Intersectoral coordination in Aedes aegypti control. A pilot project in Havana City, Cuba

Effectiveness of Aedes-borne infectious disease control in Latin America and the Caribbean region: A scoping review

Background

Aedes aegypti and Aedes albopictus are primary vectors of emerging or re-emerging arboviruses that threaten public health worldwide. Many efforts have been made to develop interventions to control these Aedes species populations. Still, countries in the Latin America and the Caribbean (LAC) region struggle to create/design/develop sustainable and effective control strategies. This scoping review synthesises evidence concerning the effectiveness of Ae. aegypti and Ae. albopictus prevention and control interventions performed in LAC (2000–2021). The findings can be used to evaluate, compare and develop more effective control strategies.

Methodology

The review is based on the methodology by Joanna Briggs Institute for conducting a scoping review. The MEDLINE (via PubMed and Web of Science), Cochrane Library, Scopus, EMBASE and ScienceDirect databases were used to search for articles. Grey literature was searched from governmental and non-governmental organisation websites. Four reviewers independently screened all titles and abstracts and full-text of the articles using the Rayyan web application, based on pre-defined eligibility criteria.

Results

A total of 122 publications were included in the review. Most studies focused on dengue virus infection and data on Ae. aegypti. Entomological data were mainly used to determine the intervention’s effectiveness. An integrated control intervention was the most commonly employed strategy in both regions. Biological control measures, environmental management, and health education campaigns on community participation achieved more sustainable results than an intervention where only a chemical control measure was used. Challenges to implementing interventions were insufficient financial support, resources, workforce, intersectoral collaboration and legislation.

Conclusions

Based on the synthesised data, an integrated vector (Aedes) management focused on community participation seems to be the most effective approach to mitigate Aedes-borne infectious diseases. Maintaining the approach’s effect remains challenging as it requires multisectoral and multi-disciplinary team engagement and active community participation. Future research needs to address the barriers to program implementation and maintenance as data on this topic is lacking.

Use of effective lids reduces presence of mosquito larvae in household water storage containers in urban and peri-urban Zika risk areas of Guatemala, Honduras, and El Salvador

BACKGROUND

In 2015, an outbreak of Zika virus spread across Latin America and the Caribbean (LAC). Public health programs promoted vector control behaviors, including covering water storage containers with lids. Such approaches disrupt Zika transmission by eliminating the habitats of the Aedes aegypti mosquito, which breeds in stagnant water.

METHODS

A quantitative household survey and observation checklist with trained enumerators were undertaken between August and October 2018 in selected urban/peri-urban USAID implementation communities in El Salvador, Guatemala, and Honduras. The survey included questions regarding knowledge, attitudes, and practices related to Zika virus. An accompanying checklist was implemented to observe water storage containers, including for short-term and long-term water use. The characteristics of these containers were tabulated, including the presence of a lid. The lids were examined for key features to determine their potential effectiveness to prevent mosquito breeding: fully covering and sealing the container, not having holes, and not having water on them (potentially creating a secondary breeding site). Multivariate logistic regression was used to estimate the effectiveness of lid types and characteristics on the presence of larvae.

RESULTS

Overall, in adjusted models, using an effective lid versus no lid was associated with a 94% decrease in odds of larval presence in long-term water storage containers (odds ratio = 0.06; 95% confidence interval [0.029, 0.152]); however, similar impacts were not observed for washbasins in the adjusted models. Models adjusted for household wealth, receiving a visit from a vector control technician, scrubbing the container in the last 7 days, and perception of more mosquitoes around.

CONCLUSIONS

Effective lids, if made available and coupled with complementary behavioral messaging, may reduce transmission of Zika and other Aedes mosquito-borne diseases in the LAC region.

A Realist Synthesis of Community-Based Interventions in Vector-Borne Diseases

Randomized control trials have provided evidence that some community-based interventions (CBIs) work in vector-borne diseases (VBDs). Conversely, there is limited evidence on how well those CBIs succeed in producing specific outcomes in different contexts. To conduct a realist synthesis for knowledge translation on this topic, we examined the extent to which realist concepts (context, mechanisms, and outcomes) and their relationships are present in the existing literature on CBIs for VBDs. Articles on CBIs were identified from prior scoping reviews of health interventions for VBDs. Content of the articles was extracted verbatim if it referred either to realist concepts or CBI features. The number of articles and the average number of words extracted per category per CBI were quantified. Content of the articles was scrutinized to inductively gather qualitative evidence on the interactions between realist concepts. We reviewed 41 articles on 17 CBIs from 12 countries. The average number of words used for mechanisms was much lower than those used for outcomes and context (309,474, and 836, respectively). The average number of words used for mechanisms increased when a CBI was described in three or more articles. There were more extensive accounts on CBI features than on mechanisms. It was difficult to gather evidence on the interactions among realist concepts from the content of the articles. Scarce reporting on mechanisms in published articles limits conducting a realist synthesis of CBIs in VBDs. More transdisciplinary research that goes beyond the biomedical paradigm is needed to boost the development of intervention mechanisms in this field.

Recommendations for building out mosquito-transmitted diseases in sub-Saharan Africa: the DELIVER mnemonic

In sub-Saharan Africa, most transmission of mosquito-transmitted diseases, such as malaria or dengue, occurs within or around houses. Preventing mosquito house entry and reducing mosquito production around the home would help reduce the transmission of these diseases. Based on recent research, we make key recommendations for reducing the threat of mosquito-transmitted diseases through changes to the built environment. The mnemonic, DELIVER, recommends the following best practices: (i) Doors should be screened, self-closing and without surrounding gaps; (ii) Eaves, the space between the wall and roof, should be closed or screened; (iii) houses should be Lifted above the ground; (iv) Insecticide-treated nets should be used when sleeping in houses at night; (v) houses should be Ventilated, with at least two large-screened windows to facilitate airflow; (vi) Environmental management should be conducted regularly inside and around the home; and (vii) Roofs should be solid, rather than thatch. DELIVER is a package of interventions to be used in combination for maximum impact. Simple changes to the built environment will reduce exposure to mosquito-transmitted diseases and help keep regions free from these diseases after elimination. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.

Dengue fever awareness: effect of an educational intervention on nursing students, Tanta, Egypt

Dengue fever (DF) is one of the world's most important vector-borne illnesses. In 2017, Egypt experienced a dengue outbreak. This study aimed to assess the knowledge and attitudes of nursing students regarding DF and the effectiveness of an education intervention to improve students' knowledge and attitude. An intervention study was conducted among 4th year nursing students of Tanta Faculty of Nursing using a self-administered predesigned validated questionnaire before and after introducing an educational session. The main DF information sources were formal teaching, social networks, television, and physicians. Less than half of the students (45.5%) had "good" knowledge grade after the intervention compared with only 7.2% in the pre-test. The students' knowledge and attitude improved after the application of the intervention session. The positive impact of the educational intervention on knowledge and attitude regarding DF and its prevention among the target group revealed the importance of the inclusion of teaching materials about DF into the students' curricula.

