Vector borne and zoonotic diseases最新文献

Background: Marsupials and rodents are the most important wild and synanthropic hosts of Trypanosoma cruzi due to the high frequency of infection, maintenance of diverse genetic populations of the parasite, and their close proximity to interact with both transmission cycles, sylvatic and peridomestic. Our aim was to identify the discrete typing units (DTU) of T. cruzi from different wild and synanthropic hosts in two regions of Mexico and to carry out a review of historical data focusing on current knowledge on the diversity and T. cruzi DTUs of host species. Materials and Methods: One hundred fifteen samples were obtained from two areas in Tabasco and Nayarit state. The presence of T. cruzi was evaluated by PCR. Results: The 12.6% (12/95) of samples from Tabasco and 65% (13/20) from Nayarit were found to be positive for parasite DNA. All the sequences analyzed were grouped in T. cruzi DTU I; low nucleotide diversity was observed in Tabasco (π = 0.00566, and ϴ = 0.00632), while high genetic diversity was observed in Nayarit sequences, up to 8.63 (π) to 11.10 (ϴ) times greater than Tabasco sequences. Genetic flow and migration between Tabasco, and Nayarit were scarce (FST = 0.37329 and Nm = 0.42), and genetic exchange was observed only between nearby areas. The bibliographic review of hosts in Mexico, together with our data, shows a heterogeneous T. cruzi prevalence in Chiroptera and domestic animals. For Atelidae and Canids, prevalence is generally below 25%. However, a high prevalence, greater than 25% and up to 100%, was recorded in Didelphimorphia, and Rodentia. Few studies in regions of Mexico have been described as infected with the parasite; in these, the genetic group with the highest prevalence is the DTU I. Conclusion: Marsupials and rodents are important reservoirs of T. cruzi; DTU I was frequently reported; however, recent genetic and reservoir studies have demonstrated the presence of greater diversity of genetic groups.

Background: The control and prevention of rodent-borne diseases are mainly based on our knowledge of ecology and the infectious status of their reservoir hosts. This study aimed to evaluate the prevalence of Francisella tularensis, Yersinia pestis, and arenavirus infections in small mammals and to assess the potential of disease occurrence in East Azerbaijan, northwest of Iran, in 2017 and 2018. Methods: Spleen and lung samples were obtained from all trapped small mammals. The real-time quantitative PCR (qPCR) method was used to detect nucleic acid sequences of F. tularensis, Y. pestis, and arenaviruses. Serum samples were tested for antibodies indicating the host response to F. tularensis and Y. pestis infections using the standard tube agglutination test and enzyme-linked immunosorbent assay (ELISA), respectively. Results: A total of 205 rodents, four Eulipotyphla, and one carnivore were captured. The most common rodent species captured (123 of 205 rodents, 60%) belonged to the genus Meriones (mainly Persian jird, Meriones persicus). In total, 317 fleas were removed from trapped animals. Flea species belonged to Xenopsylla buxtoni, Xenopsylla nuttalli, Stenoponia tripectinata, Paraceras melis, Ctenophthalmus rettigi smiti, Rhadinopsylla bivirgis, Paradoxopsyllus grenieri, and Nosopsyllus iranus. Using the qPCR tests, five spleen samples from M. persicus were positive for F. tularensis. The qPCR tests were negative for the detection of Y. pestis and arenaviruses. Finally, all serum samples tested were negative for antibodies against Y. pestis and F. tularensis. Conclusions: F. tularensis was the only zoonotic agent detected in rodents captured in East Azerbaijan. However, the diversity of trapped rodents and fleas provides the potential for the spread of various rodent-borne viral and bacterial diseases in the studied areas.

