China review finds ongoing human and canine leptospirosis burden

A new systematic review and meta-analysis in Preventive Veterinary Medicine offers one of the clearest recent snapshots of leptospirosis across humans and dogs in China, and its central message is straightforward: the pathogen is still circulating at meaningful levels, with uneven risk across regions and populations. The study synthesized 109 studies from 29 provinces, spanning 111,542 human samples and 8,875 dog samples, and found that leptospirosis remains a substantial zoonotic burden rather than a legacy problem. (sciencedirect.com)

That conclusion fits with the broader picture from China’s zoonotic disease literature. A 2025 analysis in Infectious Diseases of Poverty reported that leptospirosis is among the zoonoses in China that have not shown significant reductions in recent years, even as some other diseases have declined. The authors of that paper called for integrated surveillance linking human case reporting, animal infection data, and environmental exposure risks, which is essentially the same One Health gap highlighted by the new review. (idpjournal.biomedcentral.com)

The new review matters because it looks at humans and dogs together. That’s important epidemiologically: dogs share environments with people, may develop disease themselves, and can help signal where exposure risk is building. A recent global review in BMC Veterinary Research described dogs as both sentinels and, in some settings, reservoirs, and argued that canine serosurveys can be a practical surveillance tool when paired with public health data. (bmcvetres.biomedcentral.com)

The China-specific canine evidence supports that framing. In Changchun, one seroepidemiology study found an overall canine seropositivity rate of about 19.1%, with higher positivity in adult and older dogs than in juveniles. A more recent study from the Yangtze River region reported that seropositivity increased with age and that risk appeared higher in summer and autumn, consistent with the well-established role of rainfall, flooding, and environmental contamination in leptospiral transmission. Historical work from Guangzhou has likewise linked leptospirosis risk to suitable temperatures, frequent rainfall, flood disasters, and gaps in public awareness and protection. (pmc.ncbi.nlm.nih.gov)

Expert and industry commentary around leptospirosis increasingly centers on surveillance and cross-sector coordination rather than any single intervention. WOAH has described leptospirosis as a zoonosis that benefits from a One Health approach, especially where heavy rain, urban exposure, and animal reservoirs complicate control. WHO background materials similarly emphasize exposure to contaminated water or animal urine and note the importance of environmental and occupational risk factors in both humans and animals. Taken together, those perspectives support the review’s implication that veterinary medicine has a role well beyond treating individual canine cases. (rr-americas.woah.org)

Why it matters: For veterinary teams, this is a reminder that leptospirosis surveillance isn’t just a public health exercise happening somewhere else. Clinics may be among the first places where changing exposure patterns become visible, whether through acute kidney or liver cases, serology trends, seasonal clusters, or pet parent reports of water and rodent exposure. In practical terms, the paper strengthens the case for region-specific risk assessment, more consistent diagnostic workups in suspect dogs, and prevention conversations that connect canine health to household and community health. (sciencedirect.com)

It also highlights a familiar challenge: heterogeneity. When prevalence varies sharply by province, host factors, and study methods, national averages can obscure local risk. That makes standardized diagnostics and better-linked datasets especially important. The broader literature suggests that without coordinated surveillance, veterinary and public health systems may miss early signals or underestimate how environmental conditions are shaping transmission. (sciencedirect.com)

What to watch: The next step is whether this evidence translates into more formalized canine sentinel surveillance, stronger province-level risk mapping, and tighter integration between veterinary, public health, and environmental monitoring in China, particularly ahead of high-risk rainy seasons. (idpjournal.biomedcentral.com)