ABSTRACT
The effect of employing collars impregnated with deltamethrin 4% (DM4) to control canine visceral leishmaniasis (CVL) was evaluated. as were the individual factors associated with this infection. A cohort study that included household dogs was conducted between 2002 and 2006. The presence of pathognomonic signals, peridomiciliary sleep habits and breed were the main factors associated with the infection. The use of DM4 collars contributed to the reduction of CVL with an effectiveness of 66%, and the dogs' survival rate was greater than 90% at 50 months. In conclusion, the adoption of DM4 collars reduced the number of euthanized canines and in the incidence of CVL, and this reduction was sustained for one year after discontinuing the use of the collar.
ABSTRACT
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.
Subject(s)
Ants/parasitology , Dog Diseases/diagnosis , Dog Diseases/pathology , Leishmaniasis, Visceral/pathology , Animals , Bayes Theorem , Brazil/epidemiology , Dog Diseases/epidemiology , Dogs , Humans , Leishmania infantum/isolation & purification , Leishmaniasis, Visceral/epidemiology , Poisson Distribution , Risk Factors , Seroepidemiologic StudiesABSTRACT
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.
Subject(s)
Dog Diseases/prevention & control , Leishmaniasis, Visceral/veterinary , Animals , Brazil , Cities , Dogs , Humans , Leishmaniasis, Visceral/prevention & control , Models, Theoretical , Seroepidemiologic Studies , Surveys and QuestionnairesABSTRACT
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.
Subject(s)
Humans , Animals , Dogs , Dog Diseases/prevention & control , Leishmaniasis, Visceral/veterinary , Brazil , Seroepidemiologic Studies , Surveys and Questionnaires , Cities , Leishmaniasis, Visceral/prevention & control , Models, TheoreticalABSTRACT
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.
Subject(s)
Dog Diseases/epidemiology , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/veterinary , Adolescent , Adult , Animals , Brazil/epidemiology , Child , Child, Preschool , Disease Vectors , Dog Diseases/blood , Dog Diseases/prevention & control , Dog Diseases/transmission , Dogs , Humans , Incidence , Infant , Leishmaniasis, Visceral/prevention & control , Leishmaniasis, Visceral/transmission , Middle Aged , Seroepidemiologic Studies , Spatio-Temporal Analysis , Urban Population , Young AdultABSTRACT
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.
Subject(s)
Dog Diseases/epidemiology , Dog Diseases/parasitology , Leishmaniasis, Visceral/veterinary , Spatial Analysis , Animals , Bayes Theorem , Brazil/epidemiology , Cross-Sectional Studies , Dogs , Female , Incidence , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/mortality , Male , Residence Characteristics , Seroepidemiologic StudiesABSTRACT
INTRODUCTION: This study aimed to describe the occurrence of human visceral leishmaniasis in Araçatuba with regard to time and space and to identify high risk areas. METHODS: We included all human visceral leishmaniasis autochthonous cases reported between 1999 and 2015. The incidence rates were calculated by sex, age, and year. The human visceral leishmaniasis cases were geocoded and grouped by urban census tracts, enabling the calculation of the incidence and mortality rates by census tracts. For the identification of high risk areas, we utilized the scan statistics and univariate Ripley's K-function. RESULTS: The incidence presented a cyclic pattern in 1999-2009, with peaks in 2002 and 2007 (30.1 and 19.6 cases per 100,000 inhabitant-years, respectively). In 2010-2015, the incidence remained relatively stable with about 2.0 cases per 100,000 inhabitant-years. The scan statistics detected two spatial clusters of high risk and three spatio-temporal clusters of high risk that lasted from 2001 to 2008. A spatial autocorrelation was observed in the human visceral leishmaniasis case point distribution in 1999-2009. No spatio-temporal clusters and no spatial autocorrelation in the case point pattern were identified in 2010-2015. CONCLUSION: We identified a changing pattern of human visceral leishmaniasis occurrence in Araçatuba: the first period (1999-2009) showed a cyclic pattern, clusters, and presence of spatial dependence in the case point distribution; the second period (2010-2015) showed the lowest rates of all historical series, stable incidence, and cases with a random distribution pattern.
