Infection and Allergic Disease in Africa

During the last few decades, the prevalence of atopic disease has increased globally, not only in industrialised countries, but also in less industrialised countries, especially in urban centres with a westernised lifestyle. The hygiene hypothesis suggests that a relationship exists between improved hygiene and an increase in atopic disease prevalence. It is clear that this relationship may be more complex than initially assumed. It may be under the influence of different factors, such as genetic variability, time of exposure, amount and length of exposure, type of infection, and the prevalence of environmental allergens.