Prevention of Infection 1 Epidemiology & Infection Control dr shabeel pn www.hi-dentfinishingschool.blogspot.com
Overview <ul><li>Sources of infection </li></ul><ul><li>Transmission of Infection </li></ul><ul><li>Patterns of Infection ...
Sources of infection Where do patients get their infections from...? …in the community food salmonellosis, campylobacter ...
Sources of infection Where do patients get their infections from...? …in the hospital food salmonellosis Humans Cross -inf...
Transmission of Infection Definitions of terms by example <ul><li>Salmonella gastro-enteritis </li></ul><ul><li>Reservoi...
Transmission of Infection Definitions of terms by example <ul><li>S. aureus wound infection </li></ul><ul><li>Reservoir <...
Patterns of Infection Definitions <ul><li>Sporadic </li></ul><ul><ul><li>rare infections, occurring now and then, withou...
Patterns of Infection Definitions <ul><li>Outbreak </li></ul><ul><ul><li>commonly used to mean a limited epidemic, e.g. ...
e.g. an outbreak of salmonella gastro-enteritis No. of new cases Day Epidemic infection or outbreak Introduction of ...
Patterns of Infection Examples e.g. S. aureus wound infections in a hospital Endemic infection continuous level of inf...
Outbreaks & Epidemiological typing <ul><li>Why type organisms? </li></ul><ul><ul><li>do you have an outbreak or just an in...
Infection Control General Principles <ul><li>Remove reservoir or source of infection </li></ul><ul><li>Interrupt transmi...
Infection Control in the community <ul><li>Remove reservoirs & sources </li></ul><ul><ul><li>Human-to-human </li></ul></u...
Infection Control in the community <ul><li>Interrupt transmission </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul...
Infection Control in the community <ul><li>Increase host resistance </li></ul><ul><ul><li>Improved diet </li></ul></ul><u...
Hospital-acquired Infection why worry? <ul><li>10-15% of patients will get infected during a stay in hospital </li></ul><u...
Why is hospital-acquired infection different from community-acquired infection? <ul><li>Many patients have impaired immuni...
Why is hospital-acquired infection different from community-acquired infection? <ul><li>There is a distinct hospital flora...
Infection Control in hospital <ul><li>Remove reservoirs & sources </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul...
Infection Control in hospital <ul><li>Interrupt transmission </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul><ul>...
Infection Control in hospital <ul><li>Increase host resistance </li></ul><ul><ul><li>Good nutrition (e.g. TPN in ITU) </l...
Infection Control who’s who in hospital <ul><li>Infection Control Doctor </li></ul><ul><li>Infection Control Nurses </l...
Hospital-acquired Infection Syndromes <ul><li>Nosocomial UTI </li></ul><ul><ul><li>~30% of hospital infections </li></ul><...
Hospital-acquired Infection Syndromes <ul><li>Chest infection </li></ul><ul><ul><li>~20% of nosocomial infections </li></...
Hospital-acquired Infection Syndromes <ul><li>Wound Infections </li></ul><ul><ul><li>~20% of nosocomial infections </li><...
Hospital-acquired Infection Rogues gallery <ul><li>Methcillin-resistant Staphylococcus aureus </li></ul><ul><ul><li>MRSA ...
Hospital-acquired Infection Rogues’ gallery <ul><li>Clostridium difficile </li></ul><ul><ul><li>Causes Antibiotic-associat...
Control of Cross-Infection <ul><li>Handwashing is paramount! </li></ul><ul><ul><li>even for Consultants! </li></ul></ul><...
Control of Cross-Infection <ul><li>Isolation of infectious patients </li></ul><ul><ul><li>whenever you admit or assess a ...
Risks from Hospital Staff <ul><li>Take Care Of Yourself! </li></ul><ul><ul><li>Your first responsibility is to your patien...
Summary <ul><li>Sources of infection </li></ul><ul><li>Transmission of Infection </li></ul><ul><li>Patterns of Infection <...
