Risk factors for Leptospira seropositivity in rural Northern Germany, 2019.

We investigated seroprevalence and factors associated with Leptospira spp. infections in humans in rural Northern Germany. Sera of 450 participants were tested for leptospira-reactive IgG antibodies by two enzyme-linked immunosorbent assays (ELISA). A narrow (specific) and a broad (sensitive) case definition were applied and results compared in the analysis. Personal data were collected via questionnaire and associations with the serostatus were investigated by multivariable logistic regression. The seroprevalence estimates were 1.6% (95%-confidence interval (CI) = 0.63-3.2) under the narrow and 4.2% (95%-CI = 2.6-6.5%) under the broad case definition. Few (14%) participants knew about the pathogen. No seropositive participant recalled a prior leptospirosis diagnosis. Spending more than two hours a week in the forest was significantly associated with anti-leptospira IgG in both models (broad case definition: adjusted odds ratio (aOR) = 2.8, 95%-CI = 1.2-9.1; narrow case definition: aOR = 11.1, 95%-CI = 1.3-97.1). Regular cleaning of storage rooms was negatively associated in the broad (aOR = 0.17, 95%-CI = 0.03-0.98) and touching a dead rodent in the past 10 years in the narrow case definition model (aOR = 0.23, 95%-CI = 0.05-1.04). Our findings support risk factors identified in previous investigations. To counter the low awareness for the pathogen, we recommend that health authorities communicate risks and preventive measures to the public by using target-group specific channels.

Zoonotic Bacteria in Fleas Parasitizing Common Voles, Northwestern Spain.

We detected Francisella tularensis and Bartonella spp. in fleas parasitizing common voles (Microtus arvalis) from northwestern Spain; mean prevalence was 6.1% for F. tularensis and 51% for Bartonella spp. Contrasted vector-host associations in the prevalence of these bacteria suggest that fleas have distinct roles in the transmission cycle of each pathogen in nature.

Changing landscapes of Southeast Asia and rodent-borne diseases: decreased diversity but increased transmission risks.

The reduction in biodiversity from land use change due to urbanization and agricultural intensification appears to be linked to major epidemiological changes in many human diseases. Increasing disease risks and the emergence of novel pathogens result from increased contact among wildlife, domesticated animals, and humans. We investigated the relationship between human alteration of the environment and the occurrence of generalist and synanthropic rodent species in relation to the diversity and prevalence of rodent-borne pathogens in Southeast Asia, a hotspot of threatened and endangered species, and a foci of emerging infectious diseases. We used data from an extensive pathogen survey of rodents from seven sites in mainland Southeast Asia in conjunction with past and present land cover analyses. At low spatial resolutions, we found that rodent-borne pathogen richness is negatively associated with increasing urbanization, characterized by increased habitat fragmentation, agriculture cover and deforestation. However, at a finer spatial resolution, we found that some major pathogens are favored by environmental characteristics associated with human alteration including irrigation, habitat fragmentation, and increased agricultural land cover. In addition, synanthropic rodents, many of which are important pathogen reservoirs, were associated with fragmented and human-dominated landscapes, which may ultimately enhance the opportunities for zoonotic transmission and human infection by some pathogens.

Community perceptions of health and rodent-borne diseases along the Inter-Oceanic Highway in Madre de Dios, Peru.

BACKGROUND: Madre de Dios is located in the southeastern Amazonian region of Peru. Rodents have been estimated to be the reservoirs for up to 50 % of emerging zoonotic pathogens, including a host of viruses, bacteria, and parasites. As part of a larger study involving both human and animal research, this study serves to obtain a broader understanding of the key challenges and concerns related to health and rodent-borne illnesses from the perspective of the people living in these communities. METHODS: We used a mixed methods approach, which comprised of 12 focus group discussions, 34 key informant interviews and the application of a survey (n = 522) in four communities along the Inter-Oceanic Highway (IOH) in Madre de Dios, Peru over a two-year period. RESULTS: Although 90 % of survey respondents answered that rodents can transmit diseases and had seen rodents in their homes and immediate surroundings, most could not name specific rodent-borne diseases and, when probed, described rodents as pests or nuisance animals, but were not concerned about acquiring illnesses from them. Key informant interview data suggests that there has been a perceived increase in the amount of rodents in the communities since the construction of the IOH, however this potential increase was not coupled with increased knowledge about diseases or perceived risks among these key informants. Health providers also mentioned a lack of diagnostic tools specific for rodent-borne illnesses. This may be related to the fact that although a common rodent-borne disease like leptospirosis is frequently detected in the region, it is not routinely and readily diagnosed, therefore the real burden of the disease and exposure risk can be underestimated. If rodent-borne diseases are not on the radar of health professionals, they may not consider presumptive treatment, which could result in unnecessary morbidity and mortality. CONCLUSION: Awareness of rodent-borne diseases is still lacking in the area, even among health care professionals within the communities, despite the known burden of diseases like leptospirosis. We expect to report further findings as we obtain more information from all the study components.

