Effectiveness of insecticide-impregnated collars for the control of canine visceral leishmaniasis.

Visceral leishmaniasis is a neglected tropical disease widely distributed worldwide. In Brazil, the control measures adopted in the last decades have not been able to prevent the spread of the disease. This study aimed to evaluate the effectiveness of a population-based intervention using 4% deltamethrin-impregnated dog collars on the incidence of canine visceral leishmaniasis. A community intervention study was carried out in two areas of the city of Montes Claros, State of Minas Gerais, Brazil. In the control area, the preventive measures recommended by the Brazilian Program for Surveillance and Control of Visceral Leishmaniasis were implemented (culling of infected dogs and vector control with residual insecticides). In the intervention area, deltamethrin-impregnated collars were fit to domiciled dogs, in addition to the above mentioned preventive measures. At the beginning of the study, a census survey was carried out among domiciled dogs to detect the prevalence of L. infantum infection. Dogs found seronegative at recruitment were longitudinally followed-up to evaluate the incidence of infection. Monitoring of canine infection (control and intervention areas) and replacement of collars (intervention area) occurred through sequential surveys at 12, 18, and 24 months after the initial survey. At each survey, dogs were tested, and the owner answered a questionnaire about the general characteristics of the animal. Multilevel logistic regression models were used to test the effect of collars on the risk of canine infection, with households considered as aggregation units. Associations were expressed as odds ratios (OR) and respective 95% confidence intervals (95%CI). The prevalence of infection in the initial survey was 9.7% and 9.9% in the intervention and control areas, respectively (p = 0.732). Among a total of 20,477 dogs participating in the study, 9,770 were seronegative at recruitment. The cumulative incidence of infection was 4.1% in the intervention area and 7.9% in the control area (p < 0.001). In the multivariable analysis, the risk of infection was 52% lower in the intervention area as compared to the control area (OR = 0.48, 95%CI:0.39-0.59), after adjusting for the number of dogs in the house, period of recruitment, time of dog ownership, and age, sex, length of fur and breed. The use of 4% deltamethrin-impregnated dog collars was effective in reducing the incidence of canine leishmaniasis. Cost-effectiveness studies are recommended before the incorporation of collars in the arsenal of control measures of the Brazilian Program for Surveillance and Control of Visceral Leishmaniasis.

Operational difficulties in the use of insecticidal dog collars for the control of visceral leishmaniasis, municipality of Montes Claros, MG, Brazil, 2012. / Dificuldades operacionais no uso de coleiras caninas impregnadas com inseticida para o controle da leishmaniose visceral, Montes Claros, MG, 2012.

OBJECTIVE: to describe operational difficulties in the implementation of deltamethrin-impregnated dog collars for the control of visceral leishmaniasis. METHODS: this was a community intervention trial in the municipality of Montes Claros, MG, Brazil, comparing (i) control area - dogs without dog collars - and (ii) intervention area - use of 4% deltamethrin-impregnated collars; an initial serological survey was performed, followed by three further cycles (at 12, 18 and 24 months). RESULTS: out of 4,388 dogs initially seronegative wearing collars, 36.9% were not found in the second cycle, 27.0% of them were lost owing to disappearance/given away/sale, and 22.6% because no one was at home; 56.1% of collars were lost in one year; while among dogs that stayed longer in the study, collar loss was lower. CONCLUSION: high frequencies of collar loss and no one being at home at the time of the visit are operational difficulties for the implementation of a national control program based on the strategy evaluated.

Risk Profiles for Leishmania infantum Infection in Brazil.

The aim of this study was to characterize risk profiles for Leishmania infantum infection in a population living in an area endemic for visceral leishmaniasis. A cohort study was conducted between January 2004 and December 2006 with the participation of 430 individuals living in the city of Teresina, northeast Brazil, who were initially negative for the Montenegro test. Data analysis was performed using the classification and regression tree method. The cumulative incidence (CI) of Montenegro's test conversion was 35% at 18-month follow-up. Eight different risk profiles for L. infantum infection were identified. The profile with the highest risk (CI = 75%) comprised individuals with less than 4 years of education who had never lived outside Teresina. The profile with the lowest risk (CI = 5%) included highly educated subjects who had owned a dog for 5 years or more and lived in areas that received some type of intervention. These results show that there is a high degree of complexity involved in the risk for L. infantum infection and point out the need of developing new studies to perform a comprehensive analysis focused on investigating the interrelation between risk factors rather than their isolated roles on the determination of infection levels in urban areas.

