Infection disease Flashcards
What is a pathogen?
A disease causing organism
How do viruses cause disease?
Viruses cause disease by killing the cells in which they multiply
How do bacterial pathogens cause disease?
Due to the production of toxins
What are the modes of transmission of pathogens?
- Respiratory droplets e.g. influenza, TB;
- Faecal-oral (food and water borne) e.g. salmonella, food poisoning, polio, typhoid and cholera
- Insect vector e.g. malaria, breaks in skin e.g. HIV through needle punctures and sexual transmission (STDs e.g. HIV)
How can transmission of infectious diseases be reduced?
- Work of Ignaz Semmelweiss and importance of handwashing / hygiene in hospitals
- Importance of sanitation and clean drinking water
- Kitchen hygiene and need to cook food thoroughly
- Use of mosquito nets and draining of mosquito breeding grounds to reduce transmission of malaria
- Isolation, use of face masks, use of tissues to catch sneezes etc (catch it, bin in, kill it flu campaign)
- Use of condoms to reduce the transmission of STDs
How have we lowered the percentage of deaths due to infectious diseases?
The discovery of antibiotics and development of vaccines
What is the role of the skin against disease?
It’s a barrier
What is the role of Cilia and mucous in upper respiratory tract?
Mucous traps microbes in airways and cilia waft the mucous up, away from lungs to throat where it is swallowed.
What is the role of stomach acid against disease?
Hydrochloric acid in our stomach kills most microbes
What is the role of blood clotting at site of wound?
To prevent microbes getting into body
What is the role of white blood cells?
To kill any pathogens that have got into the body
What do phagocytes do (some white blood cells)?
Engulf and digest pathogens (phagocytosis)
What do lymophocytes do (white blood cells)?
Produce special chemicals called anti bodies that target and destroy specific pathogens or neutralise specific toxins released by pathogens
What happens to pathogens that white blood cells remember?
They will produce large amounts of the correct antibody very quickly before it can cause illness (this is the basis of immunity)
What does immunisation / vaccination involve?
Giving someone a dead or weakened form of the pathogen (in the form of an injection)
