Increased risk of urban yellow fever outbreaks in Africa
March 07, 2012 / WHO
Global Alert and Response (GAR): The risk of large and uncontrollable outbreaks in urban areas in Africa is more likely than ever. Accelerated urbanization has concentrated a non-immune population in settings where, high vector and population density, the main factors contributing to increased virus transmission are present.
While 62.1% of the African population is still rural, urban growth rates at nearly 4% a year are the most rapid in the world, and nearly twice the global average1. Not only are more people living in cities, but the cities themselves are becoming larger and more numerous. There are now 43 cities in Africa with more than one million people, a figure which is expected to increase to almost 70 by 20152.
Data from 2000, shows that the population of Lagos, Nigeria increased at a rate of 21 persons per hour; between 1994 and 2004, urban population growth rates in West African cities ranged from between 10% and 39%, with an average of 18%. By 2020, the proportion of urban population to rural population will reach 63% in sub-Saharan Africa.