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Platyhelminthes: Characteristics and Types

Platyhelminthes are bilaterally symmetrical and triploblastic animals, in other words their left and right sides are mirror images of each other; this also implies that they have distinct top and bottom surfaces, and distinct head and tail ends. Like other bilaterians they have three main cell layers, while the radially symmetrical cnidarians and ctenophores “(comb jellies)” have only two cell layers. Unlike other bilaterians, platyhelminthes have no internal body cavity and are therefore described as acoelomates. They also lack specialized circulatory and respiratory organs. Their bodies are soft and unsegmented.
Features common to all sub-groups The lack of circulatory and respiratory organs limits platyhelminths to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so that nutrients can diffuse to all parts of the body. Respiration through the whole surface of the body makes platyhelminthes vulnerable to fluid loss, and restricts them to environments where dehydration is unlikely: sea and freshwater; moist terrestrial environments such as leaf litter or between grains of soil; and as parasites within other animals.
The space between the skin and gut is filled with mesenchyme, a connective tissue that is made of cells and reinforced by collagen fibers that act as a type of skeleton, providing attachment points for muscles. The mesenchyme contains all the internal organs and allows the passage of oxygen, nutrients and waste products. It consists of two main types of cell: fixed cells, some of which have fluid-filled vacuoles; and stem cells, which can transform into any other type of cell, and are used in regenerating tissues after injury or asexual reproduction. Also they have epidermal cells that are typically multiciliated, each cell bearing multiple cilia rather than only one.
Most platyhelminths have no anus and regurgitate undigested material through the mouth. However, some long species have an anus and some with complex branched guts have more than one anus, since excretion only through the mouth would be difficult for them. The gut is lined with a single layer of endodermal cells which absorb and digest food. Some species break up and soften food first by secreting enzymes in the gut or pharynx.
All animals need to keep the concentration of dissolved substances in their body fluids at a fairly constant level. Internal parasites and free-living marine animals live in environments that have high concentrations of dissolved material, and generally let their tissues have the same level of concentration as the environment, while freshwater animals need to prevent their body fluids from becoming too dilute. Despite this difference in environments, most platyhelminths use the same system to control the concentration of their body fluids. Flame cells, so called because the beating of their flagella looks like a flickering candle flame, extract from the mesenchyme water that contains wastes and some re-usable material, and drive it into networks of tube cells which are lined with flagella and microvilli. The tube cells’ flagella drive the water towards exits called nephridiopores, while their microvilli re-absorb re-usable materials and as much water as is needed to keep the body fluids at the right concentration. These combinations of flame cells and tube cells are called protonephredia.
In all platyhelminths the nervous system is concentrated at the head end. This is least marked in the acoels, which have nerve nets rather like those of cnidarians and ctenophores, but densest around the head. Other platyhelminths have rings of ganglia in the head and main nerve trunks running along their bodies
Classification Traditional invertebrate zoology divides the platyhelminthes into four groups:
Turbellaria, Trematoda, Monogenea and Cestoda. In this classification Turbellaria includes the Acoelomorpha.
Turbellaria These have about 4,500 species, are mostly free-living, and range from 1 mm (0.039 in) to 600 mm (24 in) in length. Most are predators or scavengers, and terrestrial species are mostly nocturnal and live in shaded humid locations such as leaf litter or rotting wood. However, some are symbiotes of other animals such as crustaceans, and some are parasites. Free-living turbellarians are mostly black, brown or gray, but some larger ones are brightly colored.
Turbellarians have no cuticle (external layer of organic but non-cellular material). In a few species the skin is a syncitium, a collection of cells with multiple nuclei and a single shared external membrane. However the skins of most species consist of a single layer of cells, each of which generally has multiple cilia (small mobile “hairs”), although in some large species the upper surface has no cilia. These skins are also covered with microvilli between the cilia. They have many glands, usually submerged in the muscle layers below the skin and connect to the surface by pores through which they secrete mucus, adhesives and other substances.
