One died, one hospitalized from leptospirosis, Berkeley officials say
A rare outbreak of leptospirosis in Berkeley has resulted in one death and one hospitalization, marking the city’s first human cases of the disease in over a decade. City officials confirmed the cases in May, noting that the infected individuals lived in an RV and had been trapping and breeding wild rats. While health authorities emphasize that the risk to the general public remains extremely low, the incident underscores ongoing concerns regarding sanitation and rodent control in North Berkeley.
How the Outbreak Developed
The transmission of leptospirosis is primarily linked to infected rats, whose urine can contaminate standing water or enter the body through open wounds. According to City Manager Paul Buddenhagen, the two affected individuals had been feeding and trapping wild rats inside their living space. Public health officials, including Dr. Noemi Doohan and Director Scott Gilman, stated that the patients did not seek medical care for weeks or months after falling ill, which likely worsened their condition.
The cases were identified following a broader monitoring effort that began in late 2025, when the bacteria was detected in local rats and dogs. In response, the city has removed approximately 40 tons of trash from the encampment area at Eighth and Harrison streets since February to mitigate rodent nesting.
Did You Know?
The city of Berkeley has not recorded a human case of leptospirosis in more than 10 years, according to local health officials.
What This Means for Public Health
While the outbreak is centered near a large encampment in North Berkeley, health officials maintain that housed residents face a minimal threat. The bacteria typically requires direct contact with infected urine or contaminated environments, activities more common among those living in close proximity to rodent populations. To prevent further spread, officials have provided protective gear and vaccine information to encampment residents.
Expert Insight:
Samantha Carter notes that while leptospirosis is a global health concern—infecting roughly 1 million people annually—the rarity of human cases in developed countries often leads to delayed diagnosis. The Berkeley incident highlights the critical importance of early medical intervention, as the severity of the illness is directly tied to the duration of untreated exposure.
Future Risks and Prevention
Health authorities expect that ongoing extermination efforts by Alameda County Vector Control Services will continue to be the primary defense against the disease. Residents are advised against attempting to exterminate rats themselves and should instead contact the county at 510-567-6800. Future public health outcomes may depend on maintaining sanitary conditions near encampments and ensuring that domestic pets are vaccinated.
General safety recommendations from the city include washing produce, covering open wounds with waterproof bandages, and avoiding contact with standing water or dead animals. If residents suspect exposure, they are encouraged to shower immediately.
Frequently Asked Questions
How can I protect my dog from leptospirosis?
Health officials recommend that dog owners ensure their pets are up to date on leptospirosis vaccinations. UC Davis researchers have previously tested dogs in the area, and local authorities have offered free vaccines to pet owners in the encampment.
Is it safe to live or walk near the Eighth and Harrison encampment?
City officials believe the risk to the general public is extremely low. However, residents are advised to avoid contact with rats or their excreta and to keep food and water in sealed containers to prevent rodent infestations.
What should I do if I see rats on my property?
The public should not attempt to exterminate rats independently. Instead, residents should contact Alameda County Vector Control Services at 510-567-6800 for professional assistance.
How are you adjusting your personal safety habits to account for the presence of local wildlife in urban areas?