Several vector-borne and zoonotic diseases have emerged or re-emerged in Europe over these last decades. Besides climate change that influences disease risk at a regional scale, landscape changes could be responsible for local heterogeneities in disease risk. Spatial epidemiology tries to understand and predict spatial variations in disease risk by using spatial tools and spatially-explicit modelling methods. This study investigated the impact of fine-grained landscape patterns on the transmission of vector-borne and zoonotic infections in terms of habitat suitability for vectors and/or hosts and of exposure of people to infectious agents. This was studied through three human diseases emerging or at risk of re-emergence in Europe: the rodent-borne Puumala hantavirus, the tick-borne Lyme borreliosis and the mosquito-borne malaria infections. Statistical models were first used to study the relationships between environmental variables and host abundance, host prevalence, and human cases of Puumala hantavirus. Environmental factors were also combined with socio-economic factors to explain Puumala hantavirus and Lyme borreliosis incidence rates. The combination of factors explaining disease transmission and the complexity of such systems led to the development of an innovative, spatially-explicit modelling method: multi-agent simulation (MAS). The MALCAM simulation model was developed to assess the risk of malaria re-emergence in southern France and simulates spatial and temporal variations in contact rate between people and potential malaria vectors. The effect of changes in potential drivers of malaria re-emergence was also simulated. The different case studies showed that fine-grained landscape patterns influence the presence and abundance of vectors and hosts. Moreover, environmental conditions may also influence disease transmission through pathogen dispersal and the exposure of people to infectious agents. Finally, this study showed that people-vector contacts not only depend on the spatial distribution of people and potential vectors, but also on their behaviours and interactions.

Harris County Mosquito Control Division (HCMCD) is responsible for surveillance of mosquito species that are vectors of St. Louis Encephalitis (SLE) virus and West Nile Virus (WNV) within Harris County, Texas, including the Houston metroplex. The metroplex area has some unique attributes and a vast variety of environmental habitats that are attractive to vectors of arboviruses and for the transmission of arboviruses to the human population. Data describing the efficacy of Gravid (GV) and Underhouse (UH) CO2 traps were analyzed to determine if there is a significant difference between these two trap types with respect to the number of mosquitoes and the variety of mosquito species caught. This study was conducted during the off-peak HCMCD trapping season, to gain information in preparation for a yearround trapping program utilizing Underhouse CO2 traps for WNV and SLE virus surveillance. Adjusting for the week of collection, results suggest that Gravid traps caught significantly (P = 0.009) more mosquitoes (mean = 23.134 per trap) in the study area than Underhouse traps (mean = 3.616 per trap), and that Underhouse Traps caught a larger variety of mosquito species (n = 13) than Gravid Traps (n = 11), out of 15 total different species caught. Gravid and Underhouse traps caught 9 out of 15 of the same mosquito species during the study period. Culex quinquefasciatus mosquito catches in Gravid traps and temperature were strongly correlated (Spearman's Correlation Coefficient = 0.707, P = 0.005). Geographic Information System spatial analysis indicated clustering of Culex quinquefasciatus mosquito catches in both Gravid traps, week 9 and 21 (Moran's I = 0.69, P = 0.040 and 0.74, P = 0.021, respectfully ) and Underhouse traps, week 13 and 19 (Moran's I = 0.92, P = 0.002, and 0.89, P = 0.011, respectfully). It is recommended that Harris County Mosquito Control Division continue to utilize gravid traps as a primary method of surveillance. Gravid traps (16,194) caught 85% more mosquitoes than Underhouse traps (2,531) over the fourteen week study period. Their overall success far outweighs the additional materials or labor required for their use in a successful surveillance program.

