Fig. 1From: Streptococcus pneumoniae outbreaks and implications for transmission and control: a systematic reviewReported Streptococcus pneumoniae outbreaks by anatomical site. LRTI: Lower respiratory tract infection. LRTI was divided into three eras; pre-vaccine (pre-1977), pneumococcal polysaccharide vaccine only (1977–1999), and pneumococcal polysaccharide and conjugate vaccines (2000–2017)Back to article page