Genetic diversity of Trypanosoma cruzi strains isolated from chronic chagasic patients and non-human hosts in the state of São Paulo, Brazil.

BACKGROUND: Trypanosoma cruzi shows an exuberant genetic diversity. Currently, seven phylogenetic lineages, called discrete typing units (DTUs), are recognised: TcI-TcVI and Tcbat. Despite advances in studies on T. cruzi and its populations, there is no consensus regarding its heterogeneity. OBJECTIVES: This study aimed to perform molecular characterisation of T. cruzi strains, isolated in the state of São Paulo, to identify the DTUs involved and evaluate their genetic diversity. METHODS: T. cruzi strains were isolated from biological samples of chronic chagasic patients, marsupials and triatomines through culture techniques and subjected to molecular characterisation using the fluorescent fragment length barcoding (FFLB) technique. Subsequently, the results were correlated with complementary information to enable better discrimination between the identified DTUs. FINDINGS: It was possible to identify TcI in two humans and two triatomines; TcII/VI in 19 humans, two marsupials and one triatomine; and TcIII in one human host, an individual that also presented a result for TcI, which indicated the possibility of a mixed infection. Regarding the strains characterised by the TcII/VI profile, the correlation with complementary information allowed to suggest that, in general, these parasite populations indeed correspond to the TcII genotype. MAIN CONCLUSIONS: The TcII/VI profile, associated with domestic cycles and patients with chronic Chagas disease, was the most prevalent among the identified DTUs. Furthermore, the correlation of the study results with complementary information made it possible to suggest that TcII is the predominant lineage of this work.

Efficacies of insecticide dog collars against visceral leishmaniasis in low and high-income areas and the effects for non-collared neighbor dogs.

Previous studies demonstrated that insecticide collars are highly effective in reducing canine visceral leishmaniasis (CVL); however, it is unclear if the efficacy differs by socioeconomic conditions across diverse communities. This study aimed fourfold: (i) to evaluate the protection of 4% impregnated deltamethrin collared (DMC) dogs in different areas of an endemic city for visceral leishmaniasis (VL); (ii) to analyze socioeconomic variables with the seroconversion rates; (iii) to analyze the indirect effect of DMC on untreated dogs in areas of intervention; and, (iv) to evaluate the potential transmission to other dogs in the same household when one positive dog is present. The study employed the municipality of Bauru, São Paulo, Brazil, as the area of interest and used Geographic Information System tools to fit binary logistic regression models.  Dogs were divided into three cohort studies: intervention with DMC (I), indirect effect of DMC (IE), and control (C). Pre-intervention, lower mean income was associated with higher rates of CVL and a 142% increase in the odds of transmission (OR = 1.42, p-value = 0.001, CI 1.14,1.77). Post-intervention, lower-income areas depicted greater efficacy (76%) than higher-income areas (45%). The overall efficacy of DMC in preventing CVL was 63%; however, seroconversion rates were higher for IE (6.02%) than C (3.78%), revealing the failure of the indirect protection of DMC to manage the spread of the disease among the general non-wearing DMC canine population living in the same area. The protected dogs may repel the vectors, and non-protected dogs attract them, creating a higher transmission rate for non-protected dogs. Greater seroconversion was observed for living with an infected dog (10.20% in IE and 8.75% in C) than for the indirect effect of DMC, demonstrating the social burden of CVL. Overall, uncollared dogs have three times higher odds of being infected with CVL than DMC dogs (p < 0.005), and uncollared dogs living with (an) infected dog(s) in the same household can reach 3.5 times higher odds than those living with negative ones (p < 0.005). The results may assist in enhancing public policies and minimizing inequality in low and middle-income countries that suffer from neglected diseases such as VL.

The path of canine visceral leishmaniasis versus the path of Center for Zoonoses Control: contributions of spatial analysis to health.

Visceral leishmaniasis (VL) is a public health problem in Brazilian municipalities. As much as there is a planning of public policies regards VL in São Paulo State, new cases have been reported and spread. This paper aims to discuss how the Center for Zoonoses Control conducts its actions spatially in endemic city of Presidente Prudente, São Paulo State. Data are from the Municipal Health Department of Presidente Prudente, Adolfo Lutz Institute, and Brazilian Institute of Geography and Statistics. We spatially estimated the dog population per census tract and used geoprocessing tools to perform choropleth maps, spatial trends, and spatial autocorrelation. We found a spatial pattern of higher prevalence in the city's outskirt and a positive statistically significant spatial autocorrelation (I = 0.2, p-value < 0.000) with clusters of high-high relationships in the Northwest part of the city. Moreover, we identified a different direction in the path of the conducted serosurveys versus the canine VL trend, which stresses the fragility of the Center for Zoonoses Control actions to control the disease. The Center for Zoonoses Control always seems to chase the disease. The spatial analysis may be useful for rethinking how the service works and helps in public policies.

