Predictors of Lethality in Severe Leptospirosis in Urban Brazil

Abstract

To ascertain prognostic factors associated with fatal outcomes in severe leptospirosis, a retrospective case-control study was done using population-based surveillance data. Centralized death certificate reporting of leptospirosis mortality was combined with details of patients' hospitalizations, which were obtained from hospitals representing all sectors of São Paulo city. Among identified leptospirosis cases, 89 lethal cases and 281 survivor cases were analyzed. Predictors of death included age>40 years, development of oliguria, platelet count<70,000/microL, creatinine>3 mg/dL, and pulmonary involvement. The latter was the strongest risk factor with an estimated odds ratio of 6.0 (95% confidence interval: 3.0-12.0). Serologic findings with highest titer against Leptospira interrogans serovar Copenhageni did not show significant differences between survivors and non-survivors. Lung involvement was an important predictor of death in leptospirosis in São Paulo, of relevance in leptospirosis-endemic regions where this complication is common.

Determinants of mortality and impact of therapy in patients with leptospirosis admitted for intensive care in a Sri Lankan hospital – a three year retrospective study

“…This is contrary to findings by Dupont et al 18 and Spichler et al 15 It is important to note that the renal parameters serum creatinine > 2 and blood urea were not associated with mortality. However, oliguria and anuria were associated with mortality outcomes.…”

“…Advanced age was found to be associated with mortality by Chawla et al 9 and Spichler et al 15 Chawla et al in the same study also found chronic alcoholism 9 to be associated with the same. Although male sex has been found to be associated with mortality by Chawla et al 9 , other studies have challenged such assumption.…”

“…23 Similarly multiple studies have concluded development of oliguria to be prognostic factor in mortality. 15,24 Furthermore, significant association has been shown between established renal failure and death, 19,25 altered mental status, 25 multi-organ dysfunction syndrome (MODS) 9,21 and altered aminotransferase alanine transaminase ratio, 26 delayed antibiotic therapy, 26 platelet count 9 less 70,000/μl and leukocytosis 18 have all been demonstrated to be associated with mortality by various studies.…”

The Contribution of Bats to Leptospirosis Transmission in São Paulo City, Brazil

“…In most urban environments endemic for leptospirosis, including São Paulo City, the major sources of infection are urban rodents and sometimes dogs. [3][4][5] One potential source of leptospiral infection is bats. Bats are known to carry some human pathogens, including Leptospira , [6][7][8][9] as well as rabies 10 and histoplasmosis.…”

“…Poor urban settings present potentially ideal ecological conditions for the transmission of leptospirosis. 3,4 The source of leptospiral infection to humans is typically direct or indirect contact with the urine of infected animals. In most urban environments endemic for leptospirosis, including São Paulo City, the major sources of infection are urban rodents and sometimes dogs.…”