Barriers to Engaging Communities in a Dengue Vector Control Program: An Implementation Research in an Urban Area in Hanoi City, Vietnam

The dengue situation in the urban setting of Hanoi city, Vietnam, is emerging, focusing on inner districts. Previous studies showed that a dengue vector control program in Hanoi was not effective because of the lack of adequate engagement of the local government authorities, health sector, and community. This implementation research aimed to explore barriers to implementing community engagement in a dengue vector control program in an urban district of Hanoi city. Ten in-depth interviews and 14 focus group discussions were conducted at Lang Thuong, Khuong Thuong, Tho Quan, and Kim Lien wards in Dong Da district, Hanoi city. Data collection was implemented from April to June 2017. All discussions were recorded and transcribed verbatim. Data were analyzed using the content analysis approach. Secondary data from the dengue vector control program reports were used to support the qualitative evidence. We found that the barriers to implementing effective community engagement were as follows: 1) lack of interest and an attitude of dependency on action from the health sector of local people's committee, 2) lack of enthusiasm of mass organizations and community leaders, 3) overburdened workloads and lack of communication skills from health sector, 4) low awareness and readiness from community, 5) lack of detailed policy guidelines and low enforcement of related policy, and 6) limited budget. Recommended actions should be made to improve the community engagement in the current resource-limited context of Vietnam by both top-down and bottom-up approaches.

The effectiveness of inspections on reported mosquito larval habitats in households: A case-control study

Background

Dengue is an arboviral disease that imposes substantial health and economic burdens across the globe. Vector control remains a key strategy in settings where Dengvaxia (a dengue vaccine) has not been licenced due to safety concerns and where mass immunization programmes are not cost-effective. Though inspections are used as part of arboviral disease control programmes, evidence of their impact on the entomological activity in households is sparse.

Methodology/Principal findings

We analysed nationally representative household inspection data collected from Singapore over a 3-year period, to determine the effect of inspections on reported mosquito larval habitats in households. A case was a household with a positive report of a mosquito larval habitat in its most recent inspection in 2017. A control was a household that was reported free of mosquito larvae in its most recent inspection in 2017. Using multivariable logistic regression, we analysed 3,205 cases and 557,044 controls. Households averaging three inspections per annum were associated with reduced odds of mosquito larval habitat reports [Adjusted Odds Ratio (AOR): 0.49, 95% Confidence Interval (95% CI): 0.38 to 0.63]. The effect of inspections declined with decreasing inspection frequencies but remained protective at lower levels. Longer intervals (30 to 36 months) between the most recent two successive inspections were associated with increased odds of mosquito larval habitat reports (AOR: 1.28, 95% CI: 1.06 to 1.56) compared to those carried out less than 6 months apart. Mosquito larval habitat reports exhibited a dependence on spatial and household-level characteristics such as the location of the community district, housing type and housing floor level. We observed a four-fold increase in the odds of mosquito larval habitat reports in households with an immediate previous report of larval activity compared to those that did not have one (AOR: 4.52, 95% CI: 3.67 to 5.56).

Conclusions/Significance

Our study confirms the protective effect of inspections on reported mosquito larval habitat reporting in households. Spatial, temporal and household-level characteristics should be accounted for in prioritizing vector control resources. Alternative strategies may help address recurrent entomological activity in households.

Dengue is a disease that is transmitted by Aedes mosquitoes. In areas where the use of a dengue vaccine has not been authorized due to safety concerns and is not cost-effective, reducing the population of Aedes mosquitoes remains the key method in controlling the disease. One approach to mosquito population control is the use of inspections to identify and eliminate mosquito larval habitats in homes. However, evidence supporting the use of this approach is limited. In this study, which used national data from Singapore, we investigated the relationship between the frequency of inspections and the propensity for mosquito larval habitat reports in homes. We found that homes that had been inspected more frequently had fewer reports of mosquito larval habitats. We also found that the characteristics and locations of homes, and their history of previously reported mosquito larval habitats influenced present findings for mosquito larval habitats. We conclude that homes that are more frequently inspected have a lower number of reported mosquito larval habitats. Knowledge of the characteristics and locations of homes, and their history of previous reports may improve resource allocation for the control of mosquitoes in homes.

Neighbors help neighbors control urban mosquitoes

The worldwide spread of invasive Aedes mosquitoes and arboviral disease, have renewed the pressure for effective and sustainable urban mosquito control. We report on the success of a model we are confident will usher in a new era of urban mosquito control. The key innovation is the mobilization of neighbors guided by scientific advisors, an approach we termed Citizen Action through Science (Citizen AcTS). This approach was tested in a NE US town of approximately 1,000 residential yards infested with the invasive Asian tiger mosquito, Aedes albopictus, a major nuisance arboviral vector. We report a highly significant reduction in biting pressure that was maintained over time, and establish the thresholds needed for success. The Citizen AcTS model rejects the top-down approach consistently associated with intervention failures. Instead, it works through respectful exchanges among scientists and residents that lead to trust and individual ‘buy-in’ and transferring program ownership to the community.

Intersectoral collaboration for the prevention and control of vector borne diseases to support the implementation of a global strategy: A systematic review

Introduction

Vector Borne Diseases (VBDs) have a major impact on public health and socio-economic development. Inter-sectoral collaboration was recommended as one of the key elements of Integrated Vector Management (IVM), however limited evidence measures the effect and contribution of intersectoral approaches including but not only IVM. This systematic review aims to assess the existing evidence on all forms of inter-sectoral collaboration in VBD control and prevention, identify any gaps and develop a framework from a global perspective.

Methods

Articles were identified through a search of PUBMED, Science of Direct, Web of Knowledge, Google Scholar and WHO archives using key words and excluded duplications (n = 2,034). The exclusion of non-VBDs control and prevention interventions resulted in 194 eligible titles/abstract/keywords for full text assessment. Further exclusion of non-peer reviewed articles, non-declaration of ethical clearance, reviews and expert opinion articles resulted in 50 articles finally being included for analysis with the extraction of data on outcome, factor/s influencing the effectiveness, indicators of collaboration and sustainability.

Results

Of the 50 articles included in the analysis, 19 articles were categorized as of moderate-strong quality. All articles compared pre- and post-intervention outcomes against disease or vector variables. Three papers included outcome variables on intersectoral collaboration and participation indicator. However, no paper undertook component analysis by different sectors or different activities. Only one paper compared cost data for community-intersectoral intervention for IRS and traditional “vertical” IRS. Six factors were identified as influencing the effectiveness of inter-sectoral collaboration. Five of six factors are the main ones, namely the approach (37/47), resources (34/47), relationships (33/47), management (29/47) and shared vision (20/47) factors. A conceptual framework has been developed based on this review.

Conclusion

This review shows the importance of inter-sectoral collaboration to reduce VBDs or vector densities. However, very few studies measured how much inter-sectoral collaboration contributes to the impact. Further high-quality studies using inter-sectoral collaboration indicators are recommended to be undertaken.

Socioeconomic and Human Behavioral Factors Associated With Aedes aegypti (Diptera: Culicidae) Immature Habitat in Tucson, AZ

Aedes aegypti (L.; Diptera: Culicidae) has been established in the southwestern United States for several decades, but relationships between humans and mosquitoes in this arid region are not well-characterized. In August 2012, the outdoor premises of 355 houses within 20 neighborhoods in Tucson, Arizona were surveyed for containers that could provide larval habitat for Ae. aegypti mosquitoes. At the same time, a knowledge, attitudes and practices (KAP) questionnaire was administered to a resident of each house surveyed for immature mosquitoes. The KAP questionnaire assessed respondents' knowledge and concerns about vector-borne illnesses as well as practices they used to avoid mosquitoes. Of the houses surveyed, 91% had at least one container present, and 64% had at least one container with standing water. On average, each house had 2.2 containers with water at the time of the survey. The overall House Index (proportion of premises surveyed with at least one container with Ae. aegypti immatures present) was 13%. Based on questionnaire responses, there was a significant positive association between the number of residents in the home and the odds of finding Ae. aegypti positive containers on the premises, while household income showed a significant negative association. The reported frequency of checking for standing water was also significantly associated with the odds of finding immatures, although the nature of this association was ambiguous. Flower pots were the principal type of container with Ae. aegypti larvae. These findings show that larval habitat is widely available even in an arid environment and city with good housing and sanitation infrastructure.

