Sex differences in clinical leptospirosis in Germany: 1997-2005.

Background: Although the majority of patients with reported leptospirosis are male, several seroepidemiologic studies demonstrated that leptospirosis seroprevalences are at least identical between both sexes. To study the effect of sex on the severity--and possibly, recognition--of leptospirosis, we conducted a sex-specific analysis of the clinical manifestations of the disease among patients with reported leptospirosis in Germany during 1997-2005.
Methods: Data on demographic characteristics, symptoms, place of infection and place of residence when infection occurred, possible exposure risks, infecting serovars, and mortality were evaluated for patients with laboratory-confirmed leptospirosis reported in Germany during 1997-2005. Mantel-Haenszel odds ratios (OR(MH)), adjusted for age, were used to determine the association between sex and the frequency of reported symptoms.
Results: Among 338 patients with leptospirosis (263 male patients and 75 female patients) reported in Germany during 1997-2005, male patients were more likely than female patients to be hospitalized (OR, 2.6; P<.01) and to exhibit symptoms of severe leptospirosis with jaundice (OR(MH), 3.7; P<.01), renal impairment (OR(MH), 3.4; P<.01), and hemorrhage (OR(MH), 7.8; P<.05). These sex-related differences were not associated with differences in exposure risks, presumptive infecting serogroups, or health-seeking behavior.
Conclusions: Our results indicate that male sex is associated with a higher severity of clinical leptospirosis. Reports on male predominance in leptospirosis may thus reflect sex-related variability in the incidence of severe disease, rather than different infection rates. In clinical practice, sex differences in the manifestation of leptospirosis may cause systematic underinvestigation and undertreatment of the disease in female patients.