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Communicable diseases - Coggle Diagram

- - - - damages leaves, flowers and fruit
      - can stunt growth and reduce yields
      - infects tobacco plants and 150 other species including peppers and cucumbers
      - resistant crop strains are available but there is no cure
  - - - hyphae penetrates host cells, destroying leaves, tubers and fruits
      - no cure but resistant strains, careful management and chemical treatments can reduce risk
      - caused by a fungus like protoctist oomycete
  - - - caused by Gram positive bacteria
      - damages leaves, tubers and fruit
      - effects potatoes, tomatoes and aubergines
      - can destroy up to 80% of the crop
      - once ring rot effects a field, it cannot be used for growth again for 2 years
  - - - hyphae penetrate and digest the cells, turning the leaves black
      - resistant strains are being developed, good husbandry and fungicide can control speed
      - effects bananas
- - - - gradually destroys the immune system so affected people are open to other infections (such as TB and pneumonia), as well as some types of cancer
      - can affect humans and some nonhuman primates
      - HIV/AIDS (acquired immunodeficiency syndrome)- caused by HIV (human immunodeficiency virus), which targets T helper cells in the immune system
      - HIV is a retrovirus with RNA as its genetic material
        
        contains the enzyme reverse transcriptase, which transcribes RNA to a strangle strand of DNA to produce a single strand of DNA in the host cell. this DNA interacts with the genetic material of the host cell
      - passed between people through bodily fluids, most commonly through unprotected sex, shared needles, contaminated blood products or mothers to babies during pregnancy, birth or breast feeding
      - no vaccine or cure, but anti-retroviral drugs low the progress
      - girls and woman are at a high risk of HIV/AIDS in many countries due to traditional practices such as female genital mutilation increase infection rates
    - - affects mammals such as humans and pigs, and birds such as chickens
      - there are 3 main strains- A, B, and C strains
        
        A strain viruses are the most virulent and are classified further by the proteins on their surface
      - flu can be fatal to young children, elderly people and people with chronic illnesses- many of these deaths are from severe secondary bacterial infections such as pneumonia
      - it kills the cells, leading the airway open to secondary infection
      - flu viruses mutate regularly, and the change is usually quite small so having flu one year leaves some immunity for the next
      - viral infection of the ciliated epithelial cells in the gas exchange system
      - every so often there is a major change in the surface antigens, leading to a flu epidemic/pandemic as there are no antibodies available
  - - - they reproduce inside the mosquito, which needs to take two blood meals to provide herself with enough protein before she lays her eggs, which is when the parasite is passed
      - invades the red blood cells, liver and even the brain
      - the plasmodium parasite has a complex life cycle with two hosts- the mosquito and humans
      - around 200 million are reported to have malaria every year, and around 600 000 die
      - caused by the protoctists plasmodium and spread by the bites of female anopheles mosquitoes
      - no vaccine and limited cures, preventative measures include mosquito nets, door and window screens, and long sleeved clothing
      - the disease recurs, making people weak and vulnerable to other infections
      - the vector must be controlled, and insecticides can destroy mosquitoes, and removing standing water wear they breed
  - - - mainly affects young children and teenagers aged 15-19
      - different symptoms for different age groups, but in both a red/purple rash that does not disappear when a glass is pressed against it is a symptom of septicaemia and immediate medical treatment is needed
      - can spread to the rest of the body causing septicaemia and rapid death
      - about 10% of people infected with die
      - a bacterial infection of the meninges of the brain (protective membrane on the surface of the brain)
      - up to 25% of those who recover will have permanent damage
      - vaccines can prevent some forms of bacterial meningitis, and antibiotics will cure the disease if delivered early enough
  - - - causes grey-white crusty, infectious, circular areas of skin
      - it is not damaging, but looks unsightly and may be itchy
      - different fungi infect different species, eg. trichophyton verrucosum in cattle
      - anti fungal creams are an effective cure
      - fungal disease affecting mammals including cattle, dogs, cats and humans
    - - form of ring worm that grows on and digests the warm, moist skin between the toes
      - causes cracking and scaling, which is itchy and may become sore and can be cured with anitfungal cream
      - human fungal disease caused by tinia pedia