Infectious Diseases, Allergies and Transmission-based.pdf

TRANSMISSION-BASED PRECAUTIONS AND ALLERGIES Definition:  Transmission-based precautions are additional infection control precautions in health care, and the latest routine infection prevention and control practices applied for patients who are known or suspected to be infected or colonized wit...

TRANSMISSION-BASED PRECAUTIONS AND ALLERGIES Definition:  Transmission-based precautions are additional infection control precautions in health care, and the latest routine infection prevention and control practices applied for patients who are known or suspected to be infected or colonized with infectious agents, including certain epidemiologically important pathogens. TYPES  Contact Precautions Droplet Precautions Airborne Precautions Contact Precautions  Apply to patients with any of the following conditions and/or disease Presence of stool incontinence (may include patients with norovirus, rotavirus, or Clostridium difficile) Draining wounds Uncontrolled secretions Pressure ulcers or presence of ostomy tubes and/or bags draining body fluids MRSA Presence of generalized rash or exanthems  Perform hand hygiene before touching patient and prior to wearing gloves PPE use: Wear gloves when touching the patient and the patient’s immediate environment or belongings. Wear a gown if substantial contact with the patient or their environment is anticipated Perform hand hygiene after removal of PPE; note: use soap and water when hands are visibly soiled (e.g., blood, body fluids), or after caring for patients with known or suspected infectious diarrhea (e.g., Clostridium difficile, norovirus) Clean/disinfect the room and surroundings  Donning PPE upon room entry and discarding before exiting the patient room is done to contain pathogens, especially those that have been implicated in transmission through environmental contamination (e.g., VRE, C. difficile, noroviruses and other intestinal tract pathogens; RSV)  Provide a private room- if possible, otherwise In multi-patient rooms, >3 feet spatial separation between beds is advised to reduce the opportunities for inadvertent sharing of items between the infected/colonized patient and other patients.  Minimize the transport of patients Droplet Precautions  Apply to patients known or suspected to be infected with a pathogen(more than 5 microns) that can be transmitted by droplet route; these include, but are not limited to:  Respiratory viruses (e.g., influenza, parainfluenza virus, adenovirus, respiratory syncytial virus, human metapneumovirus)  For first 24 hours of therapy: Neisseria meningitides, group A streptococcus  A single patient room is preferred  When a single-patient room is not available, do cohorting (keeping the patient with an existing roommate with a Spatial separation of more than 3 feet)  Healthcare personnel wear a mask (a respirator is not necessary) for close contact with infectious patient; the mask is generally donned upon room entry  Patients on Droplet Precautions who must be transported outside of the room should wear a mask if tolerated and follow Respiratory Hygiene/Cough Etiquette*. Minimize the patient transfer/ transportation RESPIRATORY / COUGH Etiquette Cover your mouth and nose with a tissue when coughing or sneezing; Use in the nearest waste receptacle to dispose of the tissue after use; Perform hand hygiene (e.g., hand washing with non-antimicrobial soap and water, alcohol-based hand rub, or antiseptic hand wash) after having contact with respiratory secretions and contaminated objects/materials. AIRBORNE PRECAUTION  Apply to patients known or suspected to be infected with a pathogen that can be transmitted by airborne route; these include, but are not limited to: Tuberculosis Measles Chickenpox (until lesions are crusted over) Localized (in immunocompromised patient) or disseminated herpes zoster (until lesions are crusted over)  Place the patient immediately in an airborne infection isolation room (AIIR)  PPE use:  Wear a fit-tested N-95 or higher level disposable respirator, if available, when caring for the patient; the respirator should be donned prior to room entry and removed after exiting room*  If substantial spraying of respiratory fluids is anticipated, gloves and gown as well as goggles or face shield should be worn  Perform hand hygiene before and after touching the patient and after contact with respiratory secretions and/or body fluids and contaminated objects/materials; note: use soap and water when hands are visibly soiled (e.g., blood, body fluids)  Instruct patient to wear a facemask when exiting the exam room, avoid coming into close contact with other patients , and practice respiratory hygiene and cough etiquette  Once the patient leaves, the room should remain vacant for generally one hour before anyone enters; however, adequate wait time may vary depending on the ventilation rate of the room  If staff must enter the room during the wait time, they are required to use respiratory protection  Minimize the patient transfer/ transport  Clean and disinfect the room accordingly  Whenever possible, non-immune HCWs should not care for patients with vaccine-preventable airborne diseases (e.g., measles, chickenpox, and smallpox)  Allergies  Allergy:- is an altered reactivity of the tissues, caused by exposure to an agent (allergen) in first exposure or in second exposure to the allergen which is benign to other persons.  