Genetic diversity of Trypanosoma cruzi strains isolated from chronic chagasic patients and non-human hosts in the state of São Paulo, Brazil

BACKGROUND Trypanosoma cruzi shows an exuberant genetic diversity. Currently, seven phylogenetic lineages, called discrete typing units (DTUs), are recognised: TcI-TcVI and Tcbat. Despite advances in studies on T. cruzi and its populations, there is no consensus regarding its heterogeneity. OBJECTIVES This study aimed to perform molecular characterisation of T. cruzi strains, isolated in the state of São Paulo, to identify the DTUs involved and evaluate their genetic diversity. METHODS T. cruzi strains were isolated from biological samples of chronic chagasic patients, marsupials and triatomines through culture techniques and subjected to molecular characterisation using the fluorescent fragment length barcoding (FFLB) technique. Subsequently, the results were correlated with complementary information to enable better discrimination between the identified DTUs. FINDINGS It was possible to identify TcI in two humans and two triatomines; TcII/VI in 19 humans, two marsupials and one triatomine; and TcIII in one human host, an individual that also presented a result for TcI, which indicated the possibility of a mixed infection. Regarding the strains characterised by the TcII/VI profile, the correlation with complementary information allowed to suggest that, in general, these parasite populations indeed correspond to the TcII genotype. MAIN CONCLUSIONS The TcII/VI profile, associated with domestic cycles and patients with chronic Chagas disease, was the most prevalent among the identified DTUs. Furthermore, the correlation of the study results with complementary information made it possible to suggest that TcII is the predominant lineage of this work.

The path of canine visceral leishmaniasis versus the path of Center for Zoonoses Control: contributions of spatial analysis to health / O caminho da leishmaniose visceral canina versus o caminho do Centro de Controle de Zoonoses: contribuições da análise espacial para a saúde / La trayectoria de la leishmaniasis visceral canina versus la trayectoria del Centro para el Control de Zoonoses: contribuciones del análisis espacial a la salud

Visceral leishmaniasis (VL) is a public health problem in Brazilian municipalities. As much as there is a planning of public policies regards VL in São Paulo State, new cases have been reported and spread. This paper aims to discuss how the Center for Zoonoses Control conducts its actions spatially in endemic city of Presidente Prudente, São Paulo State. Data are from the Municipal Health Department of Presidente Prudente, Adolfo Lutz Institute, and Brazilian Institute of Geography and Statistics. We spatially estimated the dog population per census tract and used geoprocessing tools to perform choropleth maps, spatial trends, and spatial autocorrelation. We found a spatial pattern of higher prevalence in the city's outskirt and a positive statistically significant spatial autocorrelation (I = 0.2, p-value < 0.000) with clusters of high-high relationships in the Northwest part of the city. Moreover, we identified a different direction in the path of the conducted serosurveys versus the canine VL trend, which stresses the fragility of the Center for Zoonoses Control actions to control the disease. The Center for Zoonoses Control always seems to chase the disease. The spatial analysis may be useful for rethinking how the service works and helps in public policies.

A leishmaniose visceral (LV) é um problema de saúde pública nas cidades brasileiras. Por mais que haja um planejamento de políticas públicas para LV no Estado de São Paulo, Brasil, novos casos têm sido notificados e se disseminado. O artigo objetiva discutir como o Centro de Controle de Zoonoses realiza suas atividades espacialmente em uma cidade endêmica, Presidente Prudente, no Estado de São Paulo. Os dados são da Secretaria Municipal de Saúde de Presidente Prudente, Instituto Adolfo Lutz e Instituto Brasileiro de Geografia e Estatística. Estimamos espacialmente a população canina por setor censitário e utilizamos ferramentas de geoprocessamento para produzir mapas coropléticos, tendências espaciais e autocorrelação espacial. Encontramos um padrão espacial de maior prevalência na periferia da cidade e uma autocorrelação espacial positiva estatisticamente significativa (I = 0,2; p < 0,000) com clusters de relação alta-alta no noroeste da cidade. Além disso, identificamos uma direção diferente no caminho dos inquéritos sorológicos realizados versus a tendência na LV canina, o que enfatiza a fragilidade das medidas de controle do Centro de Controle de Zoonoses para controlar casos da doença. O Centro de Controle de Zoonoses parece estar sempre correndo atrás da doença. A análise espacial pode ser útil para repensar o funcionamento do serviço e auxiliar as políticas públicas.

