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Backus L, Foley P, Foley J. A compartment and metapopulation model of Rocky Mountain spotted fever in southwestern United States and northern Mexico. Infect Dis Model 2024; 9:713-727. [PMID: 38659493 PMCID: PMC11039326 DOI: 10.1016/j.idm.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 04/26/2024] Open
Abstract
Rocky Mountain spotted fever (RMSF) is a fatal tick-borne zoonotic disease that has emerged as an epidemic in western North America since the turn of the 21st century. Along the US south-western border and across northern Mexico, the brown dog tick, Rhipicephalus sanguineus, is responsible for spreading the disease between dogs and humans. The widespread nature of the disease and the ongoing epidemics contrast with historically sporadic patterns of the disease. Because dogs are amplifying hosts for the Rickettsia rickettsii bacteria, transmission dynamics between dogs and ticks are critical for understanding the epidemic. In this paper, we developed a compartment metapopulation model and used it to explore the dynamics and drivers of RMSF in dogs and brown dog ticks in a theoretical region in western North America. We discovered that there is an extended lag-as much as two years-between introduction of the pathogen to a naïve population and epidemic-level transmission, suggesting that infected ticks could disseminate extensively before disease is detected. A single large city-size population of dogs was sufficient to maintain the disease over a decade and serve as a source for disease in surrounding smaller towns. This model is a novel tool that can be used to identify high risk areas and key intervention points for epidemic RMSF spread by brown dog ticks.
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Affiliation(s)
- Laura Backus
- School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, CA, USA
| | - Patrick Foley
- Department of Biological Sciences, California State University, Sacramento, CA, USA
| | - Janet Foley
- School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, CA, USA
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Gomes IRC, Gurgel-Gonçalves R, Gazeta GS, Borsoi ABP, Bitencourth K, Leite LF, Coelho NGSS, Dislich R, Wiederhecker HC, Santos EG, Guimarães M. Effect of environmental variables on the abundance of Amblyomma ticks, potential vectors of Rickettsia parkeri in central Brazil. PLoS One 2024; 19:e0301685. [PMID: 38748697 PMCID: PMC11095677 DOI: 10.1371/journal.pone.0301685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/20/2024] [Indexed: 05/19/2024] Open
Abstract
Amblyomma ticks are vectors of both Rickettsia rickettsii and R. parkeri in the Americas, where capybaras (Hydrochoerus hydrochaeris) are the main hosts in urban areas, thus contributing to the transmission of spotted fever. Herein, we studied: (i) the seasonal dynamics and abundance of ticks in areas where capybaras live, (ii) the effect of environmental variables on tick abundance, and (iii) the presence of Rickettsia-infected ticks. Between September 2021 and September 2022, we sampled ticks using cloth-dragging at 194 sites on the shore of Lake Paranoá in Brasília, Brazil. We measured environmental data (season, vegetation type, canopy density, temperature, humidity, and presence or vestige of capybara) at each site. Nymphs and adults were morphologically identified to the species level, and a selected tick sample including larvae was subjected to genotypic identification. We investigated Rickettsia-infected ticks by PCR (gltA, htrA, ompB, and ompA genes) and associations between tick abundance and environmental variables using Generalized Linear Models. A total of 30,334 ticks (96% larvae) were captured. Ticks were identified as Amblyomma, with A. sculptum comprising 97% of the adult/nymphs. Genotype identification of a larval sample confirmed that 95% belonged to A. dubitatum. Seasonal variables showed significant effects on tick abundance. Most larvae and nymphs were captured during the early dry season, while the adults were more abundant during the wet season. Vegetation variables and the presence of capybaras showed no association with tick abundance. Rickettsia parkeri group and R. bellii were identified in A. dubitatum, while A. sculptum presented R. bellii. We conclude that: (i) Amblyomma ticks are widely distributed in Lake Paranoá throughout the year, especially larvae at the dry season, (ii) the abundance of Amblyomma ticks is explained more by climatic factors than by vegetation or presence of capybaras, and (iii) A. dubitatum ticks are potential vectors of R. parkeri in Brasília.
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Affiliation(s)
- Isadora R. C. Gomes
- Biological Sciences Course, Catholic University of Brasília, Federal District, Brasília, Brazil
- Faculty of Medicine, Laboratory of Medical Parasitology and Vector Biology, University of Brasília, Federal District, Brasília, Brazil
| | - Rodrigo Gurgel-Gonçalves
- Faculty of Medicine, Laboratory of Medical Parasitology and Vector Biology, University of Brasília, Federal District, Brasília, Brazil
| | - Gilberto S. Gazeta
- National Reference Laboratory for Rikettsiosis Vectors, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Ana B. P. Borsoi
- National Reference Laboratory for Rikettsiosis Vectors, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Karla Bitencourth
- National Reference Laboratory for Rikettsiosis Vectors, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Letícia F. Leite
- Biological Sciences Course, Catholic University of Brasília, Federal District, Brasília, Brazil
| | | | - Ricardo Dislich
- Ministry of Planning and Budget, Esplanade of Ministries, Federal District, Brasília, Brazil
| | | | - Eduardo G. Santos
- Post Graduation Program in Ecology, Institute of Biological Sciences, University of Brasília, Federal District, Brasília, Brazil
| | - Melina Guimarães
- Biological Sciences Course, Catholic University of Brasília, Federal District, Brasília, Brazil
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Szabó MPJ, Queiroz CL, Suzin A, Rodrigues VDS, Vieira RBK, Martins MM, Rezende LM, Sousa ACP, Ramos VDN, Muraro FM, Fernandes LK, Santos LCM, Maia RDC, Rezende AF. Density and behavior of capybara (Hydrochoerus hydrochaeris) ticks (Acari: Ixodidae) Amblyomma sculptum and Amblyomma dubitatum with notes on Rickettsia bellii infection: Assessing human exposure risk. Ticks Tick Borne Dis 2024; 15:102330. [PMID: 38460340 DOI: 10.1016/j.ttbdis.2024.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 02/25/2024] [Accepted: 03/01/2024] [Indexed: 03/11/2024]
Abstract
In several urban and peri‑urban areas of Brazil, populations of Amblyomma sculptum and Amblyomma dubitatum ticks are maintained by capybaras (Hydrochoerus hydrochaeris). In some of these areas, this host and these tick species are associated with Brazilian spotted fever (BSF), a lethal human disease caused by the bacterium Rickettsia rickettsii. In this work, we evaluated the risk of human exposure to these tick species using four collection techniques to discern host-seeking behavior. The study was carried out in 10 urban sites inhabited by capybaras in Uberlândia, a BSF-free municipality in southeastern Brazil. Ticks were collected in areas of 400 m2 at each site and at three seasons. Within the same municipality, the distance and speed of A. sculptum nymphs moving towards the CO2 traps were evaluated. In a sample of ticks Rickettsia DNA was investigated. During the study period, 52,953 ticks were collected. Among these, 83.4 % were A. sculptum (1,523 adults, 10,545 nymphs and 32,104 larvae) and 16.6 % were A. dubitatum (464 adults, 2,153 nymphs and 6,164 larvae). An average annual questing tick density of 4.4/m² was observed, with the highest density recorded at one site in autumn (31.8/m²) and the lowest in summer at another site (0.03/m²). The visual search yielded the highest proportion of A. sculptum larvae, constituting 47 % of the total and 63.6 % of all A. sculptum larvae. In contrast, CO2 traps collected a greater proportion of nymphs and adults of A. sculptum ticks. In the case of A. dubitatum, the CO2 trap was the most efficient technique with 57.7 % of captures of this species, especially of nymphs (94.5 % of captures) and adults (97.8 % of captures). Ticks' ambush height on vegetation (9 to 77 cm), observed by visual search 30 times, yielded a total of 20,771 ticks. Of these, 28 (93 %) were A. sculptum ticks, with only two (7 %) identified as A. dubitatum ticks. Among A. sculptum ticks, the nymph was the most attracted stage to humans and larva in the case of A. dubitatum. Amblyomma sculptum adults and nymphs were significantly more attracted to humans than those of A. dubitatum, but A. dubitatum larvae were significantly more attracted than the same stage of A. sculptum. The maximum distance and speed of horizontal displacement for A. sculptum nymphs were five meters and 2.0 m/h, respectively. The only species of Rickettsia detected in ticks, exclusively in A. dubitatum, was R. bellii. Importantly, it was observed that the higher the proportion of A. sculptum in the community of ticks, the lower the rate of infection of A. dubitatum by R. bellii. In conclusion, host-seeking behavior differed between the two tick species, as well as between stages of the same species. A greater restriction of A. dubitatum ticks to the soil was observed, while larvae and nymphs of A. sculptum dispersed higher in the vegetation. The behavior presented by A. sculptum provides greater opportunities for contact with the hosts, while A. dubitatum depends more on an active search for a host, the hunter behavior. Taken together, these observations show that a human being crossing an area infested with A. sculptum and A. dubitatum ticks will have almost exclusive contact with A. sculptum larvae and/or nymphs. Humans in a stationary position (sitting, lying or immobile) are exposed to both tick species, but they are more attractive to adults and mainly nymphs of A. sculptum compared to the corresponding stages of the tick A. dubitatum. The negative effect of A. sculptum on A. dubitatum infection by R. bellii deserves further studies.