O sequenciamento de alto desempenho, pela redução dos custos nos últimos anos, vem sendo cada vez mais utilizado para prospectar e identificar vírus. Estes métodos são extremamente mais sensíveis que outros métodos moleculares, e capazes de sequenciar genomas virais sem conhecimento prévio, clonagem ou isolamento. Neste estudo, utilizamos o sequenciamento de alto desempenho para conhecer, e caracterizar genomas completos de arbovírus isolados nas Américas, incluindo a prospecção de vírus em amostras de pequenos mamíferos do estado de São Paulo, Brasil. Assim, sequenciamos e caracterizamos 44 Bunyavirales, 35 no gênero Orthobunyavirus, família Peribunyaviridae, oito no gênero Phlebovirus, família Phenuiviridae, e um orthonairovírus, família Nairoviridae. Entre os Bunyavirales identificamos uma provável nova estratégia de codificação da proteína não estrutural do segmento pequeno, e ainda identificados sete vírus que são reassortants naturais. Caracterizamos o genoma completo do vesiculovírus Piry, determinando sua relação filogenética com arbovírus pertencentes ao gênero Vesiculovirus, família Rhabdoviridae. Prospectamos novos vírus, os quais incluímos em três famílias, Parvoviridae, Anelloviridae e Hepeviridae. Na família Parvoviridae, identificamos 20 chapparvovírus endógenos e exógenos, oriundos de grande diversidade de hospedeiros vertebrados e invertebrados, e que representam uma nova subfamília, a Chapparvovirinae. Também, descrevemos onze novas espécies de Anelloviridae em roedores silvestres e marsupiais, fornecendo importantes informações sobre a diversidade, a taxonomia, e ainda ampliamos a gama de hospedeiros de anellovírus conhecidos. Por fim, identificamos e caracterizamos uma nova espécie de Orthohepevirus de roedores Sigmodontinae, nomeada \"Orthohepevirus E\". Acreditamos que estamos a fornecer relevantes informações sobre genômica, epidemiologia molecular, evolução e taxonomia de 45 arbovírus americanos, bem como sobre 13 novas espécies virais encontradas em pequenos mamíferos. Tais informações deverão dar subsídios para múltiplos futuros estudos visando compreender a importância destes novos vírus e a desenvolver métodos diagnósticos. / In last years, high-throughput sequencing (HTS) has been cost-effective and increasingly used for prospection and identification of viruses. These methods are extremely more sensitive than other molecular methods and are capable of sequencing viral genomes without prior knowledge, cloning or isolation. In this study, we used HTS approach to identify and characterize complete genomes of arbovirus isolated in the Americas, as well as viral prospection in samples of small mammals from São Paulo State, Brazil. Thus, we sequenced and characterized 44 viruses from Bunyavirales order, including 35 in Orthobunyavirus genus, family Peribunyaviridae, eight in Phlebovirus genus, family Phenuiviridae, and one in Orthonairovirus genus, family Nairoviridae. Among the Bunyavirales we identified a novel putative strategy for encoding the non-structural protein of the small segment, as well as we identified seven viruses that are natural reassortants. Also, we characterized the complete genome of the Piry vesiculovirus, determining its phylogenetic relationship with arboviruses belonging to the Vesiculovirus genus, family Rhabdoviridae. On the other hand, we have prospected novel viruses, which included in three families, Parvoviridae, Anelloviridae, and Hepeviridae. In the Parvoviridae family, we identified 20 endogenous and exogenous chapparvoviruses from a broad diversity of vertebrate and invertebrate hosts, representing a new subfamily, the Chapparvovirinae. Also, we have described eleven new species of Anelloviridae in wild rodents and marsupials, providing important information on diversity, taxonomy and even broadening the range of known anelloviruses hosts. Finally, we identified and characterized a novel species of orthohepevirus in Sigmodontinae rodent, named \"Orthohepevirus E\". We believe that we are providing relevant relevant on genomics, molecular epidemiology, evolution and taxonomy of 45 American arboviruses, as well as on 13 new viral species found in small mammals. Thus, these informations should provide support for multiple future studies to understand the importance of these new viruses, as well as to develop diagnostic methods.