Small aquatic species use the cilia for locomotion, while larger ones use muscular movements of the whole body or of a specialized sole to creep or swim. Some are capable of burrowing, anchoring their rear ends at the bottom of the burrow and then stretching the head up to feed and then pulling it back down for safety. Some terrestrial species throw a thread of mucus which they use as a rope to climb from one leaf to another.
Most turbellarians have pigment-cup ocelli (“little eyes”), one pair in most species but two or even three pairs in some. A few large species have many eyes in clusters over the brain, mounted on tentacles, or spaced uniformly round the edge of the body. The ocelli can only distinguish the direction from which light is coming and enable the animals to avoid it. A few groups – mainly catenulids, acoelomorphs and seriates – have statocysts, fluid-filled chambers containing a small solid particle or, in a few groups, two. These statocysts are thought to be balance and acceleration sensors, as that is the function they perform in cnidarian medusae and in ctenophores. However, turbellarian statocysts have no sensory cilia, and it is unknown how they sense the movements and positions of the solid particles. On the other hand most have ciliated touch-sensor cells scattered over their bodies, especially on tentacles and around the edges. Specialized cells in pits or grooves on the head are probably smell-sensors.
Planaria, a sub-group of seriates, are famous for their ability to regenerate if divided by cuts across their bodies. Experiments show that, in fragments that do not already have a head, a new head grows most quickly on those that were closest to the original head. This suggests that the growth of a head is controlled by a chemical whose concentration diminishes from head to tail. Many turbellarians clone themselves by transverse or longitudinal division, and others, especially acoels, reproduce by budding.
All turbellarians are hermaphrodites, in other words have both female and male reproductive cells, and fertilize eggs internally by copulation. In most species “miniature adults” emerge when the eggs hatch, but a few large species produce plankton-like larvae.
Digenea These are often called flukes as most have flat rhomboid shapes like that of a flounder. They have about 11,000 species. Adults usually have two holdfasts, a ring round the mouth and a larger sucker midway along what would be the underside in a free-living flatworm. Although the name “Digeneans” means “two generations”, most have very complex lifecycles with up to seven stages, depending on what combinations of environments the early stages encounter – most importantly whether the eggs are deposited on land or in water. The intermediate stages transfer the parasites from one host to another. The definitive host in which adults develop is a
Life cycle of a fluke
land vertebrate, the earliest host of juvenile stages is usually a snail that may live on land or in water, and in many cases a fish or arthropod is the second host. For example, the adjoining illustration shows the life cycle of the intestinal fluke metagonimus, which hatches in the intestine of a snail; moves to a fish where it penetrates the body and encysts in the flesh; then moves to the small intestine of a land animal that eats the fish raw; and then generates eggs that are excreted and ingested by snails, thereby completing the cycle.
Adults range between 0.2 mm (0.0079 in) and 6 mm (0.24 in) in length. Individual adult digeneans are of a single sex, and in some species slender females live in enclosed grooves that run along the bodies of the males, and partially emerge to lay eggs. In all species the adults have complex reproductive systems and can produce between 10,000 and 100,000 times as many eggs as a free-living flatworm. In addition the intermediate stages that live in snails reproduce asexually.
Adults of different species infest different parts of the definitive host, for example the intestine, lungs, large blood vessels, and liver. The adults use a relatively large, muscular pharynx to ingest cells, cell fragments, mucus, body fluids or blood. In both the adults and the stages that life in snails, the external syncytium absorbs dissolved nutrients from the host. Adult digeneans can live without oxygen for long periods.
Major organs and systems in an adult Chinese liver fluke Aspidogastrea
Members of this small group have either a single divided sucker or a row of suckers that cover the underside. They infest the guts of bony or cartilaginous fish and of turtles, and the body cavities of marine and freshwater bivalves and gastropods. Their eggs produce ciliated swimming larvae, and the life-cycle has one or two hosts.
This group of parasites attach themselves to the host by means of disks that bear crescent-shaped hooks. They are divided into Monogea and Cestoda.
