Varicella is caused by the varicella-zoster virus (VZV), which also causes shingles (herpes zoster). The virus typically affects children aged 2‒8 years.
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.
Measles is an acute illness caused by morbillivirus. The disease is transmitted via airborne respiratory droplets, or by direct contact with nasal and throat secretions of infected individuals.
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.
Congenital syphilis is the infection of a foetus with syphilis following the infection of the mother during pregnancy. ‘Congenital’ indicates that the foetus also becomes infected during pregnancy.
Hepatitis C is a liver disease caused by infection with the hepatitis C virus (HCV). HCV can cause both acute and chronic hepatitis infection, ranging in severity from a mild illness that lasts only a few weeks to a serious, lifelong illness resulting in cirrhosis and liver cancer.
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. It may also be transmitted mother-to-child (congenital syphilis).
HIV is a virus which attacks the immune system and causes a lifelong severe illness with a long incubation period. The end-stage of the infection, acquired immunodeficiency syndrome (AIDS), results from the destruction of the immune system.