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LEGIONELLA and TAPWARE FIXTURES in HEALTH CARE FACILITIES. Madeleine McPherson. RN. MACN Infection Prevention and Control Consultant. NORMAL INDIGENOUS FLORA.
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LEGIONELLA and TAPWARE FIXTURES inHEALTH CARE FACILITIES Madeleine McPherson. RN. MACN Infection Prevention and Control Consultant
NORMAL INDIGENOUS FLORA • The normal human body is host to trillions of microbes. All are acting as a part of our normal defence mechanism against possible invaders. • Number varies between 4000 and 400,000 in each square centimetre of our skin and mucous membrane which, if stretched out covers 8 tennis courts!!!!!!. • Staphylococcus aureus (golden staph)is one of those found on the skin and in moist areas of 50% of healthy individuals. • The number of bacteria on the bowel equals the number of people who have ever inhabited this planet.
FACTS ABOUT MICROBES • We do not live in a sterile world, thank goodness. • Microbes are the most numerous living thing on earth. They are all around us. • Nearly all of them function to break down the bodies of plants and animals after they have died, to release vital nutrients that are used again. • Only a few are able to attack their larger neighbours while they are still alive, to cause disease. • To cause an infection the microbes must come in sufficient numbers and be able to reach a susceptible site.
RECOVERY OF MICROBES IN THE ENVIRONMENT • In the early days of microbiology, a simple Bacteriologists found that Streptococci , exposed to the air, after being shed from the body of a person with an infection, suffer from progressive damage before they die. • In this pre-morbid state, they can still be detected in the laboratory, but they have lost their virulence. Meers, McPherson, Sedgwick,. Infection Control in Healthcare (2000)
Legionella, a History • 1976 • An epidemic of respiratory disease occurred during an American Legion convention in Philadelphia which resulted in 220 hospitalisations and 34 deaths. • L. pneumophila was present in the air-conditioning system of the hotel where they were all staying. • Subsequent epidemics have occurred in hotels hospitals, cruise liners, shopping centres etc.
LEGIONELLACAE • A slow growing gram negative rod-shaped organism. • L pnemophilamultiples inside amoebae that inhabit the same ecological niche. • The ecological niche must provide the right temperature, plenty of organic matter and a vehicle of infection. • Severe legionellosis is seen in individuals predisposed to smoking, chronic lung disease alcoholism, old age and immunosuppressant.
LEGIONELLA • Legionella is an example of wholly environmental infection when the causative microbe may not be derived from a living thing. • There are many members of the genus but over two thirds of human infections are caused by L.pneumophia serotype 1. • Another common species is Legionella Longbeachie which is found in potting mix.
SOURCE OF BACTERIA • Survives and multiples in water including rivers, lakes, streams. • Airborne dispersal may occur when aerosols are created. • Temperature dependant. Prefers between 600 and 200. • Insensitive to pH.
LEGIONELLACAE • Does not pass from person to person. • Acquired from contaminated droplets. • Found in poorly maintained air conditioners, shower heads, mixer taps. • Control. Showers and taps that are not frequently used should be flushed through weekly for 5 minutes. • Thermostat mixing valves should be cleaned and serviced quarterly.
SPREAD OF INFECTION Source Route of transmission Port of Entry Incubation period Infection
SOURCE • The immune system in the host becomes important. • To cause an infection, a microbe must have come from somewhere ‘source of infection’. • Finds a port of exit to escape from the source and needs a ‘vector’ or vehicle of infection to conduct an ID along a pathway to reach a ‘portal of entry. • Legionnela a very good example. Aerosol transmission and a susceptible host (Legionnaires)
RESERVIOR • A place in which ‘infecting’ microbes can be found. • All microbes require transport. • Example Semmelweis. • No doubt contaminated the walls, floors, bedding, furniture and air were heavily contaminated with streptococci, yet handwashing on its own reduced infection rates from 10%-1%.
NOSOCOMIAL INFECTIONS • Renamed – Healthcare Associated Infections. • Facts: 75% of all HAI are self infections. 24% cross infection. <1% equipment. • The focus on equipment control could be said to be out of proportion to their overall significance.
24% =HAND WASHING Note: Since we were born, our hands have been used to sample the environment. Where they end up is very important in the health care setting: • HAND WASHING IS THE SINGLE MOST IMPORTANT MEASURE IN THE PREVENTION OF INFECTION.
HAND WASHING • ROUTINE: 15 seconds • ANTISEPTIC: 1 minute • SURGICAL: 2 minutes THOROUGH DRYING IS AS IMPORTANT AS THOROUGH AS WASHING.
DEFINITIONS • Transient flora. Microorganisms isolated from the skin that are not usually present. (derived from contact with previous patient of the environment) • Resident flora. Microorganisms that permanently reside on the skin. • After an aseptic hand wash, the hands could be recontaminated via the tap.
TAPS • Hand basins must be readily available and their use encouraged • The modern trend to alcohol rubs is not always a substitute for soap and water. • The water flow must not be over the outlet. (millions of microbes in the drain doing no harm until they are given help, e.g. Splashing) • The hand basins also designed not to permit splashes.
TAPS (cont’d) • In areas where asepsis is required (ORs, Procedure rooms etc) elbow taps are required. (foot taps have problems). • In areas where antisepsis is required, wrist taps are acceptable. • Sensor taps excellent if they can be guaranteed. • Hand taps in all other areas
IGNAZ SEMMELWEIS (1818-1865) • Hungarian appointed to the Obstetric Division of the Vienna General Hospital. • Comprised two clinics. Medical students in one and trainee midwives in the other. • Maternal death rate significantly higher in the first clinic. 10% as to 3%. • Semmelweis, worried, investigated.
STREPTOCOCCI • Semmelweis. • No doubt contaminated the walls, floors, bedding, furniture and air were heavily contaminated with streptococci, yet handwashing on its own reduced infection rates from 10%-1%. • Streptococci still causes serious newsworthy sepsis. • Innovative medically acquired and opportunistic pathogen.
INFECTION CONTROL • Infection Control must be based on science. • Rituals are an expensive, ridiculous waste of time. • Know your policies, they are based on science. • Monitor and recognise changing patterns. • Question the questionable.