Association of rodent-borne <i>Leptospira</i> spp. with urban environments in Malaysian Borneo

Although leptospirosis is traditionally considered a disease of rural, agricultural and flooded environments, Leptospira spp. are found in a range of habitats and infect numerous host species, with rodents among the most significant reservoirs and vectors. To explore the local ecology of Leptospira spp. in a city experiencing rapid urbanization, we assessed Leptospira prevalence in rodents from three locations in Malaysian Borneo with differing levels of anthropogenic influence: 1) high but stable influence (urban); 2) moderate yet increasing (developing); and 3) low (rural). A total of 116 urban, 122 developing and 78 rural rodents were sampled, with the majority of individuals assigned to either the Rattus rattus lineage R3 (n = 165) or Sundamys muelleri (n = 100). Leptospira spp. DNA was detected in 31.6% of all rodents, with more urban rodents positive (44.8%), than developing (32.0%) or rural rodents (28.1%), and these differences were statistically significant. The majority of positive samples were identified by sequence comparison to belong to known human pathogens L. interrogans (n = 57) and L. borgpetersenii (n = 38). Statistical analyses revealed that both Leptospira species occurred more commonly at sites with higher anthropogenic influence, particularly those with a combination of commercial and residential activity, while L. interrogans infection was also associated with low forest cover, and L. borgpetersenii was more likely to be identified at sites without natural bodies of water. This study suggests that some features associated with urbanization may promote the circulation of Leptospira spp., resulting in a potential public health risk in cities that may be substantially underestimated.尽管钩端螺旋体病（leptospirosis）传统上被视为与乡村、农业及洪涝环境相关的疾病，但钩端螺旋体属（Leptospira spp.）广泛分布于多种生境，可感染众多宿主物种，其中啮齿动物是其最重要的储存宿主与传播媒介之一。为探究快速城市化城市中钩端螺旋体属的本地生态特征，我们对马来西亚婆罗洲三个人为活动影响程度存在差异的区域开展研究，评估了其啮齿动物的钩端螺旋体感染率：1）人为影响高且稳定的城市区域；2）人为影响中等且持续升高的开发中区域；3）人为影响低的乡村区域。本次研究共采集116只城市区域、122只开发中区域及78只乡村区域的啮齿动物样本，其中绝大多数个体被归类为家鼠（Rattus rattus）分支R3（n=165）或穆勒巨鼠（Sundamys muelleri，n=100）。所有啮齿动物样本中，31.6%可检测到钩端螺旋体属脱氧核糖核酸（DNA）；城市区域啮齿动物的阳性率（44.8%）高于开发中区域（32.0%）与乡村区域（28.1%），且上述差异具有统计学显著性。多数阳性样本经序列比对鉴定为已知人类病原体：问号钩端螺旋体（Leptospira interrogans，n=57）与波摩那钩端螺旋体（Leptospira borgpetersenii，n=38）。统计学分析显示，两种钩端螺旋体均在人为活动影响更高的区域更为常见，尤其是兼具商业与居住活动的区域；其中问号钩端螺旋体感染还与低森林覆盖率显著相关，而波摩那钩端螺旋体则更易在无自然水体的采样点被检出。本研究表明，与城市化相关的部分特征可能促进钩端螺旋体属的传播循环，进而在城市中造成被大幅低估的潜在公共健康风险。