Skin infections
Staphylococcal bacteria can spread through the air, by person-to-person contact, and it can be picked up from contaminated surfaces.
Once the bacteria reach the skin, they can go on to cause infection if they become heavily concentrated on the skin surface, or they are able to enter the body through a break in the skin. Staphylococcal bacteria often enter the body through an inflamed hair follicle or oil gland. Alternatively, they can enter through skin that is damaged by burns, cuts and scrapes, other infections, or insect bites.
Food poisoning
Staphylococcal food poisoning is usually caused by contamination of food with staphylococcal bacteria from a boil, or blister, on the skin of a food-handler.
If the food is not cooked thoroughly, or kept sufficiently hot, or cold, once the bacteria have come in contact with food they will continue to reproduce. As the bacteria reproduce, they produce a toxin that causes food poisoning when the affected food is eaten. Staphylococcal food poisoning is not spread from person-to-person.
Invasive staphylococcal infections
In healthy people, the layers of skin and the immune system usually provide a good defence that prevents a skin infection spreading further into the body.
Therefore, an opportunity for an invasive staphylococcal infection to occur will usually only arise if:
- you have a weakened immune system due to an underlying medical condition, or due to a side effect of treatment,
- you are using a piece of medical equipment that goes directly inside your body, and/or
- you experience severe trauma to the skin, such as a deep impact wound, or a major burn.
Health conditions and treatments that can weaken the immune system include:
- HIV,
- diabetes (both type 1 and type 2),
- chemotherapy,
- alcohol abuse,
- intravenous drug abuse (injecting illegal drugs, such as heroin), and
- taking immunosuppressants (medication that suppresses the immune system and is used to help prevent the immune system from rejecting transplanted organs).
Medical equipment that can increase the risk of invasive staphylococcal infection include:
- the equipment that is used to perform all types of dialysis (a medical procedure that involves placing either a needle into the vein, or a tube into the abdomen),
- catheters (a catheter is a tube that is used to empty the bladder),
- feeding tubes, and
- breathing tubes.
