Programa de pós-graduação em Ecologia: Teoria, Aplicações e Valores, Instituto de Biologia, Universidade Federal da Bahia, Salvador, Brazil.
Instituto de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Ministério da Saúde, Salvador, Brazil.
PLoS One. 2022 Jul 20;17(7):e0270568. doi: 10.1371/journal.pone.0270568. eCollection 2022.
The presence of synanthropic rodents, such as Rattus norvegicus, in urban environments generates high costs of prophylaxis and control, in large part due to the environmental transmission of the pathogenic spirochete Leptospira interrogans, which causes leptospirosis. In Salvador, Brazil, The Center for Control of Zoonosis (CCZ) is responsible for planning and implementing Rodent Control Programs (RCP) which are based on chemical rodenticide. However, these strategies have not been standardized for use in developing countries.
This study aimed to identify the effect of a chemical control campaign on the demographic variables of urban R. norvegicus, analyzing relative abundance, sex structure, body mass, and age of the population, as well as the characterization of spatial distribution among households, rodent capture campaigns and interventions.
This study was carried out during 2015 in three valleys of an urban poor community in Salvador. Individuals of R. norvegicus were systematically captured before (Pre-intervention) and three months (1st post-intervention) and six months (2nd post-intervention) after a chemical control intervention conducted by the CCZ in two valleys of the study area while the third valley was not included in the intervention campaign and was used as a non-intervention reference. We used analysis of variance to determine if intervention affected demographic variables and chi-square to compare proportions of infested households (Rodent infestation index-PII).
During the chemical intervention, 939 households were visited. In the pre-intervention campaign, an effort of 310 trap nights resulted in 43 rodents captured, and in the 1st and 2nd, post-intervention campaigns resulted in 47 rodents captured over 312 trap nights and 36 rodents captured over 324 traps-nights, respectively. The rodent infestation index (PII) points did not show a reduction between the period before the intervention and the two periods after the chemical intervention (70%, 72%, and 65%, respectively). Regarding relative abundances, there was no difference between valleys and period before and two periods after chemical intervention (trap success valley 1: 0,18; 0,19; 0,18 / Valley 3 0,15; 0,17; 0,13/ P>0,05). Other demographic results showed that there was no difference in demographic characteristics of the rodent population before and after the intervention, as well as there being no influence of the application of rodenticide on the areas of concentration of capture of rodents between the campaigns.
Our study indicates that the chemical control was not effective in controlling the population of R. norvegicus and provides evidence of the need for re-evaluation of rodent control practices in urban poor community settings.
在城市环境中，共生啮齿动物（如挪威鼠）的存在会产生高成本的预防和控制费用，这在很大程度上是由于致病性螺旋体钩端螺旋体的环境传播，它会导致钩端螺旋体病。在巴西萨尔瓦多，城市动物传染病控制中心（CCZ）负责规划和实施基于化学杀鼠剂的啮齿动物控制计划（RCP）。然而，这些策略在发展中国家尚未标准化。
本研究旨在通过分析种群的相对丰度、性别结构、体重和年龄，以及家庭之间、捕鼠行动和干预措施的空间分布特征，来确定化学防治活动对城市挪威鼠的人口统计学变量的影响。
本研究于 2015 年在萨尔瓦多一个贫困城市社区的三个山谷进行。在 CCZ 在研究区域的两个山谷进行化学防治干预之前（干预前）以及之后三个月（第一次干预后）和六个月（第二次干预后），对挪威鼠个体进行了系统捕捉，而第三个山谷则未被纳入干预行动，作为非干预参考。我们使用方差分析来确定干预是否影响人口统计学变量，并使用卡方检验比较受感染家庭的比例（啮齿动物感染指数-PII）。
在化学干预期间，共访问了 939 户家庭。在干预前的行动中，310 个陷阱夜的努力捕获了 43 只啮齿动物，而在第一次和第二次干预后的行动中，分别使用 312 个陷阱夜和 36 个陷阱夜捕获了 47 只和 36 只啮齿动物。啮齿动物感染指数（PII）在干预前和两次化学干预后的两个时期之间并没有显示出减少（分别为 70%、72%和 65%）。关于相对丰度，在化学干预前后的三个时期，山谷之间以及山谷与干预前后的差异均无统计学意义（山谷 1 的陷阱成功率：0.18；0.19；0.18/山谷 3：0.15；0.17；0.13/ P>0.05）。其他人口统计学结果表明，干预前后啮齿动物种群的人口统计学特征没有差异，而且杀鼠剂的应用对两次行动之间啮齿动物捕获点的聚集区域没有影响。
本研究表明，化学防治措施对控制挪威鼠种群没有效果，并提供了需要重新评估城市贫困社区啮齿动物控制措施的证据。
