Figure 4.

Map showing the incidence and geographical distribution of households of cases of blood culture-confirmed typhoid fever occurring in 2019 in Samoa. Incidence (cases per 10⁵ population) is represented by variable shading from white to dark blue, with darker hues representing higher incidence ranges. Each yellow dot approximates index case(s) of typhoid within a household to portray the density of cases. To maintain patient confidentiality, a mapping program randomly displaced the marker slightly on the map. Households of all cases were visited by a Samoa Typhoid Epidemiologic SWAT Team that recorded GPS coordinates with a Garmin GPSMAP 64SC. The insert shows the Apia Urban Area and 3 rural regions—Northwest Upolu, Rest of Upolu, and Savaii—with the percent of the 2019 population in parentheses. Upolu’s population of 156 077 comprises 77.7% of the total population of Samoa, whereas Savaii’s population of 44 797 comprises 22.3% of the total population. Mapping and point displacement were performed using QGIS 3.8.0-Zanzibar (QGIS Development Team, QGIS Geographic Information System, Open Source Geospatial Foundation Project, http://qgis.osgeo.org).