Dynamics of Rodent and Rodent-borne Disease during Construction of the Three Gorges Reservoir from 1997 to 2012.

OBJECTIVE: To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. METHODS: Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. RESULTS: The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. CONCLUSION: This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.

Ecological interactions, local people awareness and practices on rodent-borne diseases in Africa: A review.

Several anthropogenic activities exposure humans to the risk of rodent-borne diseases. These activities are but not limited to logging, clearing land for crop cultivation, and consuming rodents. Rodents are a highly diverse mammalian group and harbor many zoonotic diseases. This review focuses on dominant rodent-flea species, rodent-borne zoonotic diseases and awareness and management practices against rodent-borne diseases in Africa. Relevant academic literature spanning from 1974 to 2021 was analysed. Dominant rodent species reported in Africa included:- Mastomys natalensis and Rattus rattus, while dominant flea species included Xenopsylla brasiliensis and Xenopsylla cheopis. Rodents were reported as hosts to a wide range of parasites which can be passed to humans. Rodents were also reported as hosts to some protozoans, trematodes, cestodes, nematodes, bacteria and viruses which are transmissible to humans. Some studies conducted in West Africa revealed good knowledge and practices on plague and Lassa fever diseases among respondents, whereas other studies reported poor practices on Lassa fever management. In part of Southern Africa, some studies reported poor knowledge and practices on plague disease. Further research on rodent-borne disease awareness and management strategies in African countries is desirable.

Streptobacillus moniliformis right hand abscess and monoarthritis following a rat bite.

Streptobacillus moniliformis is a zoonotic agent associated with rat bites. We present a patient with cellulitis, subcutaneous abscess, and septic mono-arthritis after a rat bite of the right hand. The patient had no systemic features of rat bite fever (RBF). S. moniliformis was cultured from purulent drainage of a thumb abscess. This case illustrates an unusual clinical presentation of streptobacillary infection after a rat bite.

Seroprevalence of Toxoplasma gondii among Sylvatic Rodents in Poland.

Toxoplasma gondii is an intracellular Apicomplexan parasite with a broad range of intermediate hosts, including humans and rodents. Rodents are considered to be reservoirs of infection for their predators, including cats, felids, pigs, and wild boars. We conducted a multi-site, long-term study on T. gondii in northeastern Poland. The study aimed to monitor the seroprevalence of T. gondii in the four abundant vole species found in the region (Myodes glareolus, Microtus arvalis, Microtus agrestis, and Alexandromys oeconomus) and to assess the influence of both extrinsic (year of study and study site) and intrinsic (host sex and host age) factors on seroprevalence. A bespoke enzyme-linked immunosorbent assay was used to detect antibodies against T. gondii. We examined 577 rodent individuals and detected T. gondii antibodies in the sera of all four rodent species with an overall seroprevalence of 5.5% [4.2-7.3] (3.6% [2.6-4.9] for M. glareolus and 20% [12-30.9] for M. arvalis, M. agrestis, and A. oeconomus). Seroprevalence in bank voles varied significantly between host age and sex. Seroprevalence increased with host age and was higher in females than males. These results contribute to our understanding of the distribution and abundance of T. gondii in voles in Poland and confirm that T. gondii also circulates in M. glareolus and M. arvalis, M. agrestis and A. oeconomus. Therefore, they may potentially play a role as reservoirs of this parasite in the sylvatic environment.

Should we be concerned about Venezuelan hemorrhagic fever? - A reflection on its current situation in Venezuela and potential impact in Latin America amid the migration crisis.

Venezuelan Haemorrhagic Fever is an endemic zoonosis exhibiting a high lethality. Discovered decades ago, it is still causing seasonal hemorrhagic fever outbreaks. With the ongoing migration crisis, transmission and spreading to other countries in Latin America remains a latent threat that should be monitored, particularly in light of recent cases.

Occurrence of zoonotic gastrointestinal parasites of rodents and the risk of human infection in different biomes of Brazil.

