Diseases we need to know
Viral
Measels
Spread by air - sneezing or coughing
Develop red skin rash and fever (high temperature)
Can be fatal if there are complications eg. can lead to pneumonia (lung infection) or encephalitis (brain infection)
Cure: vaccination when young
HIV
Spread by sexual contact or exchanging bodily fluids like blood eg. by sharing needles
Causes flu-like symptoms for a few weeks then nothing for a few years - can be controlled with antiretroviral drugs which stop the virus from replicating
Virus attacks immune cells - at stage where system is so damaged it cannot cope with cancer or other infections is known as AIDS - late stage of HIV
Tobacco Mosaic Virus
Virus affecting plants eg. tomatoes
Causes mosaic pattern on the leaves - parts become discoloured
Plants can't carry out photosynthesis so well so have stunted growth
Fungal
Rose Black Spot
Causes purple or black sports to develop on leaves of rose plants - causes leaves to turn yellow and drop off
Less photosynthesis so stunted growth
Spreads through environment by water or wind
Gardeners treat it using fungicides and by stripping the plant of its affected leaves, which are then destroyed. and the tools used are sterilised
Protist
Malaria
Vector of the disease is mosquitos
Mosquito first bites an infected human and becomes infected
Later after the parasite has completed its 8 day cycle when the mosquito has its blood mean it transmits the disease to an uninfected human through their blood vessel
Causes episodes of fever and can be fatal
Reduce spread by stopping mosquito's from breeding
Protection using insecticides and mosquito nets
Bacterial
Salmonella
Causes food poisoning
Infected people suffer from fever, stomach cramps, vomiting and diarrhoea
Get it by eating contaminated food - eg. it was prepared in unhygienic conditions
Controlled where poultry are given a vaccination
Gonorrhoea
Sexually transmitted infection
Passed on by sexual contact eg. unprotected sex
Symptoms are pain when urinating, thick yellow or green discharge from vagina or penis
Originally treated with penicillin, but bacteria are now resistant
People should use contraception such as condoms and take antibiotics
How to reduce/prevent spread of disease
Being hygienic - wash hands and after sneezing or being with an infected person
Destroying vectors - prevents disease being spread - use insecticides or destroy their habitat so they can no longer breed
Isolating infected individuals - prevents the disease from being passed on
Vaccination - means people and animals cannot develop the infection and pass it on to someone