One bacterium, many different diseases -- Diagnosis and treatment of the group A streptococcus -- Superficial infections : streptococcal pharyngitis and impetigo -- Scarlet fever -- Resurgence of an old pathogen : invasive streptococcal disease -- Post-streptococcal complications -- Virulence factors of group A streptococci -- Vaccine prospects and the future of the group A streptococcus.