1. NOSOCOMIAL INFECTION

2. DEFINITION nosocomial infections are any infection that acquired while in a hospital or healthcare setting. These types of infections are acquired while a patient is admitted to the hospital for treatment of other conditions. Most infections that become clinically evident after 48 hours of hospitalization are considered hospital-acquired The source of infections are: 1. other patients, 2.hospital staff, 3.contaminated objects or solutions, 4. from the patient himself (such as transfer from one site of the body to another). Most common nosocomial infections are surgical wound infections, urinary and respiratory tract infections, and bacteremia (bloodstream infections).

3. CONTAMINATED SURFACES INCREASE CROSS-TRANSMISSION

4. KNOWN NOSOCOMIAL INFECTION Ventilator-associated pneumonia Staphylococcus aureus Methicillin resistant Staphylococcus aureus Candida albicans Pseudomonas aeruginosa Acinetobacter baumannii Stenotrophomonas maltophilia Clostridium difficile Tuberculosis Urinary tract infection Hospital-acquired pneumonia Gastroenteritis Vancomycin-resistant Enterococcus Legionnaires' disease

5. REASONS WHY THE PROBLEM EXISTS Nosocomial infections are the result of three factors occurring in tandem: 1.High prevalence of pathogens. 2.Large numbers of compromised hosts. 3.Efficient mechanisms of transmission from patient to patient (chain of transmission).

6. SITES COMMONLY AFFECTED The most common sites affected by nosocomial infections are:  urinary tract.  surgical wounds.  respiratory tract.  skin (especially burns).  blood (bacteremia).  gastrointestinal tract.  central nervous system.

7. RISK FACTORS all poor health: advanced age, premature birth, and concurrent conditions (e.g. chronic obstructive pulmonary disease COPD, diabetes). Compromised immunity: Immunodeficiency, immunosuppressive therapy, irradiation, undernourishment etc.. Antimicrobial chemotherapy disturbs normal microbial flora populations (eliminating the competition for pathogens) Surgery: openings natural barriers to infection, so microbes can enter sensitive unprotected tissues and organs. Invasive devices: such as intubation tubes, catheters, surgical drains, and tracheostomy tubes all bypass the body’s natural lines of defense.

8. MODES OF TRANSMISSION Contact transmission. Droplet transmission. Airborne transmission. Common vehicle transmission. Vector borne transmission.

9. MODES OF TRANSMISSION Contact transmission is the most important and frequent mode of transmission of nosocomial infections. It is divided into two subgroups: direct contact and indirect contact. direct contact (transfer of microorganisms between a susceptible host and an infected person) Indirect-contact transmission: Involves contact between a susceptible host and a contaminated intermediate object, Such objects include contaminated instruments, needles, or dressings, or contaminated gloves that are not changed between patients.

10. MODES OF TRANSMISSION Droplet transmission:  Occurs when droplets generated by coughing, sneezing, talking (short distance ) Airborne transmission:  Dissemination can be either airborne of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or dust particles containing the infectious agent.  Microorganisms carried in this manner can be spread widely by air currents and may become inhaled by a susceptible host within the same room or over a longer distance from the source patient, therefore, special air-handling and ventilation are required to prevent airborne transmission.  Microorganisms transmitted by airborne transmission include Legionella, Mycobacterium tuberculosis and the rubeola and varicella viruses.

11. MODES OF TRANSMISSION Common vehicle transmission:  "vehicle," such as water, food, air, or the blood supply used by a transfusion service. Vector transmission:  Occurs when an insect, arthropod, or rodent is the source of infection.

12. SOURCES OF NOSOCOMIAL INFECTIONS The source of the infecting organism may be:  Exogenous: from another patient or a member of the hospital staff, or from the inanimate environment in the hospital.  Endogenous: from the patient’s own flora.

13. CAUSES The causative microorganisms may be broadly classified into the following categories: 1.“Conventional” pathogens that could cause disease in healthy persons 2.“conditional” pathogens that could cause disease (other than simple localized infections) only in persons with lowered resistance to infection or when implanted directly into tissue or normally sterile area. 3.“Opportunistic” pathogens that could cause severe disease only in patients with greatly diminished resistance to infection.

