Gonsalez C R, Casseb J, Monteiro F G, Paula-Neto J B, Fernandez R B, Silva M V, Camargo E D, Mairinque J M, Tavares L C
Rev Inst Med Trop Sao Paulo. 1998 Jan-Feb;40(1):59-61. doi: 10.1590/s0036-46651998000100012.
A clinical trial pilot study, double-blinded, randomized, and controlled with a placebo to assess the effectiveness of oral doxycycline (200 mg, single dose) in preventing leptospirosis after high exposure to potentially contaminated water was performed in São Paulo, SP, Brazil. Confirmed cases were defined as those with leptospira IgM antibody and symptoms; asymptomatic cases were those presenting with IgM antibodies but no symptoms; and suspected cases were individuals with symptoms but no IgM antibody. Forty subjects were given doxycycline and 42 were given placebo. In the drug-treated group there were 2 confirmed cases, 11 asymptomatic cases, and 6 suspected cases. In the placebo group there were 5 confirmed, 6 symptomatic, and 5 suspected cases. Even though we found a protective association of doxycycline for confirmed leptospirosis cases (RR = 2.3) and seroconversion only (RR = 2.0), the association was not statistically significant because of the small number of individuals enrolled in this pilot study. We observed that the 22% of the volunteers already had IgM antibodies to leptospirosis at the first sampling. Finally, the attack rate to confirmed, asymptomatic, and suspected cases of Leptospirosis was 8.5%, 22%, and 13%, respectively, in this population.
在巴西圣保罗进行了一项临床试验试点研究，该研究采用双盲、随机且使用安慰剂对照的方式，以评估口服强力霉素（200毫克，单剂量）在高暴露于潜在污染水后预防钩端螺旋体病的有效性。确诊病例定义为具有钩端螺旋体IgM抗体且有症状的病例；无症状病例是指呈现IgM抗体但无任何症状的病例；疑似病例是指有症状但无IgM抗体的个体。40名受试者接受了强力霉素治疗，42名受试者接受了安慰剂治疗。在药物治疗组中，有2例确诊病例、11例无症状病例和6例疑似病例。在安慰剂组中，有5例确诊病例、6例有症状病例和5例疑似病例。尽管我们发现强力霉素对确诊钩端螺旋体病病例（相对危险度=2.3）以及仅血清转化（相对危险度=2.0）存在保护关联，但由于该试点研究纳入的个体数量较少，这种关联在统计学上并不显著。我们观察到，22%的志愿者在首次采样时就已经具有钩端螺旋体的IgM抗体。最后，在该人群中，钩端螺旋体病确诊病例、无症状病例和疑似病例的发病率分别为8.5%、22%和13%。
