Meningococcal disease is caused by Neisseria meningitidis, a bacterium with human carriers as the only reservoir. It is carried in the nose, where it can remain for long periods without producing symptoms.
Poliovirus is highly contagious and infected individuals shed virus in the faeces and from oral secretions, thus the mode of transmission is person-to-person, both via the faecal-oral and the oral-oral routes.
Haemophilus influenzae type b (Hib) is an obligate human pathogen and an important cause of invasive bacterial infections in both children and adults, with the highest incidence among young children.
Haemophilus influenzae type b (Hib) is an obligate human pathogen and an important cause of invasive bacterial infections in both children and adults, with the highest incidence among young children.
Poliomyelitis, also known as polio or infantile paralysis, is a vaccine-preventable systemic viral infection affecting the motor neurons of the central nervous system (CNS). Historically, it has been a major cause of mortality, acute paralysis and lifelong disabilities but large scale immunisation programmes have eliminated polio from most areas of the world.