Leptospirosis in Hawai'i: A Retrospective Study within a Health Care System, 2010-2021

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health

Background:

• Leptospirosis is a global zoonotic disease with varied symptoms, often mistaken for other febrile illnesses.
• Hawai'i experiences the highest leptospirosis incidence in the U.S., yet recent epidemiological data is scarce.
• Understanding current trends and risk factors is crucial for effective public health interventions.

Purpose of the Study:

• To investigate the epidemiology of leptospirosis in Hawai'i.
• To identify risk factors associated with severe leptospirosis cases.
• To inform targeted prevention and treatment strategies.

Main Methods:

• Retrospective study of patients with suspected or confirmed leptospirosis from 2010-2021.
• Analysis of clinical data, laboratory results, and demographic information.
• Comparison of characteristics between mild (outpatient) and severe (inpatient) cases.

Main Results:

• 164 patients identified; 81 mild, 83 severe cases.
• Severe cases showed more frequent abnormal lab tests (electrolytes, kidney/liver function) and complications like acute kidney disease, sepsis, and rhabdomyolysis.
• Leptospirosis cases peaked in drier summer months, with higher incidence in high-rainfall areas on Kaua'i.
• Risk factors for severe illness included Native Hawaiian/Pacific Islander ethnicity and elevated body mass index (BMI).

Conclusions:

• Leptospirosis presents with diverse severity in Hawai'i, with specific demographic and clinical risk factors identified.
• Native Hawaiian/Pacific Islander ethnicity and elevated BMI are associated with increased risk of severe leptospirosis.
• Early detection and tailored interventions for at-risk populations may reduce disease severity and healthcare burden.