Synanthropic Rodents Research Articles

Detection, genetic diversity, and factors associated with infection by hemotropic mycoplasmas in rodent and marsupial populations in regions of the states of Rio de Janeiro and Parana, Brazil

Hemotropic mycoplasmas, also known as hemoplasmas, are found in several animal species around the world. New species and genotypes of mycoplasmas have been described recently but much more remains to be discovered, especially in wildlife. The objective of this study was to investigate the presence of hemotropic mycoplasmas and diversity of the 16S rDNA sequence fragment in populations of small nonflying mammals in regions with different phytophysiognomies in the states of Rio de Janeiro and Parana, Brazil, as well as to evaluate environmental and animal factors influencing infection rates. Of the 257 animals sampled, 33.8% (n=87) were considered positive by conventional PCR. Of the 230 samples from wild rodents (Cricetidae), 36.5% (n=84) amplified hemotropic mycoplasma DNA, followed by synanthropic rodents (Muridae) (12.5%, n= 2/16), and marsupials (Didelphidae) (9.0%, n= 1/11). The regions with the highest frequency of positivity were Ponta Grossa (46.5%, n=27/58) and Cruz Machado (46.1%, n= 24/52), followed by Nova Friburgo (30.8%, n= 33/107), and Lidianopolis (12.5%, n=5/40). Oligoryzomys had the highest rate of infection (78.5%), statistically different from Oxymycterus spp. (40.0%), Akodon spp. (27.0%) and Sooretamys (8.3%). Males had a higher prevalence of Mycoplasma spp., being 3.97 times more likely to be positive for hemoplasma than females. Phylogenetic analysis grouped the sequences from this study into two clades, A and E, together with other hemoplasma sequences previously detected in small wild and synanthropic rodents from Brazil, Hungary, and Japan. Haplotype network reveals exclusive haplotypes for wild and synanthropic rodents. Our study reveals considerable genetic diversity suggesting the circulation of at least two species among sequences from this study and highlights the importance of considering environmental and biological factors in the epidemiology of these infections in wild mammals.

Potentially zoonotic pathogens and parasites in opportunistically sourced urban brown rats (Rattus norvegicus) in and around Helsinki, Finland, 2018 to 2023.

BackgroundBrown rats (Rattus norvegicus) are synanthropic rodents with worldwide distribution, which are known to harbour many zoonotic pathogens and parasites. No systematic zoonotic surveys targeting multiple pathogens and parasites have previously been conducted in urban rats in Finland.AimIn Helsinki, Finland, we explored the presence and prevalence in brown rats of certain pathogens and parasites (including helminths, viruses and bacteria) across potentially zoonotic taxa.MethodsWe opportunistically received rat carcasses from pest management operators and citizens from 2018 to 2023. We searched for heart- or lungworms, performed rat diaphragm digestion to check for Trichinella and morphologically identified intestinal helminths. We assessed virus exposure by immunofluorescence assay or PCR, and detected bacteria by PCR (Leptospira) or culture (Campylobacter).ResultsAmong the rats investigated for helminths, no heart- or lungworms or Trichinella species were detected and the most common finding was the cestode Hymenolepis nana (in 9.7% of individuals sampled, 28/288). For some of the surveyed virus taxa, several rats were seropositive (orthopoxviruses, 5.2%, 11/211; arenaviruses, 2.8%, 6/211; hantaviruses 5.2%, 11/211) or tested positive by PCR (rat hepatitis E virus, 1.8%, 4/216). Campylobacter jejuni (6.6%, 17/259) and Leptospira interrogans (1.2%, 2/163) bacteria were also present in the rat population examined.ConclusionsPrevalences of potentially zoonotic pathogens and parasites in brown rats in Helsinki appeared low. This may explain low or non-existent diagnosis levels of rat-borne pathogen and parasite infections reported in people there. Nevertheless, further assessment of under-diagnosis, which cannot be excluded, would enhance understanding the risks of zoonoses.