...and some final words on Hospital Infection Control... <ul><li>An extract from the work book of Dr Fester, aged 24 and ...
 
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Prevention of Infection

Published on: Mar 4, 2016
Published in: Education      
Source: www.slideshare.net


Transcripts - Prevention of Infection

  • 1. Prevention of Infection 1 Epidemiology & Infection Control dr shabeel pn www.hi-dentfinishingschool.blogspot.com
  • 2. Overview <ul><li>Sources of infection </li></ul><ul><li>Transmission of Infection </li></ul><ul><li>Patterns of Infection </li></ul><ul><li>Outbreaks & Epidemiological typing </li></ul><ul><li>Infection Control </li></ul><ul><ul><li>General Principles: Hospital & Community </li></ul></ul><ul><ul><li>Who’s who </li></ul></ul><ul><li>Hospital-acquired infection </li></ul><ul><ul><li>Syndromes </li></ul></ul><ul><ul><li>Rogues’ gallery </li></ul></ul><ul><ul><li>Control of Cross-Infection </li></ul></ul><ul><ul><li>Risks from Hospital Staff </li></ul></ul><ul><li>Final words </li></ul>
  • 3. Sources of infection Where do patients get their infections from...? …in the community food salmonellosis, campylobacter Humans Animals (zoonoses) Environment clinical case e.g. measles tuberculosis , convalscent carrier e.g. typhoid diphtheria hepatitis B symptomless carrier e.g. typhoid, hepatitis auto-infection e.g. UTI candidiasis clinical case e.g. rabies psittacosis carrier e.g. salmonella leptospirosis vector-borne e.g. malaria Lyme disease plague soil e.g. tetanus water cryptosporidiosis, giardia, cholera airborne e.g. legionellosis
  • 4. Sources of infection Where do patients get their infections from...? …in the hospital food salmonellosis Humans Cross -infection Environment clinical case e.g. chickenpox streptococcal pharyngitis wound infection symptomless carrier e.g. MRSA gent-resistant GNRs auto-infection e.g. some Staph aureus wound infections IVI e.g. Staph aureus, diphtheroids, staph epidermidis ventilator e.g. Pseudomonas air/dust Staph aureus , legionella disinfectants, solutions etc eg. Pseudomonas endoscopes e.g. mycobacteria H. pylori Humans
  • 5. Transmission of Infection Definitions of terms by example <ul><li>Salmonella gastro-enteritis </li></ul><ul><li>Reservoir </li></ul><ul><ul><li>more commonly </li></ul></ul><ul><ul><ul><li>animal gut flora </li></ul></ul></ul><ul><ul><li>less commonly </li></ul></ul><ul><ul><ul><li>human cases & carriers </li></ul></ul></ul><ul><li>Source or Vehicle </li></ul><ul><ul><li>food from affected animals </li></ul></ul><ul><ul><li>contaminated food </li></ul></ul>
  • 6. Transmission of Infection Definitions of terms by example <ul><li>S. aureus wound infection </li></ul><ul><li>Reservoir </li></ul><ul><ul><li>Human nose & skin </li></ul></ul><ul><li>Source or Vehicle </li></ul><ul><ul><li>Hands of health care workers </li></ul></ul>insert here
  • 7. Patterns of Infection Definitions <ul><li>Sporadic </li></ul><ul><ul><li>rare infections, occurring now and then, without any particular pattern </li></ul></ul><ul><ul><ul><li>e.g. gas gangrene, or Strep. pyogenes wound infections </li></ul></ul></ul><ul><li>Epidemic </li></ul><ul><ul><li>A sudden unexpected rise in number of infections caused by a particular pathogen </li></ul></ul><ul><ul><li>Can range from the small scale </li></ul></ul><ul><ul><ul><li>e.g. a few individuals </li></ul></ul></ul><ul><ul><li>up to nationwide, </li></ul></ul><ul><ul><ul><li>e.g. the BSE epidemic in UK </li></ul></ul></ul>