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Affiliation(s)
- Matias P J Szabó
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil.
| | - Caroline Lopes Queiroz
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Adriane Suzin
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Vinicius da Silva Rodrigues
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Raíssa Brauner Kamla Vieira
- Programa de Pós-graduação em Clínica e Reprodução, Animal da Universidade Federal Fluminense. Niterói, Rio de Janeiro, Brazil
| | - Maria Marlene Martins
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Lais Miguel Rezende
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Ana Carolina P Sousa
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Vanessa do Nascimento Ramos
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Fernanda Marinho Muraro
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Lais Keocheguerian Fernandes
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Lorena C M Santos
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Rodrigo da Costa Maia
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
| | - Amanda Ferreira Rezende
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, Campus Umuarama-Bloco 6T, CEP 38405-302, Uberlândia, Minas Gerais, Brazil
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Caixeta BT, Tolesano-Pascoli GV, Mundim FL, Pascoal JDO, Rodrigues VDS, Martins MM, Ramos VDN, Torga K, Costa LF, Miranda VC, Benfatti LR, Silva LM, Limongi JE, Szabó MPJ, Yokosawa J. Survey of Rickettsia spp. in ticks (Acari: Ixodidae) infesting opossums (Didelphis albiventris) and capybaras (Hydrochoerus hydrochaeris) from an urban park in southeastern Brazil. EXPERIMENTAL & APPLIED ACAROLOGY 2024; 92:463-477. [PMID: 38361037 DOI: 10.1007/s10493-023-00885-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 12/29/2023] [Indexed: 02/17/2024]
Abstract
Ticks are hematophagous arthropods and, during feeding, may transmit pathogens to vertebrate hosts, including humans. This study aimed to investigate the presence of Rickettsia spp. in ticks collected between 2010 and 2013 from free-ranging capybaras (Hydrochoerus hydrochaeris) and opossums (Didelphis albiventris) that inhabit Sabiá Park in Uberlândia, Brazil. Overall, 1,860 ticks were collected: 1,272 (68.4%) from capybaras (487 of the species Amblyomma sculptum, 475 adults and 12 nymphs; 778 Amblyomma dubitatum, 727 adults and 51 nymphs; and seven larva clusters of the genus Amblyomma); and 588 (31.6%) from opossums (21 A. sculptum, one adult and 20 nymphs; 79 A. dubitatum, all nymphs; 15 Ixodes loricatus, 12 adults and three nymphs; 457 Amblyomma sp. larva clusters; 15 Ixodes sp. larva clusters; and one Argasidae larva cluster). Out of 201 DNA samples tested for the presence of Rickettsia spp. DNA using polymerase chain reaction (PCR) 12 showed amplification of a gtlA gene segment that was specific to Rickettsia bellii, a bacterium non-pathogenic to humans. As there has been a report showing serological evidence of infections caused by Rickettsia species of the spotted fever group (SFG) in capybaras and opossums in the park, including Rickettsia rickettsii, the etiological agent of Brazilian spotted fever, and considering the presence of A. sculptum ticks, which are aggressive to humans, as well as these vertebrate hosts, which are amplifiers of R. rickettsii, it is important to monitor the presence of SFG rickettsiae in the Sabiá Park, which is visited daily by thousands of people.
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Affiliation(s)
- Bruno Tolentino Caixeta
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil.
| | | | - Flávia Lúcio Mundim
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil
| | - Jamile de Oliveira Pascoal
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil
| | - Vinícius da Silva Rodrigues
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil
| | - Maria Marlene Martins
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil
| | - Vanessa do Nascimento Ramos
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil
| | - Khelma Torga
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil
| | - Lourenço Faria Costa
- Instituto Acadêmico de Ciências da Saúde e Biológicas, Universidade Estadual de Goiás, Quirinópolis, Brazil
| | - Vinícius Campos Miranda
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil
| | - Luisa Rodrigues Benfatti
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil
| | - Leticia Maria Silva
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil
| | | | - Matias Pablo Juan Szabó
- Laboratory of Ixodology, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Uberlândia, Brazil.
| | - Jonny Yokosawa
- Laboratory of Microorganisms of Cerrado (Brazilian Savannah), Department of Microbiology, Instituto de Ciências Biomédicas, UFU, Uberlândia, Brazil.
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Molecular detection of Babesia spp. and Rickettsia spp. in coatis (Nasua nasua) and associated ticks from midwestern Brazil. Parasitol Res 2023; 122:1151-1158. [PMID: 36890298 DOI: 10.1007/s00436-023-07815-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 03/02/2023] [Indexed: 03/10/2023]
Abstract
Procyonids are reservoirs of many zoonotic infectious diseases, including tick-borne pathogens. The role of coatis (Nasua nasua) in the epidemiology of piroplasmids and Rickettsia has not been fully addressed in Brazil. To molecularly study these agents in coatis and associated ticks, animals were sampled in two urban areas in Midwestern Brazil. Blood (n = 163) and tick (n = 248) DNA samples were screened by PCR assays targeting the 18S rRNA and gltA genes of piroplasmids and Rickettsia spp., respectively. Positive samples were further molecularly tested targeting cox-1, cox-3, β-tubulin, cytB, and hsp70 (piroplasmid) and ompA, ompB, and htrA 17-kDa (Rickettsia spp.) genes, sequenced and phylogenetically analyzed. All coatis' blood samples were negative for piroplasmids, whereas five pools of ticks (2%) were positive for two different sequences of Babesia spp.. The first from Amblyomma sculptum nymphs was close (i.e., ≥ 99% nucleotide identity) to a Babesia sp. previously found in capybaras (Hydrochoerus hydrochaeris); the second from Amblyomma dubitatum nymphs and Amblyomma spp. larvae was identical (100% nucleotide identity) to a Babesia sp. detected in opossums (Didelphis albiventris) and associated ticks. Four samples (0.8%) were positive by PCR to two different Rickettsia spp. sequences, being the first from Amblyomma sp. larva identical to Rickettsia belli and the second from A. dubitatum nymph identical to Rickettsia species from Spotted Fever Group (SFG). The detection of piroplasmids and SFG Rickettsia sp. highlights the importance of Amblyomma spp. in the maintenance of tick-borne agents in urban parks where humans and wild and domestic animals are living in sympatry.
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Binder LDC, Ramírez-Hernández A, Serpa MCDA, Pinter A, Souza CE, Labruna MB. Long-term persistence of anti-Rickettsia rickettsii antibodies in capybaras, with passive transfer to offspring. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA = BRAZILIAN JOURNAL OF VETERINARY PARASITOLOGY : ORGAO OFICIAL DO COLEGIO BRASILEIRO DE PARASITOLOGIA VETERINARIA 2022; 31:e009922. [PMID: 36169507 DOI: 10.1590/s1984-29612022052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/05/2022] [Indexed: 06/16/2023]
Abstract
The bacterium Rickettsia rickettsii is the etiological agent of Brazilian spotted fever (BSF), and its most important vector to humans in Brazil is the tick Amblyomma sculptum. Capybaras are the main hosts of A. sculptum in many BSF-endemic areas and are considered valuable sentinels for BSF surveillance. This study aimed to assess the persistence of anti-R. rickettsii antibodies for long periods in capybaras and their passive transfer to offspring. For this purpose, three adult capybaras previously exposed to multiple infections with R. rickettsii were followed up until 3.1 years after their last exposure. During the study, one female delivered five cubs, of which three survived. Blood samples were collected monthly from adults and infants, and serum samples were titrated by indirect immunofluorescence assay (IFA) to determine endpoint titers of anti-R. rickettsii antibodies. All three adults remained seroreactive to R. rickettsii with high endpoint titers until the end of the study. All infants were seroreactive to R. rickettsii after birth and remained seroreactive for one to four months. This study showed that exposure of capybaras to R. rickettsii-infected A. sculptum ticks elicits a persistent antibody response. In addition, there was evidence of passive transfer of R. rickettsii-reactive antibodies to offspring.
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Affiliation(s)
- Lina de Campos Binder
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil
| | - Alejandro Ramírez-Hernández
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil
- Grupo Parasitología Veterinaria, Universidad Nacional de Colombia, Bogotá D.C., Colombia
| | - Maria Carolina de Azevedo Serpa
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil
| | | | - Celso Eduardo Souza
- Grupo de Vigilância Epidemiológica, Coordenadoria Controle de Doenças, Secretaria de Estado da Saúde, Campinas, SP, Brasil
| | - Marcelo Bahia Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil
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Campos JBV, Martins FS, Macedo GCD, Barreto WTG, Oliveira CED, Barbieri ARM, Labruna MB, Oliveira-Santos LGR, Herrera HM. Serological exposure of spotted fever group Rickettsia in capybaras (Hydrochoerus hydrochaeris) from urban parks in Campo Grande, Brazilian Midwest. Rev Soc Bras Med Trop 2022; 55:e0192. [PMID: 36134865 PMCID: PMC9491230 DOI: 10.1590/0037-8682-0192-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/01/2022] [Indexed: 12/03/2022] Open
Abstract
Background: Rickettsia of the spotted fever group (SFG) has been reported in ticks and domestic animals in Campo Grande (CG), Midwest Brazil. Methods: We searched for Rickettsia in the SFG in capybaras and their ticks in an urban park in the CG. Results: The seropositivity rate was 88.2% (15/17). Although 87.7% of the capybaras sampled showed infestations with Amblyomma sculptum, A. dubitatum, and Amblyomma spp., no molecular results were detected in ticks. Conclusions: Since Rickettsia from the SFG circulates among capybaras in the urban parks of Campo Grande, this large rodent species should be monitored within the One Health Agenda.
