Elderly persons are more likely to have co-existing medical conditions that increase their risk, but there is evidence for an independent effect of older age.

The slide shows reports of pneumococcal bacteraemia made to the UK CDSC. Over the whole period half of the reported cases were in persons >65 years. (These UK data probably underestimate the true rate of invasive pneumococcal bacteraemia in the population because of under reporting.)

US data show case-fatality for elderly persons of 30-40% (about twice those for persons of all ages). (See also slide 3.1.)

Bacteraemia – entry of the pathogen into the blood stream – is a potentially fatal outcome of pneumococcal pneumonia which occurs in 15 – 30% of patients.

The high risk of mortality from pneumococcal bacteraemia has not diminished over the past four decades despite the introduction of new antibiotics and methods of intensive care.

S. pneumoniae is a common bacterial cause of acute meningitis.

The signs and symptoms are not specific to pneumococcal meningitis. Labortory tests of CSF are carried out to confirm the diagnosis. These will be discussed later.

Sometimes pneumococci gain access to the CNS directly (e.g. in skull fracture).