No evidence of mutations associated with anticoagulant resistance in gene Vkorc1 in brown and black rats from Barcelona

Synanthropic rodents such as the brown rat (Rattus norvegicus) and black rat (Rattus rattus) are a source of disturbance in urban areas and the focus of control programs. Control measures often rely on anticoagulant rodenticides, but their broad use is compromised by the emergence of resistance. Here we studied the prevalence of anticoagulant resistance genotypes in the Vkorc1 gene in rats in the metropolitan area of Barcelona. In this area, part of the management practices to control brown rats include anticoagulant rodenticide use, but rodenticides with different active ingredients are used in rotation. Brown rats were sampled from the sewage system during two periods: from December 2016 to November 2017 when difenacoum and brodifacoum were used, and from August 2021 to July 2022 when bromadiolone was used. Because black rats have just recently been detected in Barcelona, we only studied them during the latter sampling period, with samples obtained from a control action carried out in a green urban area. Exon 3 of the Vkorc1 gene was characterized in both species, while exon 1 was additionally analyzed in black rats. Synonymous mutations, not resulting in amino-acid changes, were found in both exons, indicating no evidence of anticoagulant resistance in the rats of Barcelona. This finding indicates that the current rodent management plan in Barcelona, which involves anticoagulant rotation for brown rats and the use of life capture traps in specific situations for black rats, has helped to prevent the emergence of resistance to anticoagulant rodenticides in rats in Barcelona. Future actions should aim to diversify the control measures included in the rodent management plan.

Susceptibility of Synanthropic Rodents (Mus musculus, Rattus norvegicus and Rattus rattus) to H5N1 Subtype High Pathogenicity Avian Influenza Viruses.

Synanthropic wild rodents associated with agricultural operations may represent a risk path for transmission of high pathogenicity avian influenza viruses (HPAIVs) from wild birds to poultry birds. However, their susceptibility to HPAIVs remains unclear. In the present study, house mice (Mus musculus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) were experimentally exposed to H5N1 subtype HPAIVs to evaluate their vulnerability to infection. After intranasal inoculation with HA clade 2.2 and 2.3.2.1 H5N1 subtype HPAIVs, wild rodents did not show any clinical signs and survived for 10- and 12-day observation periods. Viruses were isolated from oral swabs for several days after inoculation, while little or no virus was detected in their feces or rectal swabs. In euthanized animals at 3 days post-inoculation, HPAIVs were primarily detected in respiratory tract tissues such as the nasal turbinates, trachea, and lungs. Serum HI antibodies were detected in HA clade 2.2 HPAIV-inoculated rodents. These results strongly suggest that synanthropic wild rodents are susceptible to infection of avian-origin H5N1 subtype HPAIVs and contribute to the virus ecosystem as replication-competent hosts. Detection of infectious viruses in oral swabs indicates that wild rodents exposed to HPAIVs could contaminate food, water, and the environment in poultry houses and play roles in the introduction and spread of HPAIVs in farms.

Reaching new lands: Updating the distribution of Angiostrongylus cantonensis in South America with the first record in Argentina.

Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in temperate areas and considered the leading cause of eosinophilic meningitis in humans. Synanthropic rodents such as Rattus norvegicus and Rattus rattus are the most frequent definitive hosts of this parasite. The presence of this parasite was detected in the pulmonary arteries of three specimens of R. norvegicus in the city of Buenos Aires representing the species' southernmost known record in natural hosts. Species confirmation was achieved through partial sequences of 18S and COI genes. By comparing the COI gene sequences with those available in GenBank through the construction of a haplotype network, we obtained that the analysed specimen presents high similarity with those reported in Japan and Southeast Asia. All infected rats were captured in an area surrounding a port with significant import and export activity, suggesting that A. cantonensis may have been introduced through commercial ships. Specifically, the parasite was detected in a neighbourhood with vulnerable socio-economic conditions and in a nature reserve, which exhibit biotic and abiotic characteristics conducive to sustaining high-density rat populations, scattered waste, areas of spontaneous vegetation, debris accumulation and flooded areas or lagoons offering suitable habitats for intermediate hosts such as snails. Thus, the close proximity of the port to these sites creates a favourable ecological context for the establishment of A. cantonensis. This study shows the need to conduct research to detect A. cantonensis in non-endemic areas but with the characteristics that promote its arrival and development of its life cycle in order to implement control measures to prevent expansion of this parasite and its transmission to humans and other animals.

