Fig. 2. Age and infection: immune senescence leads to increased susceptibility to bacterial infections.

a The age-specific incidence of E. coli bacteraemia in all age-groups and highlights the markedly increased disease burden after age 50 years. b The number of cases of S. aureus bacteraemia with higher case numbers in older adults. The proportion of patients who died also increased with age. c The incidence of hospitalised community-acquired pneumonia in adults in the US, which increases substantially with age. Insert a reproduced from Williamson et al.¹²⁶. Insert b reproduced with permission from Turnidge et al.¹²⁷. Data for insert c from Jain et al.¹²⁸.