Protein malnutrition impairs the immune response and influences the severity of infection in a hamster model of chronic visceral leishmaniasis

Leishmaniasis remains one of the world's most devastating neglected tropical diseases. It mainly affects developing countries, where it often co-exists with chronic malnutrition, one of the main risk factors for developing the disease. Few studies have been published, however, on the relationship between leishmaniasis progression and malnutrition. The present paper reports the influence of protein malnutrition on the immune response and visceral disease development in adult hamsters infected with Leishmania infantum fed either standard or low protein diets. The low protein diet induced severe malnutrition in these animals, and upon infection with L. infantum 33% had severe visceral leishmaniasis compared to only 8% of animals fed the standard diet. The infected, malnourished animals showed notable leukocyte depletion, mild specific antibody responses, impairment of lymphoproliferation, presence of parasites in blood (16.67% of the hamsters) and significant increase of the splenic parasite burden. Animals fed standard diet suffered agranulocytosis and monocytopenia, but showed stronger specific immune responses and had lower parasite loads than their malnourished counterparts. The present results show that protein malnutrition promotes visceral leishmaniasis and provide clues regarding the mechanisms underlying the impairment of the immune system.This work was funded by project PI10/00829 from the Fondo de Investigación Sanitaria, http://www.isciii.es/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

Identification of genetic signatures in coding region of the small subunit ribosomal RNA of Cryptosporidium spp.: molecular characterization of samples from mammals and birds