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Affiliation(s)
- João Bosco Vilela Campos
- Universidade Católica Dom Bosco, Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Campo Grande, MS, Brasil
| | - Filipe Santos Martins
- Universidade Católica Dom Bosco, Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Campo Grande, MS, Brasil
| | - Gabriel Carvalho de Macedo
- Universidade Católica Dom Bosco, Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Campo Grande, MS, Brasil
| | | | - Carina Elisei de Oliveira
- Universidade Católica Dom Bosco, Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Campo Grande, MS, Brasil
| | - Amália Regina Mar Barbieri
- Universidade de São Paulo, Departamento de Medicina Veterinária Preventiva e Saúde Animal, São Paulo, SP, Brasil
| | - Marcelo Bahia Labruna
- Universidade de São Paulo, Departamento de Medicina Veterinária Preventiva e Saúde Animal, São Paulo, SP, Brasil
| | | | - Heitor Miraglia Herrera
- Universidade Católica Dom Bosco, Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Campo Grande, MS, Brasil.,Universidade Federal de Mato Grosso do Sul, Pós-Graduação em Ecologia e Conservação, Campo Grande, MS, Brasil
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Moreira Magela S, Flávia do Nascimento A, Macena Pereira de Souza B. Capybara Ticks and the Urban Context of Spotted Fever in Brazil: An Overview. Infect Dis (Lond) 2022. [DOI: 10.5772/intechopen.106639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Spotted fever is caused by Rickettsia rickettsii and is transmitted through tick’s saliva. Humans, ticks, and capybaras (Hydrochoerus hydrochaeris) are often coexisting in environments that favor the spread of Brazilian spotted fever (BSF). Although capybaras do not transmit R. rickettsii, they can amplify these bacteria among tick vector populations, playing a significant role in the one health approach and epidemiology of the disease. Urban populations of capybaras have increased, especially in Southeast Brazil, as well as the number of cases and lethality of BSF have increased in the country since the 1980s. This expansion is mainly determined by the availability of food and the absence of predators. Thus, urban areas, including parks and university campuses, provide an abundance of food and protection against predators, ensuring the multiplication of the species and increasing the risk of transmission to humans due to the proximity of man with animals in the urban environment. Therefore, this chapter aims to address aspects of spotted fever, considering the many dimensions of the species involved, contributing to public strategies and policies.
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Onyiche TE, Labruna MB, Saito TB. Unraveling the epidemiological relationship between ticks and rickettsial infection in Africa. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.952024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Tick-borne rickettsioses are emerging and re-emerging diseases of public health concern caused by over 30 species of Rickettsia. Ticks are obligate hematophagous arthropods with over 700 species of Ixodid ticks known worldwide. The escalating geographical dispersal of tick vectors and concomitant increase in the incidences of tick-borne diseases have fueled interest in the ecology of tick-borne pathogens. This review focuses on aspects of the Rickettsia pathogen, including biology, taxonomy, phylogeny, genetic diversity, epidemiology of the disease, and the role of vertebrate host in the perpetuation of rickettsioses in Africa. Our review also highlights some of the species of Rickettsia that are responsible for disease, the role of tick vectors (both hard and soft ticks) and the species of Rickettsia associated with diverse tick species across the continent. Additionally, this article emphasizes the evolutionary perspective of rickettsiae perpetuation and the possible role of amplifying vertebrate host and other small mammals, domestic animals and wildlife in the epidemiology of Rickettsia species. We also specifically, discussed the role of avian population in the epidemiology of SFG rickettsiae. Furthermore, we highlighted tick-borne rickettsioses among travelers due to African tick-bite fever (ATBF) and the challenges to surveillance of rickettsial infection, and research on rickettsiology in Africa. Our review canvasses the need for more rickettsiologists of African origin based within the continent to further research towards understanding the biology, characterization, and species distribution, including the competent tick vectors involved in their transmission of rickettsiae across the continent in collaboration with established researchers in western countries. We further highlighted the need for proper funding to encourage research despite competing demands for resources across the various sectors. We finalize by discussing the similarities between rickettsial diseases around the world and which steps need to be taken to help foster our understanding on the eco-epidemiology of rickettsioses by bridging the gap between the growing epidemiological data and the molecular characterization of Rickettsia species.
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Suzin A, da Silva Rodrigues V, Nascimento Ramos VD, Szabó MPJ. Comparing scapular morphology of Amblyomma sculptum and Amblyomma dubitatum nymphs allows a fast and practical differential diagnosis of ticks in highly infested areas with dominance of these two species. EXPERIMENTAL & APPLIED ACAROLOGY 2022; 86:455-463. [PMID: 35235094 DOI: 10.1007/s10493-022-00702-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Rickettsia rickettsii infection causes the highest human fatality rate among all Rickettsia species of the world and is endemic in Southeast Brazil. In this part of the country most human spotted fever cases are related to unnaturally high populations of ticks, usually a mix of two species, Amblyomma dubitatum Neumann and Amblyomma sculptum Berlese and their local host, capybara (Hydrochoerus hydrochaeris). At the same time, an increase in the number of SF notifications as well as its urbanization was observed, and a better characterization of disease epidemiology is mandatory for control measures and to halt its expansion. It was recently noticed in southeast Brazil that SF endemic areas were characterized by overgrowth populations of A. sculptum and decreased populations of A. dubitatum. Hence, characterization of areas with potential to endemicity, eco-epidemiological studies and control measures may rely on the evaluation of A. sculptum/A. dubitatum rate. However, in potentially endemic scenarios, discriminating the two tick species, particularly the nymphs considered the main vector stage, is a challenge in face of several hundreds to thousands of ticks that should be examined for quantitative studies. We herein present additional morphological features to an existing identification key for Amblyomma nymphs that considerably diminishes the labor to distinguish nymphs of these two tick species. Specifically, the oval-shaped scutum of A. dubitatum and a conspicuous scapula of A. sculptum are prominent discriminating features.
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Affiliation(s)
- Adriane Suzin
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, 1720/Campus Umuarama-Bloco 6T, Uberlândia, Minas Gerais, CEP 38400-902, Brazil.
- Graduate Program in Ecology and Conservation of Natural Resources, Institute of Biology, Federal University of Uberlândia, Av. Pará, 1720 Uberlândia/Campus Umuarama-Bloco 2D, CEP: 38405-320, Uberlândia, Minas Gerais, Brazil.
| | - Vinicius da Silva Rodrigues
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, 1720/Campus Umuarama-Bloco 6T, Uberlândia, Minas Gerais, CEP 38400-902, Brazil
- Postgraduate Program in Applied Immunology and Parasitology, Federal University of Uberlândia, Av. Amazonas/Campus Umuarama, Bloco 4C, CEP: 38405-320, Uberlândia, Minas Gerais, Brazil
| | - Vanessa do Nascimento Ramos
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, 1720/Campus Umuarama-Bloco 6T, Uberlândia, Minas Gerais, CEP 38400-902, Brazil
- Post-Doctoral Program in Veterinary Sciences, Faculty of Veterinary Medicine and Animal Science, Federal University of Uberlândia, Av. Pará/Campus Umuarama, 1720, CEP: 38400-902, Uberlândia, Minas Gerais, Brazil
| | - Matias Pablo Juan Szabó
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Av. Pará, 1720/Campus Umuarama-Bloco 6T, Uberlândia, Minas Gerais, CEP 38400-902, Brazil
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de Carvalho Nunes E, de Moura-Martiniano NO, de Lima Duré AÍ, de Melo Iani FC, de Oliveira SV, de Mello FL, Gazêta GS. Spotted Fever in the Morphoclimatic Domains of Minas Gerais State, Brazil. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2021.718047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In Brazil, the tick-borne rickettsiosis known as Spotted Fever (SF) has been recorded from 59% of the Federative Units, however, the knowledge of the epidemiology and dynamics of human infection remains incipient in certain areas, complicating appropriate public health actions to inform the general population and control the disease. Here, we improved the interpretation of epidemiological information of SF cases recorded for an important endemic area. A descriptive epidemiological study was carried out based on records in the SINAN (Notifiable Diseases Information System) SF case databases. Data analysis was performed using Python programming language, Pandas library and Qgis map making. To evaluate the sociodemographic, clinical, assistance, laboratory and epidemiological characteristics, simple and relative nominal values of occurrences, means and standard deviations, and molecular analyzes were performed to identify the bioagent present in biological samples collected during each case investigation. Of the 298 confirmed cases, 98 resulted in death, the number of cases increased from 2011, and the disease scenario had 32.8% lethality. Overall, 207 cases involved men, and lethality was higher in this group. The most affected age group was 30 to 59 years old. The majority of patients reported having had contact with animals such as ticks, capybara and domestic animals such as dogs and cats. The results corroborate existing studies in areas of severe SF cases in Brazil. Despite reports of SF cases from the Cerrado Biome, analyses show that serious cases occur in anthropized areas of the Atlantic Forest biome, and in a transition area between this and the Cerrado. Complex, longitudinal, multidisciplinary studies, with an eco-epidemiological focus, should be carried out to allow the construction of algorithms capable of predicting, in time and space, the risk factors associated with severe cases and deaths from SF, with the aim of avoiding their expansion.
