤寒热流行地区的健康秘鲁人通常有与年龄相关的抗体。抗体流行率高峰出现在15至19岁人群中，其中29%的人O抗体效价大于或等于40，76%的人H抗体效价大于或等于80。对于未接种疫苗的个体，如果其来自非流行地区或在流行地区是10岁以下儿童，单次肥达试验显示O抗体和H抗体效价升高强烈提示伤寒热。由于在流行地区10岁以上健康个体中抗体流行率很高，单次肥达试验对青少年和成年人几乎没有诊断帮助。
