CHAPTER ONE
INTRODUCTION
1.1            Background to the Study
Contemporary globalization and urbanization is reproducing classic conditions historically associated with the emergence of infectious diseases and the periodically recurring pattern of epidemics and pandemics. The dynamics of contemporary globalization has contributed to various institutional gaps that make dealing with infectious diseases is increasing difficult and threaten concentrated human populations with potential calamity (Gibson and Gumer, 2012). Over the past few decades, there has been a rapid urbanization of the world’s population.
According to Chilala (2015) Rapid urbanization has significant repercussions on migrants’ health. The increasing movement of people from rural to urban areas often alters the characteristic epidemiological disease profile of the country and at the same time new diseases appear or old ones remerges. Such is the case of HIV/AIDS, tuberculosis, malaria, and recent case of Ebola and Lassa fever. Urbanization is also associated with changes in diet and exercise that increase the prevalence of obesity with increased risks of type II diabetes and cardiovascular disease.
Philip (1993) defines Urbanization as involves a physical change in which increasing proportions of populations live in urban settings. It also implies considerable changes in the ways in which these people live, how they earn their livelihoods, the food which they eat, and the wide range of environmental factors to which they are exposed. There is another underlying assumption that, increasingly, urban populations will be healthier than their rural counterparts and those higher levels of urbanization will equate with better health status.
It is however; manifestly evident that in many cities, particularly in the developing world, the poor are exposed to greater risks and have much lower health status than their richer neighbours. In addition, whilst urban residents may theoretically have a better access to health care and services than do residents in many rural areas, and whilst many indicators of health do appear better in more highly urbanized societies than ones less so, there are caveats Vlahov et al., (2007).  In certain cities in middle-income countries, residents, particularly the poor, are exposed to a double risk of both infection and chronic degenerative ailments.
It has been emphasized that urbanization, and the concentration of human beings into new areas in particular, can bring exposure to new risk factors for large numbers of people. The growth of infectious and parasitic disease in some urban settings must therefore be recognized, as must the emergence of chronic diseases, with the concomitant need for investment in new types of health and social care. However, a number of constraints militate against the achievement of improved urban health, especially in developing countries (Ojogbe, 2002; Kotz, 2009; Salau, 2012).