A combination of growth and migration is resulting in substantial increases in the population of Urban and Peri-Urban (UPU) zones in Africa; with population rising from 35% of the total population in 2007 to a projected 51% by 2030. Urbanized environments in Africa are melting pots of activity and interaction; livestock live alongside people; human and livestock waste is poorly disposed of near food production areas while formal and informal trading takes place in internal and externally connected networks. This degree of mixing and contact creates ecological niches with opportunities for pathogen transmission, and several influential reports have linked urbanization to the risk of emerging infectious diseases. However, little is known on the impact of urbanization on the transmission of microbial pathogens.
Approximately 60% of human pathogens are zoonotic, and approximately 80% of novel pathogens have zoonotic origins. It is also thought that the processes leading to the emergence of novel pathogens are similar to those resulting in exposure to and spread of known zoonotic pathogens. Our understanding of the mechanisms and processes underlying the emergence of novel pathogens should benefit from investigation of pathogens that we already know about. This will go a long way in improving our ability to predict the emergence and spread of new infectious diseases hence provide an opportunity to understand the biology and ecology of existing pathogens.
The study uses an interdisciplinary approach to study E. coli as an exemplar microbe for this purpose because it is zoonotic, exists in many hosts, in most environments, on food and in milk and has pathogen and non-pathogen forms.