There are about 1,100 species of monogeans. Most are external parasites that require particular host species, mainly fish but in some cases amphibians or aquatic reptiles. However, some are internal parasites. Adult monogeans have large attachment organs at the rear, haptors (haptein, means “catch”), which have suckers and hooks. To minimize water-resistance they have flattened bodies. In some species the pharynx secretes enzymes that digest the host’s skin, allowing the parasite to feed on blood and cellular debris. Others graze externally on mucus and flakes of the host’s skin. The name “Monogenea” is based on the fact that these parasites have only one non-larval generation.
Lifecycle of the eucestode Taenia. Inset 5 shows the scolex, which has 4 suckers round the sides and, in Taenia solium, a disk with hooks on the end. Inset 6 shows the tapeworm’s whole body, in which the scolex is the tiny round tip in the top left corner, and a mature proglottid has just detached.
These are often called tapeworms because of their flat, slender but very long bodies – the name “cestode” is derived from the Latin word cestus, which means “tape”. The adults of all 3,400 cestode species are internal parasites in the organs of vertebrates, including fish, cats, dogs and humans. The head is generally tiny compared to the size of the whole animal, and forms a scolex that attaches the parasite to the lining of the host’s gut. The commonest type of scolex has four suckers round the sides and a disk equipped with hooks at the end.
Cestodes have no mouths or guts, and the syncitial skin absorbs nutrients – mainly carbohydrates and amino acids – from the host, and also disguises it chemically to avoid attacks by the host’s immune system. Shortage of carbohydrates in the host’s diet stunts the growth of the parasites and kills some. Their metabolisms generally use simple but inefficient chemical processes, and the parasites compensate by consuming large amounts of food relative to their size.
In the majority of species, known as eucestodes (“true tapeworms”), the neck produces a chain of segments called proglottids by a process known as strobilation.
-Major organs and external structures along the length of a tapeworm
Hence the most mature proglottids are furthest from the scolex. Adults of Taenia saginata, which infests humans, can form proglottid chains over 20 metres (66 ft) long, although 4 metres (13 ft) is more typical. Each proglottid has both male and female reproductive organs. If the host’s gut contains two or more adults of the same cestode species, they generally fertilize each other; but proglottids of the same worm can fertilize each other and even fertilize themselves. When the eggs are fully developed, the proglottids separate and are excreted by the host. The eucestode life-cycle is less complex than that of digeneans, but varies depending on the species. For example:
Adults of Diphyllobothrium infest fish, and the juveniles use copepod crustaceans as intermediate hosts. Excreted proglottids release their eggs into the water, and the eggs hatch into ciliated swimming larvae. If a larva is swallowed by a copepod, it sheds the cilia and the skin becomes a syncitium and the larvae makes its way into the copepod’s hemocoel (internal cavity that is the main part of the circulatory system) and attached itself with three small hooks. If the copepod is eaten by a fish, the larva metamorphoses into a small, unsegmented tapeworm, drills through to the gut and becomes an adult.
Various species of Taenia infest the guts of humans, cats and dogs. The juveniles use herbivores – for example pigs, cattle and rabbits – as intermediate hosts. Excreted proglottids release eggs that stick to grass leaves and hatch after being swallowed by a herbivore. The larva makes its way to the herbivore’s muscles and metamorphoses into an oval worm about 10 millimetres (0.39 in) long, with a scolex that is kept inside. When the definitive host eats infested and raw or undercooked meat from an intermediate host, the worm’s scolex pops out and attaches itself to the gut, and the adult tapeworm develops.
A smaller group, known as Cestodaria, have no scolex, do not produce proglottids, and have body shapes like those of diageneans. Cestodarians parasitize fish and turtles.
Interaction with humans Parasitism
Magnetic resonance image of a patient with neurocysticercosis demonstrating multiple cysticerci within the brain.
Cestodes (tapeworms) and digeneans (flukes) cause important diseases in humans and their livestock, and monogeneans can cause serious losses of stocks in fish farms.[20] Schistosomiasis, also known as bilharzia or snail fever. It is a chronic illness that can damage internal organs. It can impair the growth and cognitive development of children, and increase the risk of bladder cancer in adults. The disease is caused by several flukes of the genus Schistosoma, which can bore through human skin. The people most at risk are those who use infected bodies of water for recreation or laundry.
