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Train the Trainer (Infection Control & Microbiology Training) Basic Microbiology: Understanding Your Enemies Introduction The Bermuda Triangle ¾ Microorganisms cause infectious disease ¾ Essential to understand how microorganisms interact with their environment ¾ Need to understand how microorganisms are transmitted before you can choose which detergent / disinfectant to use AGENT HOST The Agent ¾ Where does it ¾ ¾ ¾ ¾ come from? Comes from students, patients, staff, visitors Public: Respiratory secretions, feces, wounds, other body fluids Staff: mouth, nose, hands Visitors: Respiratory secretions, hands ENVIRONMENT The Agents Incubation Period Infection and Incubation Time True or False: Incubation Time is the time from the moment of inoculation (exposure) to the development of the clinical manifestations (symptoms) of a particular infectious disease. TRUE: It’s the time from exposure to the time when symptoms appear. Allows us to ask: “When did I get this?” “Who did I get this from?” ¾ ¾ D D D D D D D Next Slide The Host D Infection doesn’ doesn’t always lead to disease The time from infection to the onset of symptoms ranges from hours to years Salmonella: Influenza: Common Cold: Chicken Pox: Hepatitis B: Scabies: Tuberculosis: HIV: 6 - 48 hrs 1 – 2 days 2 – 5 days 14 – 16 days 50 - 150 days 2 – 6 weeks 6 months - 2 years 3 - 10 years The Environment How do we get these together? ¾ Why are they susceptible? ¾ Overcrowding ¾ Age ¾ Shared equipment (toys, medical instruments & ¾ Developing or Decreasing Immunity devices, sports equipment) ¾ Poor cleaning & disinfection practices ¾ Poor hand hygiene (staff, visitors and students) ¾ Breaks in the natural defenses ¾ Other illnesses (asthma, allergies etc) Environmental Reservoirs ¾ Association between reservoirs and outbreaks ¾ Protocols should include careful cleaning of wet surfaces and equipment to prevent the build up of Biofilms ¾ Examples: z z z z z Faucet aerators, Shower Heads Sinks, Drains Flower Vase Water Ice Machines Hydrotherapy Baths Chain of Infection ¾ Microorganisms are carried with the human / animal / insect body (Reservoir) ¾ Microorganisms released from body by coughs, sneezes, feces, blood, saliva ¾ Inanimate objects, environmental surfaces, food, water become contaminated which leads to potential transmission of disease Chain of Infection Transmission Chapped Skin – Open Wound Transmission True or False: Infectious diseases are transmitted in the same way. FALSE: There are 4 main routes of transmission. Contact Airborne Vehicle Vector Next Slide How do Microorganisms Spread? ¾ Transmitted from person to person through human contact, air currents, on animals or insects, in food, in water or on inanimate objects ¾ The human hand is capable of transporting microorganisms from one person to another, from one contaminated object to another, or from a contaminated object to another person Five Routes of Transmission ¾ Contact Transmission z Most common divided into two subgroups • DirectDirect-contact transmission – body surface to body surface • Indirect –contact transmission – contaminated intermediate object ¾ Droplet transmission z Five Routes of Transmission ¾ Common vehicle transmission z Through contaminated items such as food water ¾ Vectorborne transmission z Mosquitoes, flies, rats Coughing, Sneezing, procedures ¾ Airborne transmission z Smaller evaporated droplets that remain suspended for a long time SARS Norwalk Influenza MRSA VRE Norwalk Chicken Pox Pink Eye Athelete’s Foot Plantar Warts Measles Mumps Rubella Colds Cross-Infection & Nosocomial Disease ¾ Cross Infection refers to the process ¾ ¾ West Nile Virus Malaria where microorganisms are transmitted from one person to another, causing illness ¾ Nosocomial Diseases are infections which are acquired by a patient after