Unit VII-A: Asepsis and Infection Control PDF

### Unit VII-A **Asepsis and Infection Control** **(6** **hours)** **Introduction** Microorganisms are always present in the environment. Some live on the skin, others are common inhabitants of the intestinal tract and others are found among other places, in the air, in the soil, in articles an...

### Unit VII-A **Asepsis and Infection Control** **(6** **hours)** **Introduction** Microorganisms are always present in the environment. Some live on the skin, others are common inhabitants of the intestinal tract and others are found among other places, in the air, in the soil, in articles and equipment in the hospital and on our clothes. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Therefore, knowledge of asepsis and an awareness of how microorganisms are transmitted are essential for safe nursing care environment -------------------------------------------------------------------------------------------------------------------------------------- Infections pose severe problems to people at home, in the community, and in the health care facilities. They have great impact on the health status of people in varying ages. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Furthermore, infections cause great economic burden because treatments and medications are becoming uncontrollably expensive. ----------------------------------------------------------------------------------------------------------------------------- Therefore, ASEPSIS and INFECTION CONTROL, in any health care setting should be an onerous effort among health care workers, especially among us, health workers. In this unit, you will learn the Concept on Asepsis and Infection Control, Terminologies, Stages of Infectious Process, Chain of Infection, Types of Immunization and breaking the chain of infection. -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------  **Learning Outcomes** - Apply Asepsis and Infection Control in dealing with clients/patients in any setting. **Presentation of Contents** **[TOPIC 1. ASEPSIS AND INFECTION CONTROL]** ======================================================== TERMINOLOGIES: Health and Illness Asepsis and Infection Control =============================================================== **Infection --** an invasion of the body tissue by microorganisms and their proliferation there. ------------------------------------------------------------------------------------------------ **Asepsis --** the absence of disease-producing microorganisms. Being free from infection. or --------------------------------------------------------------------------------------------- **Asepsis** is the state of being free from disease-causing contaminants (such as bacteria, viruses, fungi, and parasites) or, preventing contact with microorganisms. The term asepsis often refers to those practices used to promote or induce asepsis in an operative field in surgery or medicine to prevent infection. **Medical Asepsis-** practices designed to reduce the number and transfer of pathogens or **clean technique**. -------------------------------------------------------------------------------------------------------------- 1. Includes all practices intended to confine a specific microorganism to a specific area 2. Limits the number, growth, and transmission of microorganisms 3. Objects referred to as clean or dirty (soiled, contaminated) **Surgical Asepsis -** Practices that render and keep objects and areas free from microorganisms or **Sterile Technique** ------------------------------------------------------------------------------------------------------------------------- 1. Sterile technique 2. Practices that keep an area or object free of all microorganisms 3. Practices that destroy all microorganisms and spores 4. Used for all procedures involving sterile areas of the body. **Principles of Aseptic Technique Only sterile items are used within sterile field.** 1. Sterile objects become unsterile when touched by unsterile objects. 2. Sterile items that are out of vision or below the waist level of the health care provider are considered unsterile. 3. Sterile objects can become unsterile by prolong exposure to airborne microorganisms. 4. Fluids flow in the direction of gravity. 5. Moisture that passes through a sterile object draws microorganism from unsterile surfaces above or below to the surface by capillary reaction. 6. The edges of a sterile field are considered unsterile. 7. The skin cannot be sterilized and is unsterile. 8. Conscientiousness, alertness and honesty are essential qualities in maintaining surgical asepsis. Click on this **Medical and Surgical Asepsis** https://youtu.be/N\_FMkq4MC-U **Sepsis-** presence of infection. ---------------------------------- **Septicemia-** Transport of an infection or the products of infection, throughout the body or by blood ------------------------------------------------------------------------------------------------------- **Carrier-** a person or an animal, who is without signs of illness but who harbors pathogens within his body that can be transferred to another. ------------------------------------------------------------------------------------------------------------------------------------------------- **Contact-** a person or an animal known or believed to have been exposed to a disease. --------------------------------------------------------------------------------------- **Reservoir-** the natural habitat for the growth and multiplication of microorganisms. --------------------------------------------------------------------------------------- **Transient flora or bacteria-** the microorganisms picked up by the skin as a result of normal activities that can be removed readily. --------------------------------------------------------------------------------------------------------------------------------------- **Resident flora or bacteria-** the microorganisms that normally live on a person's skin ---------------------------------------------------------------------------------------- **Click on this Gram positive vs. Gram negative ** -------------------------------------------------------------------------------- **Sterilization**- the process by which all microorganisms including their spores are destroyed. ------------------------------------------------------------------------------------------------ **Antiseptic-** a substance, usually intended for use on persons that inhibit the growth of pathogens but not necessarily destroy them. --------------------------------------------------------------------------------------------------------------------------------------- **Example is the substance use for surgical hand washing.