Subject(s)
Leishmaniasis, Visceral/epidemiology , Adolescent , Adult , Brazil/epidemiology , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Spatio-Temporal Analysis , Young AdultABSTRACT
Abstract INTRODUCTION: This study aimed to describe the occurrence of human visceral leishmaniasis in Araçatuba with regard to time and space and to identify high risk areas. METHODS: We included all human visceral leishmaniasis autochthonous cases reported between 1999 and 2015. The incidence rates were calculated by sex, age, and year. The human visceral leishmaniasis cases were geocoded and grouped by urban census tracts, enabling the calculation of the incidence and mortality rates by census tracts. For the identification of high risk areas, we utilized the scan statistics and univariate Ripley's K-function. RESULTS: The incidence presented a cyclic pattern in 1999-2009, with peaks in 2002 and 2007 (30.1 and 19.6 cases per 100,000 inhabitant-years, respectively). In 2010-2015, the incidence remained relatively stable with about 2.0 cases per 100,000 inhabitant-years. The scan statistics detected two spatial clusters of high risk and three spatio-temporal clusters of high risk that lasted from 2001 to 2008. A spatial autocorrelation was observed in the human visceral leishmaniasis case point distribution in 1999-2009. No spatio-temporal clusters and no spatial autocorrelation in the case point pattern were identified in 2010-2015. CONCLUSION: We identified a changing pattern of human visceral leishmaniasis occurrence in Araçatuba: the first period (1999-2009) showed a cyclic pattern, clusters, and presence of spatial dependence in the case point distribution; the second period (2010-2015) showed the lowest rates of all historical series, stable incidence, and cases with a random distribution pattern.
Subject(s)
Humans , Male , Female , Pregnancy , Infant, Newborn , Child, Preschool , Child , Adolescent , Adult , Young Adult , Leishmaniasis, Visceral/epidemiology , Brazil/epidemiology , Incidence , Risk Factors , Spatio-Temporal Analysis , Middle AgedABSTRACT
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.
Subject(s)
Humans , Animals , Infant , Child, Preschool , Child , Adolescent , Adult , Dogs , Young Adult , Dog Diseases/epidemiology , Leishmaniasis, Visceral/veterinary , Leishmaniasis, Visceral/epidemiology , Urban Population , Brazil/epidemiology , Seroepidemiologic Studies , Incidence , Disease Vectors , Dog Diseases/prevention & control , Dog Diseases/blood , Dog Diseases/transmission , Spatio-Temporal Analysis , Leishmaniasis, Visceral/prevention & control , Leishmaniasis, Visceral/transmission , Middle AgedABSTRACT
Visceral leishmaniasis (VL), a neglected disease, is a serious public health problem that affects millions of people worldwide. The objectives of the study were to evaluate the sensitivity of Lutzomyia longipalpis and canine VL (CVL) autochthony early detection and describe the spatial and temporal dispersal of vector and expansion of VL in a Brazilian state. We obtained data on the leishmaniasis vector and VL cases in São Paulo State (SP), Brazil, from the Division of Endemic Disease Control and from the Epidemiological Surveillance Center of the São Paulo State Department of Health. Data were analyzed for 645 municipalities and 63 microregions and presented as thematic and flow maps. Following the verified presence of L. longipalpis in Araçatuba in 1997, the first autochthonous cases of canine VL (CVL) (1998) and of human VL (HVL) (1999) in São Paulo were reported, both in Araçatuba. From 1997 to 2014, the urban presence of the leishmaniasis vector was verified in 167 (25.9%) municipalities with cases of CVL reported in 108 (16.7%) and cases of HVL in 84 (13%). The sensitivities for vector presence early detection in relation to the identification of CVL and HVL autochthony were, respectively, equal to 76.4 and 92.5%. The sensitivity for CVL autochthony early detection in relation to the HVL autochthony identification was 75.8%. Vector dispersal and expansion of CVL and HVL were from the northwest to the southeast of the state, primarily flanking the Marechal Rondon highway at a constant rate of progression of 10, seven, and six new municipalities affected per year, respectively. We concluded that the sensitivity for vector presence and CVL autochthony presented reasonable accuracy and most of the time the vector presence and, specially, the CVL and HVL autochthony were identified in the main cities of the microregions of SP. Vector dispersal and expansion of VL started in 1997 near the state border of SP with the state of Mato Grosso do Sul. It has advanced from the northwest to the southeast flanking the Marechal Rondon highway at an arithmetic progression rate outward from the main cities of the microregions. Autochthonous cases of CVL and HVL emerged in SP, in general, after the verified presence of L. longipalpis.