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-05-19T13:08:10Z No. of bitstreams: 1 Maria Fernanda Melo Monteiro.pdf: 639501 bytes, checksum: 8ac4c3c948754bb276d69058aaf30f8b (MD5) / Made available in DSpace on 2016-05-19T13:08:10Z (GMT). No. of bitstreams: 1 Maria Fernanda Melo Monteiro.pdf: 639501 bytes, checksum: 8ac4c3c948754bb276d69058aaf30f8b (MD5) Previous issue date: 2016-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Rickettsial diseases are zoonotic infections caused by gram-negative bacteria of the family Rickettsiaceae which are transmitted by several ectoparasites such as ticks belonging to the genus Amblymomma, however, the species Rhipicephalus sanguineus sensu lato (s.l.) and Ctenocephalides felis felis have been reported as potential vectors.The aim of this study was to detect Rickettsia spp. DNA in R. sanguineus s.l. and C. felis felis through molecular examination (Polymerase Chain Reaction PCR). A total of 728 ectoparasites were collected of 155 dogs from the states of Pernambuco (municipalities of Recife and Bezerros) and Alagoas (municipalities of Viçosa and Arapiraca) were used in this study. All specimens were morphologically identified (R. sanguineus s.l. and C. felis felis), separated in pools (n = 3) and analyzed molecularly through PCR. Out of the 136 pools of R. sanguineus s.l. analyzed, 20.58% (28/136) and 80 pools of C. felis felis analyzed 31.20% (39/80) it was observed amplification fragment of 401 bp compatible with Rickettsia spp. In relation to the positivity of ectoparasites in the municipalities studied, it was observed that R. sanguineus s.l. was positive in the Metropolitan Area of Recife (20.49%) and Bezerros (22.22%), however in the state of Alagoas was not observed the positivity for Viçosa municipality, but, Arapiraca got 25% positive. With regard to C. felis felis it was observed that in Pernambuco 54.54% of samples were positive being derived from Metropolitan Area of Recife, while Bezerros municipality was not observed amplification of the fragment compatible with Rickettsia spp. In Alagoas, it was observed 12.50% of positivity for Arapiraca and 50.00% for Viçosa. This study reports, for the first time, the detection of Rickettsia spp. in R. sanguineus s.l. parasitizing dogs from the state of Pernambuco and R. sanguineus s.l. and C. felis felis parasitizing dogs from the state of Alagoas. Although there are no reports of Brazilian Spotted Fever (BSF) in the areas studied, the presence of infected ticks and fleas suggests the circulation of the pathogen between vertebrate hosts and vectors. / As riquetsioses são doenças zoonóticas causadas por bactérias gram-negativas da família Rickettsiaceae sendo transmitidas por diversos ectoparasitos, destacando-se os carrapatos do gênero Amblymomma, entretanto, as espécies Rhipicephalus sanguineus sensu lato (s.l.) e Ctenocephalides felis felis vêm sendo relatadas como vetores em potencial. Desta forma, o objetivo deste trabalho foi diagnosticar a infecção por Rickettsia spp. em R. sanguineus s.l. e C. felis felis através da Reação em Cadeia da Polimerase (PCR). Para tanto foram coletados 728 ectoparasitos de 155 cães de dois municípios do estado de Pernambuco (Recife e Bezerros) e de dois municípios do estado de Alagoas (Viçosa e Arapiraca). Todos os espécimes foram identificados morfologicamente (R. sanguineus s.l. e C. felis felis), sendo separados em pools (n = 3) e analisados através da PCR. Dos 136 pools de R. sanguineus s.l. analisados 20,58% (28/136) e dos 80 pools de C. felis felis analisadas 31,20% (39/80) foi observado amplificação de fragmento de 401 pb compatíveis com Rickettsia spp. Em relação à positividade dos ectoparasitos nos municípios estudados, observou-se que R. sanguineus s.l. foi positivo na Região Metropolitana do Recife (20,49%) e em Bezerros (22,22%), entretanto, no estado de Alagoas não foi observada positividade para o município de Viçosa, porém, Arapiraca obteve 25% de positividade. Em relação à C. felis felis observou-se que em Pernambuco 54,54% das amostras foram positivas sendo elas procedentes da Região Metropolitana do Recife, enquanto que no município de Bezerros não foi observada amplificação do fragmento compatível com Rickettsia spp. Já em Alagoas observou-se positividade de 12,50% para Arapiraca e 50,00% para Viçosa. Este estudo reporta pela primeira vez a detecção de Rickettsia spp. em R. sanguineus s.l. parasitando cães provenientes do estado de Pernambuco e R. sanguineus s.l. e C. felis felis parasitando cães provenientes do estado de Alagoas. Apesar de não existirem relatos de Febre Maculosa Brasileira (FMB) nas regiões estudadas, a presença de carrapatos e pulgas infectados sugere a circulação do patógeno entre hospedeiros vertebrados e vetores.

