VECTOS: An Integrated System for Monitoring Risk Factors Associated With Urban Arbovirus Transmission

Abstract

In Colombia, as in many Latin American countries, decision making and development of effective strategies for vector control of urban diseases such as dengue, Zika, and chikungunya is challenging for local health authorities. The heterogeneity of transmission in urban areas requires an efficient risk-based allocation of resources to control measures. With the objective of strengthening the capacity of local surveillance systems to identify variables that favor urban arboviral transmission, a multidisciplinary research team collaborated with the local Secretary of Health officials of 3 municipalities in Colombia (Giron, Yopal, and Buga), in the design of an integrated information system called VECTOS from 2015 to 2018. Information and communication technologies were used to develop 2 mobile applications to capture entomological and social information, as well as a web-based system for the collection, geo-referencing, and integrated information analysis using free geospatial software. This system facilitates the capture and analysis of epidemiological information from the Colombian national surveillance system (SIVIGILA), periodic entomological surveys-mosquito larvae and pupae in premises and peridomestic breeding sites-and surveys of knowledge, attitudes, and practices (KAP) in a spatial and temporal context at the neighborhood level. The data collected in VECTOS are mapped and visualized in graphical reports. The system enables real-time monitoring of weekly epidemiological indicators, entomological indices, and social surveys. Additionally, the system enables risk stratification of neighborhoods, using selected epidemiological, entomological, demographic, and environmental variables. This article describes the VECTOS system and the lessons learned during its development and use. The joint analysis of epidemiological and entomological data within a geographic information system in VECTOS gives better insight to the routinely collected data and identifies the heterogeneity of risk factors between neighborhoods. We expect the system to continue to strengthen vector control programs in evidence-based decision making and in the design and enhanced follow-up of vector control strategies.

FIGURE 1

Departments (gray) and Municipalities (red) in Colombia participating in the Study, 2015–2018

FIGURE 2

The Initial VECTOS Menu (“Splash Screen”) Options From top left: Información (Information) leads to data visualization and analysis of entomological (Ento), epidemiological (Epid), or sociological (Soc) data. Valoración del riesgo (Risk assessment) allows the user to create and visualize risk maps. Planes de acción (Action plans) allows the user to organize and schedule field activities. Seguimiento (Follow-up) allows the user to monitor progress on the action plans. In the center: Sistema de información geográfica (Geographic information system) shows the geo-referenced raw data.

FIGURE 3

VECTOS Graphical Report of Epidemiological Indicators This example shows actual data from the municipality of Giron in 2017. More specifically, the dengue endemic channel is indicated by the lines, which are percentiles of case numbers, from January 1, 2010, to November 18, 2016. Bars show the contemporaneous data for 2017.

FIGURE 4

VECTOS Graphical Output of Entomological Breteau Index^a for Each Neighborhood in Buga, Colombia, January 1, 2014–December 31, 2017 ^aNumber of positive containers per 100 houses.

FIGURE 5

Trends in the Quintiles of the Dengue Epidemiological Risk Component in Buga, Giron, and Yopal, Colombia, 2008–2017 Maps of quintiles of risk stratification, with 1 (blue) being the lowest and 5 (red) being the highest. 0 indicates missing data.

FIGURE 6

Epidemiological (A) and Entomological (B) Dengue Risk Maps and (C) Location of Positive Catch Basins^a in Giron Neighborhoods, Colombia, January 1, 2014–December 31, 2016 ^aIndicated by purple dots over the epidemiological risk map. Risk stratification in the maps is classified in quintiles, with 1 (blue) being the lowest risk and 5 (red) being the highest, during the observed period. 0 (white) indicates missing data.

FIGURE 7

Location of Catch Basins Surveyed in Buga, Colombia, September 2017 Negative catch basins (Sumideros Negativos) indicated by blue dots and positive catch basins (Sumideros Positivos) indicated by red stars.