Fig 1.
Spatial distribution of final 43 ES site locations.
Map created in QGIS v3.22.4. Background map: CartoDB Positron layer accessed with QuickMapServices QGIS Plugin (https://carto.com/basemaps) made available under the Creative Commons Attribution (CC BY) 4.0 license.
Fig 2.
Flow diagram of sample processing after collection for both the water grab samples and Moore swabs from culture to PCR.
Figure created with BioRender.com.
Table 1.
Environmental Surveillance Site Characteristics.
Fig 3.
Geographic distribution of ES sites and prevalence (%) of S. Typhi detection for A) grab samples and B) Moore swabs in Blantyre. Circle radius proportional to the estimated catchment population. Maps were created in QGIS v3.22.4. Background map: CartoDB Positron layer accessed with QuickMapServices QGIS Plugin (https://carto.com/basemaps) made available under the Creative Commons Attribution (CC BY) 4.0 license.
Fig 4.
Geographic distribution of prevalence (%) of HF183 detection for A) grab samples and B) Moore swabs in Blantyre. Maps were created in QGIS v3.22.4. Background map: CartoDB Positron layer accessed with QuickMapServices QGIS Plugin (https://carto.com/basemaps) made available under the Creative Commons Attribution (CC BY) 4.0 license.
Fig 5.
Monthly detection of S. Typhi in ES samples (right y axis) and the incidence of clinical cases reported (left Y axis) in Blantyre, Malawi. For the period May 2021 to April 2021 only, the monthly number of blood culture-confirmed typhoid fever cases reported among inpatient and outpatient resident in the study area (dark grey) with additional cases detected through enhanced passive surveillance at three primary health care centres shown in light grey. Light blue area indicates wet season period.
Fig 6.
Geographical distribution of crude cumulative incidence rates of typhoid fever (cases per 100,000) in Blantyre from May 2021 to April 2022 using A) hospital reported cases, and B) additional cases through enhanced passive surveillance at 3 primary health care centres. The location of the QECH shown for reference. Maps were created in QGIS v3.22.4. Background map: CartoDB Positron layer accessed with QuickMapServices QGIS Plugin (https://carto.com/basemaps) made available under the Creative Commons Attribution (CC BY) 4.0 license.