Влияние содержания действующего вещества в родентицидном средстве на эффективность дератизационных обработок

House mice, gray rats and other mouse-like rodents pose a threat to human health and cause significant damage to its activities. Despite significant advances in deratization practice, rodent control currently remains a significant problem, since these biological species have a unique genetic ability to rapidly recover and increase their numbers. The rodent control program should be based on data on the ecology, behavior and preferences of rodents, their sensitivity to active substances, the specific situation of a certain object and territory. Each species has its own characteristics. It is necessary to take into account species preferences when developing the composition and form of application of rodenticidal baits. It is important to ensure the achievement of target values in the consumption of the product by rodents, its effectiveness, safety in relation to non-target species and safety during its placement and use. It is necessary to take into account what concentration of the active substance (DV) for rodents will be fatal, how much rodenticidal bait will be required for their death and for how long this amount of bait will be eaten by them. The effectiveness of the conducted deratization treatments is directly influenced by the content of the active substance in the applied rodenticidal agent. The analysis of the effectiveness of rodenticidal baits with different contents of the active substance bromadiolone in relation to house mice and gray rats showed that with a decrease in the concentration of DV in the bait, the period from the beginning of its eating to the onset of irreversible changes in the body of rodents leading to their death occurs. The placement of baits during deratization treatments should take place taking into account the species characteristics of rodents. In terms of body weight, the amount of absorbed DV by the body of a house mouse in comparison with a gray rat when eating rodenticidal bait is significantly higher, which is observed in the average daily and total intake. But in quantitative terms, gray rats consume significantly more bait. For the death of a house mouse, an average of about 8 g of bait is required with a bromadiolone content of 0.005?%, and the minimum amount was 3.2 g. For a gray rat, the average amount of bait was 32.4 g, and the minimum ~ 10 g. Taking into account these data, the amount of bait placed at the facility will vary from the number of rodents and the feedability of baits. A lower content of DV in baits contributes to an increase in their consumption during deratization treatments. With a high number of rodents, the amount of bait placed must be multiplied. Keywords: synanthropic rodents, gray rat, house mouse, deratization measures, anticoagulants, bromadiolone.

SARS-CoV-2 infection in synanthropic rats from Guayaquil city (Ecuador) during COVID-19 pandemic: A proxy to prevent wild reservoirs in the tropics

Human-to-animal reverse transmission of SARS-CoV-2 is a risk for new reservoirs' emergence and new variants' evolution. SARS-CoV-2 infection of synanthropic rodents in urban settings has been reported during COVID-19 in New York and Mexico cities. In this study, we addressed the potential transmission of SARS-CoV-2 to synanthropic rats in the city of Guayaquil (Ecuador) during the COVID-19 pandemic. A total number of 234 rats were collected and analyzed for SARS-CoV-2 detection by RT-qPCR. A positivity rate of 6 % (14 rats) was found, and SARS-CoV-2 infection was confirmed by Sanger sequencing of the viral genome. Our results confirm the potential risk of synanthropic rats as reservoirs for SARS-CoV-2 infection. This is worrisome for low and middle income countries like Ecuador, where pest and waste control in urban settings is challenging. Moreover, the risk of spillover to wild fauna is a concern in Guayaquil, where synanthropic fauna includes raccoons or coatis and forest patches with a wild population of felids or primates existing within the city limits. In this context, SARS-CoV-2 sentinel surveillance of synanthropic rodents could serve as a proxy for a One Health approach to prevent the emergence of new wild reservoirs.