Objective: To investigate the epidemic factors of hemorrhagic fever with renal syndrome (HFRS) and compare the S and M gene sequences of hantavirus (HV) between rodents and the infected cases. Methods: Detailed epidemiological investigations were conducted on the cases' working and living areas. Captured rodents were classified by night trapping method, and their lungs and blood were collected for virus carriage detection after aseptic dissection. Viral S and M fragments of HV RNA were amplified and sequenced from positive samples of cases and mice, and their homology was analyzed. Results: After reconstruction, the geographic and living environment changed significantly, altering rodent behaviors. The industrial park, characterized by high population density, poor living conditions, and frequent contact of rodent (feces) and humans, had a high rodent density and HV virus infection ratio. Four workers infected with HV were positive for anti-HV immunoglobulin G (IgG) and IgM. Among the positive samples, HV RNA was detected in all two cases, and four Rattus norvegicus specimens were Seoul type HV S3 subtype. The virus had the closest relationship with Rod/2012/QHD/4/Gc (Hebei, China) and RuianRn180 (Zhejiang, China), with the 100% homology of M gene segment. The homology of viral S gene segment exhibited the closest relationship with the Jiangxi isolated JiangxiXinjianRn-09-2011, ranging from 99.6% to 99.8%. Conclusion: The HV sequencing showed a strong epidemiological relationship between the cases and host rodents. Improving living environmental health conditions, administering HFRS vaccine, and reducing rodent density and human-rodent contact can mitigate the risk of HFRS.

Background: Chagas disease or American trypanosomiasis, caused by Trypanosoma cruzi and vectored by triatomines, affects millions of people worldwide. In endemic countries including Mexico, infections in domestic animals, such as dogs, may affect the risk of human disease when they serve as a source of infection to vectors that subsequently infect humans. Materials and Methods: We conducted a cross-sectional study of 296 dogs from two cities near the northern and southern borders of Mexico: Reynosa, Tamaulipas, and Tuxtla Gutierrez, Chiapas. Infection was measured based on testing of blood using T. cruzi quantitative PCR (qPCR) and up to three antibody detection assays. The StatPak immunochromatographic assay was used to screen samples and the indirect fluorescent antibody (IFA) and multiplex microsphere immunoassay (MIA) tests were used as secondary tests on all samples that screened positive and a subset of negatives. Serologic positivity was defined based on reactivity on at least two independent tests. Results: Of the 280 samples tested for parasite DNA, two (0.7%) were positive, one of which (0.4%) was confirmed as T. cruzi discrete typing unit TcIV. Overall, 72 (24.3%) samples were reactive for T. cruzi antibodies via StatPak of which 8 were also positive using MIA and 2 were also positive using IFA (including one of the PCR-positive dogs). Overall, nine dogs (3.4%) met study criteria of positivity based on either/both serology or PCR tests. Positive dogs were found in both regions of Mexico; five (2.7%) from Reynosa and four (3.6%) from Tuxtla Gutierrez. We found no association between infection status and state of origin, sex, age group, breed group, neighborhood, and whether other pets lived in the home. Conclusion: Our results re-emphasize dogs' utility as sentinels for T. cruzi in Mexico and underscore the need for improved veterinary diagnostic tests and parasite surveillance at the household level in endemic countries.

