As any recent migrant would agree, for better or for worse, life in the city is very different from life in the country. Cultural and employment opportunities become more numerous; while support networks often fail to make the transition. Yet the social and health implications of increased population density are often overlooked. Firstly, concentrating more poor people and a very rich elite in a small area usually results in higher crime rates and more social tension. Since the time of the French Revolution, fear of the mob has haunted those in power and indeed has encouraged many African dictators to maintain armed forces close to urban areas in order to quell potential unrest. It is easier to control widely spread rural people than urban inhabitants.
There is little doubt that opposition to government becomes intensified in an urban setting. It was protests in Cairo and Tunis, for example, that forced the respective leaders out of those two capitals. The State of African Cities 2010 report by UN Habitat argues: "When public policies are of benefit only for small political or economic elites, urbanisation will almost inevitably result in instability, as cities become unliveable for rich and poor alike."
Perhaps unexpectedly, urban growth and development can also support rural social and economic structures. Many African urban workers send money to family members in country areas, In addition, the more concentrated the urban population density, the more demand it can create for agricultural produce from surrounding areas. Such patterns of rural-urban trade, however, can be interrupted by historic conflicts or poor development policies. In Luanda, for instance, a large proportion of the country's food requirements are imported from over-seas; while oil-rich Nigeria is forced to import much of its basic foodstuff requirements.
Exposure to most infectious diseases increases in cities, largely because of greater population density. However, in the case of some illnesses, such as HIV/AIDS, rural areas on major transport routes are perhaps even more at risk of infection than urban areas.
Most research concludes that urban dwellers also have greater resistance to fighting infection. A specific gene variant that makes people resistant to tuberculosis...