Synanthropic rodents and urbanization processes: understanding the spatiotemporal pattern of rodent activity during urbanization works in a low-income neighborhood

Synanthropic rodents and urbanization processes: understanding the spatiotemporal pattern of rodent activity during urbanization works in a low-income neighborhood

Widespread human exposure to ledanteviruses in Uganda: A population study.

Le Dantec virus (LDV), assigned to the species Ledantevirus ledantec, genus Ledantevirus, family Rhabdoviridae has been associated with human disease but has gone undetected since the 1970s. We describe the detection of LDV in a human case of undifferentiated fever in Uganda by metagenomic sequencing and demonstrate a serological response using ELISA and pseudotype neutralisation. By screening 997 individuals sampled in 2016, we show frequent exposure to ledanteviruses with 76% of individuals seropositive in Western Uganda, but lower seroprevalence in other areas. Serological cross-reactivity as measured by pseudotype-based neutralisation was confined to ledanteviruses, indicating population seropositivity may represent either exposure to LDV or related ledanteviruses. We also describe the discovery of a closely related ledantevirus in blood from the synanthropic rodent Mastomys erythroleucus. Ledantevirus infection is common in Uganda but is geographically heterogenous. Further surveys of patients presenting with acute fever are required to determine the contribution of these emerging viruses to febrile illness in Uganda.

Synanthropic rodents and shrews are reservoirs of zoonotic bacterial pathogens and act as sentinels for antimicrobial resistance spillover in the environment: A study from Puducherry, India

Antimicrobial resistance (AMR) is a global public health concern and needs to be monitored for control. In this study, synanthropic rodents trapped from humans and animal habitats in Puducherry, India, were screened as sentinels for bacterial pathogens of public health importance and antimicrobial resistance spillover. From the trapped rodents and shrews (n = 100) pathogens viz., Staphylococcus sp, E. coli and Salmonella sp were isolated from oropharyngeal and rectal swabs on Mannitol salt, Mac Conkey and Xylose lysine deoxycholate media respectively. The AMR genes in these isolates were screened by PCR. A total of 76, S. aureus and 19, Staphylococcus non aureus were isolated. E. coli was isolated in 89 samples and among the Salmonella sp (n = 59), 16, were S. enteritidis and 29, were S. typhimurium. A total of 46 MRSA isolates with mec A (n = 40) and mec C (n = 6) were detected. Also, 36.84% and 5.3% Staphylococcus non aureus isolates were tested to have mec A and mec C genes. AMR genes encoding ESBL [blaTEM in 21, blaSHV in 45 and blaCTX-M in 11] was tested positive in 77 E. coli isolates. Among, Salmonella isolates 44/45 were screened to have AMR genes [tet in 13, sul3 & sul4 in 20 and qnrA in 11]. Antibiotic sensitivity test confirmed the antimicrobial resistance. Isolation of pathogens of public health importance and demonstration of genetic elements conferring antimicrobial resistance in the synanthropic rodents confirms that they act as reservoirs and appropriate sentinels to monitor AMR spillover in the environment.

Leptospirosis in a mixed breed female dog (Canis familiaris)

