Affiliations 

  • 1 Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg Sweden
  • 2 Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
  • 3 Department of Public Health and Clinical Medicine, Epidemiology and Global Health, Umeå University, Sweden
  • 4 Ministry of Health, Mexico City, Mexico
  • 5 Information and Documentation Surveillance section, Disease Control Division, Ministry of Health, Putrajaya, Malaysia
  • 6 Office of the Deputy Director General of Health (Public Health), Ministry of Health, Level 12, Block E7, Federal Government Administrative Complex, Putrajaya, Malaysia
  • 7 Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasília, DF, Brasil
  • 8 Umeå Centre for Global Health Research, Umeå University, Sweden
  • 9 Health Metrics Unit, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
PLoS One, 2018;13(5):e0196811.
PMID: 29727447 DOI: 10.1371/journal.pone.0196811

Abstract

BACKGROUND: Dengue outbreaks are increasing in frequency over space and time, affecting people's health and burdening resource-constrained health systems. The ability to detect early emerging outbreaks is key to mounting an effective response. The early warning and response system (EWARS) is a toolkit that provides countries with early-warning systems for efficient and cost-effective local responses. EWARS uses outbreak and alarm indicators to derive prediction models that can be used prospectively to predict a forthcoming dengue outbreak at district level.

METHODS: We report on the development of the EWARS tool, based on users' recommendations into a convenient, user-friendly and reliable software aided by a user's workbook and its field testing in 30 health districts in Brazil, Malaysia and Mexico.

FINDINGS: 34 Health officers from the 30 study districts who had used the original EWARS for 7 to 10 months responded to a questionnaire with mainly open-ended questions. Qualitative content analysis showed that participants were generally satisfied with the tool but preferred open-access vs. commercial software. EWARS users also stated that the geographical unit should be the district, while access to meteorological information should be improved. These recommendations were incorporated into the second-generation EWARS-R, using the free R software, combined with recent surveillance data and resulted in higher sensitivities and positive predictive values of alarm signals compared to the first-generation EWARS. Currently the use of satellite data for meteorological information is being tested and a dashboard is being developed to increase user-friendliness of the tool. The inclusion of other Aedes borne viral diseases is under discussion.

CONCLUSION: EWARS is a pragmatic and useful tool for detecting imminent dengue outbreaks to trigger early response activities.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.