Este trabalho teve como objetivos a identificação de sequências 18S rDNA amplificadas de Cryptosporidium spp. de diversas espécies de hospedeiros e avaliar variabilidade em sequências gênicas deste lócus, com vistas ao desenho de sondas moleculares com melhor eficiência diagnóstica para detecção e identificação deste parasito. Foram coletadas 392 amostras de animais domésticos (bovinos, eqüinos, suínos, ovinos, cães e felinos) de 98 propriedades rurais do município de Teodoro Sampaio, Estado de São Paulo, 474 de aves silvestres de cativeiro de diversas famílias, provenientes de criadouros comerciais do Estado de São Paulo e criadas como estimação, 141 de sagüis de cativeiro do Estado de São Paulo, e 24 de humanos imunodeprimidos provenientes de hospital do município de São Paulo. As amostras foram submetidas a prova coproparasitológica e molecular para detecção e identificação de Cryptosporidium. Alinhamentos múltiplos obtidos de seqüências 18S rDNA de Cryptosporidium spp. determinadas neste estudo e de sequências recuperadas do Genbank foram analisados visualmente para a definição das regiões polimórficas. Após a definição das regiões polimórficas, foram realizadas análises filogenéticas empregando-se separadamente cada uma delas. Pelo exame coproparasitológico foi encontrado positividade em amostras de nove (4,57%) bovinos, três (11,11%) cães, 41 (8,64%) aves silvestres, 13 (9,20%) sagüis e todas as de humanos. As outras espécies de animais domésticos não apresentaram positividade para o parasita no exame coproparasitológico. Nos bovinos foi encontrado o Cryptosporidium Andersoni, em cães o Cryptosporidium canis, em sagüis o Cryptosporidium parvum e em humanos, C. parvum, Cryptosporidium hominis, Cryptosporidium felis e C. canis. Dentre as amostras de aves nenhuma foi identificada como Cryptosporidium meleagridis. As amostras de curiós (Oryzoborus angolensis) foram classificadas como Cryptosporidium galli, com exceção de uma, identificada como Cryptosporidium baileyi. C. galli foi encontrado também em um Sabiá Laranjeira (Turdus rufiventris), um Picharro (Saltator similis), dois canários e um Pintassilgo (C. carduelis). C. baileyi foi encontrado em um pintassilgo (Carduelis carduelis) um Pichochó (Sporophila frontalis), um Galo da Campina (Paroaria dominicana) e dois Canários (Sicalis flaveola). Pelos resultados, duas regiões polimórficas em sequência 18S rDNA de Cryptosporidium spp. (denominadas regiões 1 e 3) permitiram discriminar as diferentes espécies neste gênero de parasita, podendo ser utilizadas isoladamente como marcadores moleculares para identificação molecular dentro deste gênero. Saguis (Chalitrix spp.) de cativeiro são espécies susceptíveis a infecção por Cryptosporidium parvum apresentando-se como um hospedeiro de importância epidemiológica para esta zoonose. Curiós (O. angolensis) de cativeiro são espécies susceptíveis a infecção por Cryptosporidium galli apresentando-se como hospedeiro de importância epidemiológica para esta espécie de parasito. A não detecção de Cryptosporidium parvum em animais domésticos na região de Teodoro Sampaio, Estado de São Paulo, mostra uma condição sanitária favorável, já que este agente é causador de importante zoonose. A presença de espécies de Cryptosporidium spp. adaptadas a animais domésticos (como o C. felis e o C. canis) em humanos na cidade de São Paulo mostra que estes animais podem desempenhar importante papel na cadeia epidemiológica da criptosporidiose humana.The objectives of this study were to identify 18S rDNA sequences of Cryptosporidium spp. From various species of hosts and to avaluate the variability in gene sequences of this locus, aiming the design of molecular probes with better diagnostic efficiency for the detection and identification of this parasite. It was collected 392 samples of domestic animals (cattle, horses, pigs, sheeps, dogs and cats) of 98 rural properties of Teodoro Sampaio city, São Paulo State, 474 captive wild birds of various families, from pet and comercial breeding in São Paulo State, 141 captive marmosets, of São Paulo State, and 24 immunossupressed humans from a São Paulo city hospital. The samples were submitted to coproparasitological and molecular tests for the detection and identification of Cryptosporidium. Multiple alignment of Cryptosporidium 18S rDNA sequences, that was determinated in this study and other download from GenBank were visually inspected in order to define polymorphic regions. After the definition of polymorphic regions, phylogenetic trees were reconstructed using each polymorphic region. Cryptosporidium spp. Were found by using coproparasitological tests in nine (4,57%) samples of cattle, tree (11,11%) dogs, 41 (8,64%) wild birds, 13 (9,20%) marmosets and all human samples. The other animal species were negative by coproparasitological tests. In cattle it was found Cryptosporidium andersoni, in dogs Cryptosporidium canis, in marmosets Cryptosporidium parvum and in humans, C. parvum, Cryptosporidium hominis, Cryptosporidium felis e C. canis. Among the samples of birds Cryptosporidium meleagridis was not found. All the samples of lesser seed-finch (Oryzoborus angolensis) were classified as Cryptosporidium galli, except for that from one individual with was identified as Cryptosporidium baileyi. Cryptosporidium galli was also found in one rufous-bellied thrush (Turdus rufiventris), one green-winged saltator (Saltator similis), two saffron finch (Sicalis flaveola) and one eurasian goldfinch (Carduelis carduelis). C. baileyi was found in one eurasian goldfinch (C. carduelis), one buffy-fronted seedeater (Sporophila Frontalis), one red-cowled cardinal (Paroaria dominicana) and two saffron finch (S. flaveola). From the results two polymorphic regions within 18S rDNA sequences of Cryptosporidium spp. (named as regions 1 and 3) enabled the discrimination of the different species in this genera, and then could be used alone as molecular markers for identification within this genera. Captive marmosets (Chalitrix spp.) are susceptible species for Cryptosporidium infection, presenting itself as an important source of infection for this zoonosis. Captive lesser seed-finch (Oryzoborus angolensis) are susceptible species for Cryptosporidium galli infection presenting itself as an epidemologic important host for this parasite. The absence of Cryptosporidium parvum in domestic animals of Teodoro Sampaio, São Paulo State, is indicative of a favorable health condition, as C. parvum is an agent causative of an important zoonosis. The presence of Cryptosporidium spp. species adapted to domestic animals (as C. felis and C. canis) in humans at São Paulo State indicate that these animals could play an important role in the epidemiology of human cryptosporidiosis

Impact of different control methods of visceral leishmaniasis dynamics in endemic areas of Brazil