In Hawaii the planarian Endeavouria septemlineata has been used to control the imported giant African snail Achatina fulica, which was displacing native snails, and Platydemus manokwari.P. manokwari is given credit for severely reducing and in places exterminating A. fulica – achieving much greater success than most biological pest control programmes.

Infections: Types, Causes and Prevention

Health care professionals share the responsibility of preventing the spread of infection between themselves and clients and between clients.
Clients at health facilities are more at risk than the rest of the people
Sources of infecting microorganisms can be people or environmental objects, such as medical or nursing equipment that has become contaminated
What is an infection?
An infection is the growth of a parasitic organism within our body. In other words a person with an infection has another organism growing within him, drawing its nourishment from the person.
Infective diseases that are readily communicable from person to person are called infectious or contagious
Normal Flora- microorganisms found on or in the body that do not cause any infection
What is a microorganism?
Microorganisms are forms of animal or plant life too small to be seen without the aid of a microscope.
One of three events occur when a microorganism invade the human body:
Microorganism are destroyed by the body’s immune defence mechanisms
Microorganisms stay within the body and cause diseases
Microorganisms cause infection or an infectious disease
Causes of Infection An infection can be caused by:
A microorganism smaller than bacteria
Cannot grow or reproduce apart from a living cell.
Invades living cells and uses their chemical machinery to keep itself alive and to replicate itself.
It may reproduce with fidelity or with errors (mutations)-this ability to mutate is responsible for the ability of some viruses to change slightly in each infected person, making treatment more difficult.

How can viruses be cured?
Many viruses cannot be cured with drugs; you just have to wait until your immune system gets strong enough to fight the virus. Viruses like the flu can not be cured by antibiotics
Can you be immune to them?
Yes, if your body can protect itself against a virus, you are immune to it. You also can create immunity after you suffered from a virus infection.
You can also have a vaccine (like the polio vaccine) and this can protect you against catching the polio virus. Each vaccine only protects you against that particular virus
A simple living thing that is made up of single cells and that have the capacity to reproduce rapidly , this microorganism can exist either as independent (free-living) organisms or as parasites (dependent upon other organism for life).
Bacteria can be 100 times bigger than viruses. They work differently from viruses, but like viruses, they can make you ill.
Some bacteria can infect open wounds, others can get inside your body by being eaten or breathed in as in the case of infections such as bronchitis or strep throat
Some species of bacteria have the ability to develop highly resistant round or oval structure, called spores, when they are exposed to adverse conditions such as lack of nutrients and /or water
Spores are resistant to disinfectants and to high or low temperatures, so they are difficult to destroy. They are resistant to sunlight and even freezing conditions so many remain viable in adverse environments for many years until the right conditions arise and they multiply again

How can they be cured?
Bacteria can be killed by antibiotics; some bacteria have become immuned to antibiotics, which in turn make these bacteria difficult to kill.
Can you be immune to them?
Yes, if your body can protect itself against bacteria, you are immune. You can have a vaccine (like the tetanus vaccine) and this can protect you against catching that bacteria. Each vaccine only protects you against those particular bacteria.
Tiny organisms that belong to the world of plants but contain no chlorophyll.
Fungi are present in the soil, air and water and they multiply by producing various kinds of spores
There are three types of fungal infections: superficial, which affect the skin, mucous membranes, hair and nails; intermediate, which affects subcutaneous tissues; and systemic, which infect deep tissues and organs
Fungi like wet conditions and are most likely associate with skin infections and do not get inside your body .
An example of common fungus is the yeast
Fungi are also used for the development of antibiotics.
Another example of fungi’s infection is athlete’s foot
How can they be cured? Anti fungal drugs, powders or creams get rid of fungal infections
Can you be immune to them? There are no vaccines for fungal infections but there are ways you can prevent them. For example, by making sure you dry between your toes to prevent athlete’s foot, as fungi like damp, warm conditions
An organism that lives in or takes its food from another organism. A parasite can not live independently. An examples of a common parasites is the lice
Parasites are usually classified as: endoparasites (usually living inside the body of the host), and ectoparasites usually live on the surface of the host.