Rodents are synanthropic mammals adapted to several ecosystems, where they can contribute to the transmission of zoonotic pathogens, including gastrointestinal parasites. The aim of this study was to study the occurrence of gastrointestinal parasites from rodents and discuss the risk of transmission to humans. Fecal samples (n = 110) from different rodent species, namely, Cerradomys subflavus (n = 4), Mus musculus (n = 14), Rattus norvegicus (n = 80), Rattus rattus (n = 8) and Thrichomys apereoides (n = 4), were analyzed using the FLOTAC technique. Of the samples examined, 73.6% (81/110) tested positive for at least one gastrointestinal parasite. The most commonly identified parasites were Aspiculuris sp., Hymenolepis nana, Moniliformis sp., Syphacia sp., Strongyloides spp., Taenia spp., and Trichuris spp. eggs, Angiostrongylus cantonensis larvae and Entamoeba spp. cysts. The findings of this study demonstrate that rodents living in different Brazilian biomes are parasitized by a wide range of parasites, including some of public health concern. Therefore, the proximity of rodents to human settlements may represent a tangible risk of infection for people living in these areas.

Roedores são mamíferos sinantrópicos adaptados a vários ecossistemas, onde podem contribuir para a transmissão de patógenos zoonóticos, incluindo parasitas gastrointestinais. O objetivo deste estudo foi descrever a ocorrência de parasitos gastrointestinais de roedores e discutir o risco de transmissão ao ser humano. Amostras fecais (n = 110) de diferentes espécies de roedores, a saber, Cerradomys subflavus (n = 4), Mus musculus (n = 14), Rattus norvegicus (n = 80), Rattus rattus (n = 8) e Thrichomys apereoides (n = 4), foram analisados pela técnica FLOTAC. Das amostras examinadas, 73,6% (81/110) apresentaram resultado positivo para pelo menos um parasito gastrointestinal. Os parasitos mais comumente identificados foram ovos de Aspiculuris sp., Hymenolepis nana, Moniliformis sp., Syphacia sp., Strongyloides spp., Taenia spp., Trichuris spp., larvas de Angiostrongylus cantonensis e cistos de Entamoeba spp. Os resultados deste estudo demonstraram que os roedores que vivem em diferentes biomas brasileiros são parasitados por uma ampla variedade de parasitos, incluindo alguns problemas de saúde pública. Portanto, a proximidade de roedores com assentamentos humanos pode representar um risco de infecção nessas áreas.

Babesia Occurrence in Rodents in Relation to Landscapes of Mainland Southeast Asia.

The purpose of this study is to investigate the relationships between habitat structure and Babesia spp. occurrence in rodents in mainland Southeast Asia. Of 1439 rodents and insectivores investigated, the protist Babesia was found in only 81 individuals (5.6% of the micromammals investigated) with Babesia microti U.S. type the more prevalent (4.1%), followed by the B. microti Kobe type (1.2%), and by the very rare Babesia BiCM002 (0.04%). We used georeferenced data of rodents analyzed for Babesia infection and land cover maps produced for the seven study sites in Thailand, Cambodia, and Lao PDR, where they were collected. Rodents infected by Babesia were more likely to be found in settlements close to forested areas, which may represent risky place for spillover of Babesia species to humans.

An Evaluation of Removal Trapping to Control Rodents Inside Homes in a Plague-Endemic Region of Rural Northwestern Uganda.

Rodents pose a significant threat to human health, particularly in rural subsistence farming communities in Africa, where rodents threaten food security and serve as reservoirs of human pathogens, including the agents of plague, leptospirosis, murine typhus, rat-bite fever, Lassa fever, salmonellosis, and campylobacteriosis. Our study focused on the plague-endemic West Nile region of Uganda, where a majority of residents live in Uganda government-defined poverty, rely on subsistence farming for a living, and frequently experience incursions of rodents into their homes. In this study, we show that rodent removal was achieved in a median of 6 days of intensive lethal trapping with multiple trap types (range: 0-16 days). However, rodent abundance in 68.9% of homesteads returned to pretreatment levels within a median of 8 weeks (range 1-24 weeks), and at least a single rodent was captured in all homesteads by a median of 2 weeks (range 1-16 weeks) after removal efforts were terminated. Results were similar between homesteads that practiced rodent control whether or not their neighbors implemented similar strategies. Overall, intensive lethal trapping inside homes appears to be effective at reducing rodent abundance, but control was short lived after trapping ceased.

First evidence of Seoul hantavirus in the wild rat population in the Netherlands.

