Mapping for Zika
The Zika Communication Network will be publishing a series of success stories from the Zika AIRS Project (ZAP). This is the third in the series.
ZAP Uses Mapping Data to Target Interventions in Areas with High Rates of Zika Transmission
Public health officials have used maps to track pest and disease outbreaks for more than 150 years. Knowing when and where pests and diseases are concentrated allows for targeted interventions to reduce illnesses and the further spread of infection. The Zika AIRS Project (ZAP), funded by the United States Agency for International Development (USAID), uses the QGIS application to follow cases of the Zika virus, which is spread by infected mosquitoes. ZAP is helping to improve Honduras’ national capacity to prevent, detect, and respond to vector-borne diseases.
Developed by the Open Source Geospatial Foundation, the QGIS helps to track households with positive cases of larvae or pupae indices of Aedes aegypti. ZAP and the Ministry of Health work together to evaluate the data to make informed, evidence-based decisions in vector control, targeting interventions to areas with the highest mosquito infestation levels, thereby preventing a potential outbreak.
The recorded data is used to identify patterns of transmission through entomological indicators, such as mosquito infestation indices of Aedes aegypti and Aedes albopictus, and ovitrap positivity and distribution. The ongoing collection of precise data enhances Honduras’ capacity to prepare and respond to future epidemics.
ZAP and the Ministry also evaluate the efficacy of vector control operations by monitoring positive cases of mosquito larvae per household recorded in the field. Subsequent operations are then tailored to the needs of specific locations. For example, in the Department of Choluteca, ZAP is evaluating the reduction of larval indices in two different locations where vector control and environmental cleanup are conducted. Larvicide dosages applied in both locations vary slightly, to determine whether a lower dosage of larvicide is an effective control measure for Zika prevention. Although both dosages are within the recommended range provided by the manufacturer, ZAP and the Ministry are looking for more sustainable and cost-effective alternatives to maintain national vector control campaigns, once ZAP ends implementation and the Ministry of Health assumes full responsibility.
Overall, ZAP Honduras has improved its ability to prevent and control the number of Zika, dengue, and chikungunya cases (91% reduction in Choluteca between 2016 and 2017, from 1,391 to 129 cases of the three arboviruses) by implementing QGIS in daily field vector control operations.