Fornazari Felipe, Richini-Pereira Virgínia Bodelão, Joaquim Sâmea Fernandes, Nachtigall Pedro Gabriel, Langoni Helio
Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Husbandry, São Paulo State University (UNESP), Botucatu, SP, Brazil.
Center of Regional Laboratory II Bauru, Adolfo Lutz Institute, Bauru, SP, Brazil.
J Venom Anim Toxins Incl Trop Dis. 2021 Mar 26;27:e20200118. doi: 10.1590/1678-9199-JVATITD-2020-0118.
The early symptoms of leptospirosis and dengue fever are difficult to distinguish and can cause diagnostic confusion. Due to the large dengue epidemics that has occurred in Brazil in recent years, it is possible that cases of leptospirosis were unreported. Therefore, we performed a retrospective study to detect leptospirosis in patients who were tested for dengue, but whose laboratory diagnoses were negative.
Sera samples from 2,017 patients from 48 cities located in the central region of São Paulo state, Brazil, were studied. All samples were subjected to the microscopic agglutination test (MAT), 305 of which were taken from patients five days or less since the onset of symptoms, and were additionally subjected to real-time polymerase chain reaction (PCR).
The overall prevalence of leptospirosis cases was 21 (1.04%), with 20 through MAT (18 for Icterohaemorrhagiae and two for the Cynopteri serogroup) and one through PCR (amplicon sequencing compatible with ). According to previously established criteria, eight cases of leptospirosis were classified as "confirmed" and 13 as "probable". The Brazilian notification system for health surveillance had no records for 16 patients positive for leptospirosis and, thus, they were considered unreported cases. Statistical analyses revealed that the prevalence of leptospirosis was higher in men (1.56%) than in women (0.56%), and the mean age was higher in positive patients (43.7 years) than in negative ones (32.3 years).
The results indicated that patients suspected of dengue fever had evidence of leptospirosis or infection, and most of these cases were unreported in the Brazilian notification system. The high burden of dengue may contribute to the misdiagnosis of leptospirosis, and health professionals should increase their awareness of leptospirosis as an important differential diagnosis of patients with suspicion of dengue.
钩端螺旋体病和登革热的早期症状难以区分，可能导致诊断混淆。由于近年来巴西发生了大规模登革热疫情，钩端螺旋体病病例可能未被报告。因此，我们进行了一项回顾性研究，以检测登革热检测呈阴性但实验室诊断为阴性的患者中的钩端螺旋体病。
对来自巴西圣保罗州中部地区48个城市的2017名患者的血清样本进行了研究。所有样本均进行了显微镜凝集试验（MAT），其中305份样本取自症状出现后5天或更短时间的患者，并额外进行了实时聚合酶链反应（PCR）。
钩端螺旋体病病例的总体患病率为21例（1.04%），其中20例通过MAT确诊（出血性黄疸型18例，犬血清群2例），1例通过PCR确诊（扩增子测序与之相符）。根据先前制定的标准，8例钩端螺旋体病病例被分类为“确诊”，13例为“可能”。巴西卫生监测通报系统没有16例钩端螺旋体病阳性患者的记录，因此，这些病例被视为未报告病例。统计分析显示，男性钩端螺旋体病患病率（1.56%）高于女性（0.56%），阳性患者的平均年龄（43.7岁）高于阴性患者（32.3岁）。
结果表明，疑似登革热的患者有钩端螺旋体病或感染的证据，其中大多数病例在巴西通报系统中未被报告。登革热的高负担可能导致钩端螺旋体病的误诊，卫生专业人员应提高对钩端螺旋体病的认识，将其作为疑似登革热患者的重要鉴别诊断。