admittance to a health care facility but were not present or in an incubative stage at the time of admission (generally 3 days) FACTS ¾ Hand Hygiene ¾ ¾ Hand Hygiene ¾ Recognized as the best way of stopping the spread of organisms in this setting ¾ Soap and water z z No indication for antimicrobial soap 1010-15 seconds of lathering ¾ Alcohol z more research into concentration required to kill all viruses How Environmental Services can STOP transmission Environmental services professionals can prevent the spread of infectious agents among patients and healthcare workers by protecting themselves in the following ways: • Wearing gloves while handling any form of hospital waste to include biohazard bags, infectious waste containers, and trash bags of any color Play a major role in the transmission of pathogenic microorganisms to susceptible hosts Hands acquire known or potential pathogens by contact with objects and animate and inanimate surfaces Strict adherence to HH is more likely to prevent the spread of infections than procedures exceeding routine cleaning of the environment Hand Hygiene ¾ Towelettes z Must be alcohol based if used for hand hygiene ¾ Children z z z z after toileting before and after eating after pets, sand, dirt, art, …….. …….. Education on sneezing and coughing • never too early to start! How Environmental Services can STOP transmission • Change gloves between patient rooms to avoid transfer of microorganisms from one patient to another • Wear proper personal protective equipment when cleaning up spills of potentially infectious material • Change gloves immediately after contact with blood and/or body fluids, soiled linen, or contaminated equipment How Environmental Services can STOP transmission • Wash hands before and after eating, smoking, applying cosmetics, or preparing food Knowing The Bugs! • Stay home to rest when feverish and sick with a cold, flu, or other infection Bacteria, Viruses, Fungi, Spores Bacteria vs Virus Major Groups Of Microbes True or False: A virus is a more virulent bacteria. Virus: Are “dead” unless living in someone else’s living cell. It takes over the resources of a host cell (like humans) and makes the host cell make more virus! Bacteria: One-celled living organisms. All bacteria are surrounded by a cell wall. They can reproduce independently. They inhabit virtually every environment on earth. Some are good (break down organic waste, make yogurt & cheese). Some are not so good (cause disease). ¾ Bacteria (Gram (Gram +ve +ve & Gram -ve) ve) ¾ Viruses (enveloped & nonnon-enveloped) ¾ Fungi ¾ Protozoa ¾ Bacterial Spores ¾ Prions Next Slide Computer Keyboards May Harbor Harmful Bacteria ¾ ¾ ¾ ¾ ¾ ¾ Harmful bacteria can survive for prolonged periods on keyboards & keyboard covers VRE & MRSA evident 24 hrs after contamination PSAE evident only up to 1hr More contact with contaminated keyboard increase likelihood of transmitting bacteria to hands (MRSA: 42% - 92%, VRE: 22% to 50%, PSAE: 9% to 18%) Hand Hygiene important helps cut down on transmission Cleaning & Disinfection of keyboards & keyboard covers helps decrease contamination Infection Control Today Computer Keyboards May Harbor Harmful Bacteria; Experts Advise to Use Disinfectant and Wash Your Hands April 2005 Bacteria ¾ ¾ ¾ ¾ Microscopic, oneone-celled organisms that are invisible to the naked eye (400 million bacteria grouped together would be the size of a grain of sugar) Classified by shape: round, rod and spiral Classified by Gram Straining Vegetative forms relatively easily killed by chemical germicides Round Shaped Bacteria ¾ Rod-Shaped Bacteria ¾ Examples: E. Coli & Salmonella choleraesuis (food poisoning), Klebsiella spp. (pneumonia), Mycobacterium spp. (tuberculosis) The Gram Stain ¾ Developed in the late 1800’ 1800’s by Dr. Gram, a pathologist ¾ Originally being developed to stain kidney cells ¾ Gram positive organisms are purple (S. aureus) ¾ Gram negative organisms are red (S. choleraesuis, Pseudomonas spp.) ¾ Based on cell wall composition Examples: Staphylococcus (cause wound infections, food poisonings) & Streptococcus (strep throat) Spiral Shaped Bacteria ¾ Examples: Treponema pallidum (venereal disease, syphilis) The Gram Stain ¾ Determination is done through a chemical process where bacteria are stained with dyes and other substances, rinsed clean, then stained again with another dye ¾ Final staining indicates if the bacteria is gram +ve +ve (bacteria stains purple / blue) or gram –ve (bacteria stain red) Gram Stain ¾ Gives a quick look at the specimen ¾ Can interpret quality of specimen ¾ Can help direct antibiotic therapy ¾ Not so helpful if lots of normal flora present ¾ Quite significant on sterile body sites Elements of Survival & Growth ¾ Bacteria are selfself-sufficient if they have the basic elements of survival z z z z z Water Food Oxygen Temperature pH level Water & Food ¾ ¾ ¾ ¾ ¾ ¾ Oxygen ¾ Oxygen requirements vary by type of bacteria ¾ Aerobic bacteria require oxygen to survive (Salmonella, Pseudomonas) ¾ Anaerobic bacteria grow only in environments without oxygen (Clostridium difficile) ¾ Facultative anaerobic bacteria can survive in either environment (Salmonella) Water is essential for survival Structure of bacteria is primarily comprised of water & protein Water “holds” holds” the structure of bacteria together Water transports food into cell & removes waste Both organic & inorganic materials are utilized as food Requirements of food types and quantity needed varies by bacteria type Temperature & pH ¾ Temperature affects the reproduction cycle ¾ Bacteria that affect humans thrive at normal body temps 98.6 F ¾ pH level refers to amount of acid or alkali present in an environment ¾ Optimal growth environment for bacteria is usually pH 7 or neutral Bacteria – Tough Enemies ¾ Bacteria reproduce by process called Binary Fission ¾ Single Cell divides into two cells, these new cells split into 2 more cells etc, etc ¾ The whole process can occur as rapidly as every 15 minutes ¾ Under ideal conditions, one cell can generate an entire colony of over 1 million bacteria in under 5 hours Laboratory Testing ¾ Most human pathogenic bacteria take 24 hours to grow enough on the laboratory media to be visible and to be able to distinguish single colonies with the naked eye. ¾ Sensitivity testing from a pure culture can be anywhere from 4 – 24 hours later. ¾ Full identification can also take up to 24 – 48 hours. Viruses ¾ Classified as either DNA virus or RNA virus ¾ New research shows there is a small group of viruses that contain both DNA & RNA ¾ Viruses are also classified by shape, size & other structural characteristics for example z Enveloped or NonNon-enveloped Viruses Bacteria – Tough Enemies ¾ Bacteria can develop an immunity or resistance to antibiotics designed to kill them ¾ Hence the requirement for new treatment options ¾ However, resistance to antibiotics does not necessarily mean a bacterium is resistant to disinfectants Viruses ¾ Viruses are even smaller than bacteria and cannot be seen under an ordinary microscope ¾ Viruses cannot live independently and are not self sufficient ¾ Viruses are referred to as obligate parasites meaning they are dependent on cells of a living host to replicate & multiply Enveloped Viruses ¾ ¾ ¾ Envelop refers to the Lipoprotein outer layer of some viruses derived from plasma membrane of the host cell Considered easier to kill than even Vegetative Bacteria Examples: HIV, Herpes, Hepatitis B & C, Influenza, Coronavirus Non-Enveloped Viruses ¾ ¾ ¾ NonNon-enveloped viruses lack the lipoprotein coat Considered hardier and more resistant Examples: Polio, Norovirus, Rhinovirus, Rotavirus, Parvovirus Fungi Fungi ¾ ¾ ¾ ¾ ¾ ¾ UniUni-cellular or multimulti-cellular