A Leishmaniose visceral (LV) é uma zoonose de ampla distribuição, e atualmente, representa sério problema para a saúde pública. Nas Américas, agente etiológico é a Leishmania (Leishmania) infantum, transmitido, principalmente, pela picada da fêmea de Lutzomyia longipalpis (Diptera: Psychodidae) infectada. O cão doméstico é considerado o principal reservatório da doença. No Brasil, embora sejam utilizadas diversas estratégias para o controle da doença, a mesma persiste e continua sendo dispersada. Devido ao fato dessas estratégias apresentarem dificuldades, por sua complexidade e custo de seus protocolos, faz-se necessária a reavaliação da eficácia e viabilidade das mesmas em estudos teóricos. O uso da modelagem matemática tem auxiliado essas avaliações. Após a adaptação de um modelo já existente para LV, foi avaliada a eficácia do uso de intervenções em cães, como coleira impregnada com deltametrina, vacina e sacrifício, em diferentes coberturas e de modo regular e contínuo. Como base, foram utilizados dados característicos de áreas endêmicas do Brasil. Os cinco melhores cenários simulados foram capazes de diminuir as prevalências de cães e humanos, consideravelmente. Por ordem de eficácia são: 1) Coleira em 75% dos cães; 2) Sacrifício de 90% dos cães; 3) Coleira em 50% dos cães; 4) Sacrifício de 75% dos cães; 5) Vacina (eficácia vacinal de 80%) em 75% dos cães. Algumas medidas foram capazes de gerar cenários parecidos ou semelhantes, de prevalências em cães e humanos, quando utilizadas em diferentes coberturas de cães. Visto que a dinâmica da LV apresentou-se altamente dependente dos parâmetros relacionados ao vetor, e, uma vez que a coleira impregnada com inseticida interfere nestes parâmetros, o uso da mesma em cães se mostra como uma medida eficaz no controle da LV. Entretanto, o efeito repelente da coleira se mostrou eficaz quando se encoleira grande cobertura de animais. Sendo assim, todas medidas enfocadas em cães, simuladas no presente estudo, são capazes de controlar a prevalência da LV nas populações de cães e humanos, desde que utilizadas em alta cobertura de animais.Visceral Leishmaniasis (VL) is a zoonosis of worldwide distribution, representing serious public health problem. At the Americas, the etiologic agent is Leishmania (Leishmania) infantum, transmitted, mainly, by the bite of the female of infected Lutzomyia longipalpis (Diptera: Psychodidae). The natural hosts are rodents, edentulous, marsupials, primates and canids, with the domestic dog considered the main reservoir of the disease. In Brazil, although several strategies to control the disease are used, the VL still persist and are dispersing. Due to the fact of the control for LV presents difficulties because its complexity and cost of its protocols, becomes necessary reassessment of their effectiveness and viability in theoretical studies. The mathematical modeling has helped these reassessments. After the adaptation of an existing model for LV, was evaluated the impact of the use of interventions in dogs, like as deltamethrin-impregnated collar, vaccine and sacrifice. Were used, as the basis, characteristic datas from endemic areas of Brazil. The top five simulated measures were: collar in 75% of dogs, sacrifice of 90% and 75% of the seropositive dogs, collar in 50% of the dogs and vaccine (vaccine effectiveness 80%) in 75% of seronegative dog. There was observed that different measures, to both prevention and control, resulted in similar scenarios of dogs and humans prevalence. The repellent effect of the collar was effective since a extensive coverage animals be conduced. The LV dynamics showed to be highly dependent on the parameters related to the vector, and because of this the use of deltamethrin-impregnated collar can be the best measure, to interfere directly in the both mortality of the same and inhibition of the bite. Thus, these measures, focused on dogs, in this study, are able to significantly decrease the populations of infected dogs and humans, since be used for high coverage of animals and are regularly implemented with the same intensities and for prolonged period

Identification of genetic signatures in coding region of the small subunit ribosomal RNA of Cryptosporidium spp.: molecular characterization of samples from mammals and birds