Invasive species are generally problematic where they occur, especially in terms of ecology, economy and disease. Members of the genus Rattus Fischer, 1803 particularly, are known as one of the most destructive invasive species to date since they cause widespread damage on terrestrial and island ecosystems. Two Rattus species have historically been reported as invasive species in South Africa, Rattus rattus Linnaeus, 1758, which has a widespread distribution throughout the country and Rattus norvegicus Berkenhout, 1769 which is primarily distributed along the coast of South Africa. A third species, Rattus tanezumi Temminck, 1844 (which forms part of the R. rattus species complex), a south-east Asian endemic, was first reported in 2005 to also occur in South Africa (and Africa). As this species is morphologically similar to R. rattus, its identification is reliant on molecular typing approaches. In the current study, molecular, morphological and disease aspects of South African Rattus were assessed. The nature and extent of variation between the three species was investigated using cytochrome b sequences and extensive mitochondrial d-loop database for comparative purposes. D-loop data identified one, four and two haplotypes for R. tanezumi, R. rattus and R. norvegicus, respectively whereas cytochrome b data identified additional haplotypes for R. rattus and R. tanezumi. Pairwise sequence divergence was highest between R. norvegicus and R. tanezumi (12.5% for D-loop and 12.0% for cyt b). Rattus norvegicus was recovered in the central parts of South Africa for the first time and occurred sympatrically with R. tanezumi at one locality, whereas Rattus rattus and R. tanezumi occurred sympatrically at three localities. The external and qualitative cranial morphology of all three species was compared in an attempt to find differences that could be used to morphologically differentiate between these Rattus species. Whereas R. norvegicus can easily be distinguished from R. rattus and R. tanezumi, there are no discernible morphological differences to distinguish R. rattus and R. tanezumi. A taxonomic synthesis and an identification key of the three species of Rattus based on qualitative morphology, molecular and cytogenetic data using genetically-identified individuals is provided. Members of South African Rattus were also found to be carriers of the bacteria Bartonella Strong et al., 1915 and Helicobacter Goodwin et al., 1989 emend. Vandamme et al., 1991. Bartonella elizabethae (Daly et al., 1993) Brenner et al., 1993, occurring in Rattus around the world was for the first time recovered from South African Rattus. This bacterium has been associated with infective endocarditis in humans and may pose a threat to immuno-compromised individuals in rural South African communities where Rattus occurs commensally. Two Helicobacter species, H. rodentium Shen et al., 1997 and H. muridarum Lee et al., 1992, were identified neither of which have known zoonotic potential. Apart from contributing to general small mammal studies in Africa, the present study may have implications in epidemiological, agricultural, biological conservation, and invasion biology research associated with problem rodents in the southern African subregion and beyond. / Dissertation (MSc)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

abstract: Land-use change has arguably been the largest contributor to the emergence of novel zoonotic diseases within the past century. However, the relationship between patterns of land-use change and the resulting landscape configuration on disease spread is poorly understood as current cross-species disease transmission models have not adequately incorporated spatial features of habitats. Furthermore, mathematical-epidemiological studies have not considered the role that land-use change plays in disease transmission throughout an ecosystem. This dissertation models how a landscape's configuration, examining the amount and shape of habitat overlap, contributes to cross-species disease transmission to determine the role that land-use change has on the spread of infectious diseases. To approach this, an epidemiological model of transmission between a domesticated and a wild species is constructed. Each species is homogeneously mixed in its respective habitat and heterogeneously mixed in the habitat overlap, where cross-species transmission occurs. Habitat overlap is modeled