La leishmaniasis visceral (LV) es un problema de salud pública en las ciudades brasileñas. Aunque hay políticas públicas de planificación relacionadas con la LV en el estado de São Paulo, Brasil, se han informado de nuevos casos, además de su propagación. El objetivo de este trabajo es discutir cómo el Centro de Control de Zoonosis dirige sus acciones espacialmente en una ciudad endémica del estado de São Paulo, Presidente Prudente. Los datos proceden de la Secretaría Municipal de Salud de Presidente Prudente, del Instituto Adolfo Lutz, y del Instituto Brasileño de Geografía y Estadística. Estimamos espacialmente la población de perros por sector censal y utilizamos herramientas de geoprocesamiento para elaborar mapas de coropletas, tendencias espaciales, y autocorrelación espacial. Encontramos un patrón espacial de más alta prevalencia en la periferia de la ciudad, además de una autocorrelación espacial positiva y estadísticamente significativa (I = 0,2; valor de p < 0,000) con clústeres de relaciones alto-alto en la parte noroccidental de la ciudad. Además, identificamos una dirección diferente en la trayectoria de las encuestas serológicas llevadas a cabo, frente a la tendencia de LV canina, que enfatiza la debilidad de acciones del Centro de Control de Zoonosis para controlar casos de la enfermedad. El Centro de Control de Zoonosis parece siempre estar tras la enfermedad. El análisis espacial podría ser útil para repensar cómo está funcionando el servicio, además de ayudar a políticas públicas.

Impact of the dog population and household environment for the maintenance of natural foci of Leishmania infantum transmission to human and animal hosts in endemic areas for visceral leishmaniasis in Sao Paulo state, Brazil.

When it comes to visceral leishmaniasis (VL) in Brazil, one of the main targets of public health policies of surveillance is the control of domestic canine reservoirs of Leishmania infantum. This paper aims to evaluate the effect of the dog population and household environment for the maintenance of natural foci in the transmission to human and animal hosts in an endemic city for VL, Bauru, in Brazil. We collected 6,578 blood samples of dogs living in 3,916 households from Nov.2019 to Mar.2020 and applied geospatial models to predict the disease risk based on the canine population. We used Kernel density estimation, cluster analysis, geostatistics, and Generalized Additive Models (GAM). To validate our models, we used cross-validation and created a receiver operating characteristic (ROC) curve. We found an overall canine VL (CVL) seroprevalence of 5.6% for the sampled dogs, while for the households, the positivity rate was 8.7%. Odds ratios (OR) for CVL increased progressively according to the number of canines for >2 dogs (OR 2.70); households that already had CVL in the past increased the chances for CVL currently (OR 2.73); and the cases of CVL increase the chances for human VL cases (OR 1.16). Our models were statistically significant and demonstrated a spatial association between canine and human disease cases, mainly in VL foci that remain endemic. Although the Kernel density ratio map had the best performance (AUC = 82), all the models showed high risk in the city's northwest area. Canine population dynamics must be considered in public policies, and geospatial methods may help target priority areas and planning VL surveillance in low and middle-income countries.

Validation of ELISA with recombinant antigens in serological diagnosis of canine Leishmania infantum infection.

BACKGROUND: Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE: We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS: Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS: For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS: For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.

Predicted distribution of sand fly (Diptera: Psychodidae) species involved in the transmission of Leishmaniasis in São Paulo state, Brazil, utilizing maximum entropy ecological niche modeling.

Leishmaniasis is a public health problem worldwide. We aimed to predict ecological niche models (ENMs) for visceral (VL) and cutaneous (CL) leishmaniasis and the sand flies involved in the transmission of leishmaniasis in São Paulo, Brazil. Phlebotomine sand flies were collected between 1985 and 2015. ENMs were created for each sand fly species using Maximum Entropy Species Distribution Modeling software, and 20 climatic variables were determined. Nyssomyia intermedia (Lutz & Neiva, 1912) and Lutzomyia longipalpis (Lutz & Neiva, 1912), the primary vectors involved in CL and VL, displayed the highest suitability across the various regions, climates, and topographies. L. longipalpis was found in the border of Paraná an area currently free of VL. The variables with the greatest impact were temperature seasonality, precipitation, and altitude. Co-presence of multiple sand fly species was observed in the cuestas and coastal areas along the border of Paraná and in the western basalt areas along the border of Mato Grosso do Sul. Human CL and VL were found in 475 of 546 (86.7%) and 106 of 645 (16.4%) of municipalities, respectively. Niche overlap between N. intermedia and L. longipalpis was found with 9208 human cases of CL and 2952 cases of VL. ENMs demonstrated that each phlebotomine sand fly species has a unique geographic distribution pattern, and the occurrence of the primary vectors of CL and VL overlapped. These data can be used by public authorities to monitor the dispersion and expansion of CL and VL vectors in São Paulo state.