** ----------------------------------------------------------- The most commonly used products for surgical hand antisepsis are chlorhexidine or povidone-iodine-containing soaps. The most active agents (in order of decreasing activity) are chlorhexidine gluconate, iodophors, triclosan, and plain soap.  **Disinfectant-** a substance**,** usually intended for use on inanimate objects, that destroys pathogens but generally not the spores -------------------------------------------------------------------------------------------------------------------------------------- **Examples of items that are disinfected: surgical instruments, thermometers.** ------------------------------------------------------------------------------- Cidex Dialehyde Disinfectant Solution, Pack of 4 **Sterilants and high-level disinfectants to reduce healthcare-associated infection** 1\. **Formaldehyde**  2\. Glutaraldehyde Pro Advantage Glutaraldehyde High Level Disinfectant N099001 from 4MD Medical 3\. Ortho-phthalaldehyde 4\. **Hydrogen peroxide** 5. **Peracetic acid** 6\. **Hydrogen peroxide**/**peracetic acid** combination **Asymptomatic carrier-** (healthy carrier or just carrier) is a person or other [organism](https://en.wikipedia.org/wiki/Organism) that has become [infected](https://en.wikipedia.org/wiki/Infection) with a [pathogen](https://en.wikipedia.org/wiki/Pathogen), but that [displays](https://en.wikipedia.org/wiki/Displays) no signs or [symptoms](https://en.wikipedia.org/wiki/Symptom). ============================================================================================================================================================================================================================================================================================================================================================================================= **Bactericidal-** a chemical that kills microorganisms. ------------------------------------------------------- **Bacteriostatic**- an agent that prevents bacterial multiplication but does not kill all forms of organisms. ------------------------------------------------------------------------------------------------------------- **Contamination**- the process by which something is rendered unclean or unsterile. ----------------------------------------------------------------------------------- **Convalescent carriers** are those who have recovered from their illness but remain capable of transmitting to others. **Disinfection-** the process by which pathogens but not their spores are destroyed from inanimate objects. ----------------------------------------------------------------------------------------------------------- **Communicable Disease-** results if the infectious agent can be transmitted to an individual by direct or indirect contact through a vector or vehicle, or as an airborne infection. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Incubatory carriers** are those who can transmit the agent during the **incubation** period before clinical illness begins. **Concept on Infection** **Signs of Localized Infection** - Localized swelling - Localized redness - Pain or tenderness with palpation or movement - Palpable heat in the infected area - Loss of function of the body part affected, depending on the site and extent of involvement - **Signs of Systemic Infection** - Fever - Increased pulse and respiratory rate if the fever high - Malaise and loss of energy - Anorexia and, in some situations, nausea and vomiting - Enlargement and tenderness of lymph nodes that drain the area of infection **Factors Influencing Microorganism's Capability to Produce Infection** - Number of microorganism's present - Virulence and potency of the microorganisms (pathogenicity) - Ability to enter the body - Susceptibility of the host - Ability to live in the host's body - ###### **Anatomic and Physiologic Barriers Defend Against Infection** - - - - - - - - - **NANDA Diagnosis** **Risk for Infection** - **Risks factors** - - - ***Related Diagnoses *** - - - - - **Interventions to Reduce Risk for Infection** - Proper hand hygiene techniques - Environmental controls - Sterile technique when warranted - Identification and management of clients at risk **Infectious Disease**- results from the invasion and multiplication of microorganisms in a host. ------------------------------------------------------------------------------------------------- **Stages of Infectious Process** -------------------------------- **1. Incubation Period**- extends from the entry of microorganisms into the body to the onset of signs and symptoms. -------------------------------------------------------------------------------------------------------------------- **2. Prodromal Period**- extends from the onset of non-specific signs and symptoms to the appearance of specific signs and symptoms ----------------------------------------------------------------------------------------------------------------------------------- **3. Illness Period**- specific signs and symptoms develop and become evident. ------------------------------------------------------------------------------ **4. Convalescent Period**- signs and symptoms start to abate until the client returns to normal state of health. ----------------------------------------------------------------------------------------------------------------- **Intermediaries host-** a host in which a parasite passes one or more of its asexual stages, usually designated first and second, if there is more than one. ------------------------------------------------------------------------------------------------------------------------------------------------------------- **Pathogen**- a disease producing microorganisms ------------------------------------------------ **Pathogenicity**- the ability to produce a disease. ---------------------------------------------------- **Virulence**- the vigor with which the organisms can grow and multiply. ------------------------------------------------------------------------ **Specificity**- the organisms' attraction to a specific host, which may include humans --------------------------------------------------------------------------------------- **Opportunistic Pathogen**- causes disease only in susceptible individual. -------------------------------------------------------------------------- **Nosocomial Infection**- hospital-acquired infection ----------------------------------------------------- **Isolation**- the separation of persons with communicable diseases from other persons so that either direct/indirect transmission to susceptible persons is prevented. