Abstract:
The 2014 Ebola outbreak that affected about 30,000 people and caused over 11,000 deaths, severely impacted Sierra Leone. By the end of the outbreak in 2015, Port Loko District, an epicentre, had reported about a fifth of all cases and deaths in the country. This study examined the spatial implication of distance on case reporting pattern (patient delay) and mortality, among other factors, during the 2014/2015 Ebola outbreak in Sierra Leone. The study utilized the principles of geographic information systems and statistics to understand epidemiological characteristics of the outbreak. It was a geographically referenced cohort study using datasets of 1619 Ebola confirmed and probable cases in Port Loko District reported between 01 September, 2014 and 28 February, 2015. Geocoding techniques were used to assign geolocation to patient addresses. Geographic distance from the District Ebola Response Centre (DERC) was modelled using reclassified layers of landuse landcover, digital elevation model, roads and water network from which distance to each geocoded address was derived. The relationship between the outcome variable; status at case report (dead/alive), and factors such as distance, patient delay, age and gender was investigated. P-value was statistically significant at <0.05. The mean age of the cohort was 31±19years; a significant 56% were female. Patient distance from DERC varied between 3km and 172km (average=85km ±4km) while mean patient delay was 4±3 days. At the sub-district administrative level, Koya recorded the highest CFR (18.9%) among the eleven chiefdoms that comprised the district. There was no association (p=0.513) between delay in case reporting and patients’ distance from DERC. Also, the patients’ gender was not significantly associated with patient delay (p=0.27). Similarly, distance from the centre was not associated with mortality (p=0.5650). However, delay in reporting a case (at p<0.0001) and increasing age (at p<0.0001) were found to be associated with mortality. The study established that mortality was not associated with patient’s distance from response facilities. Cases were more likely to be dead at time of reporting with longer patient delay and increased age. Hence, it is recommended that in the event of future outbreaks, enhanced social mobilization activities targeted at the older population is important to drive early reporting which minimizes mortality.
