Zavala-Velazquez J E, Yu X J, Walker D H
Faculty of Medicine, Universidad Autonoma de Yucatan, Merida, Mexico.
Am J Trop Med Hyg. 1996 Aug;55(2):157-9. doi: 10.4269/ajtmh.1996.55.157.
Although Rocky Mountain spotted fever was documented in northern Mexico during the 1940s, spotted fever group (SFG) rickettsioses have subsequently received little attention in Mexico. In this study, sera collected in 1993 from 50 patients from the Mexican states of Yucatan and Jalisco, who were suspected clinically to have dengue fever but had no antibodies to dengue virus, were examined by indirect immunofluorescence for IgM antibodies reactive with Rickettsia rickettsii, R. akari, and R. typhi. Twenty (40%) of the patients' sera contained IgM antibodies to SFG rickettsiae at a titer of 128 or greater. Among five sera reactive only against R. akari, four were from patients in Jalisco where a cluster of cases occurred in June and July. Among five sera reactive only with R. rickettsii, all were from Yucatan patients. Sera of 10 patients contained antibodies reactive with antigens shared by R. rickettsii and R. akari. The clinical signs and symptoms (fever, 100%; myalgia, 95%; headache, 85%; rash, 85%) were similar to those of dengue fever patients identified in this study. However, the incidence of rash was substantially higher than the nondengue, nonrickettsiosis patients. One or more SFG rickettsioses appear to be present in areas of Mexico not previously recognized to harbor these organisms. The etiologic agent or agents are as yet unknown.
尽管20世纪40年代在墨西哥北部记录到落基山斑疹热，但此后斑点热群（SFG）立克次体病在墨西哥很少受到关注。在本研究中，对1993年从墨西哥尤卡坦州和哈利斯科州的50名患者采集的血清进行了检测，这些患者临床上疑似患有登革热，但没有登革热病毒抗体，采用间接免疫荧光法检测与立氏立克次体、小蛛立克次体和伤寒立克次体反应的IgM抗体。20名（40%）患者的血清中含有效价为128或更高的抗SFG立克次体的IgM抗体。在仅对小蛛立克次体有反应的5份血清中，4份来自哈利斯科州的患者，该州6月和7月出现了病例聚集。在仅与立氏立克次体有反应的5份血清中，所有血清均来自尤卡坦州的患者。10名患者的血清含有与立氏立克次体和小蛛立克次体共有的抗原发生反应的抗体。临床体征和症状（发热，100%；肌痛，95%；头痛85%；皮疹，85%）与本研究中确诊的登革热患者相似。然而，皮疹的发生率明显高于非登革热、非立克次体病患者。在墨西哥以前未被认为存在这些病原体的地区似乎存在一种或多种SFG立克次体病病原体。病原体尚不明确。