Background: The burden of zoonotic diseases in developing countries is significantly underestimated, influenced by various factors such as misdiagnosis, underreporting, natural disasters, climate change, resource limitations, rapid unplanned urbanization, poverty, animal migration, travel, ecotourism, and the tropical environmental conditions prevalent in the region. Despite Sri Lanka's provision of a publicly funded free health care system, zoonoses still contribute significantly to the burden of communicable diseases in the country. This study serves as a timely and exhaustive systematic review of zoonoses reported over the past 22 years in Sri Lanka. Materials and Methods: This systematic review adhered to the guidelines provided by the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) statement. A systematic literature search was conducted between July and September 2022, utilizing the following databases and sources: Google Scholar, PubMed, Cochrane Library, Weekly Epidemiological Reports, and Rabies Statistical Bulletins published by the Ministry of Health, Sri Lanka. Results: From the initial database search, 1,710 articles were identified. After excluding nonzoonotic diseases, duplicated reports, inaccessible articles, and those not meeting the inclusion criteria, 570 reports were evaluated for eligibility. Of these, 91 reports were selected for data extraction, comprising 58 original research articles, 10 case reports, 16 weekly epidemiological reports, and 7 rabies statistical bulletins. Over the study period (2000-2022), 14 parasitic, 7 bacterial, and 7 viral zoonoses have been reported in Sri Lanka. Notably, leptospirosis emerged as the most reported zoonotic disease in the country. Conclusions: In response to these findings, we strongly recommend the implementation of a tailored, country-specific prevention and control program. To achieve this goal effectively, we emphasize the importance of adopting a country-specific "One Health" approach as a comprehensive framework for managing and controlling zoonotic diseases in Sri Lanka.

Background: Urban areas are unique ecosystems with stark differences in species abundance and composition compared with natural ecosystems. These differences can affect pathogen transmission dynamics, thereby altering zoonotic pathogen prevalence and diversity. In this study, we screened small mammals from natural and urban areas in the Netherlands for up to 19 zoonotic pathogens, including viruses, bacteria, and protozoan parasites. Materials and Methods: In total, 578 small mammals were captured, including wood mice (Apodemus sylvaticus), bank voles (Myodes glareolus), yellow-necked mice (Apodemus flavicollis), house mice (Mus musculus), common voles (Microtus arvalis), and greater white-toothed shrews (Crocidura russula). We detected a wide variety of zoonotic pathogens in small mammals from both urban and natural areas. For a subset of these pathogens, in wood mice and bank voles, we then tested whether pathogen prevalence and diversity were associated with habitat type (i.e., natural versus urban), degree of greenness, and various host characteristics. Results: The prevalence of tick-borne zoonotic pathogens (Borrelia spp. and Neoehrlichia mikurensis) was significantly higher in wood mice from natural areas. In contrast, the prevalence of Bartonella spp. was higher in wood mice from urban areas, but this difference was not statistically significant. Pathogen diversity was higher in bank voles from natural habitats and increased with body weight for both rodent species, although this relationship depended on sex for bank voles. In addition, we detected methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase/AmpC-producing Escherichia coli, and lymphocytic choriomeningitis virus for the first time in rodents in the Netherlands. Discussion: The differences between natural and urban areas are likely related to differences in the abundance and diversity of arthropod vectors and vertebrate community composition. With increasing environmental encroachment and changes in urban land use (e.g., urban greening), it is important to better understand transmission dynamics of zoonotic pathogens in urban environments to reduce potential disease risks for public health.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic tick-borne disease, caused by an arbovirus of the genus Orthonairovirus and the family Nairoviridae. Crimean-Congo hemorrhagic fever virus (CCHFV) is widespread in several regions of the world. While the virus is not pathogenic to all susceptible livestock and wild mammals, it can lead to severe hemorrhagic fever in humans. In this review, we compiled published data on CCHFV infections in humans, animals, and ticks in Tunisia. Based on that, we discussed the epidemiology and the distribution patterns of CCHFV infections highlighting the risk factors for this virus in the country. CCHF infection prevalence in humans was estimated to 2.76% (5/181) and 5% (2/38) in Tunisian febrile patients and Tunisian slaughterhouse workers, respectively. Concurrently, seroprevalence in domestic ungulates (sheep, goats, cattle, and dromedaries) ranged from zero to 89.7%, and only one Hyalomma impeltatum tick specimen collected from dromedaries in southern Tunisian was positive for CCHFV by reverse transcriptase-polymerase chain reaction (0.6%; 1/165). As Tunisian studies on CCHFV are geographically scattered and limited due to very small sample sizes, further studies are needed to improve the knowledge on the epidemiology of CCHF in Tunisia.

