Leptospirosis review maps shared human and canine risk in China

A new Preventive Veterinary Medicine systematic review and meta-analysis is putting fresh focus on leptospirosis in China by examining the epidemiology of infection in both humans and dogs, rather than treating them as separate problems. That framing matters: the authors position leptospirosis as a persistent zoonotic threat shaped by shared environments, animal reservoirs, and uneven surveillance, even as national human incidence has declined overall. (sciencedirect.com)

The backdrop is a disease with a long, shifting history in China. National analyses suggest leptospirosis has changed geographically and epidemiologically over time, with different transmission patterns linked to paddy-field labor in the south, flood exposure in northern regions, and changing reservoir dynamics involving rodents, pigs, and dogs. More recent national zoonoses data show reported human incidence declined from 0.047 per 100,000 population in 2010 to 0.009 in 2018, before edging back up to 0.019 in 2023, suggesting control progress but not elimination. (pmc.ncbi.nlm.nih.gov)

According to the new review’s abstract and article summary, the authors conducted a PRISMA-compliant search across PubMed, Web of Science, ScienceDirect, CNKI, Wanfang, and VIP, covering studies published through November 11, 2025. Their goal was to estimate prevalence patterns and identify associated factors for pathogenic Leptospira infection in people and dogs across China. The article highlights the importance of shared environmental exposure and notes that free-roaming or stray dogs may help maintain transmission in both urban and rural settings. (sciencedirect.com)

That message lines up with adjacent evidence. A recent study from the Yangtze River region reported high seroprevalence of pathogenic Leptospira in dogs sampled through veterinary clinics and linked risk to season and age, while calling for stronger vigilance in central, northern, and northwestern China. Other recent Chinese epidemiology papers have tied human leptospirosis risk to heavy rainfall, flooding, humidity, and environmental conditions, and have identified ongoing hotspots despite the broader national decline. In Anhui, for example, investigators reported continued spatial clustering and recent outbreaks in high-risk counties, underscoring that sporadic and localized transmission is still occurring. (pmc.ncbi.nlm.nih.gov)

Direct expert reaction to this specific paper was limited in publicly available coverage, but the wider literature is consistent on the practical takeaway: canine leptospirosis surveillance works best when treated as a One Health issue. A recent review on canine leptospirosis surveillance argued for integrating veterinary, public health, academic, and environmental data, especially because stray and free-roaming dogs may face higher exposure and because transmission risk is shaped by environmental and socioeconomic factors. CDC clinician guidance also continues to describe leptospirosis as a disease spread through exposure to urine from infected animals or contaminated water or soil, with dogs among recognized animal hosts. (pmc.ncbi.nlm.nih.gov)

Why it matters: For veterinarians, this paper is a reminder that declining national case counts can obscure local risk. In practice, leptospirosis remains relevant where dogs encounter standing water, rodent-contaminated environments, flood conditions, or unmanaged outdoor exposure. For clinicians and public health teams, a combined human-canine evidence base can help sharpen risk communication to pet parents, inform diagnostic suspicion in compatible cases, and support more targeted prevention strategies in regions where environmental conditions still favor transmission. (idpjournal.biomedcentral.com)

The study also lands at a time when China’s pet and public health systems are under pressure to improve data integration across sectors. Because leptospirosis can be underdiagnosed and its ecology varies by region, systematic syntheses like this are often most useful when they expose surveillance gaps, inconsistent testing patterns, or under-studied canine populations. If veterinary authorities, researchers, and local public health teams act on that, the paper could have value beyond academia. That’s an inference based on the study’s One Health framing and the broader surveillance literature. (sciencedirect.com)

What to watch: The next step is whether this review translates into more standardized canine surveillance, more geographically targeted prevention in flood- and rodent-prone areas, and follow-on studies that better connect animal, environmental, and human data at the provincial level. (pmc.ncbi.nlm.nih.gov)