Knowledge, Attitudes, and Preventive Practices Regarding Dengue in Maracay, Venezuela

Dengue, a viral mosquito-borne disease currently affects more than 2.5 billion people living in endemic areas worldwide. In vector control, social mobilization and community behavioral changes are of crucial importance. Here, we identified the factors influencing community dengue preventive practices in a high-transmission urban area in Venezuela. Between September 2013 and February 2014, a cross-sectional study at the household level was carried out in Maracay city, Venezuela. A precoded questionnaire was used to obtain information on people's knowledge, attitudes, and use of preventive practices in relation to dengue. Concomitantly, entomological data was collected from households. In 80% of the 105 included households, 1-5 preventive practices (e.g., repellents, insecticides) against mosquito bites were used. However, 57% of the examined houses had potential Aedes breeding sites indoors and/or outdoors, most of which positive for Aedes spp. larvae/pupae. Preventive practices were associated with a previous dengue infection (P = 0.030) and a better knowledge on dengue symptoms and transmission route (P = 0.020). In turn, knowledge was associated with feeling at risk (P < 0.001), a previous dengue infection (P = 0.010), and reported exposure to information sources of dengue (P = 0.011). Even though the knowledge level of the community over transmission ways was high, and most of the individuals took measures to avoid mosquito bites, potential mosquito breeding sites were present in almost two-thirds of the examined properties. Health promotion activities in Venezuela should aim at raising awareness at the community level on the importance of combining mosquito bite prevention with removal of breeding sites in and around the households.

The additional benefit of residual spraying and insecticide-treated curtains for dengue control over current best practice in Cuba: Evaluation of disease incidence in a cluster randomized trial in a low burden setting with intensive routine control

BACKGROUND

Aedes control interventions are considered the cornerstone of dengue control programmes, but there is scarce evidence on their effect on disease. We set-up a cluster randomized controlled trial in Santiago de Cuba to evaluate the entomological and epidemiological effectiveness of periodical intra- and peri-domiciliary residual insecticide (deltamethrin) treatment (RIT) and long lasting insecticide treated curtains (ITC).

METHODOLOGY/PRINCIPAL FINDINGS

Sixty three clusters (around 250 households each) were randomly allocated to two intervention (RIT and ITC) and one control arm. Routine Aedes control activities (entomological surveillance, source reduction, selective adulticiding, health education) were applied in the whole study area. The outcome measures were clinical dengue case incidence and immature Aedes infestation. Effectiveness of tools was evaluated using a generalized linear regression model with a negative binomial link function. Despite significant reduction in Aedes indices (Rate Ratio (RR) 0.54 (95%CI 0.32-0.89) in the first month after RIT, the effect faded out over time and dengue incidence was not reduced. Overall, in this setting there was no protective effect of RIT or ITC over routine in the 17months intervention period, with for house index RR of 1.16 (95%CI 0.96-1.40) and 1.25 (95%CI 1.03-1.50) and for dengue incidence RR of 1.43 (95%CI 1.08-1.90) and 0.96 (95%CI 0.72-1.28) respectively. The monthly dengue incidence rate (IR) at cluster level was best explained by epidemic periods (Incidence Rate Ratio (IRR) 5.50 (95%CI 4.14-7.31)), the IR in bordering houseblocks (IRR 1.03 (95%CI 1.02-1.04)) and the IR pre-intervention (IRR 1.02 (95%CI 1.00-1.04)).

CONCLUSIONS

Adding RIT to an intensive routine Aedes control programme has a transient effect on the already moderate low entomological infestation levels, while ITC did not have any effect. For both interventions, we didn't evidence impact on disease incidence. Further studies are needed to evaluate impact in settings with high Aedes infestation and arbovirus case load.

Cost-Effectiveness of the Strategies to Reduce the Incidence of Dengue in Colima, México

Dengue fever is considered to be one of the most important arboviral diseases globally. Unsuccessful vector-control strategies might be due to the lack of sustainable community participation. The state of Colima, located in the Western region of Mexico, is a dengue-endemic area despite vector-control activities implemented, which may be due to an insufficient health economic analysis of these interventions. A randomized controlled community trial took place in five urban municipalities where 24 clusters were included. The study groups (n = 4) included an intervention to improve the community participation in vector control (A), ultra-low volume (ULV) spraying (B), both interventions (AB), and a control group. The main outcomes investigated were dengue cumulative incidence, disability-adjusted life years (DALYs), and the direct costs per intervention. The cumulative incidence of dengue was 17.4%, A; 14.3%, B; 14.4%, AB; and 30.2% in the control group. The highest efficiency and effectiveness were observed in group B (0.526 and 6.97, respectively) and intervention A was more likely to be cost-effective ($3952.84 per DALY avoided) followed by intervention B ($4472.09 per DALY avoided). Our findings suggest that efforts to improve community participation in vector control and ULV-spraying alone are cost-effective and may be useful to reduce the vector density and dengue incidence.

Impact of health education based intervention on community's awareness of dengue and its prevention in Delhi, India

Dengue is endemic in India. The capital, Delhi, continues to witness a higher number of cases due to urbanization-related factors. This study is intended to implement health education towards prevention of dengue, and to assess its impact on people's knowledge and practices related to causes and prevention of dengue among urban poor in Delhi. Pre- ( n = 484) and post- ( n = 496) intervention surveys from 15 sub-clusters from five slums/slum-like settlements in Delhi were carried out. Health education based intervention was carried out through partnership with the municipal bodies and non-governmental organizations. Socio-demographic characteristics of participants were similar in both surveys. Intervention resulted in significant increase in knowledge on cause, symptom perception and mosquito behaviour in terms of breeding and biting habits. Practice of personal protection measures increased significantly. The participation of people increased during intervention compared to the routine programme. Health education based interventions are instrumental in improving people's knowledge and behaviour. Hence, routine health educational activities as a supportive strategy in the health system need to be strengthened. New integrated approaches such as eco-bio-social approaches with community participation are to be developed and tested in endemic settings like Delhi.

Avaliabilidade do Projeto de Mobilização Social para Prevenção e Controle da Dengue no Estado da Bahia

RESUMO Foi realizado um estudo de avaliabilidade do Projeto de Mobilização Social para Prevenção e Controle da Dengue no Estado da Bahia, assim como foi descrito o modelo de intervenção prático. Foram conduzidas entrevistas junto a informantes-chave, análise documental e observação participante. Os resultados apontam que o Projeto pode ser considerado implementado, e seus principais resultados se situaram em torno da mudança do enfoque sobre dengue na pauta da mídia, bem como da maior integração dos entes federados e entre os Agentes Comunitários de Saúde e os Agentes de Endemias. Aspectos relacionados ao contexto municipal foram vistos como obstáculos para o alcance dos resultados esperados.