Subject(s)
Dog Diseases/parasitology , Dog Diseases/transmission , Leishmaniasis, Visceral/transmission , Leishmaniasis, Visceral/veterinary , Psychodidae/physiology , Animals , Brazil/epidemiology , Cities/statistics & numerical data , Disease Progression , Disease Reservoirs/parasitology , Disease Reservoirs/veterinary , Dog Diseases/prevention & control , Dogs , Endemic Diseases/statistics & numerical data , Endemic Diseases/veterinary , Humans , Insect Vectors/parasitology , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/prevention & control , Neglected Diseases/epidemiology , Neglected Diseases/veterinary , Population DensityABSTRACT
INTRODUCTION This paper aims to describe the dispersion of Lutzomyia longipalpis and the autochthonous occurrence of visceral leishmaniasis (VL) in the Northwest region of the State of São Paulo between 2007 and 2013 and to analyze their expansion. METHODS Information about the vector and associated cases was described using maps. The incidence, mortality, and lethality of human visceral leishmaniasis (HVL) were calculated. In municipalities in which more than one HVL case occurred, incidences were calculated according to census sector, and spatial and spatiotemporal clusters were identified. RESULTS The first case of HVL was reported in the municipality of Jales in 2007. By 2013, the vector and the disease had expanded from west to east, with the vector being detected in 29 municipalities. A total of 11 municipalities had cases of canine visceral leishmaniasis (CVL), and six had cases of HVL. Vector expansion occurred by vicinity with previously infested municipalities, and the expansion of VL was related to the major highways and the capital municipalities of the micro-regions in the study area. The highest incidence of HVL occurred in children between 0-4 years old, and the highest mortality and lethality occurred among persons aged 60 and older. The occurrence of HLV was more intense in the peripheral areas of municipalities with the disease. CONCLUSIONS The findings of this study may be useful for improving VL surveillance and control activities by slowing VL expansion and/or mitigating VL effects when they occur.
Subject(s)
Dog Diseases/transmission , Insect Vectors , Leishmaniasis, Visceral/transmission , Psychodidae , Adolescent , Adult , Animals , Brazil/epidemiology , Child , Child, Preschool , Dog Diseases/mortality , Dogs , Humans , Incidence , Infant , Infant, Newborn , Leishmaniasis, Visceral/mortality , Leishmaniasis, Visceral/veterinary , Middle Aged , Spatio-Temporal Analysis , Young AdultABSTRACT
Abstract: INTRODUCTION This paper aims to describe the dispersion of Lutzomyia longipalpis and the autochthonous occurrence of visceral leishmaniasis (VL) in the Northwest region of the State of São Paulo between 2007 and 2013 and to analyze their expansion. METHODS Information about the vector and associated cases was described using maps. The incidence, mortality, and lethality of human visceral leishmaniasis (HVL) were calculated. In municipalities in which more than one HVL case occurred, incidences were calculated according to census sector, and spatial and spatiotemporal clusters were identified. RESULTS The first case of HVL was reported in the municipality of Jales in 2007. By 2013, the vector and the disease had expanded from west to east, with the vector being detected in 29 municipalities. A total of 11 municipalities had cases of canine visceral leishmaniasis (CVL), and six had cases of HVL. Vector expansion occurred by vicinity with previously infested municipalities, and the expansion of VL was related to the major highways and the capital municipalities of the micro-regions in the study area. The highest incidence of HVL occurred in children between 0-4 years old, and the highest mortality and lethality occurred among persons aged 60 and older. The occurrence of HLV was more intense in the peripheral areas of municipalities with the disease. CONCLUSIONS The findings of this study may be useful for improving VL surveillance and control activities by slowing VL expansion and/or mitigating VL effects when they occur.
