Apodemus Agrarius Research Articles

From mice to men: Three cases of human infection with Cryptosporidium ditrichi

Most human cases of cryptosporidiosis are caused by Cryptosporidium parvum or Cryptosporidium hominis. However, the number of recognised Cryptosporidium species, some of which are capable of infecting humans, is continuously increasing. Here we present three human cases infected with Cryptosporidium ditrichi, a recently described species in Apodemus spp. (striped field mouse, yellow-necked mouse, and wood mouse) from various European countries. All three patients were infected in Sweden, but in different years and in different parts of the country. Two patients, from whom clinical data were available, showed symptoms consistent with cryptosporidiosis. For one patient, epidemiological data indicated a possible close contact with mice. The obtained sequences at the small subunit rRNA, actin, and Cryptosporidium oocyst wall protein loci showed 100% identity to C. ditrichi isolates from Apodemus spp., while no 70 kDa heat shock protein gene sequences from C. ditrichi were available for comparison. This study shows the importance of including molecular typing in Cryptosporidium surveillance programmes, and it adds one more species to the plethora of Cryptosporidium spp. hitherto diagnosed in Swedish patients.

Concentration of Mercury in the Livers of Small Terrestrial Rodents from Rural Areas in Poland.

Small terrestrial mammals could be used as accumulative biomonitors of different environmental contaminants, but the knowledge of the level of Hg in their bodies is scant. The aim of our research was to verify the factors influencing Hg bioaccumulation and to analyze the concentration of total mercury (Hg) in the livers of four species of wild terrestrial rodents from different rural areas of Poland: the yellow-necked mouse (Apodemus flavicollis), striped field mouse (Apodemus agrarius), common vole (Microtus arvalis), and bank vole (Myodes glareolus). The concentration of total Hg was analyzed in liver tissue by atomic absorption spectrometry using a direct mercury analyzer. The concentration of Hg found in the livers of rodents ranged from <1 to 36.4 µg/kg of wet weight, differed between study sites, species, and sexes, and was related to body weight. We addressed feeding habits as potential causes of differences in liver Hg concentration among species.

Comparison of targeted next-generation sequencing for whole-genome sequencing of Hantaan orthohantavirus in Apodemus agrarius lung tissues

Orthohantaviruses, negative-sense single-strand tripartite RNA viruses, are a global public health threat. In humans, orthohantavirus infection causes hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. Whole-genome sequencing of the virus helps in identification and characterization of emerging or re-emerging viruses. Next-generation sequencing (NGS) is a potent method to sequence the viral genome, using molecular enrichment methods, from clinical specimens containing low virus titers. Hence, a comparative study on the target enrichment NGS methods is required for whole-genome sequencing of orthohantavirus in clinical samples. In this study, we used the sequence-independent, single-primer amplification, target capture, and amplicon NGS for whole-genome sequencing of Hantaan orthohantavirus (HTNV) from rodent specimens. We analyzed the coverage of the HTNV genome based on the viral RNA copy number, which is quantified by real-time quantitative PCR. Target capture and amplicon NGS demonstrated a high coverage rate of HTNV in Apodemus agrarius lung tissues containing up to 103–104 copies/μL of HTNV RNA. Furthermore, the amplicon NGS showed a 10-fold (102 copies/μL) higher sensitivity than the target capture NGS. This report provides useful insights into target enrichment NGS for whole-genome sequencing of orthohantaviruses without cultivating the viruses.

1648. Prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in Striped Field Mice in Gwangju, Republic of Korea

BackgroundScrub typhus, anaplasmosis, and leptospirosis are well-known diseases that are considered common, widespread rodent-borne infectious diseasesMethodsThis study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK).ResultsA total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated >99% similarity with A. phagocytophilum and L. interrogans sequencesConclusion A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburbans. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK Disclosures All authors: No reported disclosures.