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Tick-borne zoonotic agents infecting horses from an urban area in Midwestern Brazil: epidemiological and hematological features. Trop Anim Health Prod 2021; 53:475. [PMID: 34553290 PMCID: PMC8457776 DOI: 10.1007/s11250-021-02887-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/10/2021] [Indexed: 11/24/2022]
Abstract
The emergence of tick-borne diseases has been reported as a serious problem in public health worldwide and many aspects of its epidemiology and effects on the health of its hosts are unclear. We aimed to perform an epidemiological study of tick-borne zoonotic Rickettsia, Borrelia, and Anaplasmataceae in horses from Midwestern Brazil. We also evaluated whether Borrelia spp. and Anaplasmataceae may be associated with hematological disorders in the sampled animals. Blood and serum samples as well as ticks were collected from 262 horses. Serum samples were used to perform serological tests, and hematological analyses were made using whole blood. Furthermore, DNA extracted from whole blood and ticks was used for molecular tests. Campo Grande is enzootic for tick-borne studied bacteria, since we found an overall exposure of 59.9% of the sampled horses, 28.7% of them presented co-exposure. Seropositivity rates of 20.6% for Borrelia spp., 25.6% for Rickettsia spp., and 31.6% for Anaplasmataceae were found in the sampled horses. Considering both molecular and serological tests for Borrelia spp., the infection rate was 48.0% (126/262). None of the tested horses showed molecular positivity for Anaplasma phagocytophilum. The horses sampled displayed 7.2% of parasitism by ixodid ticks in single and coinfestations. We did not find DNA of any studied bacteria in the sampled ticks. Positive horses for Borrelia spp. and Anaplasmataceae agents displayed leukopenia, monocytopenia, and lymphopenia. Together, our results suggest that horses may play a role as sentinel host for zoonotic bacteria and Borrelia spp. and Anaplasmataceae agents can impair the health of horses.
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Benatti HR, Luz HR, Lima DM, Gonçalves VD, Costa FB, Ramos VN, Aguiar DM, Pacheco RC, Piovezan U, Szabó MPJ, Ferraz KMPMB, Labruna MB. Morphometric Patterns and Blood Biochemistry of Capybaras ( Hydrochoerus hydrochaeris) from Human-Modified Landscapes and Natural Landscapes in Brazil. Vet Sci 2021; 8:vetsci8080165. [PMID: 34437487 PMCID: PMC8402786 DOI: 10.3390/vetsci8080165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/06/2021] [Accepted: 08/10/2021] [Indexed: 11/25/2022] Open
Abstract
The capybara, Hydrochoerus hydrochaeris, is the largest extant rodent of the world. To better understand the correlation between size and body mass, and biochemical parameters of capybaras from areas with different degrees of anthropization (i.e., different food supplies), we sampled free-ranging capybaras from areas of natural landscapes (NLs) and human-modified landscapes (HMLs) in Brazil. Analyses of biometrical and biochemical parameters of capybaras showed that animals from HMLs were heavier (higher body mass) than those from NL, a condition possibly related to fat deposit rather than body length, as indicated by Body Condition Index (BCI) analyses. Biochemical parameters indicated higher serum levels of albumin, creatine kinase, cholesterol, fructosamine and total protein among capybaras from HMLs than from NLs; however, when all adult capybaras were analyzed together only cholesterol and triglycerides were positively correlated with body mass. We propose that the biochemical profile differences between HMLs and NLs are related to the obesity condition of capybaras among HMLs. Considering that heavier animals might live longer and reproduce more often, our results could have important implications in the population dynamics of capybaras among HMLs, where this rodent species is frequently represented by overgrowth populations that generate several levels of conflicts with human beings.
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Affiliation(s)
- Hector R. Benatti
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
| | - Hermes R. Luz
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
- Programa de Pós-Graduação em Biotecnologia do Renorbio, Ponto Focal Maranhão, Universidade Federal do Maranhão, São Luís 65080-805, MA, Brazil
| | - Daniel M. Lima
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
| | - Vinicius D. Gonçalves
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
| | - Francisco B. Costa
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
- Faculdade de Medicina Veterinária, Universidade Estadual do Maranhão, São Luís 65055-970, MA, Brazil
| | - Vanessa N. Ramos
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
- Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia 38400-902, MG, Brazil;
| | - Daniel M. Aguiar
- Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá 78060-900, MT, Brazil; (D.M.A.); (R.C.P.)
| | - Richard C. Pacheco
- Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá 78060-900, MT, Brazil; (D.M.A.); (R.C.P.)
| | | | - Matias P. J. Szabó
- Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia 38400-902, MG, Brazil;
| | - Katia Maria P. M. B. Ferraz
- Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba 13418-900, SP, Brazil;
| | - Marcelo B. Labruna
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo 05508-270, SP, Brazil; (H.R.B.); (H.R.L.); (D.M.L.); (V.D.G.); (F.B.C.); (V.N.R.)
- Correspondence: ; Tel.: +55-11-3091-1394
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Estrada-Peña A, Binder LC, Nava S, Szabó MPJ, Labruna MB. Exploring the ecological and evolutionary relationships between Rickettsia and hard ticks in the Neotropical region. Ticks Tick Borne Dis 2021; 12:101754. [PMID: 34126403 DOI: 10.1016/j.ttbdis.2021.101754] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 11/28/2022]
Abstract
This study addresses a meta-analysis of the distribution of Rickettsia spp. in the Neotropical region, as well as their associations with ticks and vertebrates. A total of 219 published reports on Rickettsia in ticks in the target region were compiled, providing 599 records of 31 species of Rickettsia recorded in 50 species of Ixodidae. The aim is to capture the phylogenetic relationships between rickettsiae and the ticks carrying them in the target region, with a focus on the co-speciation ticks-rickettsiae. We compared the phylogeny of ticks, the records of rickettsiae, the environmental gradients colonized by ticks and the effect of the phylogenetic composition of vertebrates feeding ticks on the detection of Rickettsia in ticks. Results show that differences in rickettsial composition in ticks do not depend on the vertebrate's blood-source. This is the first time this result is demonstrated. This study pinpoints that some Neotropical rickettsial organisms are associated with well-defined phylogenetical clusters of ticks. Secondarily, and probably only in a few cases, rickettsiae share species of phylogenetically distant ticks distributed along a gradient of environmental traits in which the ticks overlap (i.e., the different strains of Rickettsia parkeri sensu lato). We outline the importance of some ticks that share hosts and habitat: these ticks may act as "bridges" for the circulation of rickettsial species. There are also many species of Rickettsia that have been detected so far in only one tick species, pointing to a tight relationship or to the lack of data preventing conclusions about the detection of these bacteria in other ticks. Two species, namely Rickettsia amblyommatis and Rickettsia bellii have been recorded in the majority of ticks in the region (mainly Amblyomma spp.) and seem to be not associated with definite tick species because they may be an essential symbiont of the ticks. We conclude that an adequate analysis of rickettsiae-ticks-habitat is necessary to address the human health issues derived from the infections by rickettsiae.
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Affiliation(s)
- Agustín Estrada-Peña
- Department of Animal Health. Faculty of Veterinary Medicine. Miguel Servet, 177. 50013 Zaragoza, Spain; Group of Research on Emerging Zoonoses, Instituto Agroalimentario de Aragón (IA2), 50013 Zaragoza, Spain.
| | - Lina C Binder
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva, 87, Cidade Universitária. São Paulo, SP, 05508-270, Brazil
| | - Santiago Nava
- IDICAL (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria (INTA), E.E.A. Rafaela, Ruta 34 km 227, CP 2300, Rafaela, Santa Fe, Argentina
| | - Matias P J Szabó
- Hospital Veterinário, Universidade Federal de Uberlândia, Av. Mato Grosso, 3289 - Bloco 2S - Umuarama, Uberlândia, MG, 38405-314, Brazil
| | - Marcelo B Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva, 87, Cidade Universitária. São Paulo, SP, 05508-270, Brazil
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15
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Bermúdez S, Martínez-Mandiche J, Domínguez L, Gonzalez C, Chavarria O, Moreno A, Góndola J, Correa N, Rodríguez I, Castillo B, Smith D, Martínez AA. Diversity of Rickettsia in ticks collected from wild animals in Panama. Ticks Tick Borne Dis 2021; 12:101723. [PMID: 33857748 DOI: 10.1016/j.ttbdis.2021.101723] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 02/08/2023]
Abstract
This paper presents new data about Rickettsia species detected in ticks collected from wild animals, using 16S rRNA, gltA and ompA. Rickettsia DNA was found in 66 of 101 ticks. Using EZ BioCloud libraries were produced reads that identified Rickettsia aeschlimannii, and Illumina BaseSpace produced reads of Rickettsia rickettsii group, Rickettsia bellii group, and unclassified Rickettsia. Using gltA and ompA gene-specific primers, R. aeschlimannii could not be confirmed, but detection of Rickettsia amblyommatis was achieved in Amblyomma auricularium, Amblyomma geayi, Amblyomma mixtum, and Amblyomma pacae; R. bellii from Amblyomma dissimile, "Candidatus Rickettsia colombianensi" from A. dissimile, Rickettsia spp. closely related to R. raoultii from A. geayi, Rickettsia tamurae from A. dissimile, and Rickettsia endosymbionts of Ixodes from Ixodes affinis. There were no databases available specifically for 16S rRNA of Neotropical Rickettsia, highlighting the need to use species primers over only 16S rRNA primers to achieve more accurate interpretations and identifications. These findings increase the number of Rickettsia species detected in Panama and highlight the need to establish isolates to further characterize the nature of Rickettsia in the area.