The State of the Art of Lethal Oviposition Trap-Based Mass Interventions for Arboviral Control

The intensifying expansion of arboviruses highlights the need for effective invasive Aedes control. While mass-trapping interventions have long been discredited as inefficient compared to insecticide applications, increasing levels of insecticide resistance, and the development of simple affordable traps that target and kill gravid female mosquitoes, show great promise. We summarize the methodologies and outcomes of recent lethal oviposition trap-based mass interventions for suppression of urban Aedes and their associated diseases. The evidence supports the recommendation of mass deployments of oviposition traps to suppress populations of invasive Aedes, although better measures of the effects on disease control are needed. Strategies associated with successful mass-trap deployments include: (1) high coverage (>80%) of the residential areas; (2) pre-intervention and/or parallel source reduction campaigns; (3) direct involvement of community members for economic long-term sustainability; and (4) use of new-generation larger traps (Autocidal Gravid Ovitrap, AGO; Gravid Aedes Trap, GAT) to outcompete remaining water-holding containers. While to the best of our knowledge all published studies so far have been on Ae. aegypti in resource-poor or tropical settings, we propose that mass deployment of lethal oviposition traps can be used for focused cost-effective control of temperate Ae. albopictus pre-empting arboviral epidemics and increasing participation of residents in urban mosquito control.

KAP Surveys and Dengue Control in Colombia: Disentangling the Effect of Sociodemographic Factors Using Multiple Correspondence Analysis

During the last few decades, several studies have analyzed and described knowledge, attitudes, and practices (KAP) of populations regarding dengue. However, few studies have applied geometric data analytic techniques to generate indices from KAP domains. Results of such analyses have not been used to determine the potential effects of sociodemographic variables on the levels of KAP. The objective was to determine the sociodemographic factors related to different levels of KAP regarding dengue in two hyper-endemic cities of Colombia, using a multiple correspondence analysis (MCA) technique. In the context of a cluster randomized trial, 3,998 households were surveyed in Arauca and Armenia between 2012 and 2013. To generate KAP indexes, we performed a MCA followed by a hierarchical cluster analysis to classify each score in different groups. A quantile regression for each of the score groups was conducted. KAP indexes explained 56.1%, 79.7%, and 83.2% of the variance, with means of 4.2, 1.4, and 3.2 and values that ranged from 1 to 7, 7 and 11, respectively. The highest values of the index denoted higher levels of knowledge and practices. The attitudes index did not show the same relationship and was excluded from the analysis. In the quantile regression, age (0.06; IC: 0.03, 0.09), years of education (0.14; IC: 0.06, 0.22), and history of dengue in the family (0.21; IC: 0.12, 0.31) were positively related to lower levels of knowledge regarding dengue. The effect of such factors gradually decreased or disappeared when knowledge was higher. The practices indexes did not evidence a correlation with sociodemographic variables. These results suggest that the transformation of categorical variables into a single index by the use of MCA is possible when analyzing knowledge and practices regarding dengue from KAP questionnaires. Additionally, the magnitude of the effect of socioeconomic variables on the knowledge scores varies according to the levels of knowledge, suggesting that other factors might be influencing higher levels of knowledge.

Social determinants of health, universal health coverage, and sustainable development: case studies from Latin American countries

Many intrinsically related determinants of health and disease exist, including social and economic status, education, employment, housing, and physical and environmental exposures. These factors interact to cumulatively affect health and disease burden of individuals and populations, and to establish health inequities and disparities across and within countries. Biomedical models of health care decrease adverse consequences of disease, but are not enough to effectively improve individual and population health and advance health equity. Social determinants of health are especially important in Latin American countries, which are characterised by adverse colonial legacies, tremendous social injustice, huge socioeconomic disparities, and wide health inequities. Poverty and inequality worsened substantially in the 1980s, 1990s, and early 2000s in these countries. Many Latin American countries have introduced public policies that integrate health, social, and economic actions, and have sought to develop health systems that incorporate multisectoral interventions when introducing universal health coverage to improve health and its upstream determinants. We present case studies from four Latin American countries to show the design and implementation of health programmes underpinned by intersectoral action and social participation that have reached national scale to effectively address social determinants of health, improve health outcomes, and reduce health inequities. Investment in managerial and political capacity, strong political and managerial commitment, and state programmes, not just time-limited government actions, have been crucial in underpinning the success of these policies.

No effect of insecticide treated curtain deployment on aedes infestation in a cluster randomized trial in a setting of low dengue transmission in Guantanamo, Cuba

Objective & Methodology

The current study evaluated the effectiveness and cost-effectiveness of Insecticide Treated Curtain (ITC) deployment for reducing dengue vector infestation levels in the Cuban context with intensive routine control activities. A cluster randomized controlled trial took place in Guantanamo city, east Cuba. Twelve neighborhoods (about 500 households each) were selected among the ones with the highest Aedes infestation levels in the previous two years, and were randomly allocated to the intervention and control arms. Long lasting ITC (PermaNet) were distributed in the intervention clusters in March 2009. Routine control activities were continued in the whole study area. In both study arms, we monitored monthly pre- and post-intervention House Index (HI, number of houses with at least 1 container with Aedes immature stages/100 houses inspected), during 12 and 18 months respectively. We evaluated the effect of ITC deployment on HI by fitting a generalized linear regression model with a negative binomial link function to these data.

Principal Findings

At distribution, the ITC coverage (% of households using ≥1 ITC) reached 98.4%, with a median of 3 ITC distributed/household. After 18 months, the coverage remained 97.4%. The local Aedes species was susceptible to deltamethrin (mosquito mortality rate of 99.7%) and the residual deltamethrin activity in the ITC was within acceptable levels (mosquito mortality rate of 73.1%) after one year of curtain use. Over the 18 month observation period after ITC distribution, the adjusted HI rate ratio, intervention versus control clusters, was 1.15 (95% CI 0.57 to 2.34). The annualized cost per household of ITC implementation was 3.8 USD, against 16.8 USD for all routine ACP activities.

Conclusion

Deployment of ITC in a setting with already intensive routine Aedes control actions does not lead to reductions in Aedes infestation levels.

A social-ecological analysis of community perceptions of dengue fever and Aedes aegypti in Machala, Ecuador

Background

The growing burden of dengue fever and the lack of a vaccine or specific medical treatment have increased the urgency of the public health sector to identify alternative management strategies. A prevailing trend in Latin America has been a shift towards decentralized vector control programs with integrated management strategies, requiring significant intersectoral coordination, community engagement, and knowledge of the local social-ecological system (SES). Community perceptions and responses are a critical component of this system, since perceptions shape actions, and thus govern behavioral responses and acceptance of shifts in policy and management.

Methods

We investigated perceptions, misconceptions, and local SES risk factors for dengue in high risk communities located at the urban periphery and center in Machala, Ecuador. We facilitated twelve focus group discussions with community members using semi-structured question guides and causal diagrams. Focus groups were recorded, transcribed, and coded to identify emergent themes using qualitative methods for theme analysis. To estimate the relative importance of the themes in each study area, we tabulated the number of focus groups in which each theme was present. Household surveys (n = 79) were conducted to further explore these themes, and we compared survey responses from the two areas using descriptive statistics.

Results

We identified thirty biophysical, political-institutional, and community-household risk factors for dengue. People at the periphery identified a greater number of risk factors. Dengue control required considerable investment of time and resources, which presented a greater challenge for women and people at the periphery. Common misperceptions included confusion with other febrile diseases, lack of knowledge of transmission mechanisms, and misconceptions about mosquito behavior. People perceived that dengue control programs had been limited by the lack of inter-institutional coordination and lack of social cohesion.