Subject(s)
Humans , Animals , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Dogs , Young Adult , Psychodidae , Dog Diseases/transmission , Insect Vectors , Leishmaniasis, Visceral/transmission , Brazil/epidemiology , Incidence , Dog Diseases/mortality , Spatio-Temporal Analysis , Leishmaniasis, Visceral/mortality , Leishmaniasis, Visceral/veterinary , Middle AgedABSTRACT
This study aimed to investigate the occurrence of Lutzomyia longipalpis and also the canine visceral leishmaniasis (CVL) in a rural area of Ilha Solteira, state of São Paulo. Blood samples were collected from 32 dogs from different rural properties (small farms) and were analyzed by ELISA and the indirect immunofluorescence antibody test (IFAT) in order to diagnose CVL. From these serological tests, 31.25% of the dogs were positive for CVL and these were distributed in 66.7% (8/12) of the rural properties, which were positive for L. longipalpis. CDC (Center for Disease Control and Prevention) light traps were installed in 12 properties (one per property) and insects were caught on three consecutive days per month for one year. L. longipalpis was present on 100% of the rural properties visited, at least once during the twelve-month interval, totaling 64 males and 25 females. The insects were more numerous after the peak of the rain, but the association between prevalence of peridomestic vectors and the climatic data (precipitation, relative air humidity and temperature) and the occurrences of CVL among dogs on each rural property were not statistical significant (p <0.05). However, the occurrence of CVL cases in dogs and the presence of L. longipalpis indicate that more attention is necessairy for the control of this disease in the rural area studied.
Subject(s)
Dog Diseases/parasitology , Leishmaniasis, Visceral/veterinary , Psychodidae , Animals , Brazil/epidemiology , Dog Diseases/epidemiology , Dogs , Female , Leishmaniasis, Visceral/epidemiology , Male , Rural HealthABSTRACT
This study aimed to investigate the occurrence of Lutzomyia longipalpis and also the canine visceral leishmaniasis (CVL) in a rural area of Ilha Solteira, state of São Paulo. Blood samples were collected from 32 dogs from different rural properties (small farms) and were analyzed by ELISA and the indirect immunofluorescence antibody test (IFAT) in order to diagnose CVL. From these serological tests, 31.25% of the dogs were positive for CVL and these were distributed in 66.7% (8/12) of the rural properties, which were positive for L. longipalpis. CDC (Center for Disease Control and Prevention) light traps were installed in 12 properties (one per property) and insects were caught on three consecutive days per month for one year. L. longipalpis was present on 100% of the rural properties visited, at least once during the twelve-month interval, totaling 64 males and 25 females. The insects were more numerous after the peak of the rain, but the association between prevalence of peridomestic vectors and the climatic data (precipitation, relative air humidity and temperature) and the occurrences of CVL among dogs on each rural property were not statistical significant (p <0.05). However, the occurrence of CVL cases in dogs and the presence of L. longipalpis indicate that more attention is necessairy for the control of this disease in the rural area studied.
O objetivo desse trabalho foi o estudo da prevalência de Lutzomyia longipalpis e da leishmaniose visceral canina (LVC) em uma área rural do município de Ilha Solteira do estado de São Paulo. Amostras de sangue foram coletadas de 32 cães provenientes de pequenas propriedades rurais e analisadas por meio dos métodos sorológicos ELISA (imunoensaio enzimático indireto) e RIFI (reação de imunofluorescência indireta) para o diagnóstico da LVC. Pelos exames sorológicos, dos 32 cães avaliados, 31,25% foram diagnosticados positivos para LVC, os quais estavam diostribuídos em 66,67% (8/12) das propriedades positivas para Lutzomyia longipalpis. Armadilhas luminosas do tipo CDC (Center for Disease Control and Prevention) foram instaladas em 12 propriedades, sendo uma por propriedade, e as coletas dos insetos foram realizadas três dias consecutivos a cada mês, durante um ano. O inseto L. longipalpis foi encontrado em 100% das propriedades visitadas, pelo menos uma vez no ano, totalizando 65 machos e 25 fêmeas. A maior quantidade de insetos foi observada principalmente após a ocorrência dos maiores picos de precipitação pluvial, mas a associação entre a prevalência dos vetores peridomiciliares e os dados climáticos (precipitação, umidade relativa do ar e temperatura) assim como a ocorrência da CVL em cães em cada propriedade não foi estatisticamente significante (p<0.05). No entanto, alerta-se que pela presença dos casos de LVC nos cães amostrados e também de L. longipalpis, maior atenção deve ser dada durante as investigações epidemiológicas para o controle dessa doença nessa área rural estudada.
