Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.

BackgroundBats are key components to the Neotropical forests. Unfortunately, their bad reputation is a major obstacle in their conservation as it creates fear and hostility towards them. Understanding this reputation acquired by bats and studying interactions between bats and humans has shown fundamental promise when creating strategies to forge a non-antagonistic coexistence between both parts and in the promotion of bat conservation in areas with ever-rising human occupation.MethodsNinety people were surveyed from three villages that were situated around a Biological Reserve in the state of Paraiba; located in Northern Brazil. The survey was completed using semi-structured interviews addressing villager’s knowledge of the biology and ecology of bats, their interactions with bats, potential medicinal uses, and their socioeconomic situation. Additionally, we sampled the bats that reside in or visit these villages.ResultsBats were often considered harmful, dangerous and carriers of disease. Bats were often connected to hematophagia, as well. The respondents believe that impacts such as the deforestation are forcing bats into urban environments. With this research, we were able to register one of the few records of bats in popular medicine in Brazil.ConclusionThe folklore and superstition surrounding bats can form an obstacle that affects their conservation. Environmental education is an important step in order to create a harmonious coexistence between humans and bats and to mitigate the impending conflicts between humanity and nature.

As a zoonosis, Plague is also an ecological entity, a complex system of ecological interactions between the pathogen, the hosts, and the spatiotemporal variations of its ecosystems. Five reservoir system models have been proposed: (i) assemblages of small mammals with different levels of susceptibility and roles in the maintenance and amplification of the cycle; (ii) species-specific chronic infection models; (ii) flea vectors as the true reservoirs; (iii) Telluric Plague, and (iv) a metapopulation arrangement for species with a discrete spatial organization, following a source-sink dynamic of extinction and recolonization with naïve potential hosts. The diversity of the community that harbors the reservoir system affects the transmission cycle by predation, competition, and dilution effect. Plague has notable environmental constraints, depending on altitude (500+ meters), warm and dry climates, and conditions for high productivity events for expansion of the transmission cycle. Human impacts are altering Plague dynamics by altering landscape and the faunal composition of the foci and adjacent areas, usually increasing the presence and number of human cases and outbreaks. Climatic change is also affecting the range of its occurrence. In the current transitional state of zoonosis as a whole, Plague is at risk of becoming a public health problem in poor countries where ecosystem erosion, anthropic invasion of new areas, and climate change increase the contact of the population with reservoir systems, giving new urgency for ecologic research that further details its maintenance in the wild, the spillover events, and how it links to human cases.

Rats are invasive pest species that commonly infest low-income urban environments. Their association with humans constitutes a threat of rodent-borne disease transmission. We evaluated the outcome of a chemical and sanitary intervention on rat sightings in seven low-income urban settlements of New Providence, the Bahamas. The intervention consisted of rodenticide application, education about environmental sanitation, and improvement in waste disposal. Rat sightings were systematically recorded by trained staff before and three months after the intervention. The intervention slightly decreased rat sightings, with an average of 2.7-fold with varied effectiveness across locations. Four out of seven locations (57%) registered a decrease in rat sightings. Our results suggest that social and environmental differences among communities may be responsible for the mixed efficacy observed in the current rodent management practice in urban communities of the Bahamas. However, a new set of control measures needs to be developed for areas where rodent decline was not observed. This study provides novel data on how rat population behaves post-intervention in a unique ecological setting like the Bahamas, presenting an informed judgment for their management, especially in the event of a natural disaster.

Domestic rats are the principal reservoir for urban leptospirosis. However, few studies have identified infestation markers in slums and evaluated their predictivity for leptospirosis risk. We compared households with leptospirosis cases in Salvador, Brazil between 2007 and 2009 and their neighbors using a case control design, surveying for rodent infestation signs and environmental characteristics. With the 2007–2008 data, a conditional logistic regression modeling identified the peridomiciliar presence of rodent burrows (OR, 3.30; 95% CI, 1.50–7.26), rat feces (2.86; 1.24–6.59), runs (2.57; 1.06–6.22), households bordering abandoned houses (2.48; 1.04–6.02), and unplastered walls (2.22; 1.02–6.02) as risk factors and developed a predictive score for leptospirosis. With an independent data set from 2009, a receiver operating characteristic (ROC) curve analysis evaluated the prediction score performance, with the area under the curve being 0.70 (95% CI, 0.64–0.76) for score development and 0.71 (0.65–0.79) for validation. Results indicate that high proportions of urban slum households are infested with R. norvegicus. The score performed well when identifying high-risk households within slums. These findings need confirmation in other urban centers, but suggest that community-based screening for rodent infestation can allow to target rodent and environmental control measures in populations at highest risk for leptospirosis.

Plague is a zoonosis caused by Yersinia pestis, whose cycle is based on a reservoir system composed of mammals and their fleas. Its transmission cycle presents long enzootic periods with undetected cases, sometimes misleading that the cycle is extinct. While surveillance activities in Brazil are being carried out only in some focal areas, the serologic results confirm the persistence of Y. pestis in all monitored areas. We studied the small mammal assembly and Y. pestis presence in the Borborema Plateau Focus within the state of Paraíba, which staged the last Brazilian plague outbreak (1986-1987), through an inventory and Y. pestis detection survey of small mammals in peridomestic and sylvatic areas from two municipalities in the state of Paraíba. The field sampling captured 45 specimens (27 marsupials, 18 rodents), of 10 species. Only two species (one marsupial, one rodent) were captured in both peridomestic and sylvatic ecotopes. The sylvatic ecotope had higher richness and abundance. No evidence of circulation of the pathogen was detected, however, this result does not discard the necessity of continuous epidemiological surveillance due to the risk of rekindling the foci after long dormant periods, especially given the current epidemiological transition occurring on a Global scale.

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Leptospirosis is an important public health problem caused by Leptospira.The objective is to characterize the geographic distribution of pathogenic leptospira serovars in the Americas through a systematic review of the literature between 1930-2017. Searches were conducted in six scientifi c databases (PubMed, Web of Science, Embase, Lilacs, Scopus and Cochrane). We included studies conducted unambiguously in the Americas, that investigated infection of Leptospira in humans and animals in their natural environments with serovar identifi cation. 283 articles were included, of which 69 were studies in humans, 86 in wild animals, and 182 in domestic animals. Most of them conducted in Brazil (104, 36.7%) and in rural environments (158, 55.8%). Bovines, equines and dogs where the most frequently studied domestic species. However, a large diversity including 80 species of wild animals were studied. Icterohaemorrhgiae, Canicola, Pomona and Grippotyphosa were the most common serovars, described in 46 (16.2%), 38 (13.3%), 32 (11.3%) and 26 (9%) of the articles, respectively. The Results i ndicate a large concentration of studies in Latin America, with emphasis on Brazil, in wild mammals and three main domestic animal groups. Our results emphasize the need for studies that delve into the relationships of the epidemiological cycle, environment, and health.