[An evaluation of municipal actions in the control of dengue vectors in the region of São José do Rio Prêto, São Paulo, 1989 to 1995]

[Aedes aegypti larval indices and dengue incidence: an ecological study in the state of Rio de Janeiro, Brazil]

The simultaneous circulation of dengue, Zika, and chikungunya poses major challenges for Brazil. Due to climate changes and other associated factors, more than two billion people in the world may be exposed to these arbovirus infections, according to the World Health Organization. The principal strategy for Aedes aegypti control programs is based on the Infestation Index Rapid Survey for Ae. aegypti (LIRAa), a sample survey in which the Building Infestation Index (BII) is used to prioritize areas for intervention. This study analyzed the performance of LIRAa in terms of its sensitivity for predicting dengue epidemics in municipalities in the state of Rio de Janeiro in epidemic years. Incidence rates per municipality for the years 2011, 2012, 2013, 2015, and 2016, plus the BII in October of the previous years. Scatterplots were created, aimed at an exploratory analysis and graphic visualizations of the relationship between the above-mentioned variables, as well as analyses of the Spearman correlation between the BII and the Breteau Index for each year, aimed at estimating the quality of the LIRAa. Comparative analysis of the values for the BII and the respective incidence rates in the period only indicated significant correlation between these variables in 2011/2012 (rs = 0.479; p < 0.01). There was also a correlation between BII and Breteau Index. It is urgent to rethink the parameters established by the LIRAa methodology and invest in alternative methodologies in entomological and epidemiological surveillance that reliably measure transmission risk in the territory and thus design more effective strategies to control these arbovirus infections.

Space-time description of dengue outbreaks in Cruzeiro, São Paulo, in 2006 and 2011

Objective: to identify patterns in the spatial and temporal distribution of cases of dengue fever occurring in the city of Cruzeiro, state of São Paulo (SP). Methods: an ecological and exploratory study was undertaken using spatial analysis tools and data from dengue cases obtained on the SinanNet. The analysis was carried out by area, using the IBGE census sector as a unit. The months of March to June 2006 and 2011 were assessed, revealing progress of the disease. TerraView 3.3.1 was used to calculate the Global Moran’s I, month to month, and the Kernel estimator. Results: in the year 2006, 691 cases of dengue fever (rate of 864.2 cases/100,000 inhabitants) were georeferenced; and the Moran’s I and p-values were significant in the months of April and May (IM = 0.28; p = 0.01; IM = 0.20; p = 0.01) with higher densities in the central, north, northeast and south regions. In the year 2011, 654 cases of dengue fever (rate of 886.8 cases/100,000 inhabitants) were georeferenced; and the Moran’s I and p-values were significant in the months of April and May (IM = 0.28; p = 0.01; IM = 0.16; p = 0.05) with densities in the same regions as 2006. The Global Moran’s I is a global measure of spatial autocorrelation, which indicates the degree of spatial association in the set of information from the product in relation to the average. The I varies between -1 and +1 and can be attributed to a level of significance (p-value). The positive value points to a positive or direct spatial autocorrelation. Conclusion: we were able to identify patterns in the spatial and temporal distribution of dengue cases occurring in the city of Cruzeiro, SP, and locate the census sectors where the outbreak began and how it evolved.

Análise da lógica de intervenção do Programa Nacional de Controle da Dengue

OBJETIVOS: avaliar a coerência lógica do Programa Nacional de Controle da Dengue no Brasil (PNCD) quanto aos objetivos e meios definidos para o alcance dos resultados. MÉTODOS: pesquisa avaliativa, análise lógica da intervenção, utilizando-se revisão documental de três fontes de informação sobre o PNCD: relatório de painel de especialistas reunidos em seminário internacional para avaliação do programa; documentos técnicos e opinião de especialistas; e estudos científicos. Comparou-se a análise do programa ao modelo da Organização Panamericana da Saúde para prevenção e controle da dengue - Estratégia de Gestão Integrada-Dengue (EGI). RESULTADOS: encontrou-se convergência entre as estratégias quanto aos pressupostos, objetivos, metas gerais e dos componentes, e conteúdos das intervenções. Verificou-se fragilidade na implementação do PNCD no âmbito municipal em sua integralidade, especialmente de estrutura e gestão, bem como para os componentes analisados, com maior comprometimento no componente de controle vetorial. CONCLUSÕES: baixa coerência e necessidade de atualização do modelo teórico-lógico nos diferentes níveis de gestão do PNCD frente ao pequeno alcance dos objetivos gerais e específicos dos componentes.

Dengue vector-control services: how do they work? A systematic literature review and country case studies

The increasing incidence and geographic expansion of dengue suggest limitations of vector-control operations. We undertook an analysis of services with two methods: a systematic literature review; and case studies (stakeholder interviews, questionnaires) in Brazil, Guatemala, The Philippines and Viet Nam. In the systematic literature review there were only a few studies (strict criteria, 9 studies; less strict criteria, a further 16 studies and 3 guidelines). Of the 9 studies, 3 showed little change of control operations over time but did show strategic changes (decentralisation, intersectoral collaboration). Staffing levels, capacity building, management and organisation, funding and community engagement were insufficient. The case studies confirmed most of this information: (1) a lack of personnel (entomologists, social scientists, operational vector-control staff); (2) a lack of technical expertise at decentralised levels of services; (3) insufficient budgets; (4) inadequate geographical coverage; (5) interventions relying mostly on insecticides; (6) difficulties in engaging communities; (7) little capacity building; (8) almost no monitoring and evaluation. Stakeholders' doubts about service effectiveness were widespread, but interventions were assumed to be effective with increased resources. The analysis underlined the need for: operational standards; evidence-based selection/delivery of combinations of interventions; development/application of monitoring and evaluation tools; needs-driven capacity building.