Communicable Diseases

  • Communicable diseases, also known as infectious diseases, are caused by pathogens such as bacteria, viruses, protists, and fungi.

  • These diseases can be transmitted in numerous ways including direct contact, airborne transmission, contaminated food and water, and vectors such as mosquitoes and ticks.

  • Examples of communicable diseases include the flu (caused by the influenza virus), malaria (caused by the protist Plasmodium), and tuberculosis (caused by the bacterium Mycobacterium tuberculosis).

  • Hygiene practises such as washing hands regularly and preparing food safely can prevent the spread of these diseases.

  • The body’s first line of defence against pathogens is the skin and other barriers like mucus and stomach acid.

  • If a pathogen enters the body, the immune system gets to work. The white blood cells can consume and destroy pathogens, release antibodies which bind to pathogens and neutralise them, or produce antitoxins to counteract toxins produced by the pathogens.

  • Vaccines are crucial in preventing the spread of communicable diseases. They involve injecting small amounts of dead or inactive pathogens into the body so the immune system can produce antibodies to fight off a future infection.

  • Antibiotics are a type of medicine that kill or prevent the growth of bacteria, but they do not work on viral infections. Misuse of antibiotics can lead to antibiotic resistance, meaning bacteria evolve and become immune to the antibiotics.

  • Some communicable diseases, known as epidemics, can spread quickly and affect large numbers of people, like the Spanish flu in 1918. Some, known as pandemics, can spread across countries or continents.

  • Government and health organisations play a key role in the prevention and control of the spread of communicable diseases, providing guidelines, vaccination programmes and public health education.

  • Understanding life cycles and habitats of disease vectors (like mosquitoes for Malaria) can help in management and control of disease.

  • Regularly monitoring and surveying levels of disease can help to predict and control future outbreaks.

  • Many factors influence health, not just the presence of disease, such as diet, stress and life situation.

  • Both genetic and environmental factors have a role in the onset of disease. For example, people with certain genetic profiles may be more susceptible to certain diseases.