Valores normais da atividade da colinesterase plasmática em anseriformes, com destaque para Alopochen aegyptiacus / Normal values of plasma cholinesterase activity in anseriformes, with emphasis on Alopochen aegyptiacus

A inibição da enzima colinesterase plasmática (BChE) pode ser utilizada como biomarcador para os efeitos da intoxicação por organofosforados e carbamatos. Nas aves, esta inibição ocorre de forma mais acentuada que nos mamíferos, porém poucos são os trabalhos publicados nestas espécies. O objetivo do estudo fo a dosagem da BChE em gansos-egípcios (Alopochen aegyptiacus) e nos anseriformes domésticos: gansos-domésticos (Anser anser domesticus) e marrecos (Anas platyrhynchos domesticus), para o estabelecimento de valores de referência normais. O trabalho possui ineditismo com relação à determinação desta enzima nos gansos-egípcios e domésticos. Os gansos e marrecos são mantidos em confinamento com fornecimento de alimentos e água ad libitum e em espaço adequado à sua manutenção no Instituto Adolfo Lutz (IAL), com a finalidade de fornecimento de sangue para a alimentação de triatomídeos do insetário de criação no Núcleo de Parasitoses Sistêmicas. Nos Alopochen aegyptiacus a média e o desvio padrão da BChE foram de 1.868 + 263,6 U/L, nos Anser anser domesticus 2.311 + 673,2 U/L e nos Anas platyrhynchos domesticus 4.290 + 86,11 U/L. (AU)

The inhibition of the plasma cholinesterase enzyme (BChE) can be used as a biomarker for the effects of intoxication by organophosphates and carbamates. In birds, this inhibition is more pronounced than in mammals, however there are few specific studies were conducted in this field. The aim of this study was to measure BChE in Egyptian geese (Alopochen aegyptiacus) and domestic anseriforms: domestic geese (Anser anser domesticus) and mallards (Anas platyrhynchos domesticus), not exposed to pesticides, for the establishment of normal values. The work is unprecedented regarding the determination of this enzyme in egyptian geese and domestic geese. Geese and mallards are kept in confinement with ad liditum food and water supply and in adequate space for their maintenance at the Adolfo Lutz Institute (IAL), for the purpose of supplying blood for the feeding of triatomines from the insectary of the Nucleus of Systemic Parasitoses. In Alopochen aegyptiacus the mean and standard deviation of BChE were 1,868 + 263,6 U/L, in Anser anser domesticus 2,311 + 673,2 U/L and in Anas platyrhynchos domesticus 4,290 + 86.11 U/L. (AU)

Canine serological survey and dog culling ant its relationship with human visceral leishmaniasis in an endemic urban area.

BACKGROUND: Visceral leishmaniasis is an important but neglected disease that is spreading and is highly lethal when left untreated. This study sought to measure the Leishmania infantum seroprevalence in dogs, the coverage of its control activities (identification of the canine reservoir by serological survey, dog culling and insecticide spraying) and to evaluate its relationship with the occurrence of the disease in humans in the municipalities of Araçatuba and Birigui, state of São Paulo, Brazil. METHODS: Information from 2006 to 2015 was georeferenced for each municipality and modeling was performed for the two municipalities together. To do this, latent Gaussian Bayesian models with the incorporation of a spatio-temporal structure and Poisson distribution were used. The Besag-York-Mollie models were applied for random spatial effects, as also were autoregressive models of order 1 for random temporal effects. The modeling was performed using the INLA (Integrated Nested Laplace Approximations) deterministic approach, considering both the numbers of cases as well as the coverage paired year by year and lagged at one and two years. RESULTS: Control activity coverage was observed to be generally low. The behavior of the temporal tendency in the human disease presented distinct patterns in the two municipalities, however, in both the tendency was to decline. The canine serological survey presented as a protective factor only in the two-year lag model. CONCLUSIONS: The canine serological coverage, even at low intensity, carried out jointly with the culling of the positive dogs, suggested a decreasing effect on the occurrence of the disease in humans, whose effects would be seen two years after it was carried out.

[Control of canine visceral leishmaniasis by euthanasia: estimated effect based on a survey and mathematical modeling]. / Controle da leishmaniose visceral canina por eutanásia: estimativa de efeito baseado em inquérito e modelagem matemática.

Visceral leishmaniasis is an emerging and neglected disease that is currently expanding to urban areas. The incidence of human disease is related to canine infection. Araçatuba and Birigui are municipalities (counties) in the state of São Paulo, Brazil, with 8-10% seroprevalence of canine infection and that employ control strategies targeting the canine reservoir, based on serological survey and culling of seropositive dogs. Using data from these control programs to parameterize mathematical models, this study assessed the efficacy of these activities. We estimated that current control is capable of reducing the incidence of canine visceral leishmaniasis (CVL) by approximately 20%. Assuming continuous control and three times the current serological survey activities in Araçatuba and Birigui, culling dogs with a positive CVL diagnosis would be effective for the control of canine infection. Although theoretically possible, in practice the control of CVL with the currently recommended strategies is insufficient, since it would require overcoming the difficulties in these activities, such as lack of material, human, and financial resources, besides associated ethical and legal issues.