Este trabalho teve como objetivos a identificação de sequências 18S rDNA amplificadas de Cryptosporidium spp. de diversas espécies de hospedeiros e avaliar variabilidade em sequências gênicas deste lócus, com vistas ao desenho de sondas moleculares com melhor eficiência diagnóstica para detecção e identificação deste parasito. Foram coletadas 392 amostras de animais domésticos (bovinos, eqüinos, suínos, ovinos, cães e felinos) de 98 propriedades rurais do município de Teodoro Sampaio, Estado de São Paulo, 474 de aves silvestres de cativeiro de diversas famílias, provenientes de criadouros comerciais do Estado de São Paulo e criadas como estimação, 141 de sagüis de cativeiro do Estado de São Paulo, e 24 de humanos imunodeprimidos provenientes de hospital do município de São Paulo. As amostras foram submetidas a prova coproparasitológica e molecular para detecção e identificação de Cryptosporidium. Alinhamentos múltiplos obtidos de seqüências 18S rDNA de Cryptosporidium spp. determinadas neste estudo e de sequências recuperadas do Genbank foram analisados visualmente para a definição das regiões polimórficas. Após a definição das regiões polimórficas, foram realizadas análises filogenéticas empregando-se separadamente cada uma delas. Pelo exame coproparasitológico foi encontrado positividade em amostras de nove (4,57%) bovinos, três (11,11%) cães, 41 (8,64%) aves silvestres, 13 (9,20%) sagüis e todas as de humanos. As outras espécies de animais domésticos não apresentaram positividade para o parasita no exame coproparasitológico. Nos bovinos foi encontrado o Cryptosporidium Andersoni, em cães o Cryptosporidium canis, em sagüis o Cryptosporidium parvum e em humanos, C. parvum, Cryptosporidium hominis, Cryptosporidium felis e C. canis. Dentre as amostras de aves nenhuma foi identificada como Cryptosporidium meleagridis. As amostras de curiós (Oryzoborus angolensis) foram classificadas como Cryptosporidium galli, com exceção de uma, identificada como Cryptosporidium baileyi. C. galli foi encontrado também em um Sabiá Laranjeira (Turdus rufiventris), um Picharro (Saltator similis), dois canários e um Pintassilgo (C. carduelis). C. baileyi foi encontrado em um pintassilgo (Carduelis carduelis) um Pichochó (Sporophila frontalis), um Galo da Campina (Paroaria dominicana) e dois Canários (Sicalis flaveola). Pelos resultados, duas regiões polimórficas em sequência 18S rDNA de Cryptosporidium spp. (denominadas regiões 1 e 3) permitiram discriminar as diferentes espécies neste gênero de parasita, podendo ser utilizadas isoladamente como marcadores moleculares para identificação molecular dentro deste gênero. Saguis (Chalitrix spp.) de cativeiro são espécies susceptíveis a infecção por Cryptosporidium parvum apresentando-se como um hospedeiro de importância epidemiológica para esta zoonose. Curiós (O. angolensis) de cativeiro são espécies susceptíveis a infecção por Cryptosporidium galli apresentando-se como hospedeiro de importância epidemiológica para esta espécie de parasito. A não detecção de Cryptosporidium parvum em animais domésticos na região de Teodoro Sampaio, Estado de São Paulo, mostra uma condição sanitária favorável, já que este agente é causador de importante zoonose. A presença de espécies de Cryptosporidium spp. adaptadas a animais domésticos (como o C. felis e o C. canis) em humanos na cidade de São Paulo mostra que estes animais podem desempenhar importante papel na cadeia epidemiológica da criptosporidiose humana.The objectives of this study were to identify 18S rDNA sequences of Cryptosporidium spp. From various species of hosts and to avaluate the variability in gene sequences of this locus, aiming the design of molecular probes with better diagnostic efficiency for the detection and identification of this parasite. It was collected 392 samples of domestic animals (cattle, horses, pigs, sheeps, dogs and cats) of 98 rural properties of Teodoro Sampaio city, São Paulo State, 474 captive wild birds of various families, from pet and comercial breeding in São Paulo State, 141 captive marmosets, of São Paulo State, and 24 immunossupressed humans from a São Paulo city hospital. The samples were submitted to coproparasitological and molecular tests for the detection and identification of Cryptosporidium. Multiple alignment of Cryptosporidium 18S rDNA sequences, that was determinated in this study and other download from GenBank were visually inspected in order to define polymorphic regions. After the definition of polymorphic regions, phylogenetic trees were reconstructed using each polymorphic region. Cryptosporidium spp. Were found by using coproparasitological tests in nine (4,57%) samples of cattle, tree (11,11%) dogs, 41 (8,64%) wild birds, 13 (9,20%) marmosets and all human samples. The other animal species were negative by coproparasitological tests. In cattle it was found Cryptosporidium andersoni, in dogs Cryptosporidium canis, in marmosets Cryptosporidium parvum and in humans, C. parvum, Cryptosporidium hominis, Cryptosporidium felis e C. canis. Among the samples of birds Cryptosporidium meleagridis was not found. All the samples of lesser seed-finch (Oryzoborus angolensis) were classified as Cryptosporidium galli, except for that from one individual with was identified as Cryptosporidium baileyi. Cryptosporidium galli was also found in one rufous-bellied thrush (Turdus rufiventris), one green-winged saltator (Saltator similis), two saffron finch (Sicalis flaveola) and one eurasian goldfinch (Carduelis carduelis). C. baileyi was found in one eurasian goldfinch (C. carduelis), one buffy-fronted seedeater (Sporophila Frontalis), one red-cowled cardinal (Paroaria dominicana) and two saffron finch (S. flaveola). From the results two polymorphic regions within 18S rDNA sequences of Cryptosporidium spp. (named as regions 1 and 3) enabled the discrimination of the different species in this genera, and then could be used alone as molecular markers for identification within this genera. Captive marmosets (Chalitrix spp.) are susceptible species for Cryptosporidium infection, presenting itself as an important source of infection for this zoonosis. Captive lesser seed-finch (Oryzoborus angolensis) are susceptible species for Cryptosporidium galli infection presenting itself as an epidemologic important host for this parasite. The absence of Cryptosporidium parvum in domestic animals of Teodoro Sampaio, São Paulo State, is indicative of a favorable health condition, as C. parvum is an agent causative of an important zoonosis. The presence of Cryptosporidium spp. species adapted to domestic animals (as C. felis and C. canis) in humans at São Paulo State indicate that these animals could play an important role in the epidemiology of human cryptosporidiosis

