Communicable diseases are diseases that are passed from person to person either by direct contact with an infected person or indirectly, such as through contaminated (dirty/unclean) food or water. Another example of indirect transmission is when the disease is spread through the air, such as when an infected person coughs or sneezes and another person breathes in the air that contains the germs. Communicable diseases can be caused by:
Improvements to personal and environmental cleanliness, and the introduction of new immunisations (vaccines), have greatly reduced the number of people who catch some communicable diseases .
If a person develops certain communicable diseases (like tuberculosis), the disease must be 'notified'; this means that the information is collected by health authorities. Data from state and territory collections are collected and published by the National Notifiable Disease Surveillance System (NNDSS), but Indigenous status is often not reported for large proportions of notifications.
Recent information about communicable diseases includes:
Tuberculosis: a lung infection caused by a bacterium that can trigger a range of symptoms, such as coughing, weight loss, and fever .
Hepatitis: an inflammation of the liver caused by viral infections, alcohol or other drugs, toxins, or an attack by the body's immune system on itself . The most common types of hepatitis are hepatitis A, B, and C.
Invasive pneumococcal disease (IPD): caused by a bacterium and can lead to several major health conditions, such as pneumonia and meningitis .
Meningococcal disease: caused by a bacterium and can lead to meningitis, meningococcaemia without meningitis, and septic arthritis .
Sexually transmissible infections: caused by bacteria and viruses and can lead, if left untreated, to a range of health conditions, such as pelvic inflammatory disease in women .
Human immunodeficiency virus (HIV): an infection that destroys cells in the body's immune system .