plants Can cause many diseases in humans & animals Grow on dead and decaying matter Can be as small as a single cell or as large as a mushroom Common forms are yeast and molds including mildew Most fungi are harmless or “nonnon-pathogenic” pathogenic” Mycobacteria ¾ Vegetative bacteria: ¾ Examples: Trichophyton mentagrophytes (Athlete’ (Athlete’s foot) used as surrogate to achieve disinfectant claims ¾ Gram positive rods, nonnon-spore forming, nonnon-motile, slightly curved, forming strands and cords, acidacid-fast staining, aerobic, slowslow-growing, ¾ More resistant to chemical germicides than other types of vegetative bacteria ¾ Mycobacterium terrae is surrogate for High Level disinfection claim Mycobacteria ¾ ¾ Examples: M. tuberculosis (tuberculosis), M. bovis, M. leprae (leprosy) Mycobacterium terrae is surrogate for High Level disinfection claim Protozoa ¾ A very diverse group comprising some 50,000 eukaryotic organisms that consist of one cell ¾ Most of them are motile and heterotrophic ¾ Infected animals & humans shed protozoa in feces in the form of an oocyst (Cryptosporidium) or cyst (Giardia) ¾ These protozoans can remain dormant for long periods in the oocyst/cyst form. They become active upon entering a host. Protozoa ¾ Bacterial Spores Cryptosporidium and Giardia are protozoan parasites affecting the gastrointestinal tract of humans and animals. ¾ Produced by certain types of GramGram- positive bacteria ¾ Heat & stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria ¾ Sporidcidal activity for highhigh-level disinfectant claim (chemical sterilant) Spores ¾ Examples of spores: z z z ¾ Clostridium difficile Bacillus subtilis Bacillus anthracus Outbreak Scenario Spores of Bacillus subtilis & Clostridium sporogenes are surrogates in tests Norovirus, Norwalk Norovirus Critical Characteristics Norovirus Transmission ¾ “OralOral-fecal” fecal” ¾ Mouth route Gut (Replication) Anus ¾ Hands ¾ Air ¾ Environmental surfaces ¾ Food ¾ Water HANDS ES ¾ Multiple modes of transmission ¾ Stable in the environment FOOD H2O AIR ¾ Highly contagious ¾ Resistant to routine disinfection methods ¾ Asymptomatic infections ¾ Limited immunity Norovirus Infection ¾ 2424-48 hour incubation period ¾ 1212-60 hour duration of illness ¾ “Winter vomiting disease” disease” ¾ “Stomach flu” flu” ¾ Vomiting ¾ Diarrhea ¾ Nausea ¾ Abdominal cramps ¾ Headache, muscle aches ¾ “Lurgy” Lurgy” ¾ A “mild” mild” Norovirus Infection Symptoms and short lived illness ¾ Fever ¾ Dehydration in young and elderly victims ¾ Up to 30% may be asymptomatic Evidence for airborne transmission of NorwalkNorwalk-like virus (NLV) in a hotel restaurant; PJ Marks; Epidemiol. Epidemiol. Infect. 2000, 124: 481481-487 Widespread environmental contamination with NLV detected in a prolonged hotel outbreak of gastroenteritis; JS Cheeseborough; Cheeseborough; Epidemiol Infect 2000, 125: 9393-98 ¾ 71% 91% 56% ¾ Hotel restaurant with 126 patrons ¾ Patron ( ) vomited at table ¾ 52 of 83 survey responders ill z 63% overall attack rate 50% ¾ Attack rates higher at closer tables 40% ¾ Consistent with airborne 25% transmission of NLV Norovirus Transmission RTRT-PCR environmental surface testing + z z z z z z z z z Carpets (known vomiting) Carpets (no vomiting) Toilet rims/seats Toilet handles, taps, basins Horizontal surfaces below 1.5 m Horizontal surfaces above 1.5 m Phones, door handles, etc. Soft furnishings Total 5/8 (62%) 9/12 (75%) 8/11 (73%) 13/39 (39%) 11/29 (37%) 6/12 (50%) 7/29 (24%) 2/10 (20%) 61/144 (42%) ENVIRONMENTAL ENVIRONMENTAL SPREAD SPREAD OF OF VIRUSES VIRUSES AND ITS CONTROL AND ITS CONTROL VIRUS RELEASE CLEANING ¾ Food (39%) ¾ Hands (12% “person to person” person”) (3%) ¾ Environmental surfaces (fomites) ¾ Air (aerosolization with vomitus) vomitus) ¾ 46% unknown or no data available CONTAMINATION ¾ Water MMWR 2001; 50: RRRR-9 SURVIVAL