1. 1 Identify the differences between bacteria, viruses, fungi and parasites Viruses – With the exception of newly discovered prions, viruses are the smallest agents of infectious disease. Most viruses are exceedingly small (about 20 – 200 nanometers in diameter) and essentially round in shape. They consist of little more than a small piece of genetic material surrounded by a thin protein coating. Some viruses are also surrounded by a thin, fatty envelope. Viruses are different from all other infectious microorganisms because they are the only group of microorganisms that cannot replicate outside of a host cell.
Because viruses do not eat food – instead they seize materials and energy from host cells by hijacking cellular machinery – some scientists argue that they are more like complex molecules than living creatures. Viruses are known to infect nearly every type of organism on Earth. Some viruses, called bacteriophages, even infect bacteria. Bacteria – Bacteria are ten to 100 times larger than viruses. They are typically 1 to 3 microns in length and take the shape of a sphere or rod. Most bacteria consist of a ring of DNA surrounded by cellular machinery, all contained within a fatty membrane.
They acquire energy from the same essential sources as humans, including sugars, proteins, and fats. Some bacteria live and multiply in the environment while others are adapted to life within human or animal hosts. Some bacteria can double in number every fifteen minutes while others take weeks or months to multiply. Bacteria cause many types of diseases, ranging from mild skin irritation to lethal pneumonia. Parasites – Parasites are part of a large group of organisms called eukaryotes. Parasites are different from bacteria or viruses because their cells share many features with human cells including a defined nucleus.
Parasites are usually larger than bacteria, although some environmentally resistant forms are nearly as small. Some parasites only replicate within a host organism, but some can multiply freely in the environment. Parasites can be made of one cell, as in the case of Giardia, or many cells, as with parasitic worms. Fungi – Fungi are diverse in terms of their shape, size and means of infecting humans. Fungi are eukaryotes, meaning that like parasites, their cells have a true nucleus and complex internal structures. They are most commonly found as environmentally resistant spores and molds, but can cause disease in humans in the form of yeasts.
Fungi most often cause skin infections and pneumonia. Fungal diseases are particularly dangerous to immunocompromised people, such as those suffering from AIDS. 1. 2 Identify common illnesses and infection caused by bacteria, viruses, fungi and parasites Common illnesses ad infection from bacteria, viruses, fungi and parasites Viruses: – common colds, Hepatitis, Herpes, and Rabies Bacteria: – Salmonella, Chlamydia, Gonorrhoea and E. coli Parasites: – Malaria, Amoebic dysentery and Toxoplasmosis.
Fungi: – Athlete’s foot, jock itch, and ringworm 1. 3 Describe what is meant by infection and colonisation An infection means that germs are in or on the body and make you sick, which results in signs and symptoms such as fever, pus from a wound, a high white blood cell count, or pneumonia. Germs can also be in or on the body, but not make you sick this is called colonization. People who are colonized will have no signs or symptoms they feel fine. 1. 4 Explain what is meant by systemic infection and localised infection Localized infections remain in one part of the body.
Examples include a cut on the hand that gets infected with bacteria, but does not cause problems anywhere else. Localized infections can be very serious if they are internal, such as in the appendix or in the heart. Systemic infections most serious infections, however, occur when the microorganisms spread throughout the body, usually in the bloodstream. These are called systemic infections, and they include flu, malaria, AIDS, tuberculosis, plague, and most of the infectious diseases whose names are familiar. 1.
5 Identify poor practices that may lead to the spread of infection Poor practice that could lead to the spread of infection could be from Poor staff training, not washing hands properly, not washing them at all, poor infection control 2. 1Explain the conditions needed for the growth of micro-organisms In the correct conditions with warmth, moisture and nutrients bacteria can multiply rapidly. The human body can provide these conditions for bacteria to multiply, for example in a cut. Each bacterium splits into two up to every 20 minutes.
So, after one hour a single bacterium could have reproduced to give eight bacteria. 2. 2Explain the ways an infective agent might enter the body There are many different ways that infectious organisms can potentially enter the human body. The respiratory system – The infectious organisms that cause communicable diseases such as the common cold, the flu, and pneumonia enter the body through the nose, and then start multiplying. If they’re not treated right away, they can cause additional problems. The digestive system – Some infectious organisms are found in food, such as the organisms that cause food poisoning.
If the food isn’t cooked long enough or at a high enough temperature to kill these organisms, they enter the body through the digestive system and can make you sick when the body starts trying to digest the tainted food. If you suspect you have food poisoning, it’s important that you get treated right away, because some forms of food poisoning can be fatal if they’re left untreated. Penetrating through the skin – Infections organisms that cause sicknesses like tetanus and hepatitis C enter the body through the skin.
Once they’ve entered the body through the skin, they start multiplying and can cause more serious problems if you don’t get treatment as soon as you start noticing symptoms. Sexual transmission – Some infections, such as the ones that cause sexually-transmitted diseases like HIV and gonorrhea, are transmitted through body fluids such as semen. Once the infected body fluid enters the body, the infection multiplies and can cause complications if it’s not treated right away. Contact with animals – if you come in contact with an animal, such as a dog that’s infected with rabies, the virus can enter your body through the skin.
If you suspect you’ve contracted an infection from being around an animal, make sure you’re treated immediately. Transferred from mother to child – If a woman is pregnant, she may transfer certain infections such as Rubella, or German measles, to her child without realizing it. That’s why it’s important for children to get vaccinated against diseases such as measles, mumps and rubella. 2. 3Identify common sources of infection The source of infection is the location from which a host acquires the infection, either endogenous or exogenous. This means that a source usually can be identified in a specific place, and a specific time.
A person can be a source of infection, objects, Inanimate sources and animals can be sources of infection. 2. 4Explain how infective agents can be transmitted to a person Infective agents can be transmitted to a person several ways for example, by piercing the skin and letting germs enter by inhaling it you can absorb some things through the skin through having sex with infected person injected deep into muscle, through infected needles or other sharp objects infected through contaminated IVs ingest (eat) something that has infectious germs Urinary tract infections by wiping the wrong way with soiled toilet tissue.
vaginal infections by wiping the wrong way with soiled toilet tissue 2. 5Identify key factors that will make it more likely that infection will occur An infection is more likely to occur when a person has a low immunity or is on long term antibiotic therapy. Poor hygiene when treating wounds or dealing with personal care can aid the transmission of infection. Some of the factors that make it more likely that an infection will occur include proximity to others either infected or uninfected people, dirty and/or contaminated areas, equipment or laundry, and contact with body fluids.