Occasionally the definition of “parasitic disease” is restricted to diseases due to endoparasites.
Humans can get parasites from contaminated food or water, bug bites or sexual contact.
Parasites normally enter the body through the skin or mouth.
Close contact with pets can lead to parasite infestation as dogs and cats are host to many parasites.
Other risks that can lead people to get parasites are walking barefoot, inadequate disposal of faeces lack of hygiene, close contact with someone who carries specific parasites, eating undercooked or exotic foods.
Common parasites of the human body
(1) The hookworm latches on the walls of the colon with its sharp teeth where it feeds on blood.
(2) The tapeworm is the longest parasite. A mature adult can lay a million eggs a day.
(3) Tapeworm eggs embedded in the colon. (4)
The roundworm can grow to be 20 inches (50 cm) long and lay 200,000 eggs per day.
(5) Pinworms migrate outside the colon during the night to lay their eggs around the anus. This causes the nightly itching of many unsuspecting victims.
How can they be cured? There are different treatments depending upon the type of parasite. For example, lice can be treated with special shampoos or by combing the hair with a special comb
Can you be immune to them? No, there are no vaccines for parasites. There are ways you can reduce your chances of catching parasites. You can avoid contact with people who have head lice, or avoid sharing equipment such as hairbrushes
Passing and preventing infections The process of the spread of infection can be conceived as a chain of events. Each event is a link in the chain and must occur sequentially for an infection to develop.
For the chain of events to continue, the following elements must be present:
Reservoir, pathogenic organisms , portal of exit from the reservoir, mode of transmission, portal of entry to the new host, and susceptible new host
Importantly, infection prevention and control is directed towards breaking the links n the chain of infection
Chain of infection
Chain of infection/ Reservoir
The reservoirs of pathogenic microorganism are human, animal or inanimate sources. A reservoir is a place where a pathogen can survive but may or may not multiply.
Human reservoir: variety of microorganism (normal flora) reside on the surface of the skin or within body cavities, fluids and discharges, when this normal flora is transferred from their normal place of residence to a different site in the same host an auto-infection may occur
Cross infection may occur when organisms form one person are transferred to another person.
A person incubating a disease is another source of infection.
During the incubation period the organisms multiply and can be transmitted and infect others before the host or anyone else knows the disease is present.
Health care professionals therefore should treat every client as if they were a potential sources of infection
Animal reservoir: animals, birds and insects (vectors) can also be reservoirs for infectious microorganisms example: malaria.
Inanimate reservoir : soil, seawater, food, water and milk are additional reservoirs for microorganism.
Chain of infection / Portal of exit
Portal of exit from the reservoir:
if microorganisms are to enter another host and cause disease, they must first find a portal of exit, then a new site in which to reside .
Chain of infection / Portal of exit
Portal of exit from the reservoir:
When the human body is the reservoir , microorganisms can exit through a variety of sites such as:
Skin and mucous membranes
Gastrointestinal tract: saliva, expectorated sputum, faeces, vomitus, bile
Urinary tract
Respiratory tract: sneezing, coughing, talking or even breathing .
Reproductive tract : semen, vaginal discharge
Blood: blood is normally sterile but, when a client has blood borne infectious disease such as hepatitis B or C or AIDS, it becomes a reservoir for the causative pathogens . Any break in the skin that allows blood to escape, and menstrual blood from the vagina, are portals of exit for blood-borne pathogens.
Chain of infection/ Modes of transmission
Microorganisms move from a reservoir to a new host in a variety of ways. Disease may be transmitted via :
Airborne (inhalation)
Contact (touching)
Indirect Contact
* Some microorganisms may be spread by more than one route
Airborne transmission
it may occur via either airborne droplet or dust particle.
Tiny pathogens can be carried on airborne particles such as dust, water, and respiratory droplets and, if inhaled by a susceptible host, cause infection .
Examples of illnesses spread by this via are measles, rubella, influenza, pneumonia, meningitis, tuberculosis and polio.
