Communicable Diseases Flashcards
Describe the term ‘communicable disease’ and give examples of some communicable diseases.
A communicable disease is a disease that can be spread from one living thing to another, or through the environment.
Examples include: HIV, COVID-19 and chickenpox/shingles.
How are communicable diseases spread?
An infectious agent is transmitted from a source to a susceptible host.
Communicable diseases can be spread:
From one living thing to another, e.g., HIV (human to human)
Through the environment, e.g., lyme disease (animal to human)
Why are communicable diseases major causes of mortality worldwide?
Primary effects of communicable diseases include diarrhoea (results in dehydration, especially in children) and acute respiratory problems.
Secondary effects include trauma and malnutrition.
What is the ‘communicable period/window of infection’?
How can the window of infection be controlled/reduced?
The time required for the infectious agent to be transmitted from the reservoir to the susceptible host.
Improvements in personal and social hygiene e.g., hand washing and mask wearing
Greater awareness of health and disease.
What are the two types of communicable diseases?
Give an example of each type.
Emerging infectious diseases e.g., COVID-19
Re-emerging infectious diseases e.g., Tuberculosis
Describe the term ‘emerging infectious disease’.
Diseases that appear for the first time.
OR
Diseases that have previously occurred but emerge in a population where they have not been previously reported.
Describe the term ‘re-emerging infectious disease’.
Diseases that are familiar and caused by well understood infectious agents that were once under control or in decline, but are now increasing in incidence.
Why might re-emerging infectious diseases increase in incidence?
Resistance to drugs e.g., antibiotic resistance
Gain new footholds in the population e.g., people not getting vaccinated.
Describe the term ‘pathogen’, and describe how pathogens cause disease.
A pathogen is an organism that causes disease.
Pathogens cause disease when they invade, multiply and destroy body cells.
What are the four types of pathogenic organisms?
Bacteria, Virus, Protozoa and Fungi
Describe a virus and give an examples of viral infections.
A virus is a piece of genetic material encased in a protein coat.
Viral infections include:
- COVID-19
- HIV
- Polio
- Meningitis
- Rabies
- Smallpox
- Influenza
How does a virus infect a host?
A virus cannot reproduce without the assistance of a host.
- virus attaches to a host cell
- viruses genetic material enters the host cell
- cell is ‘hijacked’ to make viral genetic material and proteins
- new viruses form inside host cell
- cell bursts open and dies
- copies of the virus are released and infect other host cells in the same way.
Describe bacteria and give an example of a bacterial infection.
Bacteria are single celled organisms that come in three forms:
- bacilli (rod shaped)
- cocci (spherical)
- helical (spiral)
Bacteria can infect any part of the body:
- genitalia (STI’s and UTI’s)
- gastrointestinal system (gastritis and food poisoning)
- respiratory system (pneumonia).
Describe protozoa and give an example of a protozoan infection.
Protozoans are parasites that are infectious to humans, that occur in many different structures e.g., amoeba (can change shape) and paramecium (fixed and complex structure).
Protozoan infections include:
- Malaria
- Toxoplasmosis
- Amoebic Dysentery
Briefly describe fungi and give an example of a fungal infection including symptoms)
Fungi are plant-like organisms that commonly cause diseases of the skin and mucous membranes.
Fungal infections are also called mycosis.
Fungal infections include:
- Athletes foot
- Ringworm
- Vaginal yeast infection
Symptoms include:
- scaly skin
- redness
- itchiness
- blistering
