China review links canine and human leptospirosis risk

A new systematic review and meta-analysis in Preventive Veterinary Medicine brings fresh attention to leptospirosis in China by looking at humans and dogs together rather than as separate surveillance problems. The study included 109 papers from 29 provinces, covering 111,542 human samples and 8,875 dog samples, and aimed to clarify prevalence patterns and associated factors for pathogenic Leptospira infection across both populations. (sciencedirect.com)

That broader framing matters because leptospirosis sits squarely in the One Health space. The disease is caused by pathogenic Leptospira spp., spreads through exposure to urine from infected animals or contaminated water and soil, and can affect both people and dogs sharing the same environments. CDC notes that dogs are among the animal species involved in transmission ecology, and that the organism can persist for weeks to months in contaminated environments. Severe human disease can involve kidney failure, liver failure, pulmonary hemorrhage, or shock. (cdc.gov)

The new review lands against a backdrop of declining, but persistent, human leptospirosis in China. A 2025 analysis of national zoonotic disease trends reported that human leptospirosis incidence in China dropped overall from 0.047 per 100,000 population in 2010 to 0.009 in 2018, before rising modestly to 0.019 in 2023. Reported cases fell from 679 in 2010 to 156 in 2018, then increased to 304 in 2023, with incidence consistently higher in males than females. That doesn’t suggest a major national resurgence, but it does show continued transmission and the potential for local risk pockets. (idpjournal.biomedcentral.com)

Within that context, the review’s main contribution is scale and synthesis. According to the article abstract page, the authors systematically searched six databases through November 11, 2025, and used the resulting literature to estimate prevalence and examine associated factors in both species. The paper argues that shared environmental exposure between humans and dogs remains central to the epidemiology of leptospirosis in China, and it positions dogs not only as patients, but also as potential sentinels, and in some settings as a source of environmental contamination through urinary shedding. (sciencedirect.com)

Direct outside commentary on this specific paper appears limited so far, but the findings align with the wider literature. Prior canine seroepidemiology work from Changchun concluded that monitoring leptospiral infection in dogs can support human prevention and control efforts. More broadly, environmental risk mapping studies in China have linked leptospirosis risk to ecological and socioeconomic factors, while CDC clinical guidance continues to emphasize flooding, freshwater exposure, wet soil, and animal contact as recurring risk pathways. Taken together, that supports the review’s emphasis on integrated surveillance rather than siloed human-versus-animal monitoring. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary teams, the practical takeaway is that leptospirosis remains easy to underestimate when national human case counts are relatively low. Dogs may present with acute illness or remain subclinical, yet still matter epidemiologically. In day-to-day practice, that means careful exposure histories, attention to renal and hepatic presentations, infection-control precautions when leptospirosis is on the differential, and client education for pet parents whose dogs have access to standing water, flood-prone areas, rodent exposure, or other high-risk environments. It also strengthens the case for seeing canine surveillance data as useful beyond companion animal medicine, especially where public health systems are trying to identify localized zoonotic risk. (cdc.gov)

The paper also fits a larger trend in veterinary and public health research: using meta-analyses to identify where surveillance is thin, where methods differ, and where regional variation may be masking risk. Because the review spans 29 provinces, its value may be less about delivering a single headline prevalence figure and more about showing how uneven the evidence base is across geography, populations, and testing approaches. That’s especially relevant for veterinarians, diagnostic labs, and public health agencies trying to decide where additional sampling or standardized reporting would have the most value. (sciencedirect.com)

What to watch: The next step is whether the review leads to more standardized canine surveillance, province-level follow-up studies, or policy discussions in China around coordinated One Health monitoring of leptospirosis in dogs, people, and environmental reservoirs. (sciencedirect.com)