Tissot Dupont H, Raoult D, Brouqui P, Janbon F, Peyramond D, Weiller P J, Chicheportiche C, Nezri M, Poirier R
Unité des Rickettsies, Faculté de Médecine, Marseille, France.
Am J Med. 1992 Oct;93(4):427-34. doi: 10.1016/0002-9343(92)90173-9.
To contribute to the knowledge of epidemiologic and clinical features of patients hospitalized with Q fever in France.
We conducted a retrospective analysis of 22,496 sera submitted between 1982 and 1990 to the French National Reference Center for Rickettsial Diseases (NRC). The diagnosis of acute Q fever was based on an IgG titer greater than or equal to 1:200 and an IgM titer greater than or equal to 1:25 against phase II Coxiella burnetii antigen on an indirect immunofluorescence test (IFA). Fifteen cases prior to 1985 were diagnosed on the basis of a complement fixation titer greater than or equal to 1:8. A serosurvey of blood donors from Marseille was also conducted in 1988 on 924 sera, using IFA with a cutoff titer of 1:25.
The serosurvey conducted in 1988 showed a seroprevalence of 4.03%, without age or sex prediction. The incidence rate of acute Q fever detection at the NRC was 0.58 per 100,000 inhabitants over the 9-year period. Three hundred twenty-three clinical cases were diagnosed, rising from 1 in 1982 to 107 in 1990. In patients hospitalized for acute Q fever, there was a significantly higher sex ratio of males to females (2.3), which, coupled with the age distribution, indicated that elder males, who are overrepresented due to our recruitment bias, are more susceptible to C. burnetii infections. The mean age of the patients was 45.5 years, while the risk was increased in the 30 to 39 age group as well as in the 60 to 69 age group. Usual epidemiologic risk factors were found in 20.1% of the cases. Hepatitis (61.9%) was a more common clinical presentation in our patients with Q fever than pneumonia (45.8%). This might reflect differences in strains of C. burnetii or the biology of the host. However, French farmers and stock breeders commonly drink unpasteurized raw milk from their cattle, which might indicate a relationship between hepatitis and infection via the digestive tract.
Our results indicate that many cases of acute Q fever are undiagnosed. A greater awareness of the disease and more extensive serologic testing of patients with symptoms compatible with Q fever may improve the situation.
增进对法国因Q热住院患者的流行病学和临床特征的了解。
我们对1982年至1990年间提交给法国立克次体病国家参考中心（NRC）的22496份血清进行了回顾性分析。急性Q热的诊断基于间接免疫荧光试验（IFA）中针对II相伯氏考克斯体抗原的IgG滴度大于或等于1:200以及IgM滴度大于或等于1:25。1985年之前的15例病例是根据补体结合滴度大于或等于1:8进行诊断的。1988年还对来自马赛的924份献血者血清进行了血清学调查，使用IFA，临界滴度为1:25。
1988年进行的血清学调查显示血清阳性率为4.03%，无年龄或性别倾向。在9年期间，NRC检测到的急性Q热发病率为每10万居民0.58例。共诊断出323例临床病例，从1982年的1例增至1990年的107例。因急性Q热住院的患者中，男性与女性的性别比显著更高（2.3），这与年龄分布一起表明，由于我们的招募偏差而占比过高的老年男性更容易感染伯氏考克斯体。患者的平均年龄为45.5岁，30至39岁年龄组以及60至69岁年龄组的风险增加。20.1%的病例发现有常见的流行病学危险因素。在我们的Q热患者中，肝炎（61.9%）比肺炎（45.8%）是更常见的临床表现。这可能反映了伯氏考克斯体菌株的差异或宿主的生物学特性。然而，法国农民和畜牧者通常饮用未经巴氏消毒的自家奶牛产的生牛奶，这可能表明肝炎与经消化道感染之间存在关联。
我们的数据表明，许多急性Q热病例未被诊断出来。提高对该病的认识并对有Q热相关症状的患者进行更广泛的血清学检测可能会改善这种情况。