A leishmaniose visceral é uma doença emergente e negligenciada em processo de expansão para áreas urbanas. A incidência da doença humana está relacionada com a infecção canina. Araçatuba e Birigui são municípios do Estado de São Paulo, Brasil, com soroprevalência da infecção canina de 8 a 10%, que empregam estratégias de controle voltadas ao reservatório canino baseado em inquérito sorológico e eutanásia dos cães soropositivos. Usando dados desses programas de controle para parametrizar modelos matemáticos, este estudo avaliou a eficácia dessas atividades. Estimamos que o controle atualmente empregado é capaz de reduzir em cerca de 20% a incidência de casos de leishmaniose visceral canina (LVC). Considerando-se um controle contínuo e um esforço das atividades de inquérito sorológico igual ao triplo da média do observado em Araçatuba e Birigui, a atividade de eutanásia de cães com diagnóstico positivo seria efetiva para o controle da infecção canina. Embora teoricamente possível, na prática, o controle da LVC com as estratégias preconizadas atualmente é insuficiente, pois exigiria superpor dificuldades enfrentadas por estas atividades como falta de recursos materiais, humanos e financeiros, além das questões éticas e jurídicas associadas.

La leishmaniasis visceral es una enfermedad emergente y pasada por alto en proceso de expansión hacia áreas urbanas. La incidencia de la enfermedad humana está relacionada con la infección canina. Araçatuba y Birigui son municipios del estado de São Paulo, Brasil, con una seroprevalencia de infección canina de un 8 a un 10% que emplean estrategias de control dirigidas al reservorio canino, basado en una encuesta serológica y eutanasia de los perros seropositivos. Usando datos de esos programas de control para proporcionar parámetros en modelos matemáticos, este estudio evaluó la eficacia de esas actividades. Estimamos que el control actualmente empleado es capaz de reducir cerca de un 20% la incidencia de casos de leishmaniasis visceral canina (LVC). Si se considera un control continuo y un esfuerzo de las actividades de encuesta serológica igual al triple de la media de lo observado en Araçatuba y Birigui, la actividad de eutanasia de perros con diagnóstico positivo sería efectiva para el control de la infección canina. A pesar de que teóricamente es posible, en la práctica el control de la LVC con las estrategias preconizadas actualmente es insuficiente, puesto que exigiría superar dificultades a las que se enfrentan estas actividades como la falta de recursos materiales, humanos y financieros, además de las cuestiones éticas y jurídicas asociadas.

Preservação de ovos de helmintos e cistos de protozoários em iodo­mercurato de potássio. Revisitando experimentos realizados há cerca de 40 anos / Preservation of helminth eggs and protozoan cysts in potassium iodine­mercurate. Revisiting experiments carried out about 40 years ago

Foi realizada reavaliação sobre o estado de preservação de ovos de helmintos e cistos de protozoários mantidos por cerca de 40 anos em solução de iodo­mercurato de potássio a 0,2%. Foi observado que ovos de Schistosoma mansoni, Ancylostomidae e Trichuris trichiura e oocistos de Isospora belli mantiveram­se em condições adequadas para a sua identificação ao microscópio ótico comum. No material examinado, foi possível verificar a presença de miracídio em ovo de Schistosoma mansoni, forma larvada em ovo de T. trichiura e esporozoitos em oocistos de I. belli. (AU)

A reassessment was carried out on the preservation status of helminth eggs and protozoan cysts maintained for about 40 years in 0.2% potassium iodine­mercurate solution. It was observed that Schistosoma mansoni, Ancylostomidae and Trichiuris trichiura eggs and Isospora belli oocysts were kept in conditions suitable for their identification under a common light microscope. In the examined material, it was possible to verify the presence of miracidium in S. mansoni egg, larvae in T. trichiuraegg and sporozoites in I. belli oocysts. (AU)

Preservação de ovos de helmintos e cistos de protozoários em iodo-mercurato de potássio. Revisitando experimentos realizados há cerca de 40 anos / Preservation of helminth eggs and protozoan cysts in potassium iodine-mercurate. Revisiting experiments carried out about 40 years ago

Foi realizada reavaliação sobre o estado de preservação de ovos de helmintos e cistos de protozoários mantidos por cerca de 40 anos em solução de iodo‑mercurato de potássio a 0,2%. Foi observado que ovos de Schistosoma mansoni, Ancylostomidae e Trichuris trichiura e oocistos de Isospora belli mantiveram‑se em condições adequadas para a sua identificação ao microscópio ótico comum. No material examinado, foi possível verificar a presença de miracídio em ovo de Schistosoma mansoni, forma larvada em ovo de T. trichiura e esporozoitos em oocistos de I. belli.