Introduction: Brucellosis, which is among the endemic regions of Turkey, is a common zoonotic disease. The gold standard in diagnosing brucellosis is culture. We aimed to compare demographic characteristics, risk factors, and clinical and laboratory variables between cases with culture positivity and undetected in culture. Materials and Methods: This single-center study was conducted between January 2007 and April 2022. Clinical and laboratory data of patients with brucella growth in blood culture and patients without growth were compared. Results: A total of 150 patients were included in the study. The median age was 10 (1-18 years). Of the patients, 66 (44%) were female and 84 (56%) were male. Forty (26.7%) of the patients were bacteremic and 110 (73.3%) were nonbacteremic. In the bacteremic group, white blood cell count, platelet, and hemoglobin counts were lower, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were higher. In clinical evaluation, fever, hepatomegaly, splenomegaly, and abdominal pain were more common in the bacteremic group. Conclusion: The distinction between bacteremic and nonbacteremic brucellosis can be predicted using laboratory values such as white blood cells, hemoglobin counts, platelet, ALT, and AST, and clinical findings such as fever, abdominal pain, hepatomegaly, and splenomegaly.

Retrospective serological and case diagnostic data of endemic bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) provide evidence of viral transmission among livestock and wildlife from 2016 in Kansas and Nebraska. Serological testing of mature cattle in nine distinct regional zones of Kansas revealed 76% to 100% had detectable antibodies to BTV and/or EHDV. Specimens tested in the Kansas Veterinary Diagnostic Laboratory (55 submissions) were 51% test positive for antibodies to BTV and/or EHDV. Specimens tested in the Nebraska Veterinary Diagnostic Center (283 submissions) were 25% test positive for antibodies to BTV and/or EHDV. Low disease incidence in white-tailed deer and other susceptible wild ungulates was observed during 2016. However, there were no confirmed reports of disease in livestock in either state. The reasons for emergence of significant clinical disease in livestock and wildlife populations remain undefined.

Background: Ehrlichia canis has been the main hemopathogen affecting domestic dogs in Brazil. Even though tick-infested dogs may lead to household infestation and predispose human exposure and public health concern, no comprehensive study has surveyed humans, dogs, and environmental ticks altogether. Materials and Methods: Accordingly, the present study aimed to assess tick-infested households, identify tick species, perform serological (immunofluorescence assay) and molecular (PCR and q-PCR) detection of Ehrlichia in ticks, in the eighth biggest metropolitan area of Brazil. Results: Between 2007 and 2020, 233/5973 (3.9%) out of all complaints were from tick-infested households of 200 different addresses. Overall, 370/552 (67.0%) ticks were collected and identified as adult and 182/552 (33.0%) as immature forms of Rhipicephalus sanguineus s.l. complex; a single tick from one owner, a female tick of Amblyomma sculptum; and 395 ticks from dogs, 319/395 (80.8%) adult and 72/395 (18.2%) immature forms of Rhipicephalus spp., and 4/395 (1.01%) female Amblyomma aureolatum. Overall, 2/135 (1.5%) owners and 13/136 (9.6%) dogs were seropositive for E. canis. The DNA of Anaplasmataceae family was molecularly detected in 16/50 (32.0%) R. sanguineus s.l. As expected, the number of monthly tick infestation complaints were directly associated, and mean (p = 0.01), maximum (p = 0.011), and minimum (p = 0.008) temperature were statistically significant and had a low positive correlation (0.24, 0.23, and 0.24, respectively). In addition, complaints were highly associated to all socioeconomic variables (p < 0.001), with the exception of the presence of vacant lots. Conclusions: Despite low samplings and human negative results, areas with low-income with adequate temperature and urban agglomerations have been shown to be associated risks for tick infestations, predisposing tick-borne diseases. In conclusion, monitoring should always be conducted in such areas, including One Health approach with serosurvey of owners and dogs, along with identification and molecular screening of ticks.