Subject(s)
DNA-Binding Proteins/physiology , DNA-Directed RNA Polymerases/chemistry , Escherichia coli/enzymology , Sigma Factor/chemistry , Transcription Factors/physiology , Viral Proteins/physiology , DNA , DNA-Binding Proteins/chemistry , DNA-Directed RNA Polymerases/physiology , Sigma Factor/physiology , Transcription Factors/chemistry , Transcription, Genetic , Two-Hybrid System Techniques , Viral Proteins/chemistryABSTRACT
INTRODUCTION: In 1999, Birigui and Araçatuba were the first municipalities in the State of São Paulo to present autochthonous cases of visceral leishmaniasis in humans (VLH). The aim of this study was to describe the temporal, spatial and spatiotemporal behaviors of VLH in Birigui. METHODS: Secondary data were obtained from the Notifiable Diseases Information System from 1999 to 2012. The incidence, mortality and case fatality rates by sex and age were calculated. The cases of VLH were geocoded and grouped according to census tracts. Local empirical Bayesian incidence rates were calculated. The existence of spatial and spatiotemporal clusters was investigated using SaTScan software. RESULTS: There were 156 confirmed cases of autochthonous VLH. The incidence rate was higher in the 0-4-year-old children, and the mortality and case fatality rates were higher in people aged 60 years and older. The peaks of incidence occurred in 2006 and 2011. The Bayesian rates identified the presence of VLH in all of the census tracts in the municipality; however, spatial and spatiotemporal clusters were found in the central area of the municipality. CONCLUSIONS: Birigui, located in the Araçatuba region, has recently experienced increasing numbers of VLH cases; this increase is contrary to the behavior observed over the entire region, which has shown a decreasing trend in the number of VLH cases. The observations that the highest incidence is in children 0-4 years old and the highest mortality is in people 60 years and older are in agreement with the expected patterns of VLH.
Subject(s)
Leishmaniasis, Visceral/epidemiology , Adolescent , Adult , Bayes Theorem , Brazil/epidemiology , Child , Child, Preschool , Disease Notification , Female , Geographic Information Systems , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Spatio-Temporal Analysis , Young AdultABSTRACT
The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a "Munck" truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.
Subject(s)
Arecaceae/parasitology , Housing , Insect Vectors , Rhodnius , Animals , Brazil , Chagas Disease/transmission , Female , Humans , MaleABSTRACT
The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a “Munck” truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.
O objetivo deste trabalho é relatar a colonização de palmeiras por Rhodnius neglectus, sua invasão em área urbana, na cidade de Araçatuba - São Paulo, o controle e as medidas de vigilância instituídas. As pesquisas de triatomíneos nos domicílios ocorreram nos apartamentos quando da notificação pelo morador. Os insetos coletados foram identificados, examinados quanto à infecção natural e teste de precipitina. Na pesquisa das palmeiras foram utilizados lonas para forração do chão e caminhão Munck equipado com moto poda. O controle químico foi realizado com a utilização de compressor manual. No ano de 2009, foram coletados pela população 81 exemplares de Rhodnius neglectus em domicílios. O teste de precipitina acusou presença de sangue humano em 2,7% das amostras. Pesquisas entomológicas foram realizadas nestas edificações e naquelas situadas em um raio de 200 metros onde ocorreram as invasões. A pesquisa realizada nas palmeiras resultou na captura de 882 exemplares de triatomíneos, negativos para tripanosomatídeos. Foi realizado controle mecânico e químico. Novas pesquisas realizadas nas palmeiras avaliadas no mesmo ano resultaram na coleta de seis exemplares. Os controles mecânicos e químicos das palmeiras aliado ao trabalho de participação popular mostraram-se factíveis impedindo a colonização destes insetos nos domicílios da cidade.