  • 8. Patterns of Infection Definitions <ul><li>Outbreak </li></ul><ul><ul><li>commonly used to mean a limited epidemic, e.g. in a hospital ward </li></ul></ul><ul><li>Pandemic </li></ul><ul><ul><li>a world-wide epidemic </li></ul></ul><ul><ul><li>e.g. HIV or influenza </li></ul></ul><ul><li>Endemic implies a constant significant number of infections indefinitely </li></ul><ul><ul><li>e.g. methicillin-resistant S. aureus is endemic to many hospitals </li></ul></ul>
  • 9. e.g. an outbreak of salmonella gastro-enteritis No. of new cases Day Epidemic infection or outbreak Introduction of pathogen followed by point source outbreak with abrupt start outbreak sputters on due to limited human-to- human spread Patterns of Infection Examples Days
  • 10. Patterns of Infection Examples e.g. S. aureus wound infections in a hospital Endemic infection continuous level of infection predominantly due to human-to-human spread (cross-infection)
  • 11. Outbreaks & Epidemiological typing <ul><li>Why type organisms? </li></ul><ul><ul><li>do you have an outbreak or just an increase in endemic or sporadic infection?? </li></ul></ul><ul><ul><ul><li>e.g. S. aureus infections in surgical unit </li></ul></ul></ul><ul><ul><li>identification of the source or extent of outbreak </li></ul></ul><ul><ul><ul><li>may have legal importance, e.g. close down restaurant </li></ul></ul></ul><ul><ul><li>identification of more virulent strains, </li></ul></ul><ul><li>Typing methods show whether isolates same or different </li></ul><ul><ul><li>Biochemistry, Antibiogram, Phage typing, Serotyping, Molecular methods </li></ul></ul>
  • 12. Infection Control General Principles <ul><li>Remove reservoir or source of infection </li></ul><ul><li>Interrupt transmission of infection </li></ul><ul><li>Increase host resistance to infection </li></ul>
  • 13. Infection Control in the community <ul><li>Remove reservoirs & sources </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul><ul><ul><li>Case finding & treatment </li></ul></ul></ul><ul><ul><ul><ul><li>e.g. TB </li></ul></ul></ul></ul><ul><ul><ul><li>Contact tracing </li></ul></ul></ul><ul><ul><ul><ul><li>STDs, diphtheria, TB, meningitis </li></ul></ul></ul></ul><ul><ul><li>Animals </li></ul></ul><ul><ul><ul><li>Culling of infected animals </li></ul></ul></ul><ul><ul><ul><ul><li>E.g. TB, Brucella </li></ul></ul></ul></ul><ul><ul><li>Environment </li></ul></ul><ul><ul><ul><li>Clean water, good housing </li></ul></ul></ul>
  • 14. Infection Control in the community <ul><li>Interrupt transmission </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul><ul><ul><li>avoid overcrowding </li></ul></ul></ul><ul><ul><ul><li>changes in behaviour (e.g. safe sex) </li></ul></ul></ul><ul><ul><ul><li>isolation of infectious cases (e.g. from school, work) </li></ul></ul></ul><ul><ul><li>Animals & Environment </li></ul></ul><ul><ul><ul><li>Food hygiene, vector control, animal vaccination & treatment, “poop-scooping” </li></ul></ul></ul>
  • 15. Infection Control in the community <ul><li>Increase host resistance </li></ul><ul><ul><li>Improved diet </li></ul></ul><ul><ul><li>Vaccination </li></ul></ul><ul><ul><li>Chemoprophylaxis </li></ul></ul><ul><ul><ul><li>Meningitis, diphtheria, TB </li></ul></ul></ul>