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Isolation Technique**- practices designed to prevent the transfer of specific microorganisms. ----------------------------------------------------------------------------------------------- **Etiology**- the study of causes. ---------------------------------- **The Chain of Infection** ========================== Watch this video about Chain of Infection https://youtu.be/2O4FgoYPjuE ====================================================================== 1. The **chain of infection** refers to those elements that must be present to cause an infection from a microorganism 2. from a microorganism does not occur in client 4\. **Modes of transmission**: 5\. Susceptible host describes a host (human or animal) not possessing enough resistance against a particular pathogen to prevent disease or infection from occurring when exposed to the pathogen; in humans this may occur if the person's resistance is low because of poor nutrition, lack of exercise of a coexisting illness that weakens the host. 6\. Portal of entry: the means of a pathogen entering a host: the means of entry can be the same as one that is the portal of exit (gastrointestinal, respiratory, genitourinary tract). 7\. Reservoir: the environment in which the microorganism lives to ensure survival; it can be a person, animal, arthropod, plant, oil or a combination of these things; reservoirs that support organism that are pathogenic to humans are inanimate objects food and water, and human. 8\. Portal of exit: the means in which the pathogen escapes from the reservoir and can cause disease; there is usually a common escape route for each type of microorganism; on humans, common escape routes are the gastrointestinal, respiratory and the genitourinary tract.  **The Chain of Infection** ========================== **1. The Infectious agent** These are microorganisms capable of causing infections are referred to as an infectious agent or pathogen (bacteria, virus, fungi, or parasites). The ability of the infectious agent to cause a disease depends on its pathogenicity, virulence, invasiveness and specificity. The infectious agent is simply the germ that causes the infection. Germs are all around us and within us, and many plays very important roles in keeping us healthy. The problem comes when a germ leaves its normal place to go elsewhere in the body -- the germs that sit on your skin and which usually cause no harm, for instance, getting into a cut. The germ could then cause infection. There are also many germs that are not helpful to health and which cause disease. Entry of any of these germs into the body is likely to cause problems. **2. Reservoir** **or Host** The reservoir of an agent is the habitat in which an infectious agent normally lives, grows, and multiplies. Reservoirs include humans, animals, and the environment. The reservoir may or may not be the source from which an agent is transferred to a host. By 'reservoir', we mean a place where germs can live and multiply. The 'place' can be a person -- a patient/client or a member of staff -- but it can also be any part of the surrounding area of a health care setting, furnishings in the patient's/client's room and the equipment we use in health care. For example, the reservoir of Clostridium botulinum is soil, but the source of most botulism infections is improperly canned food containing C. botulinum spores. **2.a Human reservoir.** Many of the common infectious diseases have human reservoirs. Diseases which are transmitted from person to person without intermediaries include the sexually transmitted diseases, measles, mumps, streptococcal infection, most respiratory pathogens, and many others. Smallpox was eradicated after the last human case was identified and isolated because humans were the only reservoir for the smallpox virus. Two types of human reservoir exist: persons with symptomatic illness carriers A **carrier** is a person without apparent disease who is nonetheless capable of transmitting the agent to others. Carriers may be **asymptomatic carriers,** who never show symptoms during the time they are infected, or may be incubatory or convalescent carriers, who are capable of transmission before or after they are clinically ill. A chronic carrier is one who continues to harbor an agent (such as hepatitis B virus or Salmonella typhi---the agent of typhoid fever) for an extended time (months or years) following the initial infection. Carriers commonly transmit disease because they do not recognize they are infected and consequently take no special precautions to prevent transmission. **Symptomatic persons**, on the other hand, are usually less likely to transmit infection widely because their symptoms increase their likelihood of being diagnosed and treated, thereby reducing their opportunity for contact with others. **2.b Animal reservoirs.** Infectious diseases that are transmissible under normal conditions from animals to humans are called zoonosis (ZOH-uh-NOH-seez). In general, these diseases are transmitted from animal to animal, with humans as incidental hosts. Such diseases include brucellosis (cows and pigs), anthrax (sheep), plague (rodents), trichinosis (swine), and rabies (bats, raccoons, dogs, and other mammals). Another group of diseases with animal reservoirs are those caused by viruses transmitted by insects and caused by parasites that have complex life cycles, with different reservoirs at different stages of development. Such diseases include St. Louis encephalitis and malaria (both requiring mosquitos) and schistosomiasis (requiring fresh water snails). Lyme disease is a zoonotic disease of deer incidentally transmitted to humans by the deer tick. **2.c Environmental reservoirs**. Plants, soil, and water in the environment are also reservoirs for some infectious agents. Many fungal agents, such as those causing histoplasmosis, live and multiply in the soil. The primary reservoir of Legionnaires' bacillus appears to be pools of water, including those produced by cooling towers and evaporative condensers. **3. Portal of exit** It is the path by which an agent leaves the source host. The portal of exit usually corresponds to the site at which the agent is localized. Thus, tubercle bacilli and influenza viruses exit the respiratory tract, schistosomes through urine, cholera vibrio in feces, Sarcoptic in scabies skin lesions, and enterovirus 70, an agent of hemorrhagic conjunctivitis, in conjunctival secretions. Some bloodborne agents can exit by crossing the placenta (rubella, syphilis, toxoplasmosis), while others exit by way of the skin (percutaneously) through cuts or needles (hepatitis B) or blood-sucking arthropods (malaria). **4. Modes of transmission** The microorganism must have a means of transmission to get from one location to another, called direct and indirect After an agent exits its natural reservoir. It may be transmitted to a susceptible host in numerous ways. These modes of transmission are classified as: Direct (Direct contact --- Droplet spread) Indirect (Airborne, Vehicle-borne, Vector-borne, Mechanical, Biologic) **Direct contact transmission** occurs when pathogens are transferred between individuals without a contaminated intermediate person, object, or environmental surface. For example, when blood or other potentially infectious materials from an infected person enters the body of a susceptible person through direct contact with mucous membrane or breaks in the skin, e.g., when pathogens are transferred from a patient to HCP during ungloved contact with mucous membrane or skin. **Indirect contact transmission** occurs when pathogens are transferred between individuals via a contaminated intermediate person, object, or environmental surface. For example, when the hands of HCP become contaminated and hand hygiene is not performed prior to touching the next patient; when contaminated patient-care items are shared between patients without having been adequately cleaned, disinfected, or sterilized; or in association with contaminated sharps and needlestick injuries. **Airborne transmission** is a form of respiratory transmission associated with inhalation of **droplet nuclei**, i.e., residuals of droplets ranging in size from 1-5 µm that while suspended in air dried out, but may still contain potentially infectious pathogens. In a cool setting, droplet nuclei may remain in the air indefinitely and travel long distances, i.e., extend beyond 3 feet of the source. Droplet nuclei may also contaminate intermediate objects or environmental surfaces. Droplets and droplet nuclei are generated when people talk, breath, cough, or sneeze; or when water is converted to a fine mist by medical/dental devices, such as high-speed handpieces, ultrasonic instruments, or by lasers and electrosurgical units. In **direct transmission**, there is essentially immediate transfer of the agent from a reservoir to a susceptible host by direct contact or droplet spread. Direct contact occurs through kissing, skin-to-skin contact, and sexual intercourse. Direct contact refers also to contact with soil or vegetation harboring infectious organisms. Thus, infectious mononucleosis ("kissing disease") and gonorrhea are spread from person-to-person by direct contact. Hookworm is spread by direct contact with contaminated soil. Droplet spread refers to spray with relatively large, short-range aerosols produced by sneezing, coughing, or even talking. Droplet spread is classified as direct because transmission is by direct spray over a few feet, before the droplets fall to the ground. In **indirect transmission**, an agent is carried from a reservoir to a susceptible host by suspended air particles or by animate (vector) or inanimate (vehicle) intermediaries. Most vectors are arthropods such as mosquitoes, fleas, and ticks. These may carry the agent through purely **mechanical** means. For example, flies carry Shigella on appendages; fleas carry Yersinia pestis (agent that causes plague) in the gut and deposit the agent on the skin of a new host. In **mechanical transmission**, the agent does not multiply or undergo physiologic changes in the vector. This is in contrast to instances in which an agent undergoes part of its life cycle inside a vector before being transmitted to a new host. When the agent undergoes changes within the vector, the vector is serving as both an intermediate host and a mode of transmission. This type of indirect transmission is a **biologic transmission**. Guinea worm disease and many other vector-borne diseases have complex life cycles which require an intermediate host. **Read the life cycle of Dracunculus medinensis (Guinea worm)** What type of transmission does this illustrate? Since the agent undergoes part of its life cycle in the intermediate host, the agent cannot be transmitted by the intermediate host until the agent has completed that part of its life cycle. Therefore, this is an indirect, vector-borne, biologic transmission. **Vehicles** that may indirectly transmit an agent include food, water, biologic products (blood), and fomites (inanimate objects such as handkerchiefs, bedding, or surgical scalpels). As with vectors, vehicles may passively carry an agent---as food or water may carry hepatitis A virus---or may provide an environment in which the agent grows, multiplies, or produces toxin---as improperly canned foods may provide an environment in which C. botulinum produces toxin. **Airborne transmission** is by particles that are suspended in air. There are **two types** of these particles: **dust and droplet nuclei.** Airborne dust includes infectious particles blown from the soil by the wind as well as material that has settled on surfaces and become resuspended by air currents. Droplet nuclei are the residue of dried droplets. The nuclei are less than 5 µ (microns) in size and may remain suspended in the air for long periods, may be blown over great distances, and are easily inhaled into the lungs and exhaled. This makes them an important means of transmission for some diseases. Tuberculosis, for example, is believed to be transmitted more often indirectly, through droplet nuclei, than directly, through droplet spread. Legionnaires' disease and histoplasmosis are also spread through airborne transmission. **5. Portal of entry** An agent enters a susceptible host through a portal of entry. The portal of entry must provide access to tissues in which the agent can multiply or a toxin can act. Often, organisms use the same portal to enter a new host that they use to exit the source host. For example, influenza virus must exit the respiratory tract of the source host and enter the respiratory tract of the new host. The route of transmission of many enteric (intestinal) pathogenic agents is described as "fecaloral" because the organisms are shed in feces, carried on inadequately washed hands, and then transferred through a vehicle (such as food, water, or cooking utensil) to the mouth of a new host. Other portals of entry include the skin (hookworm), mucous membranes (syphilis, trachoma), and blood (hepatitis B). **6. Host** The final link in the chain of infection is a susceptible host. Susceptibility of a host depends on genetic factors, specified acquired immunity, and other general factors which alter an individual's ability to resist infection or to limit pathogenicity. An individual's genetic makeup may either increase or decrease susceptibility. A host is a person who is at risk for infection; whose own body defense mechanisms, when exposed, are unable to withstand the invasion of pathogens. Examples: malnourished children, the elderly, the client with leukemia are immune -- compromised, and therefore, have propensity to develop numerous types of infection. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Factors Influencing the Host's Susceptibility** ------------------------------------------------- 1. Intact skin and mucous membrane are the body's first line of defense. ------------------------------------------------------------------------ 2. The normal ph. levels of secretions and of genital-urinary tract help ward ----------------------------------------------------------------------------- off microbial invasion. ----------------------- 3. The body's WBC influence resistance to certain pathogens. ------------------------------------------------------------ 4. The age, sex, and race have been shown to influence susceptibility. ---------------------------------------------------------------------- 5. Immunization. (natural/acquired), acts to resist infection. -------------------------------------------------------------- 6. Fatigue, climate, general health status, presence of pre-existing illness, previous/current treatments and some kinds of medications may play a part in the susceptibility of a potential host. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **General factors which defend against infection** include the skin, mucous membranes, gastric acidity, cilia in the respiratory tract, the cough reflex, and nonspecific immune response. **Skin** Anatomical Structures of Human Skin The skin is the largest organ of the body, with a total area of about 20 square feet. The skin protects us from microbes and the elements, helps regulate body temperature, and permits the sensations of touch, heat, and cold. **Skin has three layers:** - The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. - The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands. - The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue. The skin's color is created by special cells called melanocytes, which produce the pigment melanin. Melanocytes are located in the epidermis. **Skin Conditions** - [Rash](https://www.webmd.com/skin-problems-and-treatments/guide/common-rashes): Nearly any change in the skin's appearance can be called a [rash](https://www.webmd.com/skin-problems-and-treatments/guide/common-rashes). Most rashes are from simple skin irritation; others result from medical conditions. - [Dermatitis](https://www.webmd.com/skin-problems-and-treatments/understanding-dermatitis-basics): A general term for inflammation of the skin. Atopic dermatitis (a type of eczema) is the most common form. - [Eczema](https://www.webmd.com/skin-problems-and-treatments/eczema/understanding-eczema-basics): Skin inflammation ([dermatitis](https://www.webmd.com/skin-problems-and-treatments/contact-dermatitis)) causing an itchy rash. Most often, it's due to an overactive immune system. - [Psoriasis](https://www.webmd.com/skin-problems-and-treatments/psoriasis/psoriasis-topic-overview): An autoimmune condition that can cause a variety of skin rashes. Silver, scaly plaques on the skin are the most common form. - [Dandruff](https://www.webmd.com/skin-problems-and-treatments/understanding-dandruff-basics): A scaly condition of the scalp may be caused by seborrheic dermatitis, psoriasis, or eczema. - [Acne](https://www.webmd.com/skin-problems-and-treatments/acne/acne-vulgaris-topic-overview): The most common skin condition, acne affects over 85% of people at some time in life. - [Cellulitis](https://www.webmd.com/skin-problems-and-treatments/guide/cellulitis): Inflammation of the dermis and subcutaneous tissues, usually due to an infection. A red, warm, often painful skin rash generally results. - [Skin abscess](https://www.webmd.com/a-to-z-guides/abcess) (boil or furuncle): A localized skin infection creates a collection of pus under the skin. Some abscesses must be opened and drained by a doctor in order to be cured. - [Rosacea](https://www.webmd.com/skin-problems-and-treatments/understanding-rosacea-basics): A chronic skin condition causing a red rash on the face. Rosacea may look like acne, and is poorly understood. - [Warts](https://www.webmd.com/skin-problems-and-treatments/understanding-common-warts-basics): A virus infects the skin and causes the skin to grow excessively, creating a wart. Warts may be treated at home with chemicals, duct tape, or freezing, or removed by a physician. - [Melanoma](https://www.webmd.com/melanoma-skin-cancer/melanoma-guide/melanoma-skin-cancer-overview-facts): The most dangerous type of skin cancer, melanoma results from sun damage and other causes. A skin biopsy can identify melanoma. - [Basal cell carcinoma](https://www.webmd.com/melanoma-skin-cancer/basal-cell-carcinoma): The most common type of skin cancer. Basal cell carcinoma is less dangerous than melanoma because it grows and spreads more slowly. - [Seborrheic keratosis](https://www.webmd.com/skin-problems-and-treatments/tc/seborrheic-keratosis-topic-overview): A benign, often itchy growth that appears like a "stuck-on" wart. Seborrheic keratoses may be removed by a physician, if bothersome. - [Actinic keratosis](https://www.webmd.com/melanoma-skin-cancer/understanding-actinic-keratosis-basics): A crusty or scaly bump that forms on sun-exposed skin. [Actinic keratoses](https://www.webmd.com/skin-problems-and-treatments/understanding-actinic-keratosis-basics) can sometimes progress to cancer. - [Squamous cell carcinoma](https://www.webmd.com/cancer/carcinoma-squamous-cell): A common form of skin cancer, squamous cell carcinoma may begin as an ulcer that won't heal, or an abnormal growth. It usually develops in sun-exposed areas. - [Herpes](https://www.webmd.com/genital-herpes/pain-management-herpes): The herpes viruses HSV-1 and HSV-2 can cause periodic blisters or skin irritation around the lips or the genitals. - [Hives](https://www.webmd.com/skin-problems-and-treatments/guide/hives-urticaria-angioedema): Raised, red, itchy patches on the skin that arise suddenly. Hives usually result from an allergic reaction. - [Tinea versicolor](https://www.webmd.com/skin-problems-and-treatments/tc/tinea-versicolor-topic-overview): A benign fungal skin infection creates pale areas of low pigmentation on the skin. - [Viral exantham](https://firstaid.webmd.com/skin-rashes-in-children-treatment): Many viral infections can cause a red rash affecting large areas of the skin. This is especially common in children. - [Shingles](https://www.webmd.com/skin-problems-and-treatments/shingles/shingles-topic-overview) (herpes zoster): Caused by the chickenpox virus, shingles is a painful rash on one side of the body. A new adult vaccine can prevent shingles in most people. - [Scabies](https://www.webmd.com/skin-problems-and-treatments/understanding-lice-scabies-basics): Tiny mites that burrow into the skin cause scabies. An intensely itchy rash in the webs of fingers, wrists, elbows, and buttocks is typical of scabies. - [Ringworm](https://www.webmd.com/skin-problems-and-treatments/understanding-ringworm-basics): A