Some of these diseases can be also spread by other means
Droplets of moisture that contain organism do not have to be inhaled to spread infection.
They contaminate all surfaces on which they fall, so transmission can occur via indirect contact
How to prevent passing on this type of infection:
Avoiding close contact with an infected person is the best way to avoid airborne infections
Covering the mouth and nose when coughing or sneezing can decrease the spread of infection
Avoid close contact with people in crowed or enclosed spaces such as shopping malls
Wearing a mask may help reduce spread of infection for short exposures.
Contact transmission
This is the most significant route of transmission in health care setting .
Microorganisms can be transferred directly from one individual to another by physical contact between an infected person and a new host, or throughout the use of contaminated equipment.
The hands can be the means of transfer if, after contact with an infectious client, they are not washing adequately before attending another client .
Effective hand washing is the single most important way to prevent the spread of infections.
Direct contact
How to prevent passing on this type of infection:
Good hand washing
Avoid direct contact with an infected person
Use barriers such as gloves for contact with infected skin and body fluids
Condoms prevent the spread of sexually transmitted diseases
Indirect contact
Contact with objects that are infected such as doorknobs, handrails, tables, counter tops, taps, cups, cutlery, computer keyboards, telephones, pens and children’s toys.
Infections that can be passed in this way include: Chicken pox, colds, conjunctivitis.
How to prevent passing on this type of infection:
Frequent hand washing, especially before touching the face , eyes, mouth, or nose with your hands
Using gloves when handling things that may be infected
Frequent disinfecting and not sharing personal items (cups, cutlery, combs, or towels)
Transmission by ingestion
Microorganism can enter the gastrointestinal tract in a variety of ways, including via infected food or water or contaminated eating or drinking utensils
Example of a disease transferred in this way is the cholera.
Vector borne transmission (via mosquitoes ,flies, rats and other animals) as a health concern is not as significant in Australia and New Zealand .
The most common example of a disease spread in this way is the malaria.
Chain of infection/ Portals of entry
Microorganisms can enter the body through the same routes they use for exiting:
Inhalation into the respiratory tract
Inoculation through the skin or mucous membrane
Chain of infection/ Susceptible host
Susceptibility the degree of resistance an individual has to pathogens. Whether a person acquires an infection depends on their susceptibility to the infectious agent.
A susceptible host is the last link in the chain of infection
Susceptibility can be reduced by lifestyle practices that boost resistance, such as healthy nutrition, adequate exercise, rest and sleep and effective hygiene practices among other.
Body Flora
Microbes live on our bodies
Normal flora
Flora are different in different areas
Balance can be disturbed. E coli is normally found in the intestines, however, there are types of E. Coli that can cause diarrhea and can even lead to kidney failure.
E. Coli infection is common during summer and complications are likely to occur on elderly and children population.
Reduce problems by
Attention to health
Natural Body Defenses
Mucous membranes
Intact skin
Stomach acid, saliva enzymes
Hair in nose, eyelashes
White blood cells
Ability to fight off disease
Pathogenic microbe enters body
Body responds by producing antibodies
Weak immune system
Points to Consider for older Adults:
There is a decrease in the function of immune system and and slowed response to treatment in older adults.
There is a marked physical change that may increased easy access of infection into the body such as atrophic skin, decreased gastric acid, decreased cough reflex, etc…
Slower cellular response due to decreased protein reserves and serum albumin resulting to slow healing of wounds.
Changes in mental status and decreased functional ability resulting to limited ability to use preventive health practices to improve resistance to infection.
Protection from pathogens
Vaccines are weak antigens
Make body produce antibodies
Prevent childhood diseases
Vaccinations How vaccines work:
A. Vaccines contain antigens (weakened or dead viruses, bacteria, and fungi that cause disease and infection). When introduced into the body, the antigens stimulate the immune system response by instructing B cells to produce antibodies, with assistance from T-cells.
B. The antibodies are produced to fight the weakened or dead viruses in the vaccine.
C. The antibodies practice on the weakened viruses, preparing the immune system to destroy real and stronger viruses in the future.
