Leptospirosis Outbreak in Aftermath of Hurricane Fiona - Puerto Rico, 2022

Area of Science:

• Infectious Diseases
• Public Health
• Environmental Health

Background:

• Leptospirosis is a severe bacterial zoonotic disease endemic to Puerto Rico.
• Flooding events globally are linked to increased leptospirosis incidence.
• Hurricane Fiona caused significant flooding in Puerto Rico in 2022.

Purpose of the Study:

• To evaluate changes in leptospirosis risk in Puerto Rico after Hurricane Fiona.
• To compare leptospirosis case characteristics and geographic distribution before and after the hurricane.

Main Methods:

• The Puerto Rico Department of Health (PRDH) updated reporting guidelines and surveillance systems post-hurricane.
• Leptospirosis cases were quantified and compared for the 15 weeks after Hurricane Fiona to the preceding 37 weeks.
• Patient characteristics and geographic distribution were analyzed.

Main Results:

• A 3.6-fold increase in the mean weekly number of leptospirosis cases was observed post-hurricane (10.4 cases/week) compared to pre-hurricane (2.9 cases/week).
• The proportion of cases linked to contaminated water exposure rose from 11% to 35% after the hurricane.
• Increased testing and reporting contributed to the surge in identified cases.

Conclusions:

• Hurricane Fiona was associated with a significant increase in leptospirosis cases in Puerto Rico.
• Enhanced surveillance and public health interventions are crucial for managing leptospirosis outbreaks after flooding.
• Early case identification and public awareness are vital to mitigate severe outcomes.