Genotype and evolution of hantavirus in Tiantai of Zhejiang province, 2011-2018

Objective: By investigating the genotype and evolutionary variation of hantavirus (HV) in Tiantai county, a national surveillance site for hemorrhagic fever with renal syndrome (HFRS) was set in Zhejiang province, from 2011 to 2018, to reveal the molecular epidemiological characteristics of hantavirus (HV) in Tiantai. Methods: Total RNA was extracted from ultrasound treated HV antigen- positive rat lung samples in Tiantai from 2011 to 2018. After cDNA was prepared, nested PCR was used to amplify partial sequence of M fragments by using specific primers of HV. The sequences of HV in Tiantai from 2011 to 2018 were compared with other known HV sequences in order to identify the genotype and analyze the evolution and variation of the virus. Results: In 67 HV antigen-positive lung specimens, 31 were positive in nested PCR amplification with type-specific primers, including 30 Hantaan virus (HTNV) positive samples, 1 Seoul virus (SEOV) positive sample, and all the 31 samples were from Apodemus agrarius. The phylogenetic tree based on partial M segment was divided into monophyletic group, 30 strains were distributed in HTNV group and 1 was in SEOV group. The HTNV strain Tiantai T2018-130 was independently in one branch, sharing 84.8%-87.9% homology with other strains both at home and abroad, including 29 strains in HTNV group in Tiantai. The other 29 HTNV strains in Tiantai showed closer relationship. The SEOV strain T2016-31 from Apodemus agrarius showed closer relationship with previous strains of SEOV, Tiantai ZT71, ZT10 and Z37 strains of Wenzhou, Zhejiang province. Conclusions: HTNV, the main genotype of HV in Tiantai of Zhejiang province, showed obvious geographic clustering, but the strain T2018-130 was distinct from the others in Tiantai. Meanwhile, by sequence analysis, we confirmed that The SEOV strain T2016-31 existed in in Apodemus agrarius, indicating there was a phenomenon of "spillover" between virus and host in SEOV evolution.

Induction of abnormal sperm heads in small mammals under chronic ionizing radiation

The results of this study show a mutagenic effect of low-dose ionizing radiation in male germ cells. The damage of male germ cells was assessed by the frequency of abnormal sperm heads in tundra voles (Microtus oeconomus Pall.), bank voles (Myodes glareolus Schreb.), and field mice (Apodemus agrarius Pall.) from the 30 km exclusion zone around the Chernobyl nuclear power station and for laboratory animals (mice and rats) under chronic γ-irradiation. The abnormal sperm head detection method used appeared to be sensitive to conditions of low-dose irradiation and can consequently be recommended as a bioindicator to monitor environmental radiation pollution.

The prevalence of pathogenic forms of Leptospira in natural populations of small wild mammals in Serbia.

The greatest epidemiological significance of leptospirosis in Europe comes from the fact that it is the most widespread zoonosis in the world. However, epizootiological data, especially information on maintenance hosts such as small wild mammals, are largely missing. To fill this gap in data in Serbia, we used RT-PCR for the detection of pathogenic Leptospira species and analysed 107 animals belonging to six species of small wild mammals (Apodemus agrarius, Apodemus flavicollis, Microtus arvalis, Myodes glareolus, Microtus subterraneus and Sorex araneus) collected from two localities. The animals from the first locality that was situated in a tourist area, were collected for four consecutive years (2014-2017). We found persistent incidence of infection from year to year ranging from 6.67% to 78.57%. The average frequency of infected animals was 33.3% with the highest frequency in 2014, the year characterised by a very high number of flooding days. All animals proved to be infected with pathogenic Leptospira species that were collected from the second locality situated in an agricultural area in a single year, 2014. The findings show a variable but constant presence of pathogenic Leptospira species in populations of small wild mammals in the studied areas, which indicates the need for constant monitoring.

Prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum and Leptospira interrogans in striped field mice in Gwangju, Republic of Korea.

This study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK). A total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated > 99% similarity with A. phagocytophilum and L. interrogans sequences. A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburban areas. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK.

Bartonella Species Detected in Rodents from Eastern China.

