Causes and Spread of Infection

Identify the differences between bacteria, viruses, fungi and parasites  

Viruses are pieces of nucleic acid (DNA or RNA) wrapped in a thin coat of protein that replicate only within the cells of living hosts.
Bacteria are one-cell microorganisms with a simple cellular organization whose nucleus lacks a membrane.
Parasites may be protozoa, yeasts, or multicellular organisms such as fungi or worms that live in or on a host to obtain nourishment without providing any benefit to the host.
There are many different varieties of fungi, and we eat quite a few of them. Mushrooms are fungi, as is the mold that forms the blue or green veins in some types of cheese. And yeast, another type of fungi, is a necessary ingredient to make most types of bread.

Identify   common   illnesses   and   infections   caused   by   bacteria,   viruses,   fungi   and  

MRSA infections, flu, Noroviris infections, gastroenteritis, blood borne infections e.g hepatitis A, B, C and HIV
Clostridium difficile
Salmonella. E.Coli
AIDS,           Athlete'sfoot,
Lyme disease, Scabies, malaria  


Describe   what   is   meant   by   “infection”   and   “colonisation”

Infection begins when an organism successfully colonizes by entering the body, growing and multiplying. Most humans are not easily infected. Those who are weak, sick, malnourished, have cancer or are diabetic have increased susceptibility to chronic or persistent infections. Individuals who have a suppressed immune system are particularly susceptible to opportunistic infections. Entrance to the host generally occurs through the mucosa in orifices like the oral cavity, nose, eyes, genitalia, anus, or open wounds. While a few organisms can grow at the initial site of entry, many migrate and cause systemic infection in different organs. Some pathogens grow within the host cells (intracellular) whereas others grow freely in bodily fluids....