TRANSFER TO OTHER VEHICLES DISINFECTION STERILIZATION INOCULATION INFECTION (DISEASE) INTERRUPTION Antibiotic Resistant Organisms (AROs) ¾ Antibiotic resistant strains do not mean Antibiotic Resistant Organisms (AROs) ¾ There are differing opinions within the scientific community as whether over use of disinfectants can lead to chemical resistance. A literature search showed that there are several published studies that suggest disinfectant chemistries such as Quats that leave an active residual on the surface can lead to resistance. chemical resistance. These bacteria have developed resistance to antibiotics pertaining to human clinical situations. This does not imply that these strains are resistant to chemical disinfection. Chemical are now tested against antibiotic resistant strains such as VRE, MRSA etc. These are shown on the label claims. Vancomycin Resistant Enterococci (VRE) ¾ Enteric, Gram +ve +ve cocci ¾ Enterococcus sp. normal flora in GI & female genital tract ¾ Transmission via fecalfecal-oral route by contact (direct & indirect) ¾ Healthy people are unlikely to get VRE ¾ Critically patients, patients with urinary catheters, patients with underlying disease ¾ Hospital Acquired Infection (HAI) Methicillin Resistant Staphylococcus Aureus (MRSA) ¾ Gram +ve +ve cocci, normal flora on skin, in nose or groin area (opportunistic) ¾ Incubation Time: 4 – 10 days, but can be up to several months ¾ Transmission by contact (direct or indirect) ¾ Concern for elderly or patients with serious health problems ¾ Causes urinary tract infections or wound infections (Surgical Site Infections) Pseudomonas aeruginosa ¾ ¾ ¾ ¾ Gram –ve bacillus (opportunistic, thrives in moist conditions) Incubation Time: dependant on infection (Ex. eye infection 24 – 72hrs) Transmission by direct contact with contaminated water (vehicle), Infected solutions such as soap, IV (vehicle), contact (direct & indirect), Risk of disease to immunocompromised patients Influenza Virus ¾ ¾ ¾ ¾ ¾ Influenza types A, B & C Enveloped virus Incubation Time: 1 – 4 days (infectious 3 – 5 days of clinical onset) Transmission by direct contact through droplet infection, airborne spread among crowded populations in enclosed spaces Virus may persist for hours in dried mucous & be transmitted by direct contact (occasionally fomites) Human Immunodeficiency Virus (HIV) ¾ HIV is classified as an enveloped virus ¾ Incubation Time: 6 months to 7 years ¾ Transmitted from person to person through direct exposure to infected body fluids (blood, semen) sexual contact, sharing unclean needles etc.; transplacental transfer can occur ¾ Drying of virus in the environment causes rapid reduction Clostridium difficile Mycobacterium tuberculosis ¾ Gram +ve +ve rod ¾ Incubation Time: 4 – 12 weeks ¾ Transmission by airborne particles (inhalation) ¾ Higher risk of infection among Health Canada MSDS – Infectious Substances ¾ Anaerobic, Gram +ve rod, spore forming (Opportunistic) ¾ Commonly part of normal flora in gut ¾ Incubation Time: Not Known ¾ Transmission by direct contact (fecal-oral route), indirect contact of contaminated surfaces ¾ Risk of infection increases for patients on prolonged antibiotic therapy, elderly, immunocompromised patients Health Canada MSDS – Infectious Substances ¾ ¾ ¾ Listed by infectious agent Include information on characteristic of organism, mode of transmission, reservoir etc http://www.hchttp://www.hc-sc.gc.ca/pphbsc.gc.ca/pphb-dgspsp/msdsdgspsp/msdsftss/index.html#menu Conclusions What YOU need to know ¾ ¾ “Coughs and Sneezes Spread Diseases” Diseases” “If Its Moist and Its not Yours, Don’ Don’t Touch It” It” Handwashing ¾ Contaminated hands are probably the single most common vector for the spread of Infectious disease Stay Healthy–Wash Your Hands Virox Technologies Inc. Engineering Revolutionary Disinfectants for the War Against Microbes