Dificuldades operacionais no uso de coleiras caninas impregnadas com inseticida para o controle da leishmaniose visceral, Montes Claros, MG, 2012 / Dificultades operativas en el uso de collares impregnados con insecticida para el control de la leishmaniasis visceral, municipio de Montes Claros, MG, Brasil, 2012 / Operational difficulties in the use of insecticidal dog collars for the control of visceral leishmaniasis, municipality of Montes Claros, MG, Brazil, 2012

Objetivo: descrever dificuldades operacionais na implementação de coleiras caninas impregnadas com deltametrina para o controle da leishmaniose visceral. Métodos: estudo de intervenção comunitária no município de Montes Claros, MG, Brasil, comparando (i) área-controle - sem encoleiramento canino - e (ii) área de intervenção - uso de coleiras caninas impregnadas com deltametrina 4%; foi realizado inquérito sorológico inicial, seguido de três outros ciclos (aos 12, 18 e 24 meses). Resultados: de 4.388 cães inicialmente soronegativos encoleirados, 36,9% não foram encontrados no segundo ciclo, 27,0% foram perdidos por sumiço/doação/venda e 22,6% porque a casa estava fechada; a perda de coleiras foi de 56,1% em um ano; entre os cães que permaneceram mais tempo no estudo, a perda foi menor. Conclusão: as altas frequências de perda de coleiras e de domicílios fechados são dificuldades operacionais para a implementação de um programa de controle baseado na estratégia avaliada.

Objetivo: describir las dificultades operativas en la implementación de los collares impregnados con deltametrina para el control de la leishmaniasis visceral. Métodos: ensayo comunitario de intervención en la municipalidad de Montes Claros, MG, Brasil, comparando (i) área control - perros sin collares - y (ii) área de intervención - uso de collares impregnados con deltametrina 4% -; se realizó una encuesta serológica inicial, seguida de otros tres ciclos (a los 12, 18 y 24 meses). Resultados: de 4.388 perros inicialmente seronegativos y con los collares, 36,9% no participaron del segundo ciclo, 27,0% se perdieron por desaparición/donación/venta y 22,6% porque el domicilio estaba cerrado; la pérdida de los collares fue del 56,1% en un año; entre los perros que permanecieron más tiempo en estudio, la pérdida fue menor. Conclusión: alta frecuencia de pérdida de los collares y de domicilios cerrados son dificultades operativas para la implementación de un programa nacional de control basado en la estrategia evaluada.

Objective: to describe operational difficulties in the implementation of deltamethrin-impregnated dog collars for the control of visceral leishmaniasis. Methods: this was a community intervention trial in the municipality of Montes Claros, MG, Brazil, comparing (i) control area - dogs without dog collars - and (ii) intervention area - use of 4% deltamethrin-impregnated collars; an initial serological survey was performed, followed by three further cycles (at 12, 18 and 24 months). Results: out of 4,388 dogs initially seronegative wearing collars, 36.9% were not found in the second cycle, 27.0% of them were lost owing to disappearance/given away/sale, and 22.6% because no one was at home; 56.1% of collars were lost in one year; while among dogs that stayed longer in the study, collar loss was lower. Conclusion: high frequencies of collar loss and no one being at home at the time of the visit are operational difficulties for the implementation of a national control program based on the strategy evaluated.

Mortalidade infantil no município do Rio de Janeiro / Child Mortality in Rio de Janeiro City

A taxa de mortalidade infantil é considerada indicador síntese da qualidade de vida e do nível de desenvolvimento de uma população. Este artigo analisa a evolução dessas taxas no Município do Rio de Janeiro, no período de 1979 a 2004, e as causas em 2004. Trata de estudo descritivo a partir do total de óbitos infantis e nascimentos ocorridos, utilizando-se os sistemas de informação produzidos pelo Ministério da Saúde...