viral disease

Why are viruses particularly dangerous

They can enter all types of cells, and scientists are yet to develop medicines to cure them

How do viruses harm cells

Trick antibodies so can enter cell

Replicate until cell bursts

3 examples of viral diseases

Measles

HIV

TMV

Symptoms of measles

Fever

Red skin rash

Can lead to other problems including pneumonia, encephalitis and blindness

How are measles spread

Inhalation of sneeze and cough droplets (Droplet infection)

How is measles being prevented

Vaccinations of young children to reduce transmission

Symptoms of HIV

(Initially) flu like symptoms

Then virus attacks immune system and leads to AIDS

What is AIDS

A state in which the body is susceptible to many different diseases

How is HIV spread

By sexual contact

By exchange of bodily fluids

How is HIV spread

Using condoms, not sharing needles, screening blood when it is used in transfusions

What is TMV

Tobacco mosaic virus

A widespread plant pathogen affecting many species of plants including tomatoes

Symptoms of TMV

Mosaic pattern or Discolouration on leaves, the affected part of the lead cannot photosynthesise

How is TMV spread

Contact between diseased plants and healthy plants, insects act as vectors

How is TMV being prevented

Good field hygiene and pest control

Growing TMV resistant strains