Infection and response - Communicable diseases Flashcards
what are pathogens
microorganisms that enter the body and cause disease
what are bacteria
very small cells which can reproduce rapidly inside your body
how do bacteria make you ill
- they make you feel ill by producing toxins toxins that damage your tissues
what are viruses
non - living particles which can reproduce rapidly inside your body
how do viruses make you ill
- they invade a host cell
- they then reproduce inside the host cell
- when the virus leaves the cell, it can cause the cell to burst open and die
what are protists
single celled eukaryotes which make us feel ill by damaging tissues
what are fungi
single celled organisms that have a body made of hyphae
how does hyphae make you ill
can grow and penetrate human skin and the surface of plants, causing disease
- can also produce spores, which can be spread to other plants and animals
name the 3 ways pathogens can be spread
- air
- water
- direct contact
describe how pathogens can be spread through water
- pathogens can be picked up by drinking or bathing in dirty water - e.g - cholera is a bacterial infection caused by drinking dirty water
describe how pathogens can be spread through air
- pathogens can be carried by the air and breathed in
- some are carried in droplets produced when you cough or sneeze - e.g - influenza virus
describe how pathogens can be spread through direct contact
- pathogens can be picked up by touching contaminated surfaces - e.g athletes foot
what are the three viral diseases I need to know
measles, HIV, tobacco mosaic virus
Measles, what it is, how its spread ,symptoms and preventions
- it’s a viral disease spread by droplets from an infected persons sneeze or cough
- symptoms include red skin rash, fever
- can be very serious, can lead to pneumonia or inflammation of the brain
- most people are vaccinated against measles when they’re young to prevent it
HIV , what it is, how it’s spread, symptoms and preventions
- its a virus spread by sexual contact or by exchanging bodily fluids such as blood ( sharing needles )
- causes flu like symptoms for a few weeks, they then don’t experience any other symptoms for a few years, during this time, HIV can be controlled with antiretroviral drugs
- this virus attacks the immune cells, if it’s too damaged . it can’t deal with other infections or cancers, at this stage, the virus is known as aids
Tobacco mosaic virus causes diseases etc
- its a virus that affects many species of plant
- mostly tomato plants
- causes a mosaic pattern on the leaves of the plant and causes the leaves to become discoloured
- meaning the rate of photosynthesis is reduced, so the plants growth is reduced
what is rose black spot
- fungal disease that causes purple or black spots on the leaves of rose plants, this makes the leaves turn yellow and drop off
- this means less photosynthesis , which means the plant doesnt grow very well
- fungus spreads by water or wind
- can be treated by using fungicides or cutting off and destroying affected leaves so fungus doesn’t spread to other rose plants
malaria, how its spread etc
- caused by protists
- mosquitoes ( vectors ) pick up the protist and gives it to whatever animal it feeds on by inserting it into the animals blood vessels
- causes fever, headaches, muscle aches,can be fatal
- can be stopped by stopping mosquitoes from breeding or using insecticides and mosquito nets
what bacterial diseases do I need to know
gonorrhoea and salmonella
gonorrhoea, how its spread etc
- sexually transmitted disease
- caused by bacteria
- pain when urinating, yellow or green discharge
- prevented by using protection or using antibiotics
- also prevented if you get tested for gonorrhoea after having unprotected sex
why is it harder to treat gonorrhoea with antibiotics
some strains of bacteria have become resistant to it
salmonella, how its spread etc
- type of bacteria which causes food poisoning
- symptoms include vomiting, diarrhoea, fever, stomach cramps
- caught by eating food which has been contaminated with salmonella bacteria like eating raw chicken or chicken that had been contaminated by being prepared in unhygienic conditions
- in the UK, poultry is vaccinated against salmonella
how can basic hygiene reduce/ prevent the spread of disease
for example, washing your hands after you sneeze gets rid of bacteria, stopping you from infecting another person
how can destroying vectors reduce / prevent the spread of disease
prevents the disease from being passed on as they cannot breed
how can isolation reduce / prevent the spread of diseases
isolating someone with a communicable disease prevents them from passing it to anyone else
how does vaccination prevent the spread of diseases
makes you never get the disease
what is the vector for malaria
female anopheles mosquito
what is the difference between viruses and bacteria
viruses cannot reproduce by themselves, they can only reproduce inside a host cell
ways to reduce the spread of pathogens
- drink clean water
- practising basic hygiene like washing hands
- using protection
- isolation
- vaccination
how are viral diseases treated
using antiretroviral drugs, to stop the virus from multiplying inside the patient, so it doesn’t damage the patients immune system
disadvantages of antiretroviral drugs
- they are not a cure for HIV
- must be taken for the rest of patients life
describe the life cycle of the malaria vector
- infected person is bitten by a mosquito
- The malaria pathogen passes into the mosqito
- mosquito then bites another person and gives them the disease
how to reduce the spread of malaria
- spray areas of still water with insecticide, so that they cant breed
- drain areas of still water
- use a mosquito net when sleeping