The present study aimed to report a clinical case of leptospirosis diagnosed in a mixed breed dog where treatment was chosen without hospitalization. Leptospirosis is an infectious and contagious zoonotic disease caused by the spirochete of the genus Leptospira spp. All pathogenic lineages belong to a single species, Leptospira interrogans. This microorganism can affect both humans and animals, be they domestic, wild or production. Dogs and cats are susceptible, but felines have greater resistance to leptospirosis. Synanthropic rodents in large urban centers or rural areas constitute a major problem, as they end up transmitting it to domestic and stray animals. Animals become infected and end up eliminating spirochetes into the environment through contaminated urine, since leptospirosis has a predilection for the renal tubules. Transmission can be direct through contaminated urine, venereal secretions, placental transfer, bite wounds or ingestion of contaminated tissues. Leptospira can enter the body through intact oral, nasal or ocular mucous membranes, or through skin that is damaged or macerated by moisture. Indirect transmission occurs through contact with contaminated water, soil and food sources. In Brazil, where many locations lack a garbage collection system and sewage disposal is precarious, the tropical climate favors rain during summer, all increasing the role of rodents as vectors of this zoonosis due to flooding. The canine mentioned in this study did not have their vaccination protocol up to date, lived in a place with the presence of rodents, and was diagnosed positive for L. interrogans serovars Bratislava, Pomona and Copenhageni by the microscopic agglutination test (MAT), considered the gold standard. The changes in the blood count were limited to normocytic normochromic anemia and hyperproteinemia. No noteworthy changes were observed in the white blood cell count and, in the biochemical tests, liver and kidney changes consistent with the pathology were evident. The therapeutic protocol chosen was antibiotic therapy and supportive therapy, both carried out at the guardian's home, and the prognosis was favorable. Preventive vaccination measures according to the challenge faced in the environment, rodent control and also public policies regarding basic sanitation are important in preventing in zoonosis.

Sentinels in the shadows: Exploring Toxoplasma gondii and other Sarcocystidae parasites in synanthropic rodents and their public health implications

Synanthropic rodents play a crucial role in maintaining the life cycle of Toxoplasma gondii in anthropized regions and can serve as indicators of environmental oocyst contamination. This investigation aimed to explore the occurrence of T. gondii infection within synanthropic rodent populations using a molecular diagnostic technique targeting the 18S rDNA gene, which is generic for Coccidia, with subsequent specific PCR confirmation. We examined 97 brown rats (Rattus norvegicus), 67 black rats (R. rattus), 47 house mice (Mus musculus), and 1 common shrew (Sorex araneus). PCR tests were conducted on the brain, heart, and tongue tissues. PCR tested positive in at least one of the examined tissues in 26 R. norvegicus (26.8%), 13 R. rattus (19.4%), and 13 M. musculus (27.6%). Sequencing comparisons by BLAST allowed us to identify four different species of cyst-forming Apicomplexa. In particular, T. gondii DNA was detected in 13 (6.1%) rodents, Hammondia hammondi (including H. hammondi-like organisms) in 36 (17%) subjects, Besnoitia sp. (in two cases identified as B. besnoiti) in 8 (3.7%), and Sarcocystis gigantea in two (0.94%). Rodents from peri-urban and urban environments can act as indicators of environmental contamination by oocysts of apicomplexan parasites with cats as definitive hosts, such as T. gondii, H. hammondi, and S. gigantea, the latter of which has never been previously recorded in rodents. Moreover, the presence of B. besnoiti, a parasite with an unidentified definitive host in Europe, sheds light on the potential role of these hosts as infection sentinels.

Leishmania major Infection in Synanthropic Rodents: Evidence for the Urbanization of Zoonotic Cutaneous Leishmaniasis (ZCL) in Southern Iran.

Cutaneous leishmaniasis is of particular importance in southern Iran. This study aimed to investigate the infection of rodents with Leishmania major in an urban area of Fars Province, located in southern Iran. Rodents were trapped and samples from the liver, spleen, and skin were collected. Impression smears were prepared from these tissues and any skin lesions and were examined microscopically. In addition, a portion of the samples were preserved for subsequent DNA extraction. A total of 41 rodents belonging to three species were caught from 10 trapping stations in gardens or houses within the area. The caught rodent species were Rattus rattus (n = 25, 60.97%), Mus musculus (n = 15, 36.58%), and Meriones persicus (n = 1, 2.5%). Leishmania amastigotes were seen in the spleen tissue smear of 6 (2.43%) of the rodents, including 4 of R. rattus and 2 of M. musculus. Skin lesions were observed on the muzzles of two R. rattus and one M. musculus. Samples taken from these lesions tested positive for Leishmania infection. Leishmania DNA was detected in 18 (43.9%) rodents, including 11 R. rattus, 6 M. musculus, and one M. persicus, based on DNA sequencing of the ITS2 gene and PCR of the kDNA. Phylogenetic reconstruction revealed that the parasite infecting the rodents was L. major. The detection of Leishmania infection in these rodents in urban areas raises concerns about the urbanization of cutaneous leishmaniasis caused by L. major. This urbanization poses unique challenges for control and prevention efforts.