14. CAUSES MOST COMMON PATHOGENS According to the United States National Nosocomial Infections Surveillance (NNIS) System data, the five most commonly reported pathogens are:  Escherichia coli (13·7%).  Staphylococcus aureus (11·2%).  Enterococci (10·7%).  Pseudomonas aeruginosa (10·1%).  Coagulase-negative staphylococci (9·7%).

15. CAUSES Urinary tract infection: E. coli, enterococci, and P. aeruginosa. Surgical wound infection: S. aureus, enterococci and coagulase-negative staphylococci. Bloodstream: coagulase-negative staphylococci, S. aureus, enterococci, E. coli, and Candida spp. Lower respiratory tract infection: S. aureus. P. aeruginosa and Enterobacter spp.

16. CAUSES Among patients in the intensive care unit (ICU) the commonest pathogens were:  P. aeruginosa (12·4%).  S. aureus (12·3%).  coagulase-negative staphylococci (10·2%).  Candida spp. (10·1%).  Enterobacter spp. and enterococci (8·6% each).

17. CAUSES VIRUSES There is the possibility of nosocomial transmission of many viruses, including:  The hepatitis B and C viruses (transfusions, dialysis, injections, endoscopy).  Respiratory syncytial virus (RSV), rotavirus, and enteroviruses (transmitted by hand-to- mouth contact and via the faecal-oral route).  Other viruses such as cytomegalovirus, HIV, Ebola, influenza viruses, herpes simplex virus, and varicella-zoster virus, may also be transmitted.

18. CAUSES ACCORDING TO SOURCE FungiVirusesBacteriaSource AspergillusVaricella zoster (chickenpox) Influenza Gram-positive cocci (originating from skin) Tuberculosis Air

19. CAUSES ACCORDING TO SOURCE FungiVirusesBacteriaSource Aspergillus Exophiala jeanselmei Molluscum contagiosum Human papillomavirus (bath water) Noroviruses Gram-negative bacteria : Pseudomonas aeruginosa Aeromonas hydrophilia Burkholderia cepacia Stenotrophomonas maltophilia Serratia marcescens Flavobacterium meningosepticum Acinetobacter calcoaceticus Legionella pneumophila Mycobacteria: Mycobacterium xenopi Mycobacterium chelonae Mycobacterium avium- intracellularae Water (tap and bath)

20. CAUSES ACCORDING TO SOURCE FungiVirusesBacteriaSource Rotavirus Caliciviruses Salmonella species Staphylococcus aureus Clostridium perfringens Clostridium botulinum Bacilluscereus and other aerobic spore-forming bacilli Escherichia coli Campylobacter jejuni Yersinia enterocolitica Vibrio parahaemolyticus Vibrio cholerae Aeromonas hydrophilia Streptococcus species Listeria monocytogenes Food

21. PREVENTION OF NOSOCOMIAL INFECTIONS Methods of prevention of nosocomial infection (and breaking the chain of transmission ) include: Observance of aseptic technique. Frequent hand washing especially between patients. Careful handling, cleaning, and disinfection of equipment. Where possible, use of single-use disposable items. Patient isolation.

22. PREVENTION OF NOSOCOMIAL INFECTIONS Methods of prevention of nosocomial infection (continued) : Avoidance where possible of medical procedures that can lead with high probability to nosocomial infection. Various institutional methods such as air filtration within the hospital (Architectural Design). General awareness that prevention of nosocomial infection requires constant personal surveillance. Active oversight within the hospital.

23. PREVENTION OF NOSOCOMIAL INFECTIONS HAND WASHING Proper hand washing is the single most important measure for the Prevention of nosocomial infections. Yet, compliance among healthcare workers is suboptimal ranging from 16% to 81%. This is due to a variety of reasons, including:  Lack of appropriate accessible equipment  High staff-to-patient ratios  Allergies to hand washing products.  Insufficient knowledge of staff about risks and procedures.  Too long a duration recommended for washing.

24. PREVENTION OF NOSOCOMIAL INFECTIONS PROTECTIVE CLOTHING Caps and dedicated shoes are required for