Allergen:- is a foreign substance or antigen that can elicit allergic symptoms. It is a class of antigens that can elicit IgE production in some individuals or stimulate immune reaction in the body.  Hapten:- it is a small molecular weight substance that by it self can not stimulate an immune response but must bind with protein in the body to form antigen complex which will be antigenic and elicit an allergic reaction. Route of administration of the allergen:-  Inhalation of the allergen  Ingestion of the allergen  Injection of the allergen  Contact of the allergen with the skin. Classification of the allergic hypersensitivity reactions  The best classification is based on the mechanism of their production:- Type I (Anaphylactic tissue injury):-  Antigen + IgE on the surface of mast cells -sensitization -- histamine-action of histamin -- clinical features of allergy Type II (Immune cytotoxic tissue damage):-  Antigen fixed on any cell (may be the cell membrane itself) + IgM/G -- complement activation -- cell destruction. Type III Immune complex formation  Antibody (IgM/G) + free antigen -- immune complex ---complement activation -membrane attack complex -- tissue destruction. Type II (Immune cytotoxic tissue damage):-  Antigen fixed on any cell (may be the cell membrane itself) + IgM/G -- complement activation -- cell destruction. Type III Immune complex formation  Antibody (IgM/G) + free antigen -- immune complex ---complement activation -membrane attack complex -- tissue destruction. Type IV delayed hypersensitivity:-  Antigen + antigen presenting cell (macrophage, langerhans cells) --- T –lymphocytes will be activated to produce lymphokines which stimulates other leukocytes - tissue destruction. Type V antibody dependent cellular cytotoxicity  IgG/M + antigens on the host cell membrane - attract leukocytes that bind to the IgG or M on the surface of the cell leading to its destruction.  Types I, II and III are termed immediate allergic reactions.  Type IV is termed delayed hypersensitivity reaction.  Type V is newly introduced in the classification. It is semilar to type II but in type II there is direct destruction of the cells without the presence of neutrophils.  Allergies to chlorhexidine  Practitioners using chlorhexidine mouth rinses, hand washes, or irrigants should be aware of the potential risks of allergic responses. . Thechlorhexidine molecular structure has two identical  epitopes and can cross-link IgE antibodies on the surface of mast cells and basophils, causing them to degranulate . This leads to histamine release and the possibility of anaphylaxis in sensitized individuals.  There have been over 60 reports of anaphylaxis to chlorhexidine in the literature since 1983.  The greatest risk situation is when chlorhexidine gains access o the systemic circulation.  This concern underpins advice that chlorhexidine rinses, irrigants, or gels should not be applied onto bleeding sites (e.g., subgingival irrigation during periodontal debridement, or by irrigation into extraction sites  The Australian Guidelines for the Prevention and Control of Infection in Healthcare (2019) discuss emerging issues with allergy and resistance to chlorhexidine and recommend that its use be limited to clearly defined applications that are evidence based. Latex sensitivity  Suspected natural latex allergy (NLA) in dental practitioners, clinical support staff, or patients must be treated as a serious medical issue.  Symptoms may manifest as delayed hypersensitivity such as rash, conjunctivitis, or rhinitis (Type 4), which could then progress with time to an acute allergic anaphylactic reaction (Type 1), which may result in death.  All patient medical histories and new dental staff employment forms must include questions about NLA and/or sensitivity or allergy to latex/rubber products.   Staff who have allergies to latex should have this documented in the clinic’s allergy records for staff, and should inform the practice so that all necessary accomodations can be made to minimise and prevent exposure to latex in the workplace.  Patients with proven anaphylactic reactions to latex should be wearing a medical alert bracelet and should be carrying self injectable adrenaline.  If latex sensitivity is identified, then a ‘latex-free’ environment should be created for the persons affected.  This involves the use of latex-free gloves and removal of identifiable latex products likely to cause a reaction from the operatory.  Such items include:  latex gloves, latex prophylaxis cups, latex dental dams, rubber bite blocks, and latex rubber alginate mixing bowls. Non-latex versions of these items are available. Key compliance items for allergies and sensitivity  Consider the use of chlorhexidine and determine the evidence- based applications for judicious use.  Ensure dental staff with latex sensitivities are able to work in a latex-free environment by selecting nonlatex products. Thank you