fungal skin infection (also called tinea). The characteristic rings it creates are not due to worms. - [Skin biopsy](https://www.webmd.com/skin-problems-and-treatments/guide/skin-biopsies): A piece of skin is removed and examined under a microscope to identify a skin condition. - [Skin testing](https://www.webmd.com/allergies/skin-testing) (allergy testing): Extracts of common substances (such as pollen) are applied to the skin, and any allergic reactions are observed. - [Tuberculosis skin test](https://www.webmd.com/a-to-z-guides/tuberculin-skin-tests) (purified protein derivative or PPD): Proteins from the tuberculosis (TB) bacteria are injected under the skin. In someone who's had TB, the skin becomes firm. - [Corticosteroids](https://www.webmd.com/allergies/tc/atopic-dermatitis-medications) (steroids): Medicines that reduce immune system activity may improve dermatitis. Topical steroids are most often used. - [Antibiotics](https://www.webmd.com/skin-problems-and-treatments/guide/medications-skin-conditions): Medicines that can kill the bacteria causing cellulitis and other skin infections. - [Antiviral drugs](https://www.webmd.com/genital-herpes/antiviral-medications-for-genital-herpes): Medicines can suppress the activity of the herpes virus, reducing symptoms. - [Antifungal drugs](https://www.webmd.com/skin-problems-and-treatments/guide/medications-skin-conditions): Topical creams can cure most fungal skin infections. Occasionally, oral medicines may be needed. - [Antihistamines](https://www.webmd.com/skin-problems-and-treatments/eczema/oral-antihistamines-for-atopic-dermatitis): Oral or topical medicines can block histamine, a substance that causes itching. - [Skin surgery](https://www.webmd.com/melanoma-skin-cancer/tc/skin-cancer-treatment-patient-information-nci-pdq-treatment-option-overview): Most skin cancers must be removed by surgery. - [Immune modulators](https://www.webmd.com/skin-problems-and-treatments/psoriasis-treatment-8/injectables): Various drugs can modify the activity of the immune system, improving psoriasis or other forms of dermatitis. - [Skin moisturizers](https://www.webmd.com/skin-problems-and-treatments/tc/dry-skin-and-itching-home-treatment) (emollients): Dry skin is more likely to become irritated and itchy. Moisturizers can reduce symptoms of many skin conditions. **Mucous Membranes** The mucous membranes are located in areas that are contiguous with the skin. Like the latter, their role is to protect the body against external elements. Most of them secrete a thick, viscous substance called mucous, hence their name. **Location of the mucous membranes** The mucous membranes are thin and soft tissue that lines the cavities of the body which are contiguous with the skin and exposed to the external environment. Thus, mucous membranes can be found in five parts of the body:\ The digestive system, from the mouth to the anus.\ The respiratory system, from the nostrils to the lungs.\ The urogenital system: urethra, bladder, ureter, as well as the uterus and vagina in women, and the glans in men.\ The inside of the eyelids.\ The inside of the ears. **Structure of the mucous membranes\ **The mucous membranes are structured in three layers:\ First, on the surface there is a layer of epithelial tissue, composed of cells that are set closely against one another. The shape and arrangement of the epithelial cells vary depending on their location.\ The epithelial tissue rests on the corium, a supporting tissue composed of connective fibers and elastic fibers. Along this layer runs a network of blood vessels which nourish the epithelial tissue and absorb certain substances.\ Lastly, the deepest layer of the mucous membranes is composed of muscle cells.  **Function of the mucous membranes\ **First and foremost, the role of the mucous membranes is to protect the body from harmful external agents. This protection occurs in two ways: Because of its dense structure, the epithelial tissue in the mucous membranes forms a barrier which prevents pathogens from entering.\ At the same time, most mucous membranes secrete mucous, a viscous substance that keeps them constantly slightly moist. This thick gel, produced by the cells in the epithelial tissue called **goblet cells**, contains **natural antibiotics called defenses**. Thus, any pathogens (viruses, bacteria, etc.) that attempt to penetrate the mucous membrane are both caught in the mucous and attacked by the defenses. Only the mucous membranes of the urinary tract are free of mucous, because they are constantly soaked in urine, which is sterile. The role of some mucous membranes is also to absorb. Thus, the mucous membranes in the digestive tract are capable of absorbing part of the nutrients to transfer them elsewhere in the body. The nasal mucous membranes are covered in a multitude of short hairs and their role is also to block out most inhaled particles. **Gastric acidity gastric juice, or stomach acid,** is a digestive fluid formed within the [stomach lining](https://en.wikipedia.org/wiki/Gastric_mucosa).  Composed of hydrochloric acid, potassium chloride, and sodium chloride, **gastric** acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. **Cilia in the Respiratory Tract** Tiny hairs called **cilia** protect the nasal passageways and other parts of the **respiratory tract**, filtering out dust and other particles that enter the nose through the breathed air. \... The pharynx is part of the digestive **system** as well as the **respiratory system** because it carries both food and air. Respiratory cilia: MedlinePlus Medical Encyclopedia Image **Cough reflex** The **cough reflex** has both sensory ([afferent](https://en.wikipedia.org/wiki/Afferent_nerve_fiber)) mainly via the vagus nerve and motor ([efferent](https://en.wikipedia.org/wiki/Efferent_nerve_fiber)) components. Pulmonary irritant receptors (cough receptors) in the epithelium of the respiratory tract are sensitive to both mechanical and chemical stimuli. The [bronchi](https://en.wikipedia.org/wiki/Bronchi) and [trachea](https://en.wikipedia.org/wiki/Trachea) are so sensitive to light touch that slight amounts of foreign matter or other causes of irritation initiate the cough reflex. The [larynx](https://en.wikipedia.org/wiki/Larynx) and [carina](https://en.wikipedia.org/wiki/Carina_of_trachea) are especially sensitive. [Terminal bronchioles](https://en.wikipedia.org/wiki/Terminal_bronchioles) and even the [alveoli](https://en.wikipedia.org/wiki/Pulmonary_alveolus) are sensitive to chemical stimuli such as [sulfur dioxide](https://en.wikipedia.org/wiki/Sulfur_dioxide) gas or [chlorine](https://en.wikipedia.org/wiki/Chlorine) gas. Rapidly moving air usually carries with it any foreign matter that is present in the bronchi or trachea. Stimulation of the cough receptors by dust or other foreign particles produces a cough, which is necessary to remove the foreign material from the respiratory tract before it reaches the [lungs](https://en.wikipedia.org/wiki/Lungs). **Innate or nonspecific immune response** The **immune response** is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful. The immune system protects the body from possibly harmful substances by recognizing and responding to [antigens](https://medlineplus.gov/ency/article/002224.htm). Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as [toxins](https://medlineplus.gov/ency/article/002331.htm), chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens. Your body\'s cells have proteins that are antigens. These include a group of antigens called [HLA antigens](https://medlineplus.gov/ency/article/003550.htm). Your immune system learns to see these antigens as normal and usually does not react against them. The human leukocyte **antigen** (**HLA**) system or complex is a group of related proteins that are encoded by the major **histocompatibility** complex (MHC) gene complex in humans. These cell-surface proteins are responsible for the regulation of the immune system. **Innate, or nonspecific, immunity** is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response. Examples of innate immunity include: - [Cough](https://medlineplus.gov/ency/article/003072.htm) reflex - Enzymes in tears and skin oils - Mucus, which traps bacteria and small particles - Skin - Stomach acid Innate immunity also comes in a protein chemical form, called innate humoral immunity. Examples include the body\'s complement system and substances called interferon and interleukin-1 (which causes fever). If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system. **General factors that may increase susceptibility are:** malnutrition, alcoholism, and disease or therapy which impairs the nonspecific immune response. Specific acquired immunity refers to protective antibodies that are directed against a specific agent. **Individuals gain protective antibodies in two ways:** 1\) They develop antibodies in response to infection, vaccine, or toxoid; immunity developed in these ways is called active immunity. 2\) They acquire their mothers' antibodies before birth through the placenta or they receive injections of antitoxins or immune globulin; immunity that is acquired in these ways is called passive immunity. Note that the chain of infection may be interrupted when an agent does not find a susceptible host. This may occur if a high proportion of individuals in a population is resistant to an agent. These persons' limit spread to the relatively few who are susceptible by reducing the probability of contact between infected and susceptible persons**. This concept is called herd immunity**. The degree of herd immunity necessary to prevent or abort an outbreak varies by disease. In theory, herd immunity means that not everyone in a community needs to be resistant (immune) to prevent disease spread and occurrence of an outbreak. In practice, herd immunity has not prevented outbreaks of measles and rubella in populations with immunity levels as high as 85 to 90%. One problem is that, in highly immunized populations, the relatively few susceptible persons are often clustered in population subgroups, usually defined by socioeconomic or cultural factors. If the agent is introduced into one of these subgroups, an outbreak may occur. **IMMUNITY** **Immunity** to a disease is achieved through the presence of antibodies to that disease in a person's system. **Antibodies** are proteins produced by the body to neutralize or destroy toxins or disease-carrying organisms. Antibodies are disease-specific. For example, measles antibody will protect a person who is exposed to measles disease, but will have no effect if he or she is exposed to mumps. Immunity can be described as either active or passive, depending on how it is acquired: **Types of Immunity** **1. Active immunity** involves the production of antibodies by the body itself and the subsequent development of memory cells **2. Passive immunity** results from the acquisition of antibodies from another source and hence memory cells are not developed Active immunity will result in long-term immunity but passive immunity will not (due to the presence or absence of memory cells)  Both active and passive immunity can be induced by either natural or artificial mechanisms **Examples of Active Immunity** - *Natural* -- Producing antibodies in response to exposure to a pathogenic infection (i.e. challenge and response) - *Artificial* -- Producing antibodies in response to the controlled exposure to an attenuated pathogen (i.e. vaccination)  **Examples of Passive Immunity** - *Natural* -- Receiving antibodies from another organism (e.g. to the fetus via the colostrum or a newborn via breast milk) - *Artificial* -- Receiving manufactured antibodies via external delivery (e.g. blood transfusions of monoclonal antibodies) **[Types of Immunity]**  **1. Acquired Immunity** Acquired immunity is immunity that develops with exposure to various antigens. Your immune system builds a defense against that specific antigen. **Acquired Immunity ** Immunity that develops during a person\'s lifetime. There are **two types** of acquired immunity: **active immunity and passive immunity.** **Related Term(s):** [Active Immunity](https://clinicalinfo.hiv.gov/en/glossary/active-immunity) [Immunity](https://clinicalinfo.hiv.gov/en/glossary/immunity) [Passive Immunity](https://clinicalinfo.hiv.gov/en/glossary/passive-immunity) **Image(s): (Click to enlarge)** Acquired Immunity **2. Passive Immunity** **Related Term(s):** [Acquired Immunity](https://clinicalinfo.hiv.gov/en/glossary/acquired-immunity) [Active Immunity](https://clinicalinfo.hiv.gov/en/glossary/active-immunity) [Antibody](https://clinicalinfo.hiv.gov/en/glossary/antibody) **Image(s): (Click to enlarge)**  **Blood Components** The immune system includes certain types of white blood cells. It also includes chemicals and proteins in the blood, such as antibodies, complement proteins, and interferon. Some of these directly attack foreign substances in the body, and others work together to help the immune system cells. **Lymphocytes are a type of white blood cell. There are B and T type lymphocytes.