We report the first detection of Seoul hantavirus (SEOV)-specific antibodies in the wild brown rat population in the Netherlands. SEOV-reactive antibodies were found in three rats out of 16 in a repeated series of tests including immunofluorescence assay, immunoblot, and enzyme-linked immunosorbent assay. Focus reduction neutralization test confirmed the presence of SEOV-specific antibodies, and reverse-transcription polymerase chain reaction (RT-PCR) confirmed the presence of hantaviral RNA. This discovery follows the recent findings of SEOV infections in wild and pet brown rats and humans in England, Wales, France, Belgium, and Sweden, indicating an even higher importance of this hantavirus for public health in large areas of Europe.

Transmission ecology of rodent-borne diseases: New frontiers.

Rodents are recognized reservoir hosts for many human zoonotic pathogens. The current trends resulting from anthropocene defaunation suggest that in the future they, along with other small mammals, are likely to become the dominant mammals in almost all human-modified environments. Recent intricate studies on bat-borne emerging diseases have highlighted that many gaps exist in our understanding of the zoonotic transmission of rodent-borne pathogens. This has emphasized the need for scientists interested in rodent-borne diseases to integrate rodent ecology into their analysis of rodent-borne pathogen transmission in order to identify in more detail the mechanisms of spillover and chains of transmission. Further studies are required to better understand the true impact of rodent abundance and the importance of pathogen sharing and circulation in multi-host- multi-pathogen communities. We also need to explore in more depth the roles of generalist and abundant species as the potential links between pathogen-sharing, co-infections and disease transmission.

Co-circulation of Clade C New World Arenaviruses: New geographic distribution and host species.

Clade C, of the New World Arenaviruses, is composed of only the Latino and Oliveros viruses and, besides the geographic range of their rodent reservoirs, the distribution of these viruses has been restricted to Bolivia and Argentina. In this study, the genetic detection and phylogenetic analysis of the complete S segment sequences of sympatric arenaviruses from Brazil revealed a new geographic distribution of clade C arenaviruses, as well as the association of Oliveros virus with a new rodent reservoir.

Rodent-borne viruses survey in rural settlers from Central Brazil

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

The diversity of microparasites of rodents: a comparative analysis that helps in identifying rodent-borne rich habitats in Southeast Asia.

BACKGROUND: Predicting habitats prone to favor disease transmission is challenging due to confounding information on habitats, reservoirs, and diseases. Comparative analysis, which aims at investigating ecological and evolutionary patterns among species, is a tool that may help. The emergence of zoonotic pathogens is a major health concern and is closely linked to habitat modifications by human activities. Risk assessment requires a better knowledge of the interactions between hosts, parasites, and the landscape. METHODS: We used information from a field spatial study that investigated the distribution of murid rodents, in various habitats of three countries in Southeast Asia, in combination with their status of infection by 10 taxa of microparasites obtained from the literature. Microparasite species richness was calculated by rodent species on 20,272 rodents of 13 species. Regression tree models and generalized linear models were used to explain microparasite diversity by the average distance between the trapping site and five categories of land cover: forest, steep agriculture land, flat agriculture land, water, and built-up surfaces. Another variable taken into account was the slope. RESULTS: We found that microparasite diversity was positively associated with flat agriculture land, in this context mainly rice fields, and negatively associated with slope. Microparasite diversity decreased sharply a 100 m or less from flat agriculture land. CONCLUSION: We conclude that there is high microparasite circulation in rodents of flooded farmlands, meaning possibly a higher risk of disease for human inhabitants.

Evidence that rodent control strategies ought to be improved to enhance food security and reduce the risk of rodent-borne illnesses within subsistence farming villages in the plague-endemic West Nile region, Uganda.

Rodents pose serious threats to human health and economics, particularly in developing countries where the animals play a dual role as pests: they are reservoirs of human pathogens, and they inflict damage levels to stored products sufficient to cause food shortages. To assess the magnitude of the damage caused by rodents to crops, their level of contact with humans, and to better understand current food storage and rodent control practices, we conducted a survey of 37 households from 17 subsistence farming villages within the West Nile region of Uganda. Our survey revealed that rodents cause both pre- and post-harvest damage to crops. Evidence of rodent access to stored foods was reported in conjunction with each of the reported storage practices. Approximately half of the respondents reported that at least one family member had been bitten by a rat within the previous three months. Approximately two-thirds of respondents practiced some form of rodent control in their homes. The abundance of rodents was similar within homes that practiced or did not practice rodent control. Together, our results show that current efforts are inadequate for effectively reducing rodent abundance in homes.

Dynamics of Rodent and Rodent-borne Disease during Construction of the Three Gorges Reservoir from 1997 to 2012 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012.</p><p><b>METHODS</b>Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed.</p><p><b>RESULTS</b>The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area.</p><p><b>CONCLUSION</b>This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.</p>