D. When new antigens enter the body, white blood cells called macrophages engulf them, process the information contained in the antigens, and send it to the T-cells so that an immune system response can be mobilized.
Bacterial Infections
Culture and sensitivity
Antibiotic use and misuse
Antibiotic resistance
Methicillin-resistant Staphylococcus aureus (MRSA)
Vancomycin-resistant enterococcus (VRE)
MRSA: is an infection caused by Staphylococcus aureus that has become resistant to antibiotics that are used to treat a common infection.
Most people that are infected with MRSA are those who stay long in the hospital, people who lives in a resthome,people who are having dialysis.
VRE: Vancomycin Resistant Enterococcus. This entero coccus acquire a special DNA called plasmid.These VRE can invade the bloodstream or spread locally.Once in the bloodstream,it may cause meningitis, pneumonia orendocarditis
Other Bacterial Infections
Strep A:
high mortality
Found in water
E. coli:
Normal in intestines; if found in food it is likely from poor food prep
Other Bacterial Infections
Food poisoning
Mycobacterium tuberculosis:
Clostridium difficile:
Normal in bowel, severe diarrhea in elderly on antibiotics
Infection control and prevention
The basic principles employed in preventing the spread of infection are the same in all situations, regardless of whether clients are cared for the community, in aged cared facilities, in day clinics or in hospitals.
Standard precautions, are the basic recommended work practices to be implemented in the treatment and care of all clients regardless of diagnosis or presumed infectious status
Infection control and prevention / Standard precautions
Standard precautions are the first approach to infection control. Additional precautions form the second tier and are used in situations in which clients are known or are suspected as being infected with pathogens that may not be contained by the use of standard precautions
Standard precautions mean placing a barrier between yourself and someone else’s: Body fluids, secretions and excretions ( except sweat), non intact skin and mucous membranes
Body fluids include:
Breast milk
Nasal secretions
Vaginal secretions
Human tissue
Wound exudates/pus
Cerebrospinal, pleural, pericardial, synovial, peritoneal, and amniotic fluids
Standard precautions relate to:
Effective hand hygiene
Use of personal protective equipment such as gloves, gowns, masks or eye protection when appropriate
Safe systems for the handling of blood and all other body fluids
The safe handling of no-intact skin and mucous membranes
Hand hygiene
Hand hygiene is the most important way to prevent the spread of infection and includes washing of hands or the use of alcohol hand rubs
Micro-organisms: can be picked up from body fluids or objects in the home. They stick to the skin on your hands and then are passed on to other people. Skin is you body’s first line of defence against infection. If your skin is broken or damaged, your risk of infection increases.
When to wash your hands with soap and water:
When visibly dirty
When soiled with blood and other body fluids
After using the toilet
If alcohol-based hand rub is not available
When alcohol-based hand rub is indicated
In all other clinical situations, use alcohol-based hand rub and if hands are not visibly soiled
Soap and alcohol-based hand rub should not be used together
When you start to work
When you finish work
Before and after you have contact with each consumer
After contact with any body fluids such as blood or urine
‘After contact with mucous membranes, broken skin or skin rashes or infections
After touching contaminated items such as soiled sheets
After removing gloves
After using the toilet or changing incontinence pads
Before preparing food, eating or feeding
After touching animals
Whenever your hands look dirty
Between consumers visits
Food handling- between different food types
Before and after giving medications
After applying creams
Handling chemicals
The uses of gloves do not replace the need for washing your hands
Hand hygiene
In addition to washing, care of the hands involves:
Covering any broken or infected areas of the skin with a waterproof dressing
Wearing disposable gloves to protect larger skin lesions
Keeping fingernails clean and short and not wearing artificial nails
Keeping the skin free from cracks. If frequent immersion in water results in skin dryness, a good quality hand cream should be used
Hand hygiene procedure
Hand washing steps
Remove watched or jewellery and roll your sleeves up to your elbow
Wet your hands and wrists with warm water ( very hot water can dry your skin)
Place a small amount of soap on your hands
Rub your hands together to form lather. Make sure you clean under your fingernails, around and between your fingers and your fingertips and thumbs
Wash for 10-15 seconds
Rinse your hands well using plenty of warm running water ( removing all the soap reduces irritation from washing your hands often)
Pat your hands dry with a towel, or paper towels. Do not rub as its can damage your skin. Dry your hands thoroughly
If you can, use the towel to turn off the tap, so you do not contaminate your clean hands
Hand hygiene procedure
Tips for using alcohol based hand rubs:
Check hands for visible soil or blood/ body fluids. It is alright to use a hand rub if there is no visible soiling.
