Infection Control by Simran S Ghatore

n Epidemics and plagues throughout history (black plague..) n Physicians fear of contagious disease n Hippocrates and others suspected an unseen invisible cause n Climate and environment blamed - not the ill, dying or dead The pre-scientific era

Microbiology - scientific era Anton van Leeuwenhoek ( ) n Dutch linen draper n Amateur scientist n Grinding lenses, magnifying glasses, hobby n First to see bacteria “little beasties” n No link between bacteria and disease

Scientific era continued..... Ignaz Semmelweiss ( ) n Obstetrician, practised in Vienna n Studied puerperal (childbed) fever n Established that high maternal mortality was due to failure of doctors to wash hands after post-mortems n Reduced maternal mortality by 90% n Ignored and ridiculed by colleagues

Scientific era continued..... Louis Pasteur ( ) n French professor of chemistry n Studied how yeasts (fungi) ferment wine and beer n Proved that heat destroys bacteria and fungi n Proved that bacteria can cause infection - the “germ theory” of disease

Scientific era continued..... Joseph Lister ( ) n Scottish surgeon n Recognised importance of Pasteur’s work n Concerned about infection of compound fractures and post-operative wounds n Developed carbolic acid spray to disinfect instruments, patient’s skin, surgeon’s skin n Largely ignored by medical colleagues

Scientific era continued Robert Kock ( ) n German general practitioner n Grew bacteria in culture medium n Showed which bacteria caused particular diseases n Classified most bacteria by 1900

Contemporary issues n Antibiotic resistance n Prevalence of hospital acquired infection Prion diseases - BSE  ‘mad cow disease’ - new variant Creutzfeldt-Jakob disease (nvCJD) (thought to be the human equivalent) - Gerstmann-Straussler-Scheinker disease – kuru and fatal insomnia. Prion diseases - BSE  ‘mad cow disease’ - new variant Creutzfeldt-Jakob disease (nvCJD) (thought to be the human equivalent) - Gerstmann-Straussler-Scheinker disease – kuru and fatal insomnia. -Prions are mutated proteins -majority of prion related diseases involve neurological damage. -not all scientists accept they are the cause of disease. (see later) (more info) info

Antibiotic resistance n Not a new problem - Penicillin in 1944 (A.Flemming) – 1 st antibiotic – most resistance? n Hospital “superbugs” n Methycillin Resistant Staphylococcus Aureus [MRSA] n Vancomycin Intermediate Staphylococcus Aureus [VISA] n Tuberculosis - antibiotic resistant form u 400 deaths per year in UK u Up to £100,000 per patient to treat u Annual NHS cost - £5 million!!

MRSA n Discovered in 1981 n Found on skin and in the nose of 1 in 3 healthy people - symptomless carriers n Widespread in hospitals and community n Resistant to most antibiotics n When fatal - often due to septicaemia

Hospital acquired infection n Incidence of 10% n 5,000 deaths per year - direct result of HAI n 15,000 deaths per year linked to HAI n Delayed discharge from hospital n Expensive to treat [£3,500 extra] n Cost to NHS - £1 billion per year n Effective hand washing is the most effective preventative measure n Dirty wards and re-use of disposable equipment also blamed

Prion diseases n Prions [“pree-ons”] - proteinaceous infectious particles n Corrupted form of a normally harmless protein found in mammals and birds n Causes fatal neurodegenerative diseases of animals and humans n Animals: scrapie - sheep, bovine spongiform encephalopathy [BSE or Mad Cow Disease] n Humans: Creutzfeldt-Jakob disease [CJD] n Prions found in blood, tonsil and appendix tissue

Prions and surgery n Prions cannot be destroyed by sterilisation n Theoretical risk of cross infection from contaminated instruments and blood transfusion

Comparisons of mortality Deaths per year in the UK

The nature of infection n Micro-organisms - bacteria, fungi, viruses, protozoa and worms n Most are harmless [non-pathogenic] n Pathogenic organisms can cause infection n Infection exists when pathogenic organisms enter the body, reproduce and cause disease

Hospital acquired infection n Infection which was neither present nor incubating at the time of admission n Includes infection which only becomes apparent after discharge from hospital but which was acquired during hospitalisation (Rcn, 1995) n Also called nosocomial infection

Modes of spread Two sources of infection: n Endogenous or self-infection - organisms which are harmless in one site can be pathogenic when transferred to another site e.g., E. coli n Exogenous or cross-infection - organisms transmitted from another source e.g., nurse, doctor, other patient, environment (Peto, 1998)

Spread - entry and exit routes n Natural orifices - mouth, nose, ear, eye, urethra, vagina, rectum n Artificial orifices - such as tracheostomy, ileostomy, colostomy n Mucous membranes - which line most natural and artificial orifices n Skin breaks - either as a result of accidental damage or deliberate inoculation/incision (May, 2000)

Chain of infection n Source/reservoir of micro-organisms u infected person [host] or other source n Method of transmission u hands, instruments, clothing, coughing, sneezing, dust etc. n Point of entry u orifices, mucous membranes, skin n Susceptible host u low resistance to infection (May, 2000)

HAI - common bacteria n Staphylococci - wound, respiratory and gastro-intestinal infections n Eshericia coli - wound and urinary tract infections n Salmonella - food poisoning n Streptococci - wound, throat and urinary tract infections n Proteus - wound and urinary tract infections (Peto, 1998)