Bartonella are vector borne gram-negative facultative intracellular bacteria. Bartonella species are associated with rodents and their flea parasites worldwide. The genetic variation and distribution of Bartonella species in rodents are not clear in China. We investigated the presence and genetic diversity of Bartonella species in rodents from eastern China. We captured rodents from 2015 to 2016 in Jiaonan County, Shandong Province, and detected Bartonella species in the spleen of rodents by PCR amplification of the citrate synthase (gltA) gene and RNA polymerase beta subunit (rpoB) gene. We found that 8.38% (16/191) of the rodents were Bartonella positive by PCR for both gltA and rpoB genes; that Bartonella sequences from the rodents were phylogenetically divided into five clades, which were closely related to B. tribocorum, B. rattimassiliensis, B. grahamii, B. fuyuanensis, and B. queenslandensis, respectively; and that each Bartonella species is rodent species-specific with B. rattimassiliensis and B. tribocorum for Rattus norvegicus, B. grahamii for Tscherskia triton, B. fuyuanensis for Apodemus agrarius, and B. queenslandensis for Niviventer confucianus. This study indicated that Bartonella organisms have a broad distribution and a variety of genotypes in rodents in eastern China and the threats to public health by these Bartonella species should be monitored in China.

Serologic survey of the Crimean-Congo haemorrhagic fever virus infection among wild rodents in Hungary

Crimean-Congo haemorrhagic fever virus (CCHFV) is a tick-borne pathogen, which causes an increasing number of severe infections in many parts of Africa, Asia and in Europe. The virus is primarily transmitted by ticks, however, the spectrum of natural hosts regarding CCHFV includes a wide variety of domestic and wild animals. Although the presence of CCHFV was hypothesized in Hungary, data in support of CCHFV prevalence has thus far, proven insufficient. In the present study, rodents belonging to four species, the yellow-necked mouse (Apodemus flavicollis), the striped field mouse (A. agrarius), the wood mouse (A. sylvaticus) and the bank vole (Myodes glareolus), were all systematically trapped in the Mecsek Mountain region (Southwest Hungary), from 2011 through 2013. Rodent sera were collected and screened for CCHFV antibodies with dot-blot pre-screening and immunofluorescence assay. Among the 2085 tested rodents, 20 (0.96%) were positive for IgG antibody against CCHFV. Seroprevalence was the highest (1.25%) in A. flavicollis serum samples. Distinctly, we now provide the first data regarding CCHFV occurrence and seroprevalence among wild rodents in Hungary. This observation represents a need for large-scale surveillance to effectively assess the enzootic background and the potential public health risk of CCHFV in Hungary.

Історія вивчення мишоподібних гризунів Тернопільщини

The analysis of historical researches about muroid rodents (Muridaе, Arvicolidaе) at the territory of Ternopil region was conducted. The investigation of muroid rodents includes three stages: general faunistic (1740–1940), populational (40–80 XX cent.) and modern researches (from the end of XX cent.) Scientific papers for the last 250 years and data from Chronicles ofnature of NEPA (Natural Enviroment Protected Areas) of Ternopil region were examined. The first stage is distinguished by accumulating of sporadic data about species richest and economic value of muroid rodents. The second period is characterized by more detail studies about systematics of muroid rodents, their distribution and ecology, these aspects were only superficially investigated before. Research papers about the investigation of species dynamic and biotopical distribution of muroid rodents in Ternopil region characterize the third stage of muroid rodent’s investigation. It was shown, that systematic studies of muroid rodents in Ternopil region, wich highly increased in last few decades, were mainly conducted by scientists from objects of Nature Enviroment Protected Areas. As a result of the analysis of many years of research by the scientists of the Ternopil region, a list of 14 species of muroid rodents was compiled: the Muridae family: Micromys minutus Pall., Apodemus agrarius Pall., Rattus norvegicus Berk., Mus musculus L., Sylvaemus tauricus Melchior., S. sylvaticus L., S uralensis Pall.; Family Arvicolidae: Myodes glareolus Schr., Arvicola amphibious L., Terricola subterraneus Selys-Longchamps, Microtus oeconomus Pall., M. agrestis L., M. arvalis Pall.; Sminthidae family: Sicista betulina Pall. It is important to carry out new studies to specify the species composition, populations of populations, changes in the biotic diversity of muroid rodents as a result of anthropogenic transformation of the environment, as well as the application of modern methods of ecological and faunal studies in the Ternopil region.

