Early estimates of COVID-19 infections in small, medium and large population clusters

Dawd S Siraj; Amir S Siraj; Abigail Mapes

Since its emergence in December of 2019, SARS-CoV-2 virus has continued to spread in many regions with 824 thousand confirmed cases and more than 41 thousand reported deaths worldwide in 206 countries and territories by March 31, 2020 [1] . The rapid progression of the number of infections and deaths due to SARS-CoV-2 has taken many by surprise, with many of its characteristics related to its transmissibility under continuous update [2] . While the disease is still actively spreading in many regions of the world, researchers are working to quantify transmission parameters [2] [3] [4] [5] [6] [7] , and make estimates of infections and resulting deaths under different scenarios [8] [9] [10] [11] . However, these studies are either too specific to certain geographies [10, 12] or are too general to handle realistic scenarios [8, 11] in the context of Sub Saharan Africa where majority of the population live in rural and semi urban areas with poor physical interconnections. To overcome this problem and make estimates of infections in clusters of population with different sizes, we developed a mathematical based model with Susceptible-Exposed-Infectious-Removed states, with parameters obtained from recent studies, and based on 54 scenarios of initial number of cases, coverage of contact tracing, and population size, more suited to realities in resource poor, less inter-connected regions around the world.