ACTUALIZACIÓN SOBRE ASPECTOS EPIDEMIOLÓGICOS DE LA RICKETTSIOSIS EN EL TRÓPICO DE MÉXICO

<p><strong>Background:</strong> Rickettsioses are diseases caused by <em>Rickettsia</em> bacteria, transmitted through tick or mite bites, or through contact with feces from lice or fleas. In Mexico, these diseases are a major public health concern, particularly in the tropical states where they appear to be responsible for most cases and the highest mortality rates. In the epidemiology of rickettsiosis, domiciled dogs and rodents play a significant role in maintaining of biological vectors in the vicinity of dwellings and in domestic and companion animals that people live with. It has been determined that some characteristics of households in localities with some degree of social-economic marginalization increase the risk of occurrence of <em>Rickettsia</em> spp. in the occupants. <strong>Objective:</strong> To present a literature review on the epidemiology of rickettsiosis, delving into studies about the characteristics of the peridomiciliary space and the most common animals that live there involved in the occurrence of rickettsiosis in localities of the Mexican tropic<strong>. Methodology:</strong> Using keywords related to the objective, a search between November 2022 and April 2023 was carried out on digital sources of information from various types of scientific references. The search results were classified according to eligibility criteria. <strong>Results:</strong> The information generated in the Mexican tropic on the epidemiology of rickettsiosis involving synanthropic and domestic animals, as well as the characteristics of the peridomiciliary space, is more extensive and numerous than in other regions of the country. <strong>Implications:</strong> The present review includes part of the epidemiological panorama of endemic rickettsiosis in the Mexican tropics, which is not necessarily attributable to other regions where environmental and socioeconomic conditions can modify the behavior of these diseases. <strong>Conclusions:</strong> It has been documented that the transmission of zoonoses such as rickettsiosis is influenced by ecological or environmental conditions and the characteristics of anthropized environments such as the peridomicile, which represent factors related to the occurrence of these diseases in the households’ occupants of localities in the Mexican tropics. Several pathogenic species of Rickettsia are found in domesticated dogs and some species of wild and synanthropic rodents, indicating their significant epidemiological role in the tropical regions of Mexico.</p>

Rate of treatment demand of Omsk region population due to injuries caused by animals: dynamics and structure

Objective: to analyze the rate of treatment demand after contact with animals in the Omsk region.Materials and methods: we used data of rate of treatment demand of Omsk region population due to injuries caused by animals in 2009–2022. A descriptive-evaluative epidemiological research method was used. The characteristics of injuries from domestic owned (dogs and cats with an owner), domestic stray (stray dogs and cats) and wild (including synanthropic rodents) animals are analyzed.Results: in 2009–2022 in the Omsk region, 65142 people were injured by animals, which amounted to an average of 4653 complaints per year. Appeals from children aged 0–17 years old amounted to 36,5%, and from children aged 0–14 — 30,2% of the total. The leading role belongs to injuries caused by domestic animals — 67,1%, and of these, in 75,4% of cases — by dogs. An increase in calls regarding attacks by stray dogs has been established and is extremely pronounced regarding attacks by stray cats. The number of calls regarding bites from wild animals, namely squirrels and wild and synanthropic rodents, has increased significantly.Conclusions: In order to reduce the frequency of dangerous contacts with wild animals, in particular with squirrels, as well as with pets, it is necessary to carry out sanitary educational work with the population, especially children. The issue of installing warning boards in parks with a ban on hand-feeding squirrels, and installing feeding tables and feeders should be considered.