Conclusions

There is a need for local, policy-relevant research that can be translated to strengthen the design, implementation, and evaluation of new dengue management strategies. This study contributes to a growing body of research in this area. Based on these findings, we identify key policy and management recommendations that will inform the ongoing transition to a decentralized dengue control program in Ecuador and other dengue endemic countries.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-1135) contains supplementary material, which is available to authorized users.

[The participation of civil society in health and social policy councils in the city of Piraí, State of Rio de Janeiro (2006)]

Social policy councils began to be set up in municipalities in Brazil in the 1990s, first in the health care sector, then spreading to other sectors, for the purpose of including civil society in municipal policy management. Among the advances, studies revealed the formation of a network of government and non-government actors for the resolution of problems in the sector. Among the challenges, there was the limitation of the participation of government programs to a critical approval. This paper addresses the participation of councilors and representatives of civil society in the Health Council as being included in a network that includes councils and civil society organizations in a small municipality. Based on semi-structured interviews with councilors representing civil society, two dimensions of participation are analyzed. The first is the relationship between demand for participation generated by the simultaneous activity of various sectorial councils and the participatory basis existing in the city. The second is the relationship between the issues that the respondents identified and their role as councilors. Lastly, the article discusses the potential of municipal councils in contributing to an intersectorial management of the city's problems.

Communicating risk and promoting disease mitigation measures in epidemics and emerging disease settings

OBJECTIVE

This review aims to identify and assess evidence on interventions to communicate risk and promote disease mitigation measures in epidemics and emerging disease outbreak settings. The study focuses on data that are relevant to low and middle-income country (LMIC) settings.

METHODS

We conducted a comprehensive literature search using five major electronic databases (Pubmed Medline, Biomed Central, EMBASE, Science of Citation Index, and Cochrane Library) and other sources to identify relevant studies published from January 2002 to July 2013. The review was guided by the socio-ecological model/perspective of public health and the ideation theory and focused on interventions at the community, healthcare, and multi-sectoral settings, which also reflect key intervention levels of the Ottawa Charter for Health Promotion. Eligible quantitative studies were selected according to specific study criteria and assessed using the Critical Appraisal Skills Program (CASP) framework. Conversely, qualitative studies, reviews, case studies, and editorials were not included. Studies were selected by two independent reviewers.

RESULTS

Twenty-nine relevant studies from 16 countries were included. Most studies focused on a single intervention or intervention level, rather than multi-sectoral interventions. The majority of the evidence relates to programs aimed at behavioral and social results (or relevant intermediate steps) within a specific population group. Two studies included implications for improvements in health service delivery, two studies examined the intervention's impact on health systems-related outcomes, and three had also implications for environmental health outcomes. Cost- and health equity-related implications for select evidence were also discussed.

CONCLUSIONS

The paucity of well-designed quantitative evaluations of interventions to communicate health risk and promote disease control measures in LMICs does not allow for any definitive conclusions. Yet, the review identified several promising interventions and areas for future investigation. Among them, community-based and participatory interventions seemed to be central within epidemic and emerging disease settings, particularly in low-resource settings. Yet, evidence on their effectiveness is not conclusive and needs to be explored by future studies. Other promising areas for future investigation include multi-component and multi-sectoral approaches to intervention design. Major research gaps referred to any evaluation of the impact of these kinds of interventions on health policy adoption and/or implementation, and social determinants of health. Research on cost-effectiveness also needs to be strengthened. This review identified several research gaps and questions, and discusses potential future directions for increasing capacity for future and more rigorous assessments.

The relationship between economic status, knowledge on dengue, risk perceptions and practices

The reemergence of dengue as an important public health problem reflects the difficulties in sustaining vertically organized, effective, control programs and the need for community-based strategies for Aedes aegypti control that result in behavioral change. We aimed to disentangle the relationships between underlying determinants of dengue related practices. We conducted a cross-sectional study in 780 households in La Lisa, Havana, Cuba. A questionnaire and an observation guide were administrated to collect information on variables related to economic status, knowledge on dengue, risk perception and practices associated with Aedes aegypti breading sites. To test a conceptual model that hypothesized direct relationships among all these constructs, we first used Exploratory Factor Analysis with Principal Component Analysis to establish the relationship between observed variables and the underlying latent variables. Subsequently, we tested whether the observed data supported the conceptual model through Confirmatory Factor Analysis. Exploratory Factor Analysis indicated that the items measured could be reduced into five factors with an eigenvalue >1.0: Knowledge on dengue, Intradomiciliar risk practices, Peridomiciliar risk practices, Risk perception and Economic status. The proportion of the total variance in the data explained by these five factors was 74.3%. The Confirmatory Factor Analysis model differed from our hypothesized conceptual model. Only Knowledge on dengue had a significant, direct, positive, effect on Practices. There was also a direct association of Economic status with Knowledge on dengue, but not with Risk perception and Practices. Clarifying the relationship between direct and indirect determinants of dengue related practices contributes to a better understanding of the potential effect of Information Education and Communication on practices and on the reduction of Aedes aegypti breeding sites and provides inputs for designing a community based strategy for dengue control.

Community-based control of Aedes aegypti by adoption of eco-health methods in Chennai City, India

Background

Dengue is highly endemic in Chennai city, South India, in spite of continuous vector control efforts. This intervention study was aimed at establishing the efficacy as well as the favouring and limiting factors relating to a community-based environmental intervention package to control the dengue vector Aedes aegypti.

Methods

A cluster randomized controlled trial was designed to measure the outcome of a new vector control package and process analysis; different data collection tools were used to determine the performance. Ten randomly selected intervention clusters (neighbourhoods with 100 houses each) were paired with ten control clusters on the basis of ecological/entomological indices and sociological parameters collected during baseline studies. In the intervention clusters, Aedes control was carried out using a community-based environmental management approach like provision of water container covers through community actors, clean-up campaigns, and dissemination of dengue information through schoolchildren. The main outcome measure was reduction in pupal indices (pupae per person index), used as a proxy measure of adult vectors, in the intervention clusters compared to the control clusters.

Results

At baseline, almost half the respondents did not know that dengue is serious but preventable, or that it is transmitted by mosquitoes. The stakeholder analysis showed that dengue vector control is carried out by vertically structured programmes of national, state, and local administrative bodies through fogging and larval control with temephos, without any involvement of community-based organizations, and that vector control efforts were conducted in an isolated and irregular way. The most productive container types for Aedes pupae were cement tanks, drums, and discarded containers. All ten intervention clusters with a total of 1000 houses and 4639 inhabitants received the intervention while the ten control clusters with a total of 1000 houses and 4439 inhabitants received only the routine government services and some of the information education and communication project materials. The follow-up studies showed that there was a substantial increase in dengue understanding in the intervention group with only minor knowledge changes in the control group. Community involvement and the partnership among stakeholders (particularly women’s self-help groups) worked well. After 10 months of intervention, the pupae per person index was significantly reduced to 0.004 pupae per person from 1.075 (P = 0.020) in the intervention clusters compared to control clusters. There were also significant reductions in the Stegomyia indices: the house index was reduced to 4.2%, the container index to 1.05%, and the Breteau index to 4.3 from the baseline values of 19.6, 8.91, and 30.8 in the intervention arm.