Genetic characteristics of pathogenic Leptospira in wild small animals and livestock in Jiangxi Province, China, 2002–2015

BackgroundLeptospirosis is one of the most important neglected tropical bacterial diseases worldwide. However, there is limited information on the genetic diversity and host selectivity of pathogenic Leptospira in wild small mammal populations.Methodology/Principal findingsJiangxi Province, located in southern China, is a region highly endemic for leptospirosis. In this study, among a total of 3,531 trapped rodents dominated by Apodemus agrarius (59.7%), 330 Leptospira strains were successfully isolated from six different sites in Jiangxi between 2002 and 2015. Adding 71 local strains from humans, various kinds of livestock and wild animals in Jiangxi, a total of 401 epidemic strains were characterized using 16S rRNA gene senquencing, multilocus sequence typing (MLST) and the microscopic agglutination test (MAT). Among them, the most prevalent serogroup was Icterohaemorrhagiae (61.10%), followed by Javanica (19.20%) and Australis (9.73%); the remaining five serogroups, Canicola, Autumnalis, Grippotyphosa, Hebdomadis and Pomona, accounted for 9.97%. Species identification revealed that 325 were L. interrogans and 76 were L. borgpetersenii. Moreover, L. interrogans was the only pathogenic species in Fuliang and Shanggao and was predominant in Shangrao (95.0%); L. borgpetersenii was the most common in the remaining three sites. Twenty-one sequence types (STs) were identified. Similarly, ST1 and serogroup Icterohaemorrhagiae were most prevalent in Shangrao (86.0% and 86.4%) and Fuliang (90.4% and 90.4%), ST143 and serogroup Javanica in Shangyou (88.5% and 90.4%) and Longnan (73.1% and 73.1%), and ST105 and serogroup Australis in Shanggao (46.3% and 56.1%). Serogroup Icterohaemorhagiae primarily linked to A. agrarius (86.9%), serogroup Canicola to dogs (83.3%). There were significant differences in the distribution of leptospiral species/serogroups/STs prevalence across host species/collected locations among the 394 animal-associated strains (Fisher’s exact test, p<0.001).Conclusions/SignificanceOur study demonstrated high genetic diversity of pathogenic Leptospira strains from wild small animals in Jiangxi from 2002 to 2015. A. agrarius was the most abundantly trapped animal reservoir, and serogroup Icterohaemorrhagiae and ST1 were the most dominant in Jiangxi. Significant geographic variation and host diversity in the distribution of dominant species, STs and serogroups were observed. Moreover, rat-to-human transmission might play a crucial role in the circulation of Leptospirosis in Jiangxi. Details of the serological and molecular characteristics circulating in this region will be essential in implementing prevention and intervention measures to reduce the risk of disease transmission in China. However, phylogenetic analysis of more Leptospira isolates should explore the impact of ecological change on leptospirosis transmission dynamics and investigate how such new knowledge might better impact environmental monitoring for disease control and prevention at a public health level.

Light pollution affects space use and interaction of two small mammal species irrespective of personality

BackgroundArtificial light at night (ALAN) is one form of human-induced rapid environmental changes (HIREC) and is strongly interfering with natural dark–light cycles. Some personality types within a species might be better suited to cope with environmental change and therefore might be selected upon under ongoing urbanization.ResultsWe used LED street lamps in a large outdoor enclosure to experimentally investigate the effects of ALAN on activity patterns, movement and interaction of individuals of two species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius). We analyzed effects combined with individual boldness score. Both species reduced their activity budget during daylight hours. While under natural light conditions home ranges were larger during daylight than during nighttime, this difference vanished under ALAN. Conspecifics showed reduced home range overlap, proximity and activity synchrony when subjected to nighttime illumination. Changes in movement patterns in reaction to ALAN were not associated with differences in boldness score of individuals.ConclusionsOur results suggest that light pollution can lead to changes in movement patterns and individual interactions in small mammals. This could lead to fitness consequences on the population level.