A reassessment was carried out on the preservation status of helminth eggs and protozoan cysts maintained for about 40 years in 0.2% potassium iodine‑mercurate solution. It was observed that Schistosoma mansoni, Ancylostomidae and Trichiuris trichiura eggs and Isospora belli oocysts were kept in conditions suitable for their identification under a common light microscope. In the examined material, it was possible to verify the presence of miracidium in S. mansoni egg, larvae in T. trichiura egg and sporozoites in I. belli oocysts.

Controle da leishmaniose visceral canina por eutanásia: estimativa de efeito baseado em inquérito e modelagem matemática / Control of canine visceral leishmaniasis by euthanasia: estimated effect based on a survey and mathematical modeling / Control de la leishmaniasis visceral canina por eutanasia: estimación del efecto basado en una encuesta y modelo matemático

A leishmaniose visceral é uma doença emergente e negligenciada em processo de expansão para áreas urbanas. A incidência da doença humana está relacionada com a infecção canina. Araçatuba e Birigui são municípios do Estado de São Paulo, Brasil, com soroprevalência da infecção canina de 8 a 10%, que empregam estratégias de controle voltadas ao reservatório canino baseado em inquérito sorológico e eutanásia dos cães soropositivos. Usando dados desses programas de controle para parametrizar modelos matemáticos, este estudo avaliou a eficácia dessas atividades. Estimamos que o controle atualmente empregado é capaz de reduzir em cerca de 20% a incidência de casos de leishmaniose visceral canina (LVC). Considerando-se um controle contínuo e um esforço das atividades de inquérito sorológico igual ao triplo da média do observado em Araçatuba e Birigui, a atividade de eutanásia de cães com diagnóstico positivo seria efetiva para o controle da infecção canina. Embora teoricamente possível, na prática, o controle da LVC com as estratégias preconizadas atualmente é insuficiente, pois exigiria superpor dificuldades enfrentadas por estas atividades como falta de recursos materiais, humanos e financeiros, além das questões éticas e jurídicas associadas.

Visceral leishmaniasis is an emerging and neglected disease that is currently expanding to urban areas. The incidence of human disease is related to canine infection. Araçatuba and Birigui are municipalities (counties) in the state of São Paulo, Brazil, with 8-10% seroprevalence of canine infection and that employ control strategies targeting the canine reservoir, based on serological survey and culling of seropositive dogs. Using data from these control programs to parameterize mathematical models, this study assessed the efficacy of these activities. We estimated that current control is capable of reducing the incidence of canine visceral leishmaniasis (CVL) by approximately 20%. Assuming continuous control and three times the current serological survey activities in Araçatuba and Birigui, culling dogs with a positive CVL diagnosis would be effective for the control of canine infection. Although theoretically possible, in practice the control of CVL with the currently recommended strategies is insufficient, since it would require overcoming the difficulties in these activities, such as lack of material, human, and financial resources, besides associated ethical and legal issues.

La leishmaniasis visceral es una enfermedad emergente y pasada por alto en proceso de expansión hacia áreas urbanas. La incidencia de la enfermedad humana está relacionada con la infección canina. Araçatuba y Birigui son municipios del estado de São Paulo, Brasil, con una seroprevalencia de infección canina de un 8 a un 10% que emplean estrategias de control dirigidas al reservorio canino, basado en una encuesta serológica y eutanasia de los perros seropositivos. Usando datos de esos programas de control para proporcionar parámetros en modelos matemáticos, este estudio evaluó la eficacia de esas actividades. Estimamos que el control actualmente empleado es capaz de reducir cerca de un 20% la incidencia de casos de leishmaniasis visceral canina (LVC). Si se considera un control continuo y un esfuerzo de las actividades de encuesta serológica igual al triple de la media de lo observado en Araçatuba y Birigui, la actividad de eutanasia de perros con diagnóstico positivo sería efectiva para el control de la infección canina. A pesar de que teóricamente es posible, en la práctica el control de la LVC con las estrategias preconizadas actualmente es insuficiente, puesto que exigiría superar dificultades a las que se enfrentan estas actividades como la falta de recursos materiales, humanos y financieros, además de las cuestiones éticas y jurídicas asociadas.

Antibodies and Molecular Detection of Leishmania (Leishmania) infantum in Samples of Free-Ranging Marmosets (Primates: Callitrichidae: Callithrix spp.) in an Area of Canine Visceral Leishmaniasis in Southeastern Brazil.

