Evidence based community mobilization for dengue prevention in Nicaragua and Mexico (Camino Verde, the Green Way): cluster randomized controlled trial
BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h3267 (Published 08 July 2015) Cite this as: BMJ 2015;351:h3267
- Neil Andersson, scientific director1, professor2,
- Elizabeth Nava-Aguilera, professor1,
- Jorge Arosteguí, director3,
- Arcadio Morales-Perez, associate professor1,
- Harold Suazo-Laguna, research coordinator3,
- José Legorreta-Soberanis, director1,
- Carlos Hernandez-Alvarez, researcher3,
- Ildefonso Fernandez-Salas, professor4,
- Sergio Paredes-Solís, professor1,
- Angel Balmaseda, director5,
- Antonio Juan Cortés-Guzmán, director6,
- René Serrano de los Santos, associate professor1,
- Josefina Coloma, research scientist7,
- Robert J Ledogar, associate executive director8,
- Eva Harris, professor7
- 1Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Mexico
- 2Department of Family Medicine, McGill University, 5858 Côte-des-Neiges, Montreal, Canada
- 3CIET, Managua, Nicaragua
- 4Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Monterrey, Mexico
- 5Laboratorio Nacional de Virología, Centro Nacional de Diagnóstico y Referencia, Ministerio de Salud, Managua, Nicaragua
- 6Departamento de Prevención y Control de Enfermedades Transmisibles por Vector, Servicios Estatales de Salud Guerrero, Av Rufo Figueroa 6, Colonia Burócratas, Chilpancingo, Mexico.
- 7Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
- 8CIET International, New York, NY, USA
- Correspondence to: N Andersson andersson{at}ciet.org
- Accepted 11 June 2015
Abstract
Objective To test whether community mobilization adds effectiveness to conventional dengue control.
Design Pragmatic open label parallel group cluster randomized controlled trial. Those assessing the outcomes and analyzing the data were blinded to group assignment. Centralized computerized randomization after the baseline study allocated half the sites to intervention, stratified by country, evidence of recent dengue virus infection in children aged 3-9, and vector indices.
Setting Random sample of communities in Managua, capital of Nicaragua, and three coastal regions in Guerrero State in the south of Mexico.
Participants Residents in a random sample of census enumeration areas across both countries: 75 intervention and 75 control clusters (about 140 households each) were randomized and analyzed (60 clusters in Nicaragua and 90 in Mexico), including 85 182 residents in 18 838 households.
Interventions A community mobilization protocol began with community discussion of baseline results. Each intervention cluster adapted the basic intervention—chemical-free prevention of mosquito reproduction—to its own circumstances. All clusters continued the government run dengue control program.
Main outcome measures Primary outcomes per protocol were self reported cases of dengue, serological evidence of recent dengue virus infection, and conventional entomological indices (house index: households with larvae or pupae/households examined; container index: containers with larvae or pupae/containers examined; Breteau index: containers with larvae or pupae/households examined; and pupae per person: pupae found/number of residents). Per protocol secondary analysis examined the effect of Camino Verde in the context of temephos use.
Results With cluster as the unit of analysis, serological evidence from intervention sites showed a lower risk of infection with dengue virus in children (relative risk reduction 29.5%, 95% confidence interval 3.8% to 55.3%), fewer reports of dengue illness (24.7%, 1.8% to 51.2%), fewer houses with larvae or pupae among houses visited (house index) (44.1%, 13.6% to 74.7%), fewer containers with larvae or pupae among containers examined (container index) (36.7%, 24.5% to 44.8%), fewer containers with larvae or pupae among houses visited (Breteau index) (35.1%, 16.7% to 55.5%), and fewer pupae per person (51.7%, 36.2% to 76.1%). The numbers needed to treat were 30 (95% confidence interval 20 to 59) for a lower risk of infection in children, 71 (48 to 143) for fewer reports of dengue illness, 17 (14 to 20) for the house index, 37 (35 to 67) for the container index, 10 (6 to 29) for the Breteau index, and 12 (7 to 31) for fewer pupae per person. Secondary per protocol analysis showed no serological evidence of a protective effect of temephos.
Conclusions Evidence based community mobilization can add effectiveness to dengue vector control. Each site implementing the intervention in its own way has the advantage of local customization and strong community engagement.
Trial registration ISRCTN27581154
Footnotes
Contributors: NA was principal investigator in the Mexican trial, wrote the proposals, contributed to design and coordination, did the analysis, and prepared this article. ENA was lead researcher in Mexico and contributed to the design and drafting. JA was lead researcher in the Nicaragua feasibility study and the trial and contributed to the trial design and analysis and drafting of this article. AMP coordinated fieldwork in Mexico and contributed to the design and the drafting of this article. HS coordinated fieldwork in Nicaragua and contributed to the design and the drafting of this article. JLS, AJCG, RSS, SP, CH, IFS, and AB contributed to the fieldwork, analysis, and drafting. JC contributed to the proposals and drafting this article and was a co-investigator in the Nicaragua feasibility study. RJL contributed to the trial design, provided coordination between Nicaragua and Mexican teams, and contributed to the design and drafting of this paper. EH was principal investigator in the Nicaraguan feasibility study and trial and contributed to the proposals and drafting of this article. NA is guarantor.
Funding: The UBS Optimus Foundation provided funding for the feasibility study in Nicaragua and the full trial in both Nicaragua and Mexico. Fomix-CONACYT-GUERRERO supported the work in Acapulco (grant No 2008-02-108541). The sponsors had no role in study design, in collection or interpretation of data, in writing the report, or in the decision to submit the article for publication.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by institutional review boards at the University of California, Berkeley (22 July 2010), the Nicaraguan Ministry of Health (25 August 2010), and CIETinternational (1 August 2010) for the Nicaraguan study and the CIETcanada research ethics board (16 November 2009) and the ethics committee of the Centro de Investigación de Enfermedades Tropicales at the Universidad Autónoma de Guerrero (27 November 2009) for the Mexican study. All boards performed annual review and approval throughout the study. All participants gave informed consent.
Transparency declaration: NA (the manuscript’s guarantor) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained.
Data sharing: No additional data available.
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