Diseases caused

• pneumococci (Streptococcus pneumoniae) cause a broad spectrum of non-invasive and invasive infections

Non-Invasive Pneumococcal Diseases

• community-acquired pneumonia (CAP): pneumococcus is the most common cause of bacterial pneumonia across all age groups
• upper and lower respiratory tract infections: acute exacerbations of chronic bronchitis, sinusitis, otitis media, and conjunctivitis

Invasive Pneumococcal Diseases (IPD)

• pneumococcal meningitis: severe central nervous system infection, especially secondary to parameningeal foci or skull base fractures with cerebrospinal fluid leaks
• bacteraemia and septicaemia: severe bloodstream infection; includes "occult bacteraemia" in febrile infants/young children and rare presentations such as pneumococcal endocarditis
• musculoskeletal infections: septic arthritis and osteomyelitis resulting from haematogenous seeding

Reference:

1. UK Health Security Agency (UKHSA). Pneumococcal: guidance and immunisation schedule. UKHSA Guidance. Updated 16 October 2026.
2. European Centre for Disease Prevention and Control (ECDC). Pneumococcal disease. ECDC Surveillance Report, 2023.