Topic 3- Communicable diseases Flashcards
What is a communicable disease
A disease caused by a pathogen which can be passed between animals or plants
What is a pathogen?
A disease-causing microorgansim
How do bacteria cause disease?
Once inside the body, they divide rapidly by binary fission. Thy kill cells and produce harmful toxins
How do viruses cause disease?
They invade and reproduce inside living body cells, leading to cell damage
Give three way in which pathogens can be spread
-By air
-By water
-By direct contact
Give four ways in which the spread of pathogens can be reduced
-Hygiene
-Reducing contact with infected individuals
-Removing vectors
-Vaccinations
Why is it especially important to prevent the spread of viral diseases?
Scientists have not yet developed cures for many viral diseases
What is measles?
Measles is a serious viral disease that can cause blindness and brain damage. The main symptoms are a fever and red skin rash.
How is measles spread?
By air- through inhalation of droplets from coughs and sneezes
What is HIV/AIDS?
HIV is a virus which attacks and damages the immune system until it can no longer function properly. AIDS is the condition resulting from a long-term HIV infection. There is no cure or vaccine for HIV/AIDS
How is HIV spread?
Direct sexual contact and the exchange of bodily fluids
How can the spread of HIV/AIDS be prevented?
-use of condoms
-screening of blood for transfusions
-not sharing needles
-bottle-feeding by HIV-positive mothers
-use of antiretroviral drugs to prevent the development of AIDS
What is tobacco mosaic virus?
A plant pathogen which causes leaf discolouration when cells are damaged. Affected areas cannot photosynthesise, reducing crop yield. As there is no treatment, farmers grow TMV-resistant crop strains to avoid infection
How is tobacco mosaic virus spread?
Contact between infected and healthy plants
Insects may act as a vector
What is salmonella?
A type of bacteria found in raw meat, poultry and eggs. If they enter the body via food poisoning, they can affect natural gut bacteria
What are the symptoms of salmonella food poisoning?
Fever
Abdominal cramping
Vomiting
Diarrhoea
May be fatal in very young or elderly populations due to risk of dehydration.
How can the spread of salmonella be limited?
Vaccinating animals intended for consumption
Keep raw meat away from cooked meat
Disinfect hands and surfaces after contact with raw meat
Thoroughly cook meat
What is gonorrhoea?
A sexually transmitted bacterial infection caused by unprotected sex with an infected individual. Early symptoms include yellow/green discharge from genitals and painful urination, it can be symptomless
Its spread can be controlled through the use of antibiotics and using condoms
What is rose black spot?
A fungal disease which causes purple or black spots to develop on rose leaves. It reduces the area of the leaf which is available for photosynthesis and causes leaves to turn yellow and drop prematurely