Subject(s)
Animals , Female , Humans , Male , Arecaceae/parasitology , Housing , Insect Vectors , Rhodnius , Brazil , Chagas Disease/transmissionABSTRACT
Introduction In 1999, Birigui and Araçatuba were the first municipalities in the State of São Paulo to present autochthonous cases of visceral leishmaniasis in humans (VLH). The aim of this study was to describe the temporal, spatial and spatiotemporal behaviors of VLH in Birigui. Methods Secondary data were obtained from the Notifiable Diseases Information System from 1999 to 2012. The incidence, mortality and case fatality rates by sex and age were calculated. The cases of VLH were geocoded and grouped according to census tracts. Local empirical Bayesian incidence rates were calculated. The existence of spatial and spatiotemporal clusters was investigated using SaTScan software. Results There were 156 confirmed cases of autochthonous VLH. The incidence rate was higher in the 0-4-year-old children, and the mortality and case fatality rates were higher in people aged 60 years and older. The peaks of incidence occurred in 2006 and 2011. The Bayesian rates identified the presence of VLH in all of the census tracts in the municipality; however, spatial and spatiotemporal clusters were found in the central area of the municipality. Conclusions Birigui, located in the Araçatuba region, has recently experienced increasing numbers of VLH cases; this increase is contrary to the behavior observed over the entire region, which has shown a decreasing trend in the number of VLH cases. The observations that the highest incidence is in children 0-4 years old and the highest mortality is in people 60 years and older are in agreement with the expected patterns of VLH. .
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Young Adult , Leishmaniasis, Visceral/epidemiology , Bayes Theorem , Brazil/epidemiology , Disease Notification , Geographic Information Systems , Incidence , Spatio-Temporal AnalysisABSTRACT
Avaliou-se o hábito alimentar de Lutzomyia longipalpis em áreas de transmissão da leishmaniose visceral americana no município de Araçatuba (SP). De 1999 a 2001, capturas entomológicas mensais foram realizadas em três áreas do município, sendo pesquisadas amostras de 123 residências/área, durante 20 minutos/domicílio. As fêmeas ingurgitadas foram separadas e conservadas a -20ºC, até a realização do exame do conteúdo intestinal, pela reação de imunoprecipitação em tubo capilar. Utilizou-se anti-soros de: animais domésticos (cão, cavalo, gato e galinha), roedor e humano. Para a realização da reação, cada fêmea foi colocada em tubo com 0,2mL de solução fisiológica estéril mertiolada a 0,85%, por 12 horas. Posteriormente, foram maceradas e centrifugadas e 30ml do sobrenadante foram transferidos para o tubo capilar e adicionados 30ml de anti-soro. A reação foi dada como positiva quando observado grumo esbranquiçado até duas horas depois de seu início. Coletou-se 1.540 fêmeas de L. longipalpis, destas 699 estavam ingurgitadas quando coletadas e 613 (87,7%) foram submetidas ao teste, resultando em 45,6% de amostras reagentes. Das amostras reagentes 91,4% reagiram para sangue canino. Das 25 amostras reagentes para sangue humano 22 (88,0%) também reagiram para cão. Apenas 7,5% dos exemplares reagiram para sangue de ave. Em Araçatuba, L. longipalpis mostrou hábito eclético em relação à fonte alimentar, demonstrando alto grau de cinofilia. Embora as aves não tenham representado a principal fonte de alimento, deve-se atentar para o significado epidemiológico que elas representam, na medida em que permitem a domiciliação do vetor. Não foi observada mudança de hábito alimentar decorrente das atividades de controle vetorial.
