pneumococcus

introduction

the pneumococcus (Streptococcus pneumoniae) is a Gram-positive, alpha-hemolytic, aerotolerant anaerobic Strept. discovered in 1881, and called Diplococcus pneumoniae in 1920 but renamed in 1974 to its current name.
it is part of the normal upper respiratory tract flora
it is a major cause of the following conditions:
- pneumonia
  - community acquired pneumonia (CAP) in adults
  - pneumococcal pneumonia is more common in the very young and the very old
- meningitis and cerebral abscess
  - pneumococci are the leading cause of meningitis in adults in Western countries.
- sinusitis
- otitis media
- sepsis / septicaemia
- infective endocarditis (including SBE)
- pericarditis
- osteomyelitis
- septic arthritis
more than 90 different serotypes are known, and these types differ in virulence, prevalence, and extent of drug resistance

functional or anatomic asplenia such as splenectomy, sickle cell disease (SCD) or other haemoglobinopathies
immunocompromise:
- symptomatic IgG sublass or isolated IgA deficiency
- immunosuppressive Rx such as high dose corticosteroids for more than 1wk or radiation Rx
- haematologic and other malignancies
- solid organ transplant
- haemopoietic stem cell transplant
- HIV / AIDS
- [CRF]] or relapsing or persistent nephrotic syndrome
proven or presumptive CSF leak
cochlear implants
intracranial shunts

chronic cardiac disease (excluding isolated adult hypertension), particularly paediatric
chronic lung disease including preterm infants, cystic_fibrosis and severe asthma requiring frequent hospital visits or multiple medications
diabetes
Down's syndrome
alcoholism
chronic liver disease
preterm birth < 28wks gestation (should be vaccinated to age 5yrs)
tobacco smoking