Deadly Leptospirosis Linked to Berkeley Encampment

forensic investigators in white protective suits walking on a city street — Photo: Ververidis Vasilis / Shutterstock

Berkeley linked a deadly leptospirosis case to severe rat infestation near a long-running encampment, then moved in with hazmat crews to clear the site.

Story Snapshot

City health alerts tied leptospirosis to rats and dogs near Harrison Street encampments.
Officials began clearing the camp after one death and multiple animal positives.
A June update said general public risk was low, but the area stayed unsafe for camping.
Activists and the mayor pressed for due process and long-term housing alongside cleanup.

What Officials Say Happened at Harrison Street

City of Berkeley health officials reported rats and at least two dogs near the Harrison Street encampments tested positive for leptospirosis in late 2025. They warned that rat urine in water or mud can spread the bacteria to people and pets. The alert said these conditions made the area unsafe for human encampment. That finding set the stage for abatement, sanitation work, and eventual clearance actions at the clustered sites in West Berkeley.

Officials later updated guidance in June 2026. They said the risk to the general public was very low. They also reiterated there is no person-to-person spread of leptospirosis. Still, the city maintained that the encampment zone itself was unsafe because of active transmission among rodents and dogs. That mix of low citywide risk but high local hazard drove the decision to fence sections, remove debris, and intensify rodent control in the corridor.

From Animal Positives to a Human Death

Local outlets reported two human infections tied to the area during the summer, with one patient dying after extended treatment. Coverage described a “severely rat-infested” recreational vehicle connected to the cases, located about a mile from the Harrison Street encampment. That detail underscored how poor sanitation, clutter, and food waste can turn parked vehicles into rodent nests that seed disease risk for people living nearby.

City leaders declared the encampment a fire hazard and a public nuisance in September and began clearing it. Reports noted hazmat teams, heavy equipment, and fencing as crews removed trash and shelters. The city’s notice said leptospirosis remained present in the area and called for ongoing rodent abatement to prevent further spread. Authorities also said veterinarians first flagged the problem when dogs at the site became sick in late 2025.

Legal Fights and the Question of Where People Go

Advocates from the Berkeley Homeless Union challenged the sweep in court and accused the city of moving ahead while a hearing on a temporary restraining order was underway. The union framed the issue around rights and services for residents, including people who cannot care for themselves. Mayor Jesse Arreguín said clearing alone would not solve homelessness and stressed the need to place people into stable housing whenever possible.

Courthouse records in the civil case show a judge accepted city evidence that encampment conditions posed a serious public health problem warranting closure. The filings described confirmed leptospirosis in the encampment environment, multiple dog cases, and soil and water risks near a creek. That legal footing, plus ongoing animal positives, supported the city’s push to reduce exposure through cleanup and relocation offers, even as placements lagged demand.

Why This Outbreak Hit Hard — And What It Signals

Leptospirosis thrives where there is standing water, food scraps, and rat urine. People living outdoors face higher contact with these hazards. Research on people experiencing homelessness in other countries shows high exposure and calls for steady surveillance and prevention. In practice, that means rodent-proof trash storage, regular waste pickup, clean water access, and prompt veterinary and human testing when animals fall ill.

Berkeley’s pattern mirrors many cities: a real health threat emerges, mitigation drags amid lawsuits and policy gaps, and then a crisis forces action. Residents across the political spectrum see the cycle as proof that systems fail until danger peaks. The city said general risk stayed low, but people living in the hotspot paid the highest price. That is the core warning: when basic sanitation fails, disease moves fastest through the most vulnerable.

Accountability, Transparency, and Next Steps

Public trust rises when leaders explain what data triggered action and what resources move with it. Berkeley’s alerts and updates gave clear signals about risk levels and control steps. The next test is whether the city sustains rodent control, restores sanitation, and offers real housing paths. Without those links, encampments may shift a few blocks, and the same hazards can return with the next rain and the next pile of trash.

For readers tracking policy, this case shows how public health, housing capacity, and law collide. Faster lab testing, steady cleanup funding, and more shelter and treatment beds can break the cycle. Cities also need clear legal playbooks that protect due process but allow rapid action when animals test positive and people get sick. That balance is hard, but delay has a cost measured in lives.