Mow the Grass at the Mouse's Peril: Diversity of Small Mammals in Commercial Fruit Farms.

Simple SummaryFor the first time in the Baltic countries, small mammal communities were evaluated in commercial orchards and berry plantations to test for the influence of crop type and intensity of agricultural practices. Out of ten species registered in the fruit farms, the most dominant were common vole and striped field mouse, confirming the spread of the latter species in the country. Small mammal diversity and abundance were not dependent on crop type but decreased in line with the intensity of agricultural practices, not being found in the most intensively cultivated farms. Unexpectedly, small mammal diversity in apple orchards exceeded the diversities found in most types of forests and was significantly higher than in crop fields.Small mammals are not only pests but also an important part of agricultural ecosystems. The common vole is a reference species for risk assessment of plant protection products in the European Union, but no data about the suitability of the species in the Baltic countries are present so far. Using the snap-trap line method, we evaluated species composition, abundance, and diversity of small mammal communities in commercial orchards and berry plantations in Lithuania, testing the predictions that (i) compared with other habitats, small mammal diversity in fruit farms is low, and (ii) the common vole is the dominant species. The diversity of small mammals was compared with control habitats and the results of investigations in other habitats. Out of ten small mammal species registered, the most dominant were common vole and striped field mouse. Small mammal diversity and abundance increased in autumn and decreased in line with the intensity of agricultural practices but were not dependent on crop type. In the most intensively cultivated fruit farms, small mammals were not found. The diversity of small mammal communities in fruit farms was significantly higher than in crop fields and exceeded the diversities found in most types of forests except those in rapid succession.

The characteristics of current natural foci of hemorrhagic fever with renal syndrome in Shandong Province, China, 2012-2015.

BackgroundHemorrhagic fever with renal syndrome (HFRS), an infectious disease caused by hantaviruses, is endemic in China and remains a serious public health problem. Historically, Shandong Province has had the largest HFRS burden in China. However, we do not have a comprehensive and clear understanding of the current epidemic foci of HFRS in Shandong Province.Methodology/principal findingsThe incidence and mortality rates were calculated, and a phylogenetic analysis was performed after laboratory testing of the virus in rodents. Spatial epidemiology analysis was applied to investigate the epidemic foci, including their sources. A total of 6,206 HFRS cases and 59 related deaths were reported in Shandong Province. The virus carriage rates of the rodents Rattus norvegicus, Apodemus agrarius and Mus musculus were 10.24%, 6.31% and 0.27%, respectively. The phylogenetic analysis indicated that two novel viruses obtained from R. norvegicus in Anqiu City and Qingzhou City were dissimilar to the other strains, but closely related to strains previously isolated in northeastern China. Three epidemic foci were defined, two of which were derived from the Jining and Linyi epidemic foci, respectively, while the other was the residue of the Jining epidemic focus.Conclusions/significanceThe southeastern and central Shandong Province are current key HFRS epidemic foci dominated by A. agrarius and R. norvegicus, respectively. Our study could help local departments to strengthen prevention and control measures in key areas to reduce the hazards of HFRS.

MODERN DISTRIBUTION OF NEMATODES P. SYPHACIA (NEMATODA, OXYURIDAE) IN POPULATIONS OF MOUSE-LIKE RODENTS IN THE VORONEZH RESERVE