Leishmaniasis is a vector-borne parasitic protozoan infection that affects mammals and involves a complex epidemiology. Although dogs are considered the main reservoir in zoonotic visceral leishmaniasis (VL), the possible presence of other mammalian species acting as reservoirs has been associated as a possible cause of lack of success in the control of human VL in many endemic areas. The knowledge about natural infections of some species is still scarce, such as nonhuman primates (NHP), especially from the genus Callithrix (marmosets). We investigated the infection by Leishmania (Leishmania) infantum, the agent of VL in the Americas, in 26 marmosets captured monthly, from April 2014 to March 2015, in an environmentally protected area (EPA) in Southeastern Brazil. The EPA has undergone significant environmental changes and has a transmission focus of canine VL since 2009. Serology was performed through the direct agglutination test, which detected low antibody titers in seven marmosets (7/26; 26.9%, 95% confidence interval 9.9-44.0), being five Callithrix penicillata (black-tufted-ear marmoset) and two Callithrix jacchus (white-tufted-ear marmoset). The presence of the DNA of Leishmania was investigated in blood and skin samples by PCR and genetic sequencing. This is the first report of the detection of L. (L.) infantum in the skin of a marmoset, which was verified in a sample from one C. penicillata. The results demonstrate the natural infection of marmosets by L. (L.) infantum and may suggest the participation of these animals as hosts in the parasite's transmission cycle in the EPA. However, more comprehensive studies are needed to elucidate their role on the VL epidemiology in this area and also in different endemic areas, especially because these NHP are increasingly in contact with humans and domestic animals, particularly due to environmental changes.

Classificação epidemiológica dos municípios do Estado de São Paulo segundo o Programa de Vigilância e Controle da Leishmaniose Visceral, 2017 / Epidemiological classification of the municipalities of the Stat e of São Paulo according to the Visceral Leishmaniasis Control and Surveillance Program, 2017

Foi realizado um estudo descritivo dos casos de Leishmaniose Visceral (LV) notificados no período de 1999 a 2017 no Estado de São Paulo (ESP). Para a classificação epidemiológica dos municípios com transmissão humana de LV foram seguidas as recomendações do Ministério da Saúde1 que considera: "Municípios com transmissão recente aqueles que apresentaram o primeiro registro da doença nos últimos três anos" e "Municípios endêmicos aqueles que apresentam transmissão contínua de LV humana há pelo menos três anos

Human visceral leishmaniasis and relationship with vector and canine control measures.

OBJECTIVE: Estimate the coverage of control measures of visceral leishmaniasis and relate them with the occurrence of human visceral leishmaniasis in endemic urban area. METHODS: Cases of human and canine visceral leishmaniasis were considered as study population and evaluated by a serological survey conducted in Araçatuba, state São Paulo, from 2007 to 2015. The cases of human visceral leishmaniasis were geocoded by the address of the patients and the canine disease by the address of the dogs' owners. The coverage of serological survey, euthanasia, and insecticide spraying was calculated, as well as the canine seroprevalence and the incidence rates of human visceral leishmaniasis. The relationship between human visceral leishmaniasis and control measures was evaluated, as well as the seroprevalence by comparing maps and by linear regression. The relationship between the canine and the human disease was also evaluated by the Ripley's K function. RESULTS: The incidence rates of human visceral leishmaniasis showed a period of decline (2007 to 2009) and a period of stability (2010 to 2015), a behavior similar to that of canine seroprevalence. In general, the coverage of control measures was low, and the non-association with the incidence of human visceral leishmaniasis can be a result of the period analyzed and of the small number of analyzed units (sectors of the Superintendence for the Control of Endemic Diseases). The distribution of human cases showed spatial dependence with the distribution of seropositive dogs from 2007 to 2009. CONCLUSIONS: This study reaffirmed the relationship between the occurrence of the disease in humans and dogs, it verified a decrease in the rates of visceral leishmaniasis in Araçatuba over time, even at low coverage of control activities. However, further studies are needed to determine if factors beyond monitoring and control measures are involved in the reduction of incidences.

Canine visceral leishmaniasis in Araçatuba, state of São Paulo, Brazil, and its relationship with characteristics of dogs and their owners: a cross-sectional and spatial analysis using a geostatistical approach.