Conclusion

A community-based approach together with other stakeholders that promoted interventions to prevent dengue vector breeding led to a substantial reduction in dengue vector density.

Community-based dengue vector control: experiences in behavior change in Metropolitan Manila, Philippines

Dengue is the most important mosquito-borne disease in the Philippines, especially in Metropolitan Manila where communities are socially and economically diverse, and city governments struggle to provide basic services such as continuously available, piped water supply to residents. We examined responses to introducing water container management to control dengue vectors in two diverse communities in Masagana City: Village A (gated community) and Village B (informal settlers community). The roll out of the intervention was carried out by the study team, dengue control personnel and local health workers (BHWs). A behavioural change framework was used to describe the community responses to the introduction of a new vector control intervention - household water container management. Although, the desired outcome was not achieved during the study's timeline, observation on processes of behaviour change underscored the importance of understanding the social nature of the urban communities, often overlooked structures when dengue control program and researchers introduce new dengue control interventions.

Linking mosquito infestation to resident socioeconomic status, knowledge, and source reduction practices in suburban Washington, DC

Eliminating water-holding containers where mosquitoes oviposit and develop (source reduction) can help manage urban disease-vector mosquitoes. Source reduction requires residents to be knowledgeable of effective practices and motivated to implement them. We tested relationships between demographics, resident knowledge, attitudes, and practices (KAP), and mosquito infestation by administering larval mosquito surveys and KAP questionnaires in Washington, DC. Respondents who reported practicing source reduction had lower numbers of pupae-positive containers and Culex pipiens-positive containers, but not Aedes albopictus-positive containers or water-holding containers, in their yards. When controlling for numbers of water-holding containers in statistical models, residents who reported source reduction had lower numbers of A. albopictus-positive containers in addition to numbers of pupae-positive containers and C. pipiens-positive containers. These results suggest that while active container reduction may be effective at reducing C. pipiens and overall pupal production, it may be offset by other resident activities that add containers to yards, and that source reduction that involves mosquito habitat management without outright container removal can also be effective at reducing A. albopictus. Source reduction was related to respondent knowledge of mosquitoes and, in particular, specific knowledge of mosquito development, which both varied with demographics alongside respondent motivation to control mosquitoes. Respondents from high socioeconomic status households reported greater knowledge but lower motivation than respondents from middle and low socioeconomic-status households. We conclude that mosquito-related education will help promote community-based container management as part of integrated mosquito management programs, particularly in middle and low socioeconomic status neighborhoods with lower knowledge and high motivation.

Dengue vector surveillance programs: a review of methodological diversity in some endemic and epidemic countries

Vector surveillance is a cornerstone of dengue management yet there is a diversity of surveillance programs evident internationally. Such diversity is described in this review to enable a broader assessment of dengue vector surveillance methods. This review describes the diversity of surveillance programs for dengue vectors in several endemic and epidemic countries. Furthermore, strengths and weaknesses of vector surveillance methods, including larval surveys, BG-Sentinel trap, and autocidal and sticky ovitraps, are also discussed. The ability to compare and contrast these programs could contribute to the finding of better methods both locally and nationally and facilitate interregional technology transfer. Health authorities in both endemic and epidemic countries alike could benefit from adopting technologies and practices from other regions.

Testing the effectiveness of community-based dengue vector control interventions using semiparametric mixed models

OBJECTIVE

To evaluate the results obtained though intersectoral coordination and community empowerment in one study carried out during 6 years in Playa Municipality, Cuba.

METHODS

A longitudinal assessment comparing one intervention and one control area was conducted. The intervention encompasses two main stages separated by two dengue outbreaks. The first stage, focused on strengthening intersectoral coordination, was initiated in January 2000. In August 2003, a complementary strategy, focused on community empowerment and was initiated in half of the intervention area. In the control area, routine dengue control activities continued without additional input. We used entomologic surveillance data from January 1999 to December 2005 to assess the effectiveness. We computed the Breteau index (BI) per health area and the 95% confidence interval for the difference between the BIs at each time point. A semiparametric mixed model to capture the evolution in time of Aedes aegypti larval densities was fitted.

RESULTS

The BI in the control area showed the lowest value before starting the intervention. This was reversed 1 year after launching intersectoral activities for dengue control in the intervention area. In spite of spraying actions in all areas, the differences in BI between intervention and control areas remain significant until December 2002. Although for the next 2 years no differences were observed, they become significant again in December 2004, which corresponds with the implementation of the complementary community-based vector control strategy in the intervention area.

CONCLUSIONS

The model fitted identified monotonous trends over time and reversal trends at particular moments. The confidence bands indicate sections with significant differences between areas. Our data increase the evidence that the intersectoral coordination and community empowerment strategy for A. aegypti control is effective.

The architecture and effect of participation: a systematic review of community participation for communicable disease control and elimination. Implications for malaria elimination

BACKGROUND

Community engagement and participation has played a critical role in successful disease control and elimination campaigns in many countries. Despite this, its benefits for malaria control and elimination are yet to be fully realized. This may be due to a limited understanding of the influences on participation in developing countries as well as inadequate investment in infrastructure and resources to support sustainable community participation. This paper reports the findings of an atypical systematic review of 60 years of literature in order to arrive at a more comprehensive awareness of the constructs of participation for communicable disease control and elimination and provide guidance for the current malaria elimination campaign.

METHODS

Evidence derived from quantitative research was considered both independently and collectively with qualitative research papers and case reports. All papers included in the review were systematically coded using a pre-determined qualitative coding matrix that identified influences on community participation at the individual, household, community and government/civil society levels. Colour coding was also carried out to reflect the key primary health care period in which community participation programmes originated. These processes allowed exhaustive content analysis and synthesis of data in an attempt to realize conceptual development beyond that able to be achieved by individual empirical studies or case reports.

RESULTS

Of the 60 papers meeting the selection criteria, only four studies attempted to determine the effect of community participation on disease transmission. Due to inherent differences in their design, interventions and outcome measures, results could not be compared. However, these studies showed statistically significant reductions in disease incidence or prevalence using various forms of community participation. The use of locally selected volunteers provided with adequate training, supervision and resources are common and important elements of the success of the interventions in these studies. In addition, qualitative synthesis of all 60 papers elucidates the complex architecture of community participation for communicable disease control and elimination which is presented herein.

CONCLUSIONS

The current global malaria elimination campaign calls for a health systems strengthening approach to provide an enabling environment for programmes in developing countries. In order to realize the benefits of this approach it is vital to provide adequate investment in the 'people' component of health systems and understand the multi-level factors that influence their participation. The challenges of strengthening this component of health systems are discussed, as is the importance of ensuring that current global malaria elimination efforts do not derail renewed momentum towards the comprehensive primary health care approach. It is recommended that the application of the results of this systematic review be considered for other diseases of poverty in order to harmonize efforts at building 'competent communities' for communicable disease control and optimising health system effectiveness.

Intersectoral coordination, community empowerment and dengue prevention: six years of controlled interventions in Playa Municipality, Havana, Cuba

OBJECTIVE

To document the process, outcome and effectiveness of a community-based intervention for dengue control.