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Affiliation(s)
- Sergio Bermúdez
- Gorgas Memorial Institute of Health Studies, Panama, Panama; Coiba Scientific Station, Coiba AIP, City of Knowledge, Panama.
| | | | | | | | - Oris Chavarria
- Gorgas Memorial Institute of Health Studies, Panama, Panama
| | - Ambar Moreno
- Gorgas Memorial Institute of Health Studies, Panama, Panama
| | | | - Néstor Correa
- Panamerican Conservation Association, Panama, Panama
| | | | | | | | - Alexander A Martínez
- Gorgas Memorial Institute of Health Studies, Panama, Panama; Coiba Scientific Station, Coiba AIP, City of Knowledge, Panama; Panamerican Conservation Association, Panama, Panama; Summit, Municipal Park, Panama, Panama.
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Didelphis spp. opossums and their parasites in the Americas: A One Health perspective. Parasitol Res 2021; 120:4091-4111. [PMID: 33788021 PMCID: PMC8599228 DOI: 10.1007/s00436-021-07072-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/26/2021] [Indexed: 12/16/2022]
Abstract
Medium sized opossums (Didelphis spp.) are among the most fascinating mammals of the Americas, playing important ecological roles (e.g., dispersal of seeds and control of insect populations) in the environment they inhabit. Nevertheless, as synanthropic animals, they are well adapted to human dwellings, occupying shelters within the cities, peripheral areas, and rural settings. These marsupials can harbor numerous pathogens, which may affect people, pets, and livestock. Among those, some protozoa (e.g., Leishmania infantum, Trypanosoma cruzi, Toxoplasma gondii), helminths (e.g., Ancylostoma caninum, Trichinella spiralis, Alaria marcianae, Paragonimus spp.) and arthropods (e.g., ticks, fleas) present substantial public health and veterinary importance, due to their capacity to cause disease in humans, domestic animals, and wildlife. Here, we reviewed the role played by opossums on the spreading of zoonotic parasites, vectors, and vector-borne pathogens, highlighting the risks of pathogens transmission due to the direct and indirect interaction of humans and domestic animals with Didelphis spp. in the Americas.
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Mendoza-Roldan JA, Ribeiro SR, Castilho-Onofrio V, Marcili A, Simonato BB, Latrofa MS, Benelli G, Otranto D, Barros-Battesti DM. Molecular detection of vector-borne agents in ectoparasites and reptiles from Brazil. Ticks Tick Borne Dis 2020; 12:101585. [PMID: 33113476 DOI: 10.1016/j.ttbdis.2020.101585] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 02/02/2023]
Abstract
Trombidiformes and Mesostigmata mites, as well as Ixodida ticks, infest ectothermic tetrapods worldwide, potentially acting as vectors of bacteria, viruses and protozoa. The relationship among ectoparasites, transmitted pathogenic agents (e.g., Borrelia spp., Coxiella spp., Hepatozoon spp., and Rickettsia spp.) and ectothermic hosts has been scarcely investigated. This research focuses on a large collection of Brazilian herpetofauna screened for the presence of arthropod ectoparasites and vector-borne microbial agents. Reptiles (n = 121) and amphibians (n = 49) from various locations were infested by ectoparasites. Following genomic extraction, microbial agents were detected in 81 % of the Acari (i.e. n = 113 mites and n = 26 ticks). None of the mites, ticks and tissues from amphibians yielded positive results for any of the screened agents. Blood was collected from reptiles and processed through blood cytology and molecular analyses (n = 48). Of those, six snakes (12.5 %) showed intraerythrocytic alterations compatible with Hepatozoon spp. gamonts and Iridovirus inclusions. Hepatozoon spp. similar to Hepatozoon ayorgbor and Hepatozoon musa were molecularly identified from seven hosts, two mite and two tick species. Rickettsia spp. (e.g., Rickettsia amblyommatis, Rickettsia bellii-like, Rickettsia sp.) were detected molecularly from four mite species and Amblyomma rotundatum ticks. Phylogenetic analyses confirmed the molecular identification of the above-mentioned microbial agents of mites and ticks related to snakes and lizards. Overall, our findings highlighted that the Brazilian herpetofauna and its ectoparasites harbour potentially pathogenic agents, particularly from the northern and south-eastern regions. The detection of several species of spotted fever group Rickettsia pointed out the potential role of ectothermic hosts and related arthropod ectoparasites in the epidemiological cycle of these bacteria in Brazil.
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Affiliation(s)
- Jairo Alfonso Mendoza-Roldan
- Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy; Faculty of Veterinary Medicine, University of São Paulo, São Paulo, 05508-270, Brazil; Zoological Collections Laboratory, Butantan Institute, São Paulo, 05503-900, Brazil.
| | - Stephany Rocha Ribeiro
- Zoological Collections Laboratory, Butantan Institute, São Paulo, 05503-900, Brazil; Master's Program in Veterinary Medicine and Animal Welfare, and Doctoral Program in One Health, Santo Amaro University, São Paulo, 04829-300, Brazil
| | - Valeria Castilho-Onofrio
- Zoological Collections Laboratory, Butantan Institute, São Paulo, 05503-900, Brazil; Master's Program in Veterinary Medicine and Animal Welfare, and Doctoral Program in One Health, Santo Amaro University, São Paulo, 04829-300, Brazil
| | - Arlei Marcili
- Faculty of Veterinary Medicine, University of São Paulo, São Paulo, 05508-270, Brazil; Master's Program in Veterinary Medicine and Animal Welfare, and Doctoral Program in One Health, Santo Amaro University, São Paulo, 04829-300, Brazil
| | - Bruna Borghi Simonato
- Deparment of Veterinary Medicine, Anhembi Morumbi University Vila Tramontano, São Paulo, SP, 05650-000, Brazil
| | | | - Giovanni Benelli
- Department of Agriculture, Food and Environment, University of Pisa, via Del Borghetto 80, 56124, Pisa, Italy
| | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy; Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Felestin Sq., Hamedan, Iran
| | - Darci Moraes Barros-Battesti
- Faculty of Veterinary Medicine, University of São Paulo, São Paulo, 05508-270, Brazil; Department of Veterinary Pathology, Universidade Estadual Paulista Julio De Mesquita Filho (UNESP), Jaboticabal, 14884-900, Brazil
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18
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Dias TC, Stabach JA, Huang Q, Labruna MB, Leimgruber P, Ferraz KMPMB, Lopes B, Luz HR, Costa FB, Benatti HR, Correa LR, Nievas AM, Monticelli PF, Piovezan U, Szabó MPJ, Aguiar DM, Brites-Neto J, Port-Carvalho M, Rocha VJ. Habitat selection in natural and human-modified landscapes by capybaras (Hydrochoerus hydrochaeris), an important host for Amblyomma sculptum ticks. PLoS One 2020; 15:e0229277. [PMID: 32817698 PMCID: PMC7444575 DOI: 10.1371/journal.pone.0229277] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 08/06/2020] [Indexed: 01/07/2023] Open
Abstract
Human activities are changing landscape structure and function globally, affecting wildlife space use, and ultimately increasing human-wildlife conflicts and zoonotic disease spread. Capybaras (Hydrochoerus hydrochaeris) are linked to conflicts in human-modified landscapes (e.g. crop damage, vehicle collision), as well as the spread and amplification of Brazilian spotted fever (BSF), the most human-lethal tick-borne disease in the world. Even though it is essential to understand the link between capybaras, ticks and BSF, many knowledge gaps still exist regarding the effects of human disturbance in capybara space use. Here, we analyzed diurnal and nocturnal habitat selection strategies of capybaras across natural and human-modified landscapes using resource selection functions (RSF). Selection for forested habitats was higher across human-modified landscapes, mainly during day- periods, when compared to natural landscapes. Across natural landscapes, capybaras avoided forests during both day- and night periods. Water was consistently selected across both landscapes, during day- and nighttime. Distance to water was also the most important variable in predicting capybara habitat selection across natural landscapes. Capybaras showed slightly higher preferences for areas near grasses/shrubs across natural landscapes, and distance to grasses/shrubs was the most important variable in predicting capybara habitat selection across human-modified landscapes. Our results demonstrate human-driven variation in habitat selection strategies by capybaras. This behavioral adjustment across human-modified landscapes may be related to increases in A. sculptum density, ultimately affecting BSF.
