T3 communicable diseases Flashcards
what is a pathogen
disease-causing microorganism
how do bacteria cause disease
once inside the body, they divide rapidly by binary fission
kill cells and produce harmful toxins
how do viruses cause disease
invade and reproduce inside living body cells, leading to cell damage
give 3 ways in which pathogens can be spread
air - flu, tuberculosis and the common cold are spread by droplet infection
water - fungal spores in water spread plant diseases
direct contact - common in plant diseases and STIs
give 4 ways in which the spread of pathogens can be reduced
hygiene - handwashing, disinfectants, tissues
reducing contact with infected individuals - quarantine
removing vectors - use of pesticides and insecticides, removal of habitats
vaccination
why is it especially important to prevent the spread of viral diseases
scientists haven’t developed cures for many viral diseases
what is measles
serious viral disease that can cause blindness and brain damage.
main symptoms are fever and red skin rash
how is measles spread
air - inhalation of droplets from coughs and sneezes
what is HIV / AIDS
Hiv - virus which attacks and damages the immune system until it can no longer function properly
AIDs - condition resulting from a long-term HIV infection.
no cure or vaccine
how is HIV spread
direct sexual contact and the exchange of bodily fluids
how can the spread of HIV/AIDS be prevented
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
plant pathogen which causes lead discolouration when cells are damaged
affected areas cannot photosynthesise, reducing crop yield
no treatment so farmers grow TMV-resistant crop strains to avoid infection
how is TMV spread
contact between infected and healthy plants
insects may act as vectors which transfer the virus between different plants
what is salmonella
type of bacteria found in raw meat, poultry and eggs
if they enter the body via food poisoning, they can affect natural gut bacteria
symptoms of salmonella food poisoning
fever
abdominal cramping
vomiting
diarrhoea
may be fatal in very young or elderly 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
ST bacterial infection caused by unprotected sex with an infected individual
yellow/green discharge from genitals and painful urination
spread can be controlled through antibiotics + condoms
what is rose black spot
fungal disease which causes purple or black spots to develop on rose leaves
reduces the area of the lead which is available for photosynthesis and causes leaves to turn yellow and drop prematurely