METHODS

The primary intervention, focused on strengthening intersectoral coordination, was initiated by researchers in January 2000 in a pilot area in Playa municipality, Havana. In August 2002 health authorities extended the intervention to neighbouring areas, one of which was selected for evaluation. In August 2003 a complementary strategy, focused on community empowerment, was initiated in half of the pilot area. In our control area, routine dengue activities continued throughout the study period. Longitudinal process assessment was carried out using document analysis, interviews and group discussions. Random population surveys in 1999, 2002 and 2005 assessed levels of participation and behavioural changes. Entomological surveillance data from 1999 to 2005 were used to determine effectiveness.

RESULTS

Mean scores for participation in the pilot area were 1.6, 3.4 and 4.4 at baseline, and 2 years after initiating intersectoral coordination and intersectoral coordination plus community empowerment interventions, respectively. While in the control area little behavioural change was observed over time, changes were considerable in the pilot and extension areas, with 80% of households involved in the community empowerment intervention showed adequate behavioural patterns. The pilot and extension areas attained comparable entomological effectiveness with significantly lower Breteau indices (BIs) than the control area. The pilot (sub-) area with the community empowerment intervention reached BIs below 0.1 that continued to be significantly lower than the one in the control area until the end of the study.

CONCLUSION

The study showed a trend in the levels and quality of participation, behavioural change and effectiveness of Aedes control from the routine activities only over an intervention with intersectoral coordination to one that combined intersectoral coordination and community empowerment approach.

Augmenting frameworks for appraising the practices of community-based health interventions

This paper aims at augmenting the frameworks proposed by Rifkin in 1996 to distinguish between target-oriented and empowerment approaches to participation in community-based health interventions. In her paper, Rifkin defined three criteria: who makes decisions on resource allocation, expected outcome and outcome assessment. We propose five additional criteria: the definition of community, the characteristics of the capacity-building process, the leadership characteristics, the documentation process, and ethical issues regarding participation. Derived from our analysis of a community-based project, the proposed criteria are discussed in the light of the principles of Popular Education and other literature on community participation. The augmented frameworks are intended to assist health professionals and planners interested in the empowerment approach of community participation to consciously sharpen their practice.

Community involvement in dengue vector control: cluster randomised trial

OBJECTIVE

To assess the effectiveness of an integrated community based environmental management strategy to control Aedes aegypti, the vector of dengue, compared with a routine strategy.

DESIGN

Cluster randomised trial.

SETTING

Guantanamo, Cuba.

PARTICIPANTS

32 circumscriptions (around 2000 inhabitants each).

INTERVENTIONS

The circumscriptions were randomly allocated to control clusters (n=16) comprising routine Aedes control programme (entomological surveillance, source reduction, selective adulticiding, and health education) and to intervention clusters (n=16) comprising the routine Aedes control programme combined with a community based environmental management approach.

MAIN OUTCOME MEASURES

The primary outcome was levels of Aedes infestation: house index (number of houses positive for at least one container with immature stages of Ae aegypti per 100 inspected houses), Breteau index (number of containers positive for immature stages of Ae aegypti per 100 inspected houses), and the pupae per inhabitant statistic (number of Ae aegypti pupae per inhabitant).

RESULTS

All clusters were subjected to the intended intervention; all completed the study protocol up to February 2006 and all were included in the analysis. At baseline the Aedes infestation levels were comparable between intervention and control clusters: house index 0.25% v 0.20%, pupae per inhabitant 0.44x10(-3) v 0.29x10(-3). At the end of the intervention these indices were significantly lower in the intervention clusters: rate ratio for house indices 0.49 (95% confidence interval 0.27 to 0.88) and rate ratio for pupae per inhabitant 0.27 (0.09 to 0.76).

CONCLUSION

A community based environmental management embedded in a routine control programme was effective at reducing levels of Aedes infestation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN88405796.

Effectiveness of a capacity-building program for community leaders in a healthy living environment: a randomized community-based intervention in rural Vietnam

This randomized controlled study was performed to evaluate the effectiveness of an educational program entitled 'Capacity building for community leaders in a healthy living environment,' and to assess the usefulness of a participatory style of education and the applicability of an intersectoral approach in the educational process. An intervention group and a control group (consisting of 150 and 154 community leaders, respectively) were both evaluated, after the intervention group took part in a 5-day participatory-style educational program. Healthy living environment promotion competency (HPC) was evaluated by an instrument consisted of four competency areas: identifying the steps required for a healthy living environment; understanding the principles to reduce potential health risks; providing public health management to improve the living environment; and applying the principles of health communication skills. Scores between the intervention and control groups were examined to identify changes between the baseline and post-intervention periods. A qualitative evaluation of the educational program by participants and facilitators was conducted to assess the appropriateness of the intervention. The results indicated significant increases in the total HPC score and scores of individual HPC competency areas in the intervention group. Thus, the effectiveness of a capacity building program for community leaders in a healthy living environment was demonstrated. Qualitative evaluation revealed that the participatory-style and intersectoral collaboration approach facilitated the educational process. Community leaders, who are representatives of various sectors and mass organizations within the community, can be important implementers in the promotion of a healthy living environment.

Effect of dengue vector control interventions on entomological parameters in developing countries: a systematic review and meta-analysis

The aim of this review was to compare the effects of different dengue vector control interventions (i.e. biological control, chemical control, environmental management and integrated vector management) with respect to the following entomological parameters: Breteau index (BI), container index (CI), and house index (HI). We systematically searched PubMed, ISI Web of Science, Science Direct, the Dengue Bulletin of the World Health Organization and reference lists of retrieved articles on dengue vector control interventions in developing countries. We extracted data on the effectiveness of different dengue vector control interventions (defined as the relative reduction of an entomological measure caused by the intervention compared with the control or pre-intervention phase) and calculated a measure of combined relative effectiveness, with 95% confidence intervals (95% c.i.). We identified 56 publications covering 61 dengue vector control interventions. Integrated vector management was found to be the most effective method to reduce the CI, HI and BI, resulting in random combined relative effectiveness values of 0.12 (95% c.i. 0.02-0.62), 0.17 (95% c.i. 0.02-1.28) and 0.33 (95% c.i. 0.22-0.48), respectively. Environmental management showed a relatively low effectiveness of 0.71 (95% c.i. 0.55-0.90) for the BI, 0.49 (95% c.i. 0.30-0.79) for the CI and 0.43 (95% c.i. 0.31-0.59) for the HI. Biological control (relative effectiveness for the CI: 0.18) usually targeted a small number of people (median population size: 200; range 20-2500), whereas integrated vector management focused on larger populations (median: 12 450; range: 210-9 600 000). In conclusion, dengue vector control is effective in reducing vector populations, particularly when interventions use a community-based, integrated approach, which is tailored to local eco-epidemiological and sociocultural settings and combined with educational programmes to increase knowledge and understanding of best practice. New research should assess the density-dependent effectiveness of each control measure in order to estimate whether reducing vector numbers has an impact on dengue transmission when populations are at a critical threshold.

The unbearable lightness of technocratic efforts at dengue control

OBJECTIVE

To identify key elements that should provide an added value and assure sustainable effects of the deployment of technical tools for Aedes aegypti control.

METHODS

An observational study was conducted between April 2001 and March 2002 in 30 blocks (1574 houses) in the central zone of Guantanamo city. A trial that combined two complementary technical interventions, the distribution of new ground level water tanks and the intensive use of insecticide, was nested in May 2001. Another 30 blocks (1535 houses) were selected as control area. We assessed community perceptions and household risk behaviour at baseline and after 9 months, and measured the trial's impact through entomological indices.