BACKGROUND: The incidence of visceral leishmaniasis (VL), one of the most important neglected diseases worldwide, is increasing in Brazil. The objectives of this study were to determine the canine VL (CanL) seroprevalence in an urban area of Araçatuba municipality and to evaluate its relationship with the characteristics of dogs and their owners. RESULTS: The CanL seroprevalence in the study area was 0.081 (95% credible interval [CI]: 0.068-0.096). The following covariates/categories were positively associated with the occurrence of a seropositive dog: more than 10 dogs that had lived in the house (odds ratio [OR] = 2.36; 95% CI: 1.03-5.43) (baseline: 0-10 dogs); house with dogs that previously died of VL (OR = 4.85; 95% CI: 2.65-8.86) or died of causes other than old age (OR = 2.26; 95% CI: 1.12-4.46) (baseline: natural or no deaths); dogs that spent the day in a sheltered backyard (OR = 2.14; 95% CI: 1.05-4.40); dogs that spent the day in an unsheltered backyard or the street (OR = 2.67; 95% CI: 1.28-5.57) (baseline: inside home). Spatial dependence among observations occurred within about 45.7 m. CONCLUSIONS: The number of dogs that had lived in the house, previous deaths by VL or other cause, and the place the dog stayed during the day were associated with the occurrence of a VL seropositive dog. The short-distance spatial dependence could be related to the vector characteristics, producing a local neighbourhood VL transmission pattern. The geostatistical approach in a Bayesian context using integrated nested Laplace approximation (INLA) allowed to identify the covariates associated with VL, including its spatially dependent transmission pattern.

Human visceral leishmaniasis and relationship with vector and canine control measures / Leishmaniose visceral em humanos e relação com medidas de controle vetorial e canino

ABSTRACT OBJECTIVE Estimate the coverage of control measures of visceral leishmaniasis and relate them with the occurrence of human visceral leishmaniasis in endemic urban area. METHODS Cases of human and canine visceral leishmaniasis were considered as study population and evaluated by a serological survey conducted in Araçatuba, state São Paulo, from 2007 to 2015. The cases of human visceral leishmaniasis were geocoded by the address of the patients and the canine disease by the address of the dogs' owners. The coverage of serological survey, euthanasia, and insecticide spraying was calculated, as well as the canine seroprevalence and the incidence rates of human visceral leishmaniasis. The relationship between human visceral leishmaniasis and control measures was evaluated, as well as the seroprevalence by comparing maps and by linear regression. The relationship between the canine and the human disease was also evaluated by the Ripley's K function. RESULTS The incidence rates of human visceral leishmaniasis showed a period of decline (2007 to 2009) and a period of stability (2010 to 2015), a behavior similar to that of canine seroprevalence. In general, the coverage of control measures was low, and the non-association with the incidence of human visceral leishmaniasis can be a result of the period analyzed and of the small number of analyzed units (sectors of the Superintendence for the Control of Endemic Diseases). The distribution of human cases showed spatial dependence with the distribution of seropositive dogs from 2007 to 2009. CONCLUSIONS This study reaffirmed the relationship between the occurrence of the disease in humans and dogs, it verified a decrease in the rates of visceral leishmaniasis in Araçatuba over time, even at low coverage of control activities. However, further studies are needed to determine if factors beyond monitoring and control measures are involved in the reduction of incidences.

RESUMO OBJETIVO Estimar a cobertura das atividades de controle da leishmaniose visceral e relacioná-las com a ocorrência de leishmaniose visceral em humanos em área urbana endêmica. MÉTODOS Foram considerados como população de estudo os casos de leishmaniose visceral em humanos e em cães avaliados por inquérito sorológico censitário realizado em Araçatuba, SP, de 2007 a 2015. Os casos de leishmaniose visceral em humanos foram geocodificados pelo endereço de residência dos pacientes e, os cães, pelo endereço de residências dos respectivos tutores. Foram calculadas as coberturas do inquérito sorológico, da eutanásia e de borrifação de inseticida, as soroprevalências caninas e as taxas de incidência de leishmaniose visceral em humanos. A relação entre a leishmaniose visceral em humanos e as medidas de controle, bem como a soroprevalência foram avaliadas por comparação de mapas e por meio de regressão linear. A relação entre a doença canina e a humana também foi avaliada por meio da função K de Ripley . RESULTADOS As taxas de incidência de leishmaniose visceral em humanos apresentaram um período de declínio (2007 a 2009) e um período de estabilidade (2010 a 2015), comportamento semelhante ao das soroprevalências caninas. Em geral, a cobertura das medidas de controle foi baixa e a não associação com a incidência de leishmaniose visceral em humanos pode ser consequência do período analisado e do número pequeno de unidades analisadas (setores da Superintendência de Controle de Endemias). A distribuição dos casos humanos apresentou dependência espacial com a distribuição dos cães soropositivos de 2007 a 2009. CONCLUSÕES Este trabalho reafirmou a relação entre a ocorrência da doença no homem e no cão, verificou a diminuição das taxas de leishmaniose visceral em humanos e em cães em Araçatuba ao longo do tempo, mesmo em baixa cobertura das atividades de controle. Entretanto, novos estudos são necessários para averiguar se fatores além das atividades de vigilância e controle estariam envolvidos na diminuição das incidências.