using landscape ecology metrics. This general framework is then applied to brucellosis transmission between elk and cattle in the Greater Yellowstone Ecosystem. The application of the general framework allows for the exploration of how land-use change has contributed to brucellosis prevalence in these two species, and how land management can be utilized to control disease transmission. This model is then extended to include a third species, bison, in order to provide insight to the indirect consequences of disease transmission for a species that is situated on land that has not been converted. The results of this study can ultimately help stakeholders develop policy for controlling brucellosis transmission between livestock, elk, and bison, and in turn, could lead to less disease prevalence, reduce associated costs, and assist in population management. This research contributes novelty by combining landscape ecology metrics with theoretical epidemiological models to understand how the shape, size, and distribution of habitat fragments on a landscape affect cross-species disease transmission. The general framework demonstrates how habitat edge in single patch impacts cross-species disease transmission. The application to brucellosis transmission in the Greater Yellowstone Ecosystem between elk, cattle, and bison is original research that enhances understanding of how land conversion is associated with enzootic disease spread. / Dissertation/Thesis / Doctoral Dissertation Applied Mathematics for the Life and Social Sciences 2020

The concept of One Health is a rather new term that is used to describe the need for collaboration across expert disciplines to ensure health for humans, animals and the environment. The concept of One Health covers many different aspects of problems that pose a threat to a sustainable planet, for example zoonotic diseases, food hygiene, antibiotic resistance and animal welfare. In recent years the interest in One Health issues has expanded in a truly amazing way, therefore, it is in our interest to present an overview of One Health projects globally, regarding the topics of zoonotic diseases and animal welfare. The aim of this literature study is to conduct an overview of published studies, in the areas of zoonotic diseases and animal welfare, from geographically distinct parts of the world, including Europe, Middle East, South America, South-East Asia and Sub-Saharan Africa. This will be done by answering questions regarding the analysed publications, to explore similarities and differences between the previously mentioned geographic areas, regarding the two topics of interest. PubMed was used as search engine to identify publications suitable for the aim of this literature overview. 178 publications within the area of zoonotic diseases and 139 publications within the area of animal welfare met the inclusion criteria and were analysed and evaluated according to a question-sheet. Cross-border collaborations appeared to be more common in the field of zoonotic diseases than in the field of animal welfare. Looking at the amount of published papers, there seemed to be an elevation in number of publications focusing on zoonotic diseases from the time interval 2012-2013 to 2014-2015, in contrast to animal welfare, where the publication numbers increased some years later, from 2014-2015 to 2016-2017. Sub-Saharan African and South American publications focused more on vector borne diseases than the other investigated geographic areas. Regarding the most common cause of animal welfare issues, it appeared to be housing and human management in all investigated geographical demarcations.

The protozoan Cryptosporidium parvum is one of the major causative pathogens of diarrhoea in young ruminants; therefore, it causes economic losses and impairs animal welfare. Besides C. parvum, there are many other non-infectious and infectious factors, such as rotavirus, Escherichia coli, and Giardia duodenalis, which may lead to diarrhoeic disease in young livestock. Often, more than one infectious agent is detected in affected animals. Little is known about the interactions bet-ween simultaneously occurring pathogens and their potential effects on the course of disease. In this review, a brief overview about pathogens associated with diarrhoea in young ruminants is presented. Furthermore, information about coinfections involving Cryptosporidium is provided.

