The recent declaration of a new global pandemic caused by COVID-19 has brought about significant attention to the way governments and health organizations share information regarding the spread of various diseases and infections. Global infection has occurred several times in recent history, with some other notable examples being H1N1, Ebola, and Zika. In a study for Travel Medicine and Infectious Disease, Zambrano et al. explore the spatial distribution of Zika in Honduras between 2016 and 2017. The authors use GIS software to present the spread of Zika by departments, which is their equivalent of provinces or states, and municipalities. Prior to this, there have not been many other studies about Zika in Honduras. According to Zambrano et al., most of the existing studies regarding Zika come from multi-country surveillance and are targeted towards Guillain-Barre Syndrome and the neurological effects of Zika (2019).The goal of this study in particular is “to estimate incidence rates of ZIKV in 2016-2017 for Honduras and its departments and municipalities and to develop GIS-based epidemiological maps”, with the justification being that understanding the overall impacts of arboviruses like Zika is “essential to develop and prepare for possible future epidemics” (2019).
Between 2015 and 2017, Honduras had over 45% of reported Zika cases in Central America (Zambrano et al., 2019). One explanation for this high case rate is that Honduras presents suitable conditions for the transmission of vector-borne diseases. Determining factors include climate, geography, and epidemiological conditions (2019). The count of Zika cases from 2016-2017 was collected from Honduras’ national surveillance system and used in conjunction with official population data from the National Institute of Statistics to calculate incidence rates by cases/100,000 pop. for both departments and municipalities (2019). This data was visualized in several maps using the open sourced GIS software Kosmo. The actual technical application of GIS in this case was quite basic, with department and municipal shapefiles being spatially joined with the incidence data to create a series of chloropleth maps. While the technique was quite simple, the importance of these outputs is quite significant. According to Zambrano et al., maps like the ones they created are important for “assessment of the differentiated risk related to acquiring [diseases like Zika] in certain areas” (2019). In addition to that, GIS-based epidemiological maps are useful in the development of “preventative/control strategies and public health policies for joint control of these vector-borne diseases” as well as being able to “provide relevant information concerning the risk to individuals travelling to specific regions of the world” (2019).
Through the examination of this study, the growing importance of GIS in health geography becomes clear. The incidence maps that were created by Zambrano et al. could provide insight into the nature of how Zika spreads, and how to prevent the spread as a result. Although these authors employed a relatively basic function of GIS (spatial join), the information that they are able to communicate could prove impactful in assisting decision-makers.
Source:
Zambrano, L. I., Vasquez-Bonilla, W. O., Fuentes-Barahona, I. C., Cláudio da Silva, J., Valle-Reconco, J. A., Medina, M. T., England, J. D., Sánchez-Duque, J. A., & Rodríguez-Morales, A. J. (2019). Spatial distribution of Zika in Honduras during 2016–2017 using geographic information systems (GIS) – Implications for public health and travel medicine. Travel Medicine and Infectious Disease, 31, 101382. https://doi.org/10.1016/j.tmaid.2019.01.017