Polysaccharide encapsulated bacteria

Polysaccharide encapsulated bacteria, frequently referred to simply as encapsulated bacteria and less precisely called encapsulated organisms, are a group of bacteria that have an outer covering, a capsule, made of polysaccharide.

Examples of encapsulated bacteria

 * Haemophilus influenzae type B (Hib)
 * Streptococcus pneumoniae (pneumococcus)
 * Neisseria meningitides (meningococcus)
 * Group B streptococcus (GBS)
 * Salmonella typhi

Role in disease
Many encapsulated bacteria are pathogens that lead to a significant amount of morbidity and mortality.

Asplenia
People that lack a spleen, functionally (as in sickle cell disease ) or anatomically (due to a splenectomy or congenital absence), have been shown to be more susceptible to these pathogens. Therefore, it is standard medical practise to recommend vaccination.

People with asplenia are commonly offered vaccines against Neisseria meningitis, Haemophilus influenzae, and Streptococcus pneumoniae; these vaccines can be remembered with the mnemonic: NHS.

Children
Young children do not have the ability to make antibodies to polysaccharide and are, therefore, more susceptible to encapsulated bacteria.