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Affiliation(s)
- Thiago C. Dias
- Centro de Ciências Biológicas e da Saúde, Programa de Pós-graduação em Ecologia e Recursos Naturais, Universidade Federal de São Carlos, São Carlos, São Paulo, Brasil
- Departamento de Ciências da Natureza, Matemática e Educação, Laboratório de Fauna, Universidade Federal de São Carlos, Araras, São Paulo, Brasil
- Conservation Ecology Center, Smithsonian National Zoo & Conservation Biology Institute, Front Royal, Virginia, United States of America
- * E-mail: (TCD); (VJR)
| | - Jared A. Stabach
- Conservation Ecology Center, Smithsonian National Zoo & Conservation Biology Institute, Front Royal, Virginia, United States of America
| | - Qiongyu Huang
- Conservation Ecology Center, Smithsonian National Zoo & Conservation Biology Institute, Front Royal, Virginia, United States of America
| | - Marcelo B. Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Peter Leimgruber
- Conservation Ecology Center, Smithsonian National Zoo & Conservation Biology Institute, Front Royal, Virginia, United States of America
| | - Katia M. P. M. B. Ferraz
- Departamento de Ciências Florestais, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, São Paulo, Brasil
| | - Beatriz Lopes
- Departamento de Ciências Florestais, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, São Paulo, Brasil
| | - Hermes R. Luz
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brasil
- Departamento de Patologia, Programa de Pós-graduação em Biotecnologia do Renorbio, Universidade Federal do Maranhão, São Luís, Maranhão, Brasil
| | - Francisco B. Costa
- Departamento de Patologia, Programa de Pós-graduação em Biotecnologia do Renorbio, Universidade Federal do Maranhão, São Luís, Maranhão, Brasil
- Departamento de Patologia, Faculdade de Medicina Veterinária, Universidade Estadual do Maranhão, São Luís, Maranhão, Brasil
| | - Hector R. Benatti
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Lucas R. Correa
- Departamento de Ciências da Natureza, Matemática e Educação, Laboratório de Fauna, Universidade Federal de São Carlos, Araras, São Paulo, Brasil
| | - Ana M. Nievas
- Faculdade de Filosofia, Ciências e Letras, Laboratório de Etologia e Bioacústica, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Patrícia F. Monticelli
- Faculdade de Filosofia, Ciências e Letras, Laboratório de Etologia e Bioacústica, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Ubiratan Piovezan
- Embrapa Pantanal, Corumbá, Mato Grosso do Sul, Brasil
- Embrapa Tabuleiros Costeiros, Aracaju, Sergipe, Brasil
| | - Matias P. J. Szabó
- Faculdade de Medicina Veterinária, Laboratório de Ixodologia, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil
| | - Daniel M. Aguiar
- Faculdade de Medicina Veterinária, Laboratório de Virologia e Rickettsioses, Universidade Federal do Mato Grosso, Cuiabá, Mato Grosso, Brasil
| | - José Brites-Neto
- Programa de Vigilância e Controle de Carrapatos e Escorpiões, Secretaria Municipal de Saúde, Americana, SP, Brasil
| | - Marcio Port-Carvalho
- Divisão de Florestas e Parques Estaduais, Instituto Florestal, São Paulo, São Paulo, Brasil
| | - Vlamir J. Rocha
- Departamento de Ciências da Natureza, Matemática e Educação, Laboratório de Fauna, Universidade Federal de São Carlos, Araras, São Paulo, Brasil
- * E-mail: (TCD); (VJR)
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19
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Clinical and serological evaluation of capybaras (Hydrochoerus hydrochaeris) successively exposed to an Amblyomma sculptum-derived strain of Rickettsia rickettsii. Sci Rep 2020; 10:924. [PMID: 31969607 PMCID: PMC6976648 DOI: 10.1038/s41598-020-57607-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/02/2020] [Indexed: 11/08/2022] Open
Abstract
Brazilian spotted fever (BSF), caused by Rickettsia rickettsii, is the most lethal tick-borne disease in the western hemisphere. In Brazil, Amblyomma sculptum ticks are the main vector. Capybaras (Hydrochoerus hydrochaeris), the largest living rodents of the world (adults weighing up to 100 Kg), have been recognized as amplifying hosts of R. rickettsii for A. sculptum in BSF-endemic areas; i.e., once primarily infected, capybaras develop bacteremia for a few days, when feeding ticks acquire rickettsial infection. We conducted experimental infections of five capybaras with an A. sculptum-derived strain of R. rickettsii and performed clinical and bacteremia evaluation during primary and subsequent infections. Bacteremia was detected in all capybaras during primary infection, but not in subsequent infections. All animals seroconverted to R. rickettsii (titres range: 64-32,768), and remained seropositive throughout the study. Primary infection resulted in clinical spotted fever illness in four capybaras, of which two had a fatal outcome. Subsequent infections in seropositive capybaras resulted in no clinical signs. Capybaras developed a sustained immune response that prevented a second bacteremia. This condition may imply a high reproduction rate of capybaras in BSF-endemic areas, in order to continuously generate capybaras susceptible to bacteremia during primary infection.
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20
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Costa FB, Gerardi M, Binder LDC, Benatti HR, Serpa MCDA, Lopes B, Luz HR, Ferraz KMPMB, Labruna MB. Rickettsia rickettsii (Rickettsiales: Rickettsiaceae) Infecting Amblyomma sculptum (Acari: Ixodidae) Ticks and Capybaras in a Brazilian Spotted Fever-Endemic Area of Brazil. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:308-311. [PMID: 31504641 DOI: 10.1093/jme/tjz141] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Indexed: 06/10/2023]
Abstract
The bacterium Rickettsia rickettsii is the agent of Brazilian spotted fever (BSF), a highly fatal disease that is transmitted in Brazil mainly by the tick Amblyomma sculptum Berlese, which uses capybaras (Hydrochoerus hydrochaeris Linnaeus) as major hosts. In 2015, we captured nine capybaras in a BSF-endemic area of southeastern Brazil. From each capybara, we collected blood sera that were tested through the immunofluorescence assay using Rickettsia spp. antigens, and A. sculptum ticks, processed for isolation of R. rickettsii through guinea pig inoculation. All capybaras (100%) were seroreactive to Rickettsia spp., with highest titers to R. rickettsii. A total of 166 A. sculptum ticks were macerated and inoculated into nine guinea pigs, from which only one presented high fever and seroconverted to R. rickettsii. Blood from this febrile animal was inoculated into additional guinea pigs (guinea pig passages), which also became febrile and seroconverted, or when euthanized during the fever period, their internal organs (spleen, lung) were shown to contain R. rickettsii DNA. The present rickettsial isolate has been maintained cryopreserved as infected guinea pig organs. There was at least one R. rickettsii-infected tick among the 166 macerated ticks, giving a minimal infection rate of 0.6% (1/166). This infection rate is within the range of previous studies, which reported that only 0.05% to at most 1.28% A. sculptum ticks were infected by R. rickettsii in other BSF-endemic areas. These low infection rates support the low incidence of BSF, despite of A. sculptum being the most frequent human-biting tick in southeastern Brazil.
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Affiliation(s)
- Francisco B Costa
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
- Departamento de Patologia, Programa de Pós-graduação em Ciência Animal, Universidade Estadual do Maranhão, São Luís, MA, Brazil
| | - Monize Gerardi
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Lina de C Binder
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Hector R Benatti
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Maria Carolina de Azevedo Serpa
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Beatriz Lopes
- Departamento de Ciências Florestais, Universidade de São Paulo, Escola Superior de Agricultura 'Luiz de Queiroz', Piracicaba, SP, Brazil
| | - Hermes R Luz
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
- Departamento de Patologia, Programa de Pós-Graduação em Biotecnologia do RENORBIO, Ponto Focal Maranhão, Universidade Federal do Maranhão, São Luís, MA, Brazil
| | - Katia M P M B Ferraz
- Departamento de Ciências Florestais, Universidade de São Paulo, Escola Superior de Agricultura 'Luiz de Queiroz', Piracicaba, SP, Brazil
| | - Marcelo B Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
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21
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Rosenfield DA, Polo G, Pizzutto CS. Brazilian Spotted Fever Prevention through a Nonlethal Capybara Population Control Strategy. Rev Soc Bras Med Trop 2019; 52:e20190156. [PMID: 31596349 DOI: 10.1590/0037-8682-0156-2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/13/2019] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Brazilian spotted fever (BSF), a lethal tick-borne Rickettsioses (2000 - 2018 >600 human deaths) involving synanthropic capybara as host. METHODS We introduced an alternative to mitigate human-capybara conflicts and epidemiologic concerns of BSF. Complex aspects like transmission dynamics, risk areas, host mobility, and birth rate control, were considered to develop a prevention strategy using an anti-GnRH vaccine. RESULTS The propositioned immunocontraceptive potentially remove and prevent the spread of BSF from endemic areas. CONCLUSIONS We propose the anti-GnRH vaccine as a BSF prevention strategy based on these favorable results.
