1. Prevention of Infection 1 Epidemiology & Infection Control dr shabeel pn www.hi-dentfinishingschool.blogspot.com

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

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)