[Weil's disease: report on 5 cases in the valley of Mexico].

Leptospirosis, an acute generalized infection transmitted to humans from wild or domestic mammals, is rarely found in urban areas. We report here our experience with five cases of confirmed leptospirosis in the urban area of Mexico City. All five patients had epidemiologic risk factors, fever and a multisystemic illness, and two underwent laparotomy for acute abdominal syndrome. One patient died and four recovered completely. Problems in clinical and laboratory diagnosis are discussed. Leptospirosis should be suspected in patients with fever, jaundice and multiorgan involvement, and a proper epidemiologic setting.