The mouse-like rodents, inhabiting natural and anthropogenic biocenoses, are sources and distributors of various helminth infections, including syphaciosis. Currently, more than ten species of nematodes of the genus Syphacia are registered in mouse-like rodents. Syphacia exhibit narrow, guest specificity, parasitizing, as a rule, in one or three species of mouse-like rodents. The main sources of infection of rodents by these nematodes are vegetable feed, soil, forest litter. We have presented long-term (2000-2018) results of helminthological studies of mouse-like rodents, conducted in the Voronezh Reserve. At present, in the territory of mouse-like rodents, 5 species of Syphacia are registered: Syphacia agraria, S. obvelata, S. nigeriana, S. petrusewiczi, S. stroma. Taxonomic diagnosis of nematodes was carried out taking into account the guest specificity, localization in the host intestine, morphometric data, and also taking into account the structural features of the nematode head end. Nematodes of syphacia are noted in 7 host species: Mus musculus, Apodemus agrarius, Sylvemus flavicollis, Sylvemus uralensis, Myodes glareolus, Microtus agrestis, Microtus arvalis. The extensiveness of invasion ranges from 6 to 51% (on average, 30%).The study area is located in a densely populated region of the Central Black Earth region of Russia. Here, at the junction of natural and anthropogenic ecosystems, mouse-like rodents are a significant source of parasitic pollution. With a high number of rodents and high extensiveness of invasion by nematodes p. Syphacia, there is a significant accumulation of invasive beginning in the external environment, which increases the epidemiological and epizootological risks of this helminthiasis.

Leptospirosis in Zakarpattia Oblast (2005-2015).

Background: Leptospirosis occurs sporadically and as outbreaks throughout Ukraine and is a nationally reportable disease. Zakarpattia oblast, in the southwestern region of the country, is endemic for disease. This study examines changes in epidemic patterns from 2005 to 2015.Materials and Methods: Suspected cases from health care services were identified based on clinical presentation and serological samples were collected. Patient sera were tested by microscopic agglutination test (MAT) against serovars of Leptospira spp. belonging to 13 serogroups. Small mammals were also collected, sampled, and tested near locations of suspected exposures. Changes in leptospirosis incidence in Zakarpattia oblast were characterized over an 11-year period.Results: A total of 420/2079 possible human cases were identified as having leptospirosis and 401/420 were confirmed by MAT. There was no annual trend in prevalence. Incidence increased from 2005 to 2009, peaked in 2010 (6.24 cases/100,000), and by 2015, there were only sporadic cases (0.88/100,000). The predominant serogroups were Icterohaemorrhagiae, Hebdomadis, and Grippotyphosa of Leptospira spp. The dominant serogroups shifted during the study from predominantly Icterohaemorrhagiae to Grippotyphosa in later years. A total of 2820 small mammals were assayed for Leptospira spp. Apodemus agrarius, Rattus norvegicus, and Mus musculus were the most common species sampled (76.1% of all captures). Among small mammals, antibodies were found mostly for Icterohaemorrhagiae, Pomona, and Grippotyphosa serogroups, and were detected in 276 samples (9.79% ± 0.56%). The dominant serogroups of Leptospira spp. isolated from mammals and patients changed cyclically, but the common human serogroups tended to differ from that seen in the concurrent mammal populations.Conclusions: Patients with leptospirosis in this endemic region decreased more than fivefold during the past decade. Leptospira infections in small mammals remained common across multiple species ranging from 5% to 14%.

Resource partitioning confirmed by isotopic signatures allows small mammals to share seasonally flooded meadows.

Meadows in river deltas are characterized by a high diversity and abundance of small mammals. However, neither their spatial arrangement nor differences in their use of microhabitat can necessarily explain the dense co‐occurrence of sympatric species. We investigated how several small mammal species share a seasonally flooded meadow of limited size, testing predictions (P1) that herbivore, granivore, insectivore, and omnivore species are separated in time (dominant in different years), (P2) that sympatric species undergo isotopic partitioning, and (P3) that there are intraspecific differences in diet. Stable carbon and nitrogen isotope signatures in the hair of seven synantropic shrew, vole, and mice species were used as a proxy for their diet. We found that the three most abundant species in eight of the nine years were from different diet groups. However, based on the number of species in the functional groups, the state of small mammal community was considered unfavored in five out of the nine investigation years. In years with the greatest dominance of Apodemus agrarius, the small mammal community was characterized by decreased diversity and Micromys minutus was either in low abundance or absent. In 2014 and 2016, years of low abundance or absence of M. oeconomus, M. agrestis, and M. glareolus were both recorded in high numbers. Differences in the isotopic signatures of the three most abundant small mammal species in the community were clearly expressed and core areas in the isotopic space were separated, showing their dependence on different dietary resources. Intraspecific dietary separation between young and adult animals was observed only in M. oeconomus. Thus, the high species diversity of small mammals and the formation of their community in this investigated flooded meadow are maintained by isotopic partitioning (segregation in dietary space) and by changes in their number over time (shifting dominance).

