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.
Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is spread through contact with infected body fluids or blood products. Following acute infection with HBV, some people go on to develop a chronic infection.
Chikungunya is a viral disease transmitted by Aedes mosquitoes to humans. The word ‘chikungunya’ means 'that which bends up', an allusion to the posture of the suffering patients. The most common symptom is joint pain.
Enteric infections due to Salmonella bacteria are generally referred to by the term ‘salmonellosis’ when they are due to Salmonella species other than Salmonella typhi and Salmonella paratyphi.
Cholera is an acute diarrhoeal infection caused by the bacterium Vibrio cholera of serogroups O1 or O139. Humans are the only relevant reservoir, even though Vibrios can survive for a long time in coastal waters contaminated by human excreta.
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.
Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is spread through contact with infected body fluids or blood products.
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.