Apply a small amount of alcohol gel( about the size of a ten cent piece ) to the palm of one hand and rub hands together
Cover all surfaces of hands and fingers including areas around and under fingernails
Continue rubbing hands together until alcohol dries ( about 15-25 seconds)
Make sure hands are complete dry prior to putting on gloves or supporting a consumer
You need to wash your hands with soap and water when it fells sticky on the hands
Personal protective equipment
In accordance with standard precautions, personal protective equipment (PPE) is used with all clients when there is potential to come in contact with body substances or airborne microorganisms
PPE equipment refers to gloves, aprons/gowns, masks and protective eyewear or face shields
Disposable gloves
Purpose: to prevent the transfer of body fluids, dirt and microorganisms from person to person by the correct use of latex/plastic disposable unpowered gloves
When to use disposable gloves:
Gloves are worn for anticipated contact with blood, secretions, mucous membranes, non intact skin and moist body substances for all patients
Gloves must be changed between client procedure and after each client
Contaminated gloves should always be removed immediately after the task is completed and in such a way that the contaminated outside surfaces are enveloped within the inside surfaces
Gloves should not be reused
Gloves that are not intact or discoloured should not be use
Gloves must be used when touching contaminated items such as bed linen and continence products
Gloves should be removed before touching items such as doorknobs, light switches, telephones, medication trolley .
You should also use gloves when you are cleaning, especially commodes, shower chairs and urinals
You should use a new pair of gloves if the gloves become soiled
Important to wear gloves when you are handling continence products and sanitary napkins, which should be placed in a double plastic waterproof bag, sealed and then put in the rubbish bin
PPE/ Gowns and Aprons
These are required when procedures are likely to generate splashing of body fluids
Or when contact between the resident’s body / clothing/linen items and the health professional may not be able to be avoided
Gowns and aprons need to be disposable and used once only
Gowns and aprons need to be changed between clients
Gowns and aprons will not be stored in clients’ room
Aprons/Gowns must be worn when attending the following procedure:
Cleaning soiled/wet linen, clothes
Emptying bed pans, bowels, urinals, and vomit
Emptying / cleaning suctioning equipment, blood, I.V. equipment
PPE/Face protection devices
Depending on the mode of transmission, health care workers may wear a mask, goggles or face shield
Face mask are worn to prevent the spread of microorganisms from the respiratory tract of a client to a healthcare worker or from a healthcare worker to a client
Disposable masks are worn and discarded immediately after use and hands should be washed and dried after mask is removed
When a mask is used it must:
Be handled only by the tapes or loops at either end
Cover the nose and mouth completely
Not be allowed to hang around the neck
Be changed as soon as it becomes damp, as moisture allows microorganism s to pass through the mask
Protection devices
Protective eyewear/ face shields: ( face protection device) to be use if there is a risk of splash of blood or other body fluid
Hats: To protect your hair when you might get splashed or sprayed with blood or body fluids, or to prevent hair contaminating food or a consumer with a open wound. Hats may also be used when the person you are supporting has lice.
Infection control disposal
It is important to dispose of certain things, such as body fluids , wound dressings, suction or drainage, I.V therapy equipment, wet or soiled incontinence pads, or contaminated items in the proper manner
How to dispose body fluids :
Always use gloves when handling body fluids
Urine and faeces should be flushed down the toilet
Blood can also be flushed down the toilet
How to dispose body fluids :
Any items contaminated with body fluids , such as, bed linen, should be rinsed in the laundry sink with cold water before being washed with hot water in the washing machine. The item should be washed separately from other washing or according with the organisation P