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Affiliation(s)
- Derek Andrew Rosenfield
- Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Programa de Pós-Graduação em Reprodução Animal, São Paulo, SP, Brasil
| | - Gina Polo
- Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Medicina Veterinária Preventiva e Saúde Animal, São Paulo, SP, Brasil
| | - Cristiane Schilbach Pizzutto
- Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Programa de Pós-Graduação em Reprodução Animal, São Paulo, SP, Brasil
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22
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Luz HR, Costa FB, Benatti HR, Ramos VN, de A Serpa MC, Martins TF, Acosta ICL, Ramirez DG, Muñoz-Leal S, Ramirez-Hernandez A, Binder LC, Carvalho MP, Rocha V, Dias TC, Simeoni CL, Brites-Neto J, Brasil J, Nievas AM, Monticelli PF, Moro MEG, Lopes B, Aguiar DM, Pacheco RC, Souza CE, Piovezan U, Juliano R, Ferraz KMPMB, Szabó MPJ, Labruna MB. Epidemiology of capybara-associated Brazilian spotted fever. PLoS Negl Trop Dis 2019; 13:e0007734. [PMID: 31490924 PMCID: PMC6750615 DOI: 10.1371/journal.pntd.0007734] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/18/2019] [Accepted: 08/26/2019] [Indexed: 01/13/2023] Open
Abstract
Background Brazilian spotted fever (BSF), caused by the bacterium Rickettsia rickettsii, has been associated with the transmission by the tick Amblyomma sculptum, and one of its main hosts, the capybara (Hydrochoerus hydrochaeris). Methods During 2015–2019, we captured capybaras and ticks in seven highly anthropic areas of São Paulo state (three endemic and four nonendemic for BSF) and in two natural areas of the Pantanal biome, all with established populations of capybaras. Results The BSF-endemic areas were characterized by much higher tick burdens on both capybaras and in the environment, when compared to the BSF-nonendemic areas. Only two tick species (A. sculptum and Amblyomma dubitatum) were found in the anthropic areas; however, with a great predominance of A. sculptum (≈90% of all ticks) in the endemic areas, in contrast to a slight predominance of A. dubitatum (≈60%) in the nonendemic areas. Tick species richness was higher in the natural areas, where six species were found, albeit with a predominance of A. sculptum (≈95% of all ticks) and environmental tick burdens much lower than in the anthropic areas. The BSF-endemic areas were characterized by overgrowth populations of A. sculptum that were sustained chiefly by capybaras, and decreased populations of A. dubitatum. In contrast, the BSF-nonendemic areas with landscape similar to the endemic areas differed by having lower tick burdens and a slight predominance of A. dubitatum over A.sculptum, both sustained chiefly by capybaras. While multiple medium- to large-sized mammals have been incriminated as important hosts for A. sculptum in the natural areas, the capybara was the only important host for this tick in the anthropic areas. Conclusions The uneven distribution of R. rickettsii infection among A. sculptum populations in highly anthropic areas of São Paulo state could be related to the tick population size and its proportion to sympatric A. dubitatum populations. Brazilian spotted fever (BSF), caused by the bacterium Rickettsia rickettsii, is the deadliest tick-borne disease of the New World. In southeastern Brazil, where 489 patients succumbed to the disease from 2001 to 2018, R. rickettsii is transmitted to humans mainly by the tick Amblyomma sculptum, which uses the capybara (Hydrochoerus hydrochaeris) as its main host. During 2015–2019, we captured capybaras and ticks in seven highly anthropic areas of São Paulo state (three endemic and four nonendemic for BSF) and in two natural areas of the Pantanal biome. The BSF-endemic areas were characterized by much higher tick burdens on both capybaras and in the environment, with a predominance of Amblyomma sculptum. In the BSF-nonendemic areas, another tick species, Amblyomma dubitatum, outnumbered A. sculptum. In the natural areas, six tick species were found; however, with much lower numbers than in the anthropic areas. The BSF-endemic areas were characterized by overgrowth populations of A. sculptum that were sustained chiefly by capybaras, and decreased populations of A. dubitatum. Results of this study support the idea that any intervention resulting in a drastic reduction of the A. sculptum population shall eliminate the R. rickettsii infection from the tick population, and consequently, prevent new BSF cases.
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Affiliation(s)
- Hermes R Luz
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.,Departamento de Patologia, Programa de Pós Graduação em Biotecnologia do Renorbio, Ponto Focal Maranhão, Universidade Federal do Maranhão, São Luís, MA, Brazil
| | - Francisco B Costa
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.,Departamento de Patologia, Faculdade de Medicina Veterinária, Universidade Estadual do Maranhão, São Luís, MA, Brazil
| | - Hector R Benatti
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Vanessa N Ramos
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.,Pós-Doutorado em Ciências Veterinárias, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Maria Carolina de A Serpa
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Thiago F Martins
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Igor C L Acosta
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Diego G Ramirez
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.,Departamento de Parasitologia Animal, Instituto de Medicina Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - Sebastián Muñoz-Leal
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Alejandro Ramirez-Hernandez
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Lina C Binder
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Vlamir Rocha
- Centro de Ciências Agrárias, Universidade Federal de São Carlos, Araras, SP, Brazil
| | - Thiago C Dias
- Centro de Ciências Agrárias, Universidade Federal de São Carlos, Araras, SP, Brazil.,Programa de Pós-graduação em Ecologia e Recursos Naturais, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Camila L Simeoni
- Centro de Ciências Agrárias, Universidade Federal de São Carlos, Araras, SP, Brazil
| | - José Brites-Neto
- Departamento de Vigilância Epidemiológica, Secretaria Municipal de Saúde, Americana, SP, Brazil
| | - Jardel Brasil
- Departamento de Vigilância Epidemiológica, Secretaria Municipal de Saúde, Americana, SP, Brazil
| | - Ana Maria Nievas
- Departamento de Psicologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Patricia Ferreira Monticelli
- Departamento de Psicologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Maria Estela G Moro
- Departamento de Zootecnia, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, SP, Brazil
| | - Beatriz Lopes
- Departamento de Ciências Florestais, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Daniel M Aguiar
- Programa de Pós-graduação em Ciências Veterinárias, Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Richard C Pacheco
- Programa de Pós-graduação em Ciências Veterinárias, Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Celso Eduardo Souza
- Laboratório de Carrapatos, Superintendência de Controle de Endemias, Mogi Guaçu, SP, Brazil
| | - Ubiratan Piovezan
- Embrapa Pantanal, Corumbá, MS, Brazil.,Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil
| | | | - Katia Maria P M B Ferraz
- Departamento de Ciências Florestais, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Matias P J Szabó
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Marcelo B Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil
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23
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Makenov M, Karan L, Shashina N, Akhmetshina M, Zhurenkova O, Kholodilov I, Karganova G, Smirnova N, Grigoreva Y, Yankovskaya Y, Fyodorova M. First detection of tick-borne encephalitis virus in Ixodes ricinus ticks and their rodent hosts in Moscow, Russia. Ticks Tick Borne Dis 2019; 10:101265. [PMID: 31447316 DOI: 10.1016/j.ttbdis.2019.101265] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 07/10/2019] [Accepted: 07/28/2019] [Indexed: 12/30/2022]
Abstract
Here, we report the first confirmed autochthonous tick-borne encephalitis case diagnosed in Moscow in 2016 and describe the detection of tick-borne encephalitis virus (TBEV) in ticks and small mammals in a Moscow park. The paper includes data from two patients who were bitten by TBEV-infected ticks in Moscow city; one of these cases led to the development of the meningeal form of TBE. Both TBEV-infected ticks attacked patients in the same area. We collected ticks and trapped small mammals in this area in 2017. All samples were screened for the presence of pathogens causing tick-borne diseases by PCR. The TBEV-positive ticks and small mammals' tissue samples were subjected to virus isolation. The sequencing of the complete polyprotein gene of the positive samples was performed. A total of 227 questing ticks were collected. TBEV was detected in five specimens of Ixodes ricinus. We trapped 44 small mammals, mainly bank voles (Myodes glareolus) and pygmy field mice (Apodemus uralensis). Two samples of brain tissue from bank voles yielded a positive signal in RT-PCR for TBEV. We obtained six virus isolates from the ticks and brain tissue of a bank vole. Complete genome sequencing showed that the obtained isolates belong to the European subtype and have low diversity with sequence identities as high as 99.9%. GPS tracking showed that the maximum distance between the exact locations where the TBEV-positive ticks were collected was 185 m. We assume that the forest park had been free of TBEV and that the virus was recently introduced.
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Affiliation(s)
- Marat Makenov
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia.
| | - Lyudmila Karan
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia
| | - Natalia Shashina
- Sсiеntifiс Rеsеarсh Disinfесtology Institutе, Nauchniy proezd st. 18, Moscow, 117246, Russia
| | - Marina Akhmetshina
- Sсiеntifiс Rеsеarсh Disinfесtology Institutе, Nauchniy proezd st. 18, Moscow, 117246, Russia
| | - Olga Zhurenkova
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia
| | - Ivan Kholodilov
- Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI "Chumakov FSC R&D IBP RAS), prem. 8, k.17, pos. Institut Poliomyelita, poselenie Moskovskiy, Moscow, 108819, Russia
| | - Galina Karganova
- Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI "Chumakov FSC R&D IBP RAS), prem. 8, k.17, pos. Institut Poliomyelita, poselenie Moskovskiy, Moscow, 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov University, Bolshaya Pirogovskaya st, 2, page 4, room 106, Moscow, 119991, Russia
| | - Nina Smirnova
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia; Lomonosov Moscow State University, Leninskie Gory st. 1-12, MSU, Faculty of Biology, Moscow, 119991, Russia
| | - Yana Grigoreva
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia
| | - Yanina Yankovskaya
- Pirogov Russian National Research Medical University, Ostrovityanova st. 1, Moscow, 117997, Russia
| | - Marina Fyodorova
- Central Research Institute of Epidemiology, Novogireevskaya st 3-A, 415, Moscow, 111123, Russia
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Phenology of Amblyomma sculptum in a degraded area of Atlantic rainforest in north-eastern Brazil. Ticks Tick Borne Dis 2019; 10:101263. [PMID: 31331735 DOI: 10.1016/j.ttbdis.2019.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 07/11/2019] [Accepted: 07/14/2019] [Indexed: 11/22/2022]
Abstract
Amblyomma sculptum is the principal vector of Rickettsia rickettsii, the main agent of spotted fever rickettsiosis in Brazil. Little information is available regarding the population dynamics of this tick in some regions, including north-eastern Brazil, where cases of spotted fever rickettsioses are increasingly reported. Herein, we studied the phenology of A. sculptum in a rural area in north-eastern Brazil. Ticks were collected from the environment, using dry ice-baited traps, monthly for two consecutive years. In total, 1500 ticks were collected: 94 females (6.3%), 74 males (4.9%), 468 nymphs (31.2%), and 864 larvae (57.6%). All nymphs and females were identified as A. sculptum. Males were tentatively identified as A. sculptum and larvae as Amblyomma spp. Ticks were more numerous during spring and summer, followed by autumn and winter. Peaks of larvae and nymphs were recorded during summer and spring, respectively, whereas adults were more frequently collected in spring. A total of 380 ticks were tested by PCR for the gltA gene of Rickettsia spp., but none of them were positive. While our results revealed a seasonal pattern for A. sculptum in north-eastern Brazil that is distinct from the seasonal pattern in south-eastern Brazil, we caution that the observed pattern could have been biased by the relatively low number of ticks collected. Finally, the absence of Rickettsia-infected ticks does not rule out the possibility that rickettsial organisms are circulating in the study area and further long-term studies are warranted.
