Objective:

Present a case of severe, PCR-confirmed leptospirosis in a homeless man and discuss the disease’s urban epidemiology in relation to climate conditions and social inequities.

Approach:

• Case: A 42-year-old man with alcohol use disorder and housing instability developed fever, leg pain, jaundice, kidney and liver dysfunction, rhabdomyolysis, and thrombocytopenia. Leptospira DNA was detected by PCR.
• Context: The discussion describes NYC case trends and evidence linking urban rodent reservoirs, precipitation and flooding, environmental conditions, and socioeconomic disadvantage with leptospirosis risk.

Key Findings:

• The patient reported sleeping on a soccer field where rats might have been present, but denied known bites or direct contact.
• Doxycycline was started after PCR confirmation; his clinical status and laboratory abnormalities improved, and he was discharged in stable condition.
• NYC locally acquired cases rose from an average of about 3 annually during 2001–2020 to 15 in each of 2021 and 2022, and 24 confirmed cases in 2023; at least 6 further diagnoses had been reported by April 2024, with updated surveillance pending.
• The article describes heavy precipitation, flooding, inadequate drainage, and warmer, wetter conditions as factors that may increase environmental exposure to Leptospira in urban settings.
• The discussion links rodent burden and leptospirosis risk with vacant properties, inadequate sanitation, low-income neighborhoods, and housing instability.

Interpretation:

The authors present the case as an example of severe leptospirosis in a person experiencing homelessness and discuss how environmental exposure and structural disadvantage may shape urban disease risk.

Limitations:

• The patient’s specific exposure source was not confirmed; he reported possible rat presence but no recognized direct contact or bites.
• The article notes that updated NYC surveillance data were pending.