Данные об устойчивости серых крыс, обитающих в жилом секторе, к антикоагулянтам 2-го поколения

The chemical method of deratisation is the main means of regulating the numbers of synanthropic rodents. Low efficiency of deratisation measures can be related both to resistance of rats and mice to blood anticoagulants and to low attractiveness of baits. Thus, low eatability of baits entails insufficient cumulation of poison and, as a consequence, insufficient toxic effect on the animal organism. This paper describes the results of experiments to study the degree of sensitivity of grey rat individuals to the second generation anticoagulants bromadiolone and brodifacoum, most commonly used in deratisation practice. Sensitivity was determined by direct injection of anticoagulant solutions in neutral solvent into the stomach. The mean lethal concentration calculated by Hill’s equation for a single gastric administration was 0.35 mg/kg for bromadialone and 0.182 mg/kg for brodifacoum. The data obtained can be used in calculating the required amount of bait that must be eaten by the rodent to achieve lethality. Keywords: synanthropic rodents, grey rat, deratisation measures, anticoagulants, bromadiolone, brodifacoum.

Rats and their helminth parasites: Potential zoonosis threats of land use change in the northeastern sub-watersheds of Mount Makiling, Laguna, Philippines.

The continuous challenges of land use change have brought potential threats to biodiversity and the spread of zoonotic diseases. In this study, synanthropic rodents and their helminth parasites were used as sentinels to assess the potential impact of land use on zoonosis. Rats were collected in different ecosystems, namely agricultural, agroforest, and residential areas in the northeastern sub-watersheds of Mount Makiling, Laguna, Philippines. Three (3) species of rats were captured, namely, Rattus tanezumi, Rattus norvegicus, and Rattus exulans. Of the total 180 rats collected, 92.7 % were found infected with helminth parasites, namely Hymenolepis diminuta, Hymenolepis nana, Taenia pisiformis, and Strobilocercus fasciolaris (cestodes); Angiostrongylus cantonensis, Nippostrongylus brasiliensis, Strongyloides ratti, Capillaria hepatica, Trichuris muris, and Rictularia sp. (nematodes); and Echinostoma ilocanum (trematode). Of these 11 species, nine (9) were considered zoonotic. This study provides important information on the helminth parasites of rats in the northeastern sub-watersheds of Mount Makiling and the potential threat of zoonotic transmission due to increasing land use change and urbanization in the area. Moreover, urbanization can provide favorable eco-epidemiological conditions for rodent-borne pathogens, such as parasites, that are seriously threatening agricultural settings and human settlements in these areas.

Microbiome diversity and zoonotic bacterial pathogen prevalence in Peromyscus mice from agricultural landscapes and synanthropic habitat.

Rodents are key reservoirs of zoonotic pathogens and play an important role in disease transmission to humans. Importantly, anthropogenic land-use change has been found to increase the abundance of rodents that thrive in human-built environments (synanthropic rodents), particularly rodent reservoirs of zoonotic disease. Anthropogenic environments also affect the microbiome of synanthropic wildlife, influencing wildlife health and potentially introducing novel pathogens. Our objective was to examine the effect of agricultural development and synanthropic habitat on microbiome diversity and the prevalence of zoonotic bacterial pathogens in wild Peromyscus mice to better understand the role of these rodents in pathogen maintenance and transmission. We conducted 16S amplicon sequencing on faecal samples using long-read nanopore sequencing technology to characterize the rodent microbiome. We compared microbiome diversity and composition between forest and synanthropic habitats in agricultural and undeveloped landscapes and screened for putative pathogenic bacteria. Microbiome richness, diversity, and evenness were higher in the agricultural landscape and synanthropic habitat compared to undeveloped-forest habitat. Microbiome composition also differed significantly between agricultural and undeveloped landscapes and forest and synanthropic habitats. We detected overall low diversity and abundance of putative pathogenic bacteria, though putative pathogens were more likely to be found in mice from the agricultural landscape. Our findings show that landscape- and habitat-level anthropogenic factors affect Peromyscus microbiomes and suggest that landscape-level agricultural development may be important to predict zoonotic pathogen prevalence. Ultimately, understanding how anthropogenic land-use change and synanthropy affect rodent microbiomes and pathogen prevalence is important to managing transmission of rodent-borne zoonotic diseases to humans.