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Gerardi M, Ramírez-Hernández A, Binder LC, Krawczak FS, Gregori F, Labruna MB. Comparative Susceptibility of Different Populations of Amblyomma sculptum to Rickettsia rickettsii. Front Physiol 2019; 10:653. [PMID: 31191350 PMCID: PMC6546895 DOI: 10.3389/fphys.2019.00653] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
The bacterium Rickettsia rickettsii is the etiological agent of Brazilian spotted fever (BSF), which is transmitted in Brazil mainly by the tick Amblyomma sculptum. Herein, larvae and nymphs of six populations of A. sculptum were exposed to R. rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs or rabbits. Two tick populations were exposed to autochthone R. rickettsii strains, whereas four tick populations were exposed to non-autochthone strains. The six geographically different populations of A. sculptum showed different susceptibilities to R. rickettsii, higher among the two tick populations that were exposed to their autochthone R. rickettsii strain. In addition, higher rates of transovarial transmission of R. rickettsii and vector competence success also included the two tick populations that were exposed to autochthone R. rickettsii strains. These results indicate that the susceptibility of A. sculptum to R. rickettsii varies among different tick populations, with a clear bias for higher susceptibility to an autochthone R. rickettsii strain that has already coevolved with a tick population for some time. Our results demonstrated that the R. rickettsii infection induces higher mortality of engorged larvae and nymphs, and tend to reduce the reproductive fitness of engorged females. All together, these results might explain the low R. rickettsii-infection rates of A. sculptum under natural conditions (usually <1%), and indicate that an A. sculptum population should not be able to sustain a R. rickettsii infection for successive tick generations without the creation of new cohorts of infected ticks via horizontal transmission on vertebrate rickettsemic hosts (amplifying hosts). Finally, despite of the ubiquitous distribution of A. sculptum in southeastern and central-western Brazil, most of the populations of this tick species are devoid of R. rickettsii infection. This scenario might be related to two major factors: (i) insufficient numbers of susceptible amplifying hosts; and (ii) lower susceptibilities of many tick populations. While the first factor has been demonstrated by mathematical models in previous studies, the second is highlighted by the results observed in the present study.
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Affiliation(s)
| | | | | | | | | | - Marcelo B. Labruna
- Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
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Passos Nunes FB, da Silva SC, Cieto AD, Labruna MB. The Dynamics of Ticks and Capybaras in a Residential Park Area in Southeastern Brazil: Implications for the Risk of Rickettsia rickettsii Infection. Vector Borne Zoonotic Dis 2019; 19:711-716. [PMID: 31135286 DOI: 10.1089/vbz.2019.2479] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The bacterium Rickettsia rickettsii causes Brazilian spotted fever (BSF), a highly lethal disease that is transmitted by Amblyomma sculptum ticks in areas where capybaras (Hydrochoerus hydrochaeris) are the tick's major hosts. In this study, we evaluated the expansion of a capybara population in a residential park in São Paulo state, and the implications of such expansion to the occurrence of ticks and BSF. The capybara population was quantified during 2004-2013. In 2012, there was a BSF human case in the area, culminating in the complete fencing of the residential park and the official culling of all capybaras. Quantification of ticks in the environment was performed by dry ice traps from 2005 to 2018. Domestic dogs in 2006-2011 and capybaras in 2012 were serologically tested for the presence of anti-R. rickettsii antibodies. Our results show that capybara numbers increased ≈5 times from 2004 (41 capybaras) to 2012 (230 capybaras). Dry ice traps collected A. sculptum and Amblyomma dubitatum. The number of A. dubitatum adult ticks was generally higher than A. sculptum adults during 2005-2006; however, during 2012-2013, A. sculptum outnumbered A. dubitatum by a large difference. During 2016-2018 (after capybara culling), the number of both species fell close to zero. The low numbers of A. sculptum adult ticks during 2005-2006 coincided with relatively low capybara numbers (<80). Thereafter, in 2012, we counted the highest numbers of both A. sculptum ticks and capybaras (230 animals). All 40 canine blood samples were seronegative to R. rickettsii, in contrast to the 48.3% seropositivity (83/172) among capybaras. Our results support that the emergence of BSF in the residential park was a consequence of the increase of the local capybara population, which in turn, provided the increment of the A. sculptum population. Culling the entire capybara population eliminated the risks of new BSF cases.
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Affiliation(s)
- Fernanda B Passos Nunes
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil.,A Z Nunes & Cia Ltda, Itu, Brazil
| | | | - Alex Deiws Cieto
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Marcelo B Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
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Hosts mobility and spatial spread of Rickettsia rickettsii. PLoS Comput Biol 2018; 14:e1006636. [PMID: 30586381 PMCID: PMC6324817 DOI: 10.1371/journal.pcbi.1006636] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 01/08/2019] [Accepted: 11/09/2018] [Indexed: 12/14/2022] Open
Abstract
There are a huge number of pathogens with multi-component transmission cycles, involving amplifier hosts, vectors or complex pathogen life cycles. These complex systems present challenges in terms of modeling and policy development. A lethal tick-borne infectious disease, the Brazilian Spotted Fever (BSF), is a relevant example of that. The current increase of human cases of BSF has been associated with the presence and expansion of the capybara Hydrochoerus hydrochaeris, amplifier host for the agent Rickettsia rickettsii and primary host for the tick vector Amblyomma sculptum. We introduce a stochastic dynamical model that captures the spatial distribution of capybaras and ticks to gain a better understanding of the spatial spread of the R. rickettsii and potentially predict future epidemic outcomes. We implemented a reaction-diffusion process in which individuals were divided into classes denoting their state with respect to the disease. The model considered bidirectional movements between base and destination locations limited by the carrying capacity of the environment. We performed systematic stochastic simulations and numerical analysis of the model and investigate the impact of potential interventions to mitigate the spatial spread of the disease. The mobility of capybaras and their attached ticks was significantly influenced by the birth rate of capybaras and therefore, disease propagation velocity was higher in places with higher carrying capacity. Some geographical barriers, generated for example by riparian reforesting, can impede the spatial spread of BSF. The results of this work will allow the formulation of public actions focused on the prevention of BSF human cases. Complex systems as the Brazilian Spotted Fever (BSF), present challenges in terms of modeling and policy development. BSF human cases have been associated with the presence and expansion of the capybara Hydrochoerus hydrochaeris, amplifier host for the agent Rickettsia rickettsii and primary host for the tick vector Amblyomma sculptum. We developed a reaction-diffusion system for the spread of BSF by considering the spatial structure and migration of amplifier hosts to gain a better understanding of the spatial spread of the R. rickettsii and potentially predict future epidemic outcomes. We performed stochastic simulations and numerical analysis to investigate the impact of potential interventions to mitigate the spatial spread of the disease. Our results indicate that as we vary the amount of capybaras’ food sources, the velocity at which the disease advances is roughly proportional to the carrying capacity, hence proportional to the local risk of zoonotic infection. Some geographical barriers, generated for example by riparian reforesting, can generate positive ecological impacts and can impede the spread of BSF to humans.
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Polo G, Labruna MB, Ferreira F. Basic reproduction number for the Brazilian Spotted Fever. J Theor Biol 2018; 458:119-124. [PMID: 30222963 DOI: 10.1016/j.jtbi.2018.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 09/05/2018] [Accepted: 09/10/2018] [Indexed: 01/16/2023]
Abstract
Brazilian Spotted Fever (BSF) is an emerging and lethal disease in South America which basic reproduction number (R0) is unknown. Calculating R0 for this disease is crucial to design control interventions and prevent human deaths. BSF endemic areas are related to the presence of capybaras Hydrochoerus hydrochaeris, amplifier hosts of Rickettsia rickettsii and primary hosts of the tick Amblyomma sculptum, main vector of the agent in this area. Because of the complexity of its dynamics, we calculated R0 for the BSF system by constructing a next-generation matrix considering different categories of vectors and hosts. Each matrix element was considered as the expected number of infected individuals of one category produced by a single infected individual of a second category. We used field and experimental data to parameterize the next-generation matrix and obtain the final calculation (R0 ≈ 1.7). We demonstrated the low impact of the matrix elements corresponding to the transovarial transmission and the transmission from infected larvae in the maintenance of R. rickettsii. Sensitivity and elasticity analyzes were performed to quantify the perturbations of each matrix element in R0. We noted that the elements equivalent to the number of infected attached nymphs produced by an infected capybara, and the number of infected capybaras produced by an infected attached nymph or adult are the major contributors to changes in R0. Our results provide insights into the strategic design of preventive interventions in BSF endemic areas.
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Affiliation(s)
- Gina Polo
- Laboratory of Epidemiology and Biostatistics, Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo 05508-270 Brazil.
| | - Marcelo B Labruna
- Laboratory of Parasitic Diseases. Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo 05508-270, Brazil
| | - Fernando Ferreira
- Laboratory of Epidemiology and Biostatistics, Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo 05508-270 Brazil
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