How much does it cost to prevent and control visceral leishmaniasis in Brazil? Comparing different measures in dogs.

Visceral leishmaniasis (VL) is an important zoonosis in Brazil. Dogs are considered the main domestic reservoirs of the disease in the country; hence, control measures are focused on these reservoirs. Despite efforts to prevent and control VL, important reductions in disease prevalence and incidence have not been identified, stimulating the development and application of new strategies. The choice and implementation of new control strategies can benefit from the application of mathematical models that allow the simulation of different strategies in different scenarios. Selecting the best strategy to be implemented is also supported by cost-effectiveness studies. Here we used the results of a mathematical model in which scenarios, including isolated use of the vaccine and insecticide-impregnated collar (IIC), both at different coverage rates, were simulated to conduct a cost-effectiveness study. The costs were calculated for each scenario considering a simulation period of four years. Collar application in both infected and non-infected animals was the most cost-effective strategy. For example, to reduce the prevalence in humans and dogs by approximately 70%, the costs ranged from $250,000 and$550,000 for the IICs and vaccination, respectively. Even in the scenario with 40% loss/replacement of IICs, this measure was more advantageous in terms of cost-effectiveness than vaccination. If the vaccine were applied with culling of seropositive tested dogs, then the measure became more effective with a reduced cost compared with the vaccine alone. The use of the three first consecutive vaccine doses had the greatest impact on the cost of the vaccination strategy. The advantage of using IICs is that there is no need for a prior diagnosis, unlike vaccination, reducing costs and facilitating implementation. The present study aims to contribute to strategies to reduce hosts infected with VL by reducing public expenditure

Ecological parameters of the (S)-9-methylgermacrene-B population of the Lutzomyia longipalpis complex in a visceral leishmaniasis area in São Paulo state, Brazil

Abstract Background Visceral leishmaniasis (VL) is an important public health challenge in Brazil because of the high number of human and canine cases reported annually. Leishmania infantum is the etiological agent of VL and Lutzomyia longipalpis is its main vector. However, evidence suggests that this taxon constitutes a species complex. In Sao Paulo state, there are two populations of Lu. longipalpis, each secreting distinct pheromones, (S)-9-methylgermacrene-B and Cembrene 1; both have been associated with different patterns of VL transmission. The aim of the present study was to investigate the temporal distribution and natural infection of the (S)-9-methylgermacrene-B population of the Lu. longipalpis complex in a highly VL endemic area of Sao Paulo state to obtain information that may contribute to the surveillance of this zoonosis and to the planning of preventive and control measures. Methods The study was carried out in Panorama municipality, Sao Paulo State. Captures were made during 24 months in seven domiciles. The relation between sand fly abundance and climatic variables, temperature and humidity, was analyzed and natural infection by Leishmania spp. in sand fly females was investigated by nested PCR. Results A total of 4120 sand flies, with predominance of Lu. longipalpis (97.2%) were captured. The highest averages of sand flies/night/trap occurred in the rainy season (November-March) and a positive, significant correlation between sand fly abundance and the temperature and humidity 20 days before the capture days was found. Leishmania infantum DNA was detected in three out of 250 pools of females analyzed, giving an estimated minimum infection rate of 1.2%. Conclusion The identification of the climatic association between the high abundance of the vector in this highly endemic VL focus constitutes a fundamental point for evaluating future vector and dog control measures and this information increases the data of VL foci in Sao Paulo state that could contribute to the public health authorities in planning prevention and control measures. The identification of natural infection by Le. infantum in Lu. longipalpis specimens reinforces the importance of entomological surveillance activities in this municipality

