emm sequence typing is the most widely used method for defining group A streptococcal
(GAS) strains, and has been applied to isolates in all regions of the world. We did
a systematic review of the global distribution of GAS emm types. 102 articles and
reports were included (38 081 isolates). Epidemiological data from high-income countries
were predominant, with sparse data from low-income countries. The epidemiology of
GAS disease in Africa and the Pacific region seems to be different from that in other
regions, particularly high-income countries. In Africa and the Pacific, there were
no dominant emm types, a higher diversity of emm types, and many of the common emm
types in other parts of the world were less common (including emm 1, 4, 6, and 12).
Our data have implications for the development of GAS vaccines. On the basis of the
available data, the current formulation of the experimental multivalent emm vaccine
would provide good coverage in high-income countries, particularly USA, Canada, and
Europe, but poor coverage in Africa and the Pacific, and only average coverage in
Asia and the Middle East.