Novel infectious diseases in humans are of great concern to public health authorities and researchers in epidemiology. Zoonotic pathogens in particular have the potential to cause epidemics without any or little warning. In this thesis, I investigate evolutionary and environmental conditions, and the interactions between both, which facilitate the zoonotic emergence of novel pathogens. I start with a list of the mechanisms and processes which might influence a zoonotic emergence, and identify some unsolved problems. I address these with multiple, theoretical models. First, I use a village-city model with different adaptation scenarios to examine the influence of spatial heterogeneity on the emergence process. I derive general analytical results for the statistical properties of emergence events, including the probability distribution of outbreak sizes. My results suggest that, for typical connection strengths between communities, spatial heterogeneity has only a weak effect on outbreak size distributions, and on the risk of emergence per introduction. Next, I extend the research on environmental conditions by looking at pathogen specialisation in multi-host systems. I derive threshold connectivities for which generalist pathogens, which infect multiple species and might therefore be more dangerous to cross into the human species, can sustain transmission and are not dominated by specialists, which can only cause sustained transmission chains in a single host species, but are able to cause emergences with little warning. My third research chapter is interested in the effect of the loss of biodiversity. I analytically derive expected prevalences for fast growing and slow growing species. If fast growing species tend to perform better in degraded environments, my analytical results suggest that the overall prevalence level of infectious diseases will rise as environments degrade, which facilitates the chance of zoonotic jumps. In my last research chapter, I examine the actual impact of a novel, emerging infectious disease. I use data from the recent `Swine flu' epidemic in England to estimate epidemiological parameters of the infectious agent. My results suggest that the majority of infected cases showed no or only mild symptoms. This reveals that more data than just the estimated number of cases are necessary to fully evaluate the danger of a possible zoonotic, emerging infectious disease. I conclude by discussing my results and the implications which these might have.

A leishmaniose visceral zoonotica (LVZ) e uma das mais importantes doenc¸as parasitárias emergentes. Em particular, o Brasil é considerado um dos principais centros endêmicos para esta doença. Apesar da publicação de manuais de controle da leishmaniose visceral e dos investimentos aplicados na organizacão de serviços e no desenvolvimento de atividades preventivas e de controle, os vetores e os reservatórios em áreas urbanas são os maiores desafios para os programas de controle. Isto se deve (1) `a necessidade por melhor compreensão do comportamento do vetor no meio urbano; (2) `as dificuldades operacionais para realizar atividades em tempo suficiente para obter resultados de impacto; e (3) ao alto custo envolvido nessas atividades. O principal objetivo deste estudo foi elaborar um modelo de otimização para o controle da leishmaniose, baseado em 5 parâmetros de controle que correspondem `as seguintes estratégias: (I) controle vetorial, (II) eliminação de cães positivos, (III) uso de coleiras impregnadas com inseticida, (IV) vacinação canina e (V) tratamento canino. Este modelo foi construído a partir de um sistema composto por 17 equações diferenciais, sendo que 4 representam a dinâmica da doenc¸a sobre a população humana (humanos suscetíveis (xh), latentes (lh), clinicamente doentes (yh) e recuperados (zh)), 10 para a populacão de cães (cães suscetíveis (xd e xCd ), latentes (ld e lCd ), clinicamente doentes (yd e yCd ), recuperados (zd e zCd ) e vacinados (vd e vCd ), onde o índice C representa as categorias com a aplicação da coleira inseticida) e 3 para a população de vetores (mosquitos não-infectados (s1), infectados (mas não-infectivos) (s2), infectados e infectivos (s3)). Para a an´alise econômica dessas estratégias, foram estimados os custos de cada