** - **B lymphocytes** become cells that produce antibodies. Antibodies attach to a specific antigen and make it easier for the immune cells to destroy the antigen. - **T lymphocytes** attack antigens directly and help control the immune response. They also release chemicals, known as cytokines, which control the entire immune response. As lymphocytes develop, they normally learn to tell the difference between your own body tissues and substances that are not normally found in your body. Once B cells and T cells are formed, a few of those cells will multiply and provide \"memory\" for your immune system. This allows your immune system to respond faster and more efficiently the next time you are exposed to the same antigen. In many cases, it will prevent you from getting sick. For example, a person who has had chickenpox or has been immunized against chickenpox is immune from getting chickenpox again. Immune responseWatch this video about: [Immune response](https://medlineplus.gov/ency/anatomyvideos/000073.htm) **Inflammation** The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing [swelling](https://medlineplus.gov/ency/article/003103.htm). This helps isolate the foreign substance from further contact with body tissues. The chemicals also attract white blood cells called phagocytes that \"eat\" germs and dead or damaged cells. This process is called phagocytosis. Phagocytes eventually die. Pus is formed from a collection of dead tissue, dead bacteria, and live and dead phagocytes. Watch this video about: [Phagocytosis](https://medlineplus.gov/ency/anatomyvideos/000098.htm) **Immune System Disorders and Allergies** Immune system disorders occur when the immune response is directed against body tissue, is excessive, or is lacking. [Allergies](https://medlineplus.gov/ency/article/000812.htm) involve an immune response to a substance that most people\'s bodies perceive as harmless. **Immunization** Vaccination ([immunization](https://medlineplus.gov/ency/article/002024.htm)) is a way to trigger the immune response. Small doses of an antigen, such as dead or weakened live viruses, are given to activate immune system \"memory\" (activated B cells and sensitized T cells). Memory allows your body to react quickly and efficiently to future exposures. VaccinesWatch this video about: [Vaccines](https://medlineplus.gov/ency/anatomyvideos/000137.htm) **Complications due to an Altered Immune Response** An efficient immune response protects against many diseases and disorders. An inefficient immune response allows diseases to develop. Too much, too little, or the wrong immune response causes immune system disorders. An overactive immune response can lead to the development of [autoimmune diseases](https://medlineplus.gov/ency/article/000816.htm), in which antibodies form against the body\'s own tissues. **Complications from altered immune responses include:** - Allergy or hypersensitivity - [Anaphylaxis](https://medlineplus.gov/ency/article/000844.htm), a life-threatening allergic reaction - Autoimmune disorders - [Graft versus host disease](https://medlineplus.gov/ency/article/001309.htm), a complication of a bone marrow transplant - Immunodeficiency disorders - [Serum sickness](https://medlineplus.gov/ency/article/000820.htm) - Transplant rejection **Application** **Your task:** 1\. What can be the result when PHW consistently performing hand hygiene and 2\. Recognizing the stages of an infection, identifying the progression of an infection? What is the nonspecific to specific symptom stage of an infection? 3\. What can result from the PHW constantly performing hand hygiene and using sterile supplies when caring for patients in the hospital setting? Related image**Feedback** 1. **Fill in "What I have Learned" column by writing down what you have learned from this topic** **What I already Know** **What I Want to know** **What I have Learned** ------------------------- ------------------------- ------------------------- **Summary of the Unit:** **This unit covers terminologies: health and illness asepsis and infection control, example of substance uses for surgical hand washing, concept on infection,** signs of localized infection, signs of systemic infection, factors influencing microorganism's capability to produce infection, **anatomic and physiologic barriers defend against infection, r**isk for infection, risks factors, *Related diagnoses,* interventions to reduce risk for infection, **stages of infectious process**, **The chain of infection, Factors Influencing the host's susceptibility such as** skin and mucous membrane as the body's first line of defense, normal ph. levels of secretions and of genital-urinary tract help ward off microbial invasion, body's WBC influence resistance to certain pathogens, age, sex, and race have been shown to influence susceptibility, Immunization. (natural/acquired), acts to resist infection, fatigue, climate, general health status, presence of pre-existing illness, previous/current treatments and some kinds of medications may play a part in the susceptibility of a potential host. General factors which defend against infection, **skin conditions, skin test, skin treatments, and types and examples of immunity.** **References:** **Text books:** 1\. Josie Quiambao Udan, Fundamentals of Healthc.2009 2\. Famorca, Zenaida et al, Nursing Care in the Community, c. 2013 **Website:** 1\. Medicine plus, Trusted Health Information for you\ **2. Principles of Epidemiology \| Lesson 1 - CDC** www.cdc.gov › csels › dsepd › lesson1 › section8, Rivier Online, Published 2017 3\. [www.cdc.goc.ph](http://www.cdc.goc.ph). [National framework for universal child and family health services](https://www1.health.gov.au/internet/publications/publishing.nsf/Content/nat-fram-ucfhs-html), health Promotion 4. [**Chain of infection \| First Steps \| RCN** rcni.com › hosted-content › rcn › chain-of-infection](https://rcni.com/hosted-content/rcn/first-steps/chain-of-infection)5. Fundamentals of Epidemiology 6. Introduction to Infection Prevention Barbara [Géza T. Terézhalmy, DDS, MA](https://www.dentalcare.com/en-us/professional-education/geza-t-terezhalmy), **Modes of Transmission** =================================================================================================================================================================================== 7\. [Matthew Hoffman, MD](https://www.webmd.com/matthew-hoffman), Human Anatomy [8. Understanding the mucous membranes - Femilyane Biorga](http://www.femilyane-biorga.com/en/experts/understanding-mucous-membranes/#:~:text=The%20mucous%20membranes%20are%20thin,the%20mouth%20to%20the%20anus.)9. [Lungs and Respiratory System (for Teens) - Nemours \... Cough reflex, from Wikipedia, the free encyclopedia, Cough reflex, HIV/AIDS, Glossary](https://kidshealth.org/en/teens/lungs.html#:~:text=Tiny%20hairs%20called%20cilia%20(pronounced,nose%20through%20the%20breathed%20air.&text=The%20pharynx%20is%20part%20of,carries%20both%20food%20and%20air.)10. Bioninja, **Types of Immunity** **Infection and Prevention and *You*** Love Food Sciences, protein: coagulation 11\. Infection Prevention and Control Manual, Northern Ireland Regional 12\. Kennedy, ORNAC, Perry, Rothrock et al, Infection Control Today, 2014 CMP 203 - 10 1 Applying and Removing Sterile Gloves