RESULTS

Perceived self efficacy to solve A. aegypti infestation and prevent dengue was not modified. We found no changes in behaviour. In the study area the container indices decreased significantly from 0.7% before to 0.1% 1 month after the intervention. Six months later, they had increased to 2.7% and uncovered new water tanks constituted 75.9% of all breeding sites. Over the 9 months after the trial the average monthly house indices were similar in the study and control areas. A technical approach and lack of community involvement in the trial's implementation were the main causes of these short-lived results.

CONCLUSIONS

Top-down deployment of technical tools without active involvement of the community has a temporary effect and does not lead to the behavioural changes necessary for sustainable A. aegypti control.

An integrated ecosystem approach for sustainable prevention and control of dengue in Central Havana

The authors developed and evaluated a comprehensive participatory ecosystem health approach for preventing the transmission of dengue, the most prevalent vector-borne disease in Cuba and the Latin America-Caribbean region. The integrated surveillance system central to this initiative encompassed three main subsystems (environmental; entomological; clinical-epidemiologic), relying on extensive community involvement. The study was conducted in Central Havana, Cuba. Indicators from each subsystem were selected and mapped using a GIS procedure providing instant visualization by city block in the municipality. To elucidate the factors affecting control and prevention efforts, perceived needs and risks, as well as knowledge, attitudes, and behaviors related to dengue, were assessed. Specific factors associated with the presence of mosquito breeding sites and risks of dengue were examined in a case-control study.

Health seeking and access to care for children with suspected dengue in Cambodia: an ethnographic study

BACKGROUND

The continuing contribution of dengue fever to the hospitalization and deaths in hospital of infants and small children in Cambodia is associated with delays in presentation for medical attention, diagnosis and appropriate care. It is important to identify the reasons that influence these delays, in order to develop appropriate interventions to redress the impact of dengue.

METHODS

Data on health seeking were collected during an ethnographic study conducted in two villages in the eastern province of Kampong Cham, Cambodia in 2004. Interviews were conducted with mothers whose children had been infected with suspected dengue fever, or who had been sick for other reasons, in 2003 and 2004.

RESULTS

Women selected a therapeutic option based on perceptions of the severity of the child's condition, confidence in the particular modality, service or practitioner, and affordability of the therapy. While they knew what type of health care was required, poverty in combination with limited availability and perceptions of the poor quality of care at village health centers and public referral hospitals deterred them from doing so. Women initially used home remedies, then sought advice from public and private providers, shifting from one sector to another in a pragmatic response to the child's illness.

CONCLUSION

The lack of availability of financial resources for poor people and their continuing lack of confidence in the care provided by government centres combine to delay help seeking and inappropriate treatment of children sick with dengue.

Community participation in Aedes aegypti control: a sociological perspective on five years of research in the health area ''26 de Julio'', Havana, Cuba

OBJECTIVE

Effective dengue prevention and Aedes aegypti control is a priority for the Cuban health authorities. To enhance effectiveness, strategies oriented towards a more active involvement of communities in control activities are being tested. This paper presents a sociological perspective on a pilot project conducted in the health area ''26 de Julio'' (La Havana) in 1999-2004.

METHODS

Instrumental case study based on an exhaustive content analysis of project documents and on observations of a sociologist.

RESULTS

The context and the pilot project are systematically described and an analysis of the evolution of the underlying concept of community participation is provided. The pilot experience was a dynamic process influenced by self-reflection of the research team, feedback from research partners and changes in the epidemiological context (provoked by two dengue outbreaks during the study period). Community participation evolved from being just one component in Aedes aegypti control directed by the health staff into a learning and empowering process for the people. This change in the concept of participation was reflected in different aspects of the pilot project such as the learning and evaluation processes.

CONCLUSION

Empirical evidence from 5 years of research in the particular context of Cuba showed that moves towards community-based Aedes aegypti control are feasible. However, in order to be successful, community-based dengue prevention should be a social learning process, implying a transfer of power and responsibilities to local people. Actions undertaken must be oriented towards creating local capabilities, strengthening existing structures and organizations and promoting group work for learning participation from participation itself.

Social and environmental determinants of Aedes aegypti infestation in Central Havana: results of a case-control study nested in an integrated dengue surveillance programme in Cuba

OBJECTIVE

To characterize the social and environmental risk factors associated with the presence of Aedes aegypti in order to improve community dengue control.

METHODS

A case-control study with 'cases' being households with entomologically confirmed A. aegypti infestation; personal interviews in Central Havana, a densely populated inner city area characterized by overcrowded housing and irregular water service. The participants were residents of 278 houses with infestation and 556 houses without infestation.

RESULTS

Greater risk of infestation was associated with lack of preventive measures, such as no larvicide in the water tanks (OR = 2.21) and use of flower vases for religious practice (1.93), not being economically active (1.64), vulnerable populations with higher risks in households with older people (1.52) and households with children (1.94).

CONCLUSIONS

Efforts to reduce infestations should continue to focus on water tank sanitation and improving housing conditions, but also engage community religious leaders to help promote safe practices. Vulnerable populations should be especially targeted by prevention activities. A surveillance programme can produce evidence to guide interventions.

Towards active community participation in dengue vector control: results from action research in Santiago de Cuba, Cuba

Community participation is advocated as essential for attaining effective dengue prevention, but knowledge of how to foster this is limited. In Santiago de Cuba, multiple small task forces were created at the neighbourhood level that included all stakeholders in the control of Aedes aegypti. The task forces assessed the perceived needs and elaborated action plans to promote specific behavioural change and to reduce environmental risks through social communication strategies and intersectoral local government activities. We monitored five dimensions of the participation process and assessed behavioural and environmental results and entomological outcomes. Participation was weak to good. At the household level, uncovered water storage containers decreased from 49.3% to 2.6% between 2000 and 2002, and removing larvicide from them dropped from 45.5% to 1%. There was a reduction of 75% in the absolute number of positive containers and a significant decrease from 1.23% to 0.35% in the house index. Local task forces, in which the interests of householders as well as vector control workers are directly represented, can lead to effective government-community partnerships that resolve problems of mutual concern.

What do community-based dengue control programmes achieve? A systematic review of published evaluations

Owing to increased epidemic activity and difficulties in controlling the insect vector, dengue has become a major public health problem in many parts of the tropics. The objective of this review is to analyse evidence regarding the achievements of community-based dengue control programmes. Medline, EMBASE, WHOLIS and the Cochrane Database of Systematic Reviews were searched (all to March 2005) to identify potentially relevant articles using keywords such as 'Aedes', 'dengue', 'breeding habits', 'housing' and 'community intervention'. According to the evaluation criteria recommended by the Cochrane Effective Practice and Organisation of Care Review Group, only studies that met the inclusion criteria of randomised controlled trials (RCT), controlled clinical trials (CCT), controlled before and after trials (CBA) or interrupted time series (ITS) were included. Eleven of 1091 studies met the inclusion criteria. Of these, two were RCTs, six were CBAs and three were ITS. The selected studies varied widely with respect to target groups, intervention procedures and outcome measurements. Six studies combined community participation programmes with dengue control tools. Methodological weaknesses were found in all studies: only two papers reported confidence intervals (95% CI); five studies reported P-values; two studies recognised the importance of water container productivity as a measure for vector density; in no study was cluster randomisation attempted; and in no study were costs and sustainability assessed. Evidence that community-based dengue control programmes alone and in combination with other control activities can enhance the effectiveness of dengue control programmes is weak.