  • 16. Hospital-acquired Infection why worry? <ul><li>10-15% of patients will get infected during a stay in hospital </li></ul><ul><li>Costs >£1 billion per year in UK </li></ul><ul><li>A single large outbreak can cost 10-100K </li></ul><ul><li>Effects of nosocomial infection </li></ul><ul><ul><li>Increased mortality & morbidity </li></ul></ul><ul><ul><li>Prolonged hospital stay </li></ul></ul><ul><ul><li>Increased drugs bill </li></ul></ul><ul><ul><li>Increased staffing costs </li></ul></ul><ul><ul><li>Demoralising for staff & patients </li></ul></ul><ul><ul><li>Decreased public confidence in hospitals & doctors </li></ul></ul>
  • 17. Why is hospital-acquired infection different from community-acquired infection? <ul><li>Many patients have impaired immunity </li></ul><ul><ul><li>After anti-cancer chemotherapy </li></ul></ul><ul><ul><li>After transplants </li></ul></ul><ul><ul><li>Extremes of age </li></ul></ul><ul><li>Many patients have impaired normal physiological defences </li></ul><ul><ul><li>Breaches in skin </li></ul></ul><ul><ul><li>Implanted foreign bodies (biofilms) </li></ul></ul><ul><ul><li>Impaired phsyiology (Peristalsis, mucociliary escalator) </li></ul></ul><ul><li>Many vulnerable patients in close proximity to each other for prolonged periods of time </li></ul>
  • 18. Why is hospital-acquired infection different from community-acquired infection? <ul><li>There is a distinct hospital flora </li></ul><ul><ul><li>&quot;ordinary&quot; pathogens </li></ul></ul><ul><ul><ul><li>e.g pnemococci, E. coli, S. aureus , can all cause disease both inside and outside hospital </li></ul></ul></ul><ul><ul><li>opportunists </li></ul></ul><ul><ul><ul><li>only cause infection in patients with impaired immunity </li></ul></ul></ul><ul><ul><ul><li>e.g Serratia marsecens, Xanthomonas maltophilia, S. epidermidis, Corynebacterium jeikeium </li></ul></ul></ul><ul><ul><li>multi-resistant bacteria </li></ul></ul><ul><ul><ul><li>overlap with previous groups </li></ul></ul></ul><ul><ul><ul><li>selected for in a darwinian fashion by antibiotic usage in hospitals </li></ul></ul></ul><ul><ul><ul><li>include opportunists which are inherently multi-resistant (e.g. Xanthomonas maltophilia ) and multi-resistant varieties of common organisms, e.g. MRSA, gent-resistant E. coli </li></ul></ul></ul>
  • 19. Infection Control in hospital <ul><li>Remove reservoirs & sources </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul><ul><ul><li>Discharge infectious patients, e.g. with MRSA </li></ul></ul></ul><ul><ul><ul><li>Treat & decontaminate patients </li></ul></ul></ul><ul><ul><li>Environment </li></ul></ul><ul><ul><ul><li>Control of Legionella </li></ul></ul></ul><ul><ul><ul><li>Ward hygiene & cleaning </li></ul></ul></ul><ul><ul><ul><li>Hospital design </li></ul></ul></ul>
  • 20. Infection Control in hospital <ul><li>Interrupt transmission </li></ul><ul><ul><li>Human-to-human </li></ul></ul><ul><ul><ul><li>Hand washing </li></ul></ul></ul><ul><ul><ul><li>Ward routine (e.g. wet mopping) </li></ul></ul></ul><ul><ul><ul><li>Aseptic technique </li></ul></ul></ul><ul><ul><ul><li>Sterilisation & disinfection </li></ul></ul></ul><ul><ul><ul><li>Isolation procedures </li></ul></ul></ul><ul><ul><li>Environment </li></ul></ul><ul><ul><ul><li>Food hygiene, pest control, theatre design </li></ul></ul></ul>
