Date of Award

January 2014

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Jose E. Hagan

Abstract

ABSTRACT

Objective: Leptospirosis pulmonary hemorrhage syndrome (LPHS) is a severe form of leptospirosis, with a case fatality rate exceeding 50%. Recently, LPHS has become the principal cause of mortality in leptospirosis patients in Salvador, Brazil. This study aims to describe the epidemiology of LPHS since 2003, characterize its clinical presentation, and identify risk factors.

Methods:

Patients admitted between January 1, 2003 and December 31, 2012 in the active hospital-based surveillance who met the clinical case definition for leptospirosis were included in the study. A standardized questionnaire was used to collect data from patient charts and in-person interviews. Unadjusted logistic regression models identified individual-level risk factors. Maps showing spatial distribution and clustering of leptospirosis cases were created to identify areas of high risk.

Results:

We identified 1,316 patients meeting our case definition, which included 113 LPHS, 184 NHPL, and 1019 NPL cases. Males were at greater risk for LPHS in all age groups. The LPHS-associated mortality was 65.5% (95% CI: 56.33-73.63), compared to 30.4% and 6.2% for NHPL and NPL cases, respectively. A lower microagglutination test (MAT) titer compared for LPHS compared to NPL cases in the acute phase suggests the absence of an early robust immune response. A high-risk LPHS cluster (p= 0.01) was identified and rat sightings was associated with NHPL patients (OR: 2.77, 95% CI: 1.23-6.23). Limited unique clinical correlates observed in patients with pulmonary manifestations compared to non-pulmonary forms of leptospirosis.

Conclusion:

We describe the clinical features and epidemiology of LPHS in Salvador, Brazil, since its emergence in 2003. Few clinical correlates were identified between LPHS and NHPL patients, suggesting that leptospirosis is a disease on a clinical spectrum. Multidimensional control measures focusing on areas of high risk are necessary to reduce the burden of leptospirosis.

Comments

This is an Open Access Thesis.

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