Chapter 3 The epidemiology of human GBS carriage
Trotter C., Voysey M.
Not all human groups have the same rates of carriage of or infection with group B streptococcus, and the differential rates by genetic and geographic origin, as well as culture, are described. The factors affecting carriage rates, such as age, race, and ethnic group, are enumerated. Changes in rates over time are also described. The effect of testing regimens on the incidence of carriage and disease is explained. The various subtypes of group B streptococcus are described, and their varying distributions and pathogenicities are discussed. Variations in the accuracy of incidence monitoring by country are highlighted.