Protein Malnutrition Impairs the Immune Response and Influences the Severity of Infection in a Hamster Model of Chronic Visceral Leishmaniasis

This work was funded by project PI10/00829 from the Fondo de Investigación Sanitaria, http://www.isciii.es/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Leishmaniasis remains one of the world's most devastating neglected tropical diseases. It mainly affects developing countries, where it often co-exists with chronic malnutrition, one of the main risk factors for developing the disease. Few studies have been published, however, on the relationship between leishmaniasis progression and malnutrition. The present paper reports the influence of protein malnutrition on the immune response and visceral disease development in adult hamsters infected with Leishmania infantum fed either standard or low protein diets. The low protein diet induced severe malnutrition in these animals, and upon infection with L. infantum 33% had severe visceral leishmaniasis compared to only 8% of animals fed the standard diet. The infected, malnourished animals showed notable leukocyte depletion, mild specific antibody responses, impairment of lymphoproliferation, presence of parasites in blood (16.67% of the hamsters) and significant increase of the splenic parasite burden. Animals fed standard diet suffered agranulocytosis and monocytopenia, but showed stronger specific immune responses and had lower parasite loads than their malnourished counterparts. The present results show that protein malnutrition promotes visceral leishmaniasis and provide clues regarding the mechanisms underlying the impairment of the immune system.Instituto de Salud Carlos IIIDepto. de Medicina y Cirugía AnimalFac. de VeterinariaTRUEpu

Risk analysis and prediction of visceral leishmaniasis dispersion in São Paulo State, Brazil

<div><p>Visceral leishmaniasis (VL) is an important neglected disease caused by a protozoan parasite, and represents a serious public health problem in many parts of the world. It is zoonotic in Europe and Latin America, where infected dogs constitute the main domestic reservoir for the parasite and play a key role in VL transmission to humans. In Brazil this disease is caused by the protozoan <i>Leishmania infantum chagasi</i>, and is transmitted by the sand fly <i>Lutzomyia longipalpis</i>. Despite programs aimed at eliminating infection sources, the disease continues to spread throughout the Country. VL in São Paulo State, Brazil, first appeared in the northwestern region, spreading in a southeasterly direction over time. We integrate data on the VL vector, infected dogs and infected human dispersion from 1999 to 2013 through an innovative spatial temporal Bayesian model in conjunction with geographic information system. This model is used to infer the drivers of the invasion process and predict the future progression of VL through the State. We found that vector dispersion was influenced by vector presence in nearby municipalities at the previous time step, proximity to the Bolívia-Brazil gas pipeline, and high temperatures (i.e., annual average between 20 and 23°C). Key factors affecting infected dog dispersion included proximity to the Marechal Rondon Highway, high temperatures, and presence of the competent vector within the same municipality. Finally, vector presence, presence of infected dogs, and rainfall (approx. 270 to 540mm/year) drove the dispersion of human VL cases. Surprisingly, economic factors exhibited no noticeable influence on disease dispersion. Based on these drivers and stochastic simulations, we identified which municipalities are most likely to be invaded by vectors and infected hosts in the future. Prioritizing prevention and control strategies within the identified municipalities may help halt the spread of VL while reducing monitoring costs. Our results contribute important knowledge to public and animal health policy planning, and suggest that prevention and control strategies should focus on vector control and on blocking contact between vectors and hosts in the priority areas identified to be at risk.</p></div

Actual (2013) and predicted (2016, 2018, 2020) spatial distribution of municipalities with presence of visceral leishmaniasis vector (<i>Lu</i>. <i>longipalpis</i> sand fly), infected dogs and infected humans in São Paulo State, Brazil.

<p>The probability of “invasion” was calculated using the posterior distribution of the parameters (described in the section “Covariates”) from the Bayesian model and forward simulations, as described in the section “Predictions”.</p

Parameter estimates for VL vector (<i>Lu</i>. <i>longipalpis</i>), VL infected dogs and VL infected humans.

<p>Parameter estimates for VL vector (<i>Lu</i>. <i>longipalpis</i>), VL infected dogs and VL infected humans.</p