Identify Common Sources of Infection
Outcome 1 Understand the causes of infection
1. Identify the difference between bacteria, viruses, fungi and parasites? The difference between bacteria, viruses, fungi and parasites is: Bacteria Bacteria is a single celled organism, bacteria have evolved to thrive in almost any environment and can be found in almost any substance/surface and also in the human body, only 1% of bacteria is actually harmful. It’s bad or infectious bacteria that cause illness as they rapidly reproduce and produce a toxin that kills or mutates cells, bacteria is also self sufficient.
Viruses A virus is a small capsule that contains DNA or RNA, viruses, unlike bacteria are not self sufficient and need a host in order to reproduce I. E a human body. When a virus enters the body, it enters some certain cells and takes over making the now host cell make the parts the virus needs to reproduce, the cells are eventually destroyed through this process. The most common viruses is the common cold, which has no cure. Fungi Mould, yeast and mushrooms are all types of Fungi. Fungi live in the air, water, soil and on plants and they can live in the body, usually without causing illness.
Some fungi have beneficial uses. For example, penicillin. Fungi are also essential in making certain foods, such as bread and cheese. Certain types of Fungi can cause illness such as Candida which is a yeast that can cause infections such as thrush. Parasites A parasite is a tiny organism that lives in or on a host (A body) which they use in order to feed. Parasites can cause severe illness’s, there are 3 main types of parasites: protozoa, helminths, and ectoparasites.
- Protozoa – They are single celled organisms that can be free-living or parasitic in nature. They are able to multiply in humans, which contributes to their survival and also gives way to serious infections to develop.
- Helminths – are large, multicellular organisms that are generally visible to the naked eye in their adult stages. Like protozoa they can be either free-living or parasitic…
2. Identify common illnesses and infection caused by bacteria, viruses, fungi and parasites? Illnesses/infections caused by bacteria: Salmonellosis, tuberculosis, MRSA, coccidiosis, food poisoning, dysentery, bronchitis, ear infections, strep throat/tonsillitis, pneumonia, gonorrhoea, syphilis, chlamydia Viruses:
Influenza, common cold, stomach flu, pneumonia, ear infections, HIV/AIDS, herpes, warts, dengue, West Nile Virus, encephalitis Fungi: Valley fever, athlete’s foot, ringworm, yeast infection Parasites: Worms, schistosomiasis, malaria, sleeping sickness (trypanosomiasis), leishmaniasis
3. Describe what is meant by “infection” and “colonisation”? Infection is the invasion and multiplication of microorganisms that are not normally present within the body. An infection tends to show symptoms and may spread through the whole of the body. Colonisation is when germs are within the body, but do not make the person sick. People who are colonised will have no signs or symptoms and they can feel fine.
4. Explain what is meant by “systemic infection” and “localised infection”? A systemic infection is generally more serious. It can include things like Lyme disease, AIDs, or tuberculosis. It can also be a chest or urinary tract infection, depending upon how serious it gets. What separates a systemic infection to a localised infection is that for it to be a systemic infection the bacteria or virus must enter the bloodstream.
When bacteria or viruses are in the bloodstream there is the potential for the infection to spread to other organs and functions. Symptoms of a systemic infection include, headache, pains, nausea, seizures, cardiac problems and even death by septicaemia (blood poisoning) if medical treatment is not sought. A localised infection always has the potential to turn into a systemic infection. As another poster said, a localised infection often starts as a cut or small wound. Usually these do not require treatment, only good self-care. However, if it starts to get infected, like pus comes out or it is very hot to touch, antibiotics may be required from your doctor. If not treated, then a systemic infection may result.
5. Identify poor practices that may lead to the spread of infection? Not washing your hands, not wearing PPE, not storing or cooking foods properly, to cleaning your surroundings, not covering your nose or mouth when sneezing or coughing.
Outcome 2 Understand the transmission of infection.
- Explain the conditions needed for the growth of micro-organisms? Most micro-organisms need most of the things you and I need to flourish and grow – moisture, warmth and a source of nutrition – some (usually the most dangerous such as those responsible for some types of gangrene) can do without oxygen (anaerobic bacteria). They need a mode of spread (usually the unwashed or poorly washed hands of people or badly cleaned equipment/facilities or badly stored food) and a vulnerable person to invade.
- Explain the ways an infective agent might enter the body? Escape from the host or reservoir of infection (where the infectious agent normally lives and multiplies). Transport to new host Entry to new host Escape from the new host Person to person Touch Contaminated blood or other bodily fluids Silva Air. Food water insects fomites
- Identify common sources of infection? Common sources of infection include food, water, sick people (colds and flu or winter vomiting virus), animals and poor housing (invaded with pests such as rats and mice or damp and mouldy).
- Explain how infective agents can be transmitted to a person? The term usually refers to the transmission of microorganisms directly from one person to another by one or more of the following means:
- Droplet contact – coughing or sneezing on another person
- Direct physical contact – touching an infected person, including sexual contact.
- Indirect physical contact – usually by touching soil contamina? on or a contaminated surface
- Airborne transmission – if the microorganism can remain in the air for long periods
- Fecal-oral transmission – usually from contaminated food or water sources
Transmission can also be indirect, via another organism, either a vector (e. g. a mosquito) or an intermediate host (e. g. tapeworm in pigs can be transmi’ed to humans who ingest improperly cooked pork). Indirect transmission could involve zoonoses or, more typically, larger pathogens like macro parasites with more complex life cycles.