Ecoepidemiology of Ancylostoma spp. in Urban-Marginal and Rural Sectors of the Ecuadorian Coast and Prevalence of Cutaneous Larvae Migrans.

BACKGROUND Ancylostoma spp., including A. duodenale, A. braziliense, A. caninum, and A. ceylanicum, are hookworms that are transmitted from infected soil and by contact with domestic animals and rodent hosts, and can cause systemic disease and cutaneous larva migrans. The objective of this study was to describe the ecoepidemiology of Ancylostoma caninum and Ancylostoma spp. in urban-marginal sectors and in rural sectors located in Ecuador. MATERIAL AND METHODS Through addressed sampling, a total of 498 domestic dogs and 40 synanthropic rodents were analyzed via the following coproparasitic methods: direct, flotation, sedimentation with centrifugation using saline (egg identification), modified Baermann (larval identification), and morphometric methods (confirmation). A total of 236 people were surveyed, and a clinical analysis was performed via physical examination. The environmental variables were obtained through reports from the INAMHI of Ecuador and the use of online environmental programs. Through surveys, data related to social determinants were obtained. Epidemiological indicators (prevalence, morbidity, and mortality) were obtained through microbial analysis and surveys. RESULTS A total of 250 domestic dogs were diagnosed with Ancylostoma caninum (50, 20%), and 41 were diagnosed with Ancylostoma spp. (8.23%). One synanthropic rodent (2.5%) was positive for A. caninum. In the clinical analysis, 3 patients were identified as positive (1.27%) for cutaneous larva migrans (CLM). Likewise, environmental variables and social determinants influence the transmission, prevalence, and nature of parasitism by hookworm. CONCLUSIONS People, domestic dogs, and rodents were infected with these parasites. Consequently, there is a risk of ancylostomiasis and cutaneous larvae migrans spreading.

Detection of hepatitis E virus genotype 3 in an Algerian mouse (Mus spretus) in Portugal

Virus monitoring in small mammals is central to the design of epidemiological control strategies for rodent-borne zoonotic viruses. Synanthropic small mammals are versatile and may be potential carriers of several microbial agents. In the present work, a total of 330 fecal samples of small mammals were collected at two sites in the North of Portugal and screened for zoonotic hepatitis E virus (HEV, species Paslahepevirus balayani). Synanthropic small mammal samples (n = 40) were collected in a city park of Porto and belonged to the species Algerian mouse (Mus spretus) (n = 26) and to the greater white-toothed shrew (Crocidura russula) (n = 14). Furthermore, additional samples were collected in the Northeast region of Portugal and included Algerian mouse (n = 48), greater white-toothed shrew (n = 47), wood mouse (Apodemus sylvaticus) (n = 43), southwestern water vole (Arvicola sapidus) (n = 52), Cabrera’s vole (Microtus cabrerae) (n = 49) and Lusitanian pine vole (Microtus lusitanicus) (n = 51). A nested RT-PCR targeting a part of open reading frame (ORF) 2 region of the HEV genome was used followed by sequencing and phylogenetic analysis. HEV RNA was detected in one fecal sample (0.3%; 95% confidence interval, CI: 0.01–1.68) from a synanthropic Algerian mouse that was genotyped as HEV-3, subgenotype 3e. This is the first study reporting the detection of HEV-3 in a synanthropic rodent, the Algerian mouse. The identified HEV isolate is probably the outcome of either a spill-over infection from domestic pigs or wild boars, or the result of passive viral transit through the intestinal tract. This finding reinforces the importance in the surveillance of novel potential hosts for HEV with a particular emphasis on synanthropic animals.