  • 21. Infection Control in hospital <ul><li>Increase host resistance </li></ul><ul><ul><li>Good nutrition (e.g. TPN in ITU) </li></ul></ul><ul><ul><li>Restore normal physiology as quickly as possible </li></ul></ul><ul><ul><ul><li>Remove lines, catheters etc </li></ul></ul></ul><ul><ul><li>Vaccinate (e.g. hepatitis B) </li></ul></ul><ul><ul><li>Correct underlying defects </li></ul></ul><ul><ul><ul><li>E.g control diabetes </li></ul></ul></ul><ul><ul><li>Stimulate immunity (e.g. GM-CSF) </li></ul></ul>
  • 22. Infection Control who’s who in hospital <ul><li>Infection Control Doctor </li></ul><ul><li>Infection Control Nurses </li></ul><ul><li>Infection Control Committee </li></ul><ul><ul><li>Formulate policies </li></ul></ul><ul><ul><ul><li>waste disposal, theatre design, food hygiene etc </li></ul></ul></ul><ul><ul><li>Surveillance of infection </li></ul></ul><ul><ul><li>Management of outbreaks </li></ul></ul><ul><ul><li>Staff education </li></ul></ul><ul><ul><li>Power to close wards and even whole hospitals </li></ul></ul>
  • 23. Hospital-acquired Infection Syndromes <ul><li>Nosocomial UTI </li></ul><ul><ul><li>~30% of hospital infections </li></ul></ul><ul><ul><li>Usually catheter associated </li></ul></ul><ul><ul><ul><li>Asymptomatic colonisation common </li></ul></ul></ul><ul><ul><li>Treatment of clinical infection often requires catheter removal </li></ul></ul><ul><ul><ul><li>BUT only under antibiotic cover! </li></ul></ul></ul>
  • 24. Hospital-acquired Infection Syndromes <ul><li>Chest infection </li></ul><ul><ul><li>~20% of nosocomial infections </li></ul></ul><ul><ul><li>Gram-negative pneumonia </li></ul></ul><ul><ul><ul><li>Problem in critically ill & immunocompromised patients </li></ul></ul></ul><ul><ul><li>Legionellosis </li></ul></ul><ul><ul><ul><li>Vigilance is necessary for early detection of outbreaks </li></ul></ul></ul><ul><ul><ul><li>Control by </li></ul></ul></ul><ul><ul><ul><ul><li>raising the hot water temp </li></ul></ul></ul></ul><ul><ul><ul><ul><li>regular cleaning & inspection of water & air-cooling systems </li></ul></ul></ul></ul>
  • 25. Hospital-acquired Infection Syndromes <ul><li>Wound Infections </li></ul><ul><ul><li>~20% of nosocomial infections </li></ul></ul><ul><ul><li>Rates vary depending on whether “clean” or “dirty” surgery </li></ul></ul><ul><li>Blood-stream Infections </li></ul><ul><ul><li>~30% of nosocomial infections </li></ul></ul><ul><ul><li>Especially device-associated infection </li></ul></ul><ul><ul><li>Treatment: remove the foreign body </li></ul></ul>
  • 26. Hospital-acquired Infection Rogues gallery <ul><li>Methcillin-resistant Staphylococcus aureus </li></ul><ul><ul><li>MRSA </li></ul></ul><ul><ul><li>Infection Requires vancomycin treatment </li></ul></ul><ul><ul><li>Colonisation requires isolation, decontamination with mupirocin and betadine </li></ul></ul><ul><li>Vancomycin-resistant enterococci </li></ul><ul><ul><li>VRE, includes E, faecalis and E. faecium </li></ul></ul><ul><ul><li>Low grade pathogens </li></ul></ul><ul><ul><li>If also multi-drug resistant treatment can be difficult </li></ul></ul><ul><ul><ul><li>E. faecium but not E. faecalis treatable with quinupristin & dalfopristin (Synercid) </li></ul></ul></ul>