uma delas por cão (ou, no caso do controle vetorial, por casa tratada). Considerando a simulação sem a introdução das estratégias de controle, as densidades de equilíbrio endêmico para as categorias foram: xh = 0, 394, lh = 0, 0305, yh = 0, 00167, zh = 0, 574, xd = 0, 314, ld = 0, 165, yd = 0, 0163, zd = 0, 505, s1 = 0, 709, s2 = 0, 0858 e s3 = 0, 205. No estado de equilibrio endêmico, o número de reprodutibilidade basal foi estimado em R0 = 4, 50 e o n´umero diário de casos humanos notificados, em R = 3, 58 × 10-6/dia. Considerando a avaliação do impacto das estratégias de controle, o controle vetorial mostrou ser a estrat´egia que causa a diminuição mais rápida sobre o núumero diário de casos humanos notificados e, consequentemente, foi tambem a que mais reduz os custos m´edico-hospitalares. Entretanto, ´e a estratégia que exige o maior investimento. Por outro lado, a estrat´egia de eliminar cães positivos foi considerada a de menor custo. Dado que essas estratégias de controle atuam em pontos distintos na cadeia epidemiológica, o planejamento de um controle envolvendo a ação simultânea delas poderia não apenas apresentar resultados de controle mais interessantes, como tambem poderia otimizar ainda mais os investimentos sobre o controle da leishmaniose visceral / Zoonotic visceral leishmaniasis (ZVL) is one of the most important emerging parasitic diseases. Brazil, in particular, is considered one of the countries in which this disease is most endernic. Despite the publication of visceral leishmaniasis control guidelines and the investment in health services and controljpreventive activities, the vectors and reser- voirs in urban areas are the major challenge for those control programs. This is due to (1) the need for better comprehension regarding the vector behavior in the urban envi- ronment; (2) the operating difficulties in perforrning the activities in time to reach good results; and (3) the high cost of those activities. The main objective of this study was to elaborate an optirnization model for leishmaniasis control. This model is based on 5 con- trol parameters that correspond to the following strategies: (I) vector population control, (11) elirnination of positive dogs, (111) use of insecticide-impregnated dog collars, (IV) dog vaccination and (V) dog treatment. This model was elaborated using an equation system, composed of 17 differential equations, 4 of which represent the disease dynarnic on hu- man population (susceptible (Xh), latent (Ih), clinically ill (Yh) and recovered humans (Zft)), 10 for dog population (susceptible (Xd and xcd), latent (ld and Icd), clinically ill (Yd and Ycd), recovered (Zd and zcd) and vaccinated dogs (Vd and vcd), where C represents the categories using the insecticide-impregnated dog collars) and 3 for vector population (non-infected (SI), infected but not infective (S2), infected and infective sandflies (S3)). For econornic analysis of those control strategies, we estimated the cost of them per dog (in the case of vector control population, it was estimated per treated house). Regarding the nume- rical simulations without the control strategies, the endernic equilibrium densities were: Xh = 0.394, Ih = 0.0305, Yh = 0.00167, Zh = 0.574, Xd = 0.314, Id = 0.165, Yd = 0.0163, Zd = 0.505, SI = 0.709, S2 = 0.0858 and S3 = 0.205. In endernic equilibrium state, the basic reproduction number and the rate of reported human cases per day were estimated as 1%0 = 4.50 and R = 3.58 x 1O-6/day, respectively. Considering the impact evaluation of controI strategies, the vector population control was the strategy that resulted in a fas- ter decrease in the rate of human reported cases per day and, consequently, in the larger reduction of medical and hospital costs too. However, the investment (that is, the cost) of the vector population control was the highest one. On the other hand, the investment in elirninating positive dogs was considered the lowest one. Since those control strategies operate at different points within the epiderniological chain, the planning a control, while taking into account the simultaneous action of these strategies, could not only result in a more interesting control strategy, but could also improve the optirnization of investments on visceralleishmaniasis control