HAI - common viruses n Hepatitis A - infectious hepatitis n Hepatitis B - serum hepatitis n Human immunodeficiency virus [HIV] - acquired immunodeficiency syndrome via infected blood transfusion! [AIDS] (Peto, 1998)

Common types of HAI ( May, 2000)

Universal infection control precautions n Devised in US in the 1980’s in response to growing threat from HIV and hepatitis B n Not confined to HIV and hepatitis B n Treat ALL patients as a potential bio- hazard n Adopt universal routine safe infection control practices to protect patients, self and colleagues from infection

Universal precautions n Hand washing n Personal protective equipment [PPE] n Preventing/managing sharps injuries n Aseptic technique n Isolation n Staff health n Linen handling and disposal n Waste disposal n Spillages of body fluids n Environmental cleaning n Risk management/assessment

Hand washing n Single most effective action to prevent HAI - resident/transient bacteria n Correct method - ensuring all surfaces are cleaned - more important than agent used or length of time taken n No recommended frequency - should be determined by intended/completed actions n Research indicates: u poor techniques - not all surfaces cleaned u frequency diminishes with workload/distance u poor compliance with guidelines/training

Hand washing – areas missed Taylor (1978) identified that 89% of the hand surface was missed and that the areas of the hands most often missed were the finger- tips, finger-webs, the palms and the thumbs.

Personal protective equipment n PPE when contamination or splashing with blood or body fluids is anticipated n Disposable gloves n Plastic aprons n Face masks n Safety glasses, goggles, visors n Head protection n Foot protection n Fluid repellent gowns (May, 2000)

Sharps injuries n Prevention u correct disposal in appropriate container u avoid re-sheathing needle u avoid removing needle u discard syringes as single unit u avoid over-filling sharps container n Management u follow local policy for sharps injury (May, 2000)

Aseptic technique n Sepsis - harmful infection by bacteria n Asepsis - prevention of sepsis n Minimise risk of introducing pathogenic micro-organisms into susceptible sites n Prevent transfer of potential pathogens from contaminated site to other sites, patients or staff n Follow local policy (May, 2000)

Isolation n Single room or group n Source or protective n Source - isolation of infected patient u mainly to prevent airborne transmission via respiratory droplets u respiratory MRSA, pulmonary tuberculosis Protective - isolation of immuno - suppressed patient (May, 2000) Protective - isolation of immuno - suppressed patient (May, 2000) n Significant psychological effects (Davies et al, 1999)

Staff health n Risk of acquiring and transmitting infection n Acquiring infection u immunisation u cover lesions with waterproof dressings u restrict non-immune/pregnant staff n Transmitting infection u advice when suffering infection n Report accidents/untoward incidents n Follow local policy (May, 2000)

Linen handling and disposal n Bedmaking and linen changing techniques n Gloves and apron - handling contaminated linen n Appropriate laundry bags n Avoid contamination of clean linen n Hazards of on-site ward-based laundering n NHS Executive guidelines (1995) n Follow local policy (May, 2000)

Waste disposal n Clinical waste - HIGH risk u potentially/actually contaminated waste including body fluids and human tissue u yellow plastic sack, tied prior to incineration n Household waste - LOW risk u paper towels, packaging, dead flowers, other waste which is not dangerously contaminated u plastic sack, tied prior to incineration u black plastic sack, tied prior to incineration n Follow local policy (May, 2000)

Spillage of body fluids n PPE - disposable gloves, apron n Soak up with paper towels, kitchen roll n Cover area with hypochlorite solution e.g., Milton, for several minutes n Clean area with warm water and detergent, then dry n Treat waste as clinical waste - yellow plastic sack n Follow local policy (May, 2000)

Environmental cleaning n Recent concern regarding poor hygiene in hospital environments (NHSE, 1999) n Some pathogens survive for long periods in dust, debris and dirt n Poor hygiene standards - hazardous to patients and staff (May, 2000) n Report poor hygiene to Domestic Services (UKCC, 1992) n “Hospitals should do the sick no harm” (Nightingale, 1854)

Risk assessment n No risk of contact/splashing with blood/body fluids - PPE not required n Low or moderate risk of contact/splashing - wear gloves and plastic apron n High risk of contact/splashing - wear gloves, plastic apron, gown, eye/face protection (Rcn, 1995)

Body fluids n Cerebrospinal fluid, peritoneal fluid, pleural fluid, synovial fluid, amniotic fluid, semen, vaginal secretions, and n Any other fluid containing visible blood e.g., urine, faeces (Rcn, 1995)

Cost of HAI n Direct cost to NHS for: u extended hospital stay, extra resources, extra treatment, extra equipment, and extra community care costs if discharged needing follow-up n Direct cost to patient/family for: u pain and scarring, extended stay away from family, working days lost, family income loss, financial strain - increased visiting etc, increased morbidity, increased mortality (ICNA, 1998)

Summary n Ignaz Semmelweis in 1847 demonstrated that washing hands saves lives n Research indicates that 10% of patients develop HAI costing the NHS £1 billion and 20,000 deaths per year n Old bacteria are causing new problems n New viral and prion diseases are causing new problems n Reluctance to wash hands still the single most important cause of HAI (ICNA, 1998) n Growing concern about poor hospital hygiene

Internet sites n n n n n n n /default.htm /default.htm /default.htm n d/POSTpn247.pdf (excellent article) d/POSTpn247.pdf d/POSTpn247.pdf