  • 27. Hospital-acquired Infection Rogues’ gallery <ul><li>Clostridium difficile </li></ul><ul><ul><li>Causes Antibiotic-associated colitis </li></ul></ul><ul><ul><li>Can cause outbreaks in hospitals </li></ul></ul><ul><ul><li>Patients should be isolated </li></ul></ul><ul><li>Gentamicin-resistant GNRs </li></ul><ul><ul><li>Require treatment with expensive drugs such as amikacin and imipenem </li></ul></ul><ul><ul><li>Patients should be isolated </li></ul></ul><ul><ul><li>Can cause outbreaks e.g. on oncology wards or in ITU </li></ul></ul><ul><li>Fungal infection </li></ul><ul><ul><li>Aspergillus fumigatus and Candida albicans can cause nosocomial outbreaks </li></ul></ul>
  • 28. Control of Cross-Infection <ul><li>Handwashing is paramount! </li></ul><ul><ul><li>even for Consultants! </li></ul></ul><ul><ul><li>wash your hands before & after examining patients, especially if you look at undressed wounds </li></ul></ul><ul><ul><li>Alcoholic hand rubs may provide a convenient alternative to soap and water, especially where sinks are in short supply or during an outbreak </li></ul></ul>
  • 29. Control of Cross-Infection <ul><li>Isolation of infectious patients </li></ul><ul><ul><li>whenever you admit or assess a patient think: </li></ul></ul><ul><ul><ul><li>does this patient need to be isolated? </li></ul></ul></ul><ul><ul><li>general precautions </li></ul></ul><ul><ul><ul><li>Side-room isolation (or cohort nursing or isolation ward) </li></ul></ul></ul><ul><ul><ul><li>Hand-washing on entry & exit </li></ul></ul></ul><ul><ul><ul><li>Use of aprons and gloves </li></ul></ul></ul><ul><ul><li>consult </li></ul></ul><ul><ul><ul><li>microbiologist or infection control nurse for advice </li></ul></ul></ul><ul><ul><ul><li>infection control manual for isolation protocols </li></ul></ul></ul><ul><ul><ul><ul><li>contains advice on meningitis, D&V, open TB, MRSA, hepatitis, HIV, and lots more besides - everything from Lassa to lice!! </li></ul></ul></ul></ul><ul><li>Prophylaxis </li></ul><ul><ul><li>e.g. of contacts of chickenpox, diphtheria, meningitis </li></ul></ul>
  • 30. Risks from Hospital Staff <ul><li>Take Care Of Yourself! </li></ul><ul><ul><li>Your first responsibility is to your patients not your colleagues </li></ul></ul><ul><ul><ul><li>Do not work if you have diarrhoea, or a flu-like illness, a sore throat, or if you may be incubating a viral illness such as measles, rubella, chickenpox! </li></ul></ul></ul><ul><li>Be Considerate To Lab Staff! </li></ul><ul><ul><li>Don't send specimens to the lab without proper packing, </li></ul></ul><ul><ul><ul><li>leaking and / or blood-stained specimens are not acceptable!!! </li></ul></ul></ul><ul><ul><li>Label hazardous specimens </li></ul></ul>• •
  • 31. Summary <ul><li>Sources of infection </li></ul><ul><li>Transmission of Infection </li></ul><ul><li>Patterns of Infection </li></ul><ul><li>Outbreaks & Epidemiological typing </li></ul><ul><li>Infection Control </li></ul><ul><ul><li>General Principles: Hospital & Community </li></ul></ul><ul><ul><li>Who’s who </li></ul></ul><ul><li>Hospital-acquired infection </li></ul><ul><ul><li>Syndromes </li></ul></ul><ul><ul><li>Rogues’ gallery </li></ul></ul><ul><ul><li>Control of Cross-Infection </li></ul></ul><ul><ul><li>Risks from Hospital Staff </li></ul></ul><ul><li>Final words…. </li></ul>
  • 32. ...and some final words on Hospital Infection Control... <ul><li>An extract from the work book of Dr Fester, aged 24 and a half, newly qualified house officer... </li></ul><ul><li>50 lines as punishment for poor hand hygiene </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients </li></ul><ul><li>I promise to wash my hands between patients... </li></ul>