Long-term trends of tick-borne pathogens in regard to small mammal and tick populations from Saxony, Germany

BackgroundRodents are important in the life-cycle of ticks as hosts for immature developmental stages. Both rodents and ticks are of public health interest as they are reservoirs and vectors for different tick-borne pathogens (TBP). The aim of this study was to reassess the prevalence of TBP in previously studied areas of the city of Leipzig (Saxony, Germany).MethodsIn the years 2015–2017 rodents and ticks were collected in parks and forest areas in Saxony. DNA was extracted from the rodents, attached and questing ticks. Samples were screened for the presence of Anaplasma phagocytophilum, Babesia spp., Borrelia burgdorferi (s.l.), “Candidatus Neoehrlichia mikurensis” (CNM), Bartonella spp., Hepatozoon spp. and Rickettsia spp. using PCR methods. Rodent, attached nymph and questing tick (nymph and adult) samples were tested individually, while attached larvae were further processed in pools.ResultsA total of 165 rodents (Apodemus agrarius, n = 1; A. flavicollis, n = 59; Arvicola terrestris, n = 1; Myodes glareolus, n = 104), 1256 attached ticks (Ixodes ricinus, n = 1164; Dermacentor reticulatus, n = 92) and 577 questing ticks (I. ricinus, n = 547; D. reticulatus, n = 30) were collected. The prevalence levels in rodents were 78.2% for Bartonella spp., 58.2% for CNM, 49.1% for B. burgdorferi (s.l.) 29.1% for Rickettsia spp. and 24.2% for Hepatozoon spp. The minimal infection rates (MIR) in attached larvae ticks were 39.8% for Rickettsia spp., 32.7% for Bartonella spp., 7.1% for CNM and 8.8% for B. burgdorferi (s.l.) and the prevalence rates in attached nymphs were 33.7% for Bartonella spp., 52.9% for Rickettsia spp., 13.5% for CNM and 11.3% for B. burgdorferi (s.l.) Both rodents and attached ticks were negative for Babesia spp. The prevalence in questing ticks was 18.2% for Rickettsia spp., 7.3% for CNM, 6.4% for B. burgdorferi (s.l.) and 1.4% for Babesia spp. All tested samples were Anaplasma-negative. Sequencing revealed the occurrence of 14 identified species.ConclusionsThis research is the first evaluation of the prevalence for Hepatozoon spp. in rodents from Germany. In comparison to earlier studies, detected pathogens species remained the same; however, the prevalence for particular pathogens differed.

The ecological dynamics of hantavirus diseases: From environmental variability to disease prevention largely based on data from China.

Hantaviruses can cause hantavirus pulmonary syndrome (HPS) in the Americas and hemorrhagic fever with renal syndrome (HFRS) in Eurasia. In recent decades, repeated outbreaks of hantavirus disease have led to public concern and have created a global public health burden. Hantavirus spillover from natural hosts into human populations could be considered an ecological process, in which environmental forces, behavioral determinants of exposure, and dynamics at the human–animal interface affect human susceptibility and the epidemiology of the disease. In this review, we summarize the progress made in understanding hantavirus epidemiology and rodent reservoir population biology. We mainly focus on three species of rodent hosts with longitudinal studies of sufficient scale: the striped field mouse (Apodemus agrarius, the main reservoir host for Hantaan virus [HTNV], which causes HFRS) in Asia, the deer mouse (Peromyscus maniculatus, the main reservoir host for Sin Nombre virus [SNV], which causes HPS) in North America, and the bank vole (Myodes glareolus, the main reservoir host for Puumala virus [PUUV], which causes HFRS) in Europe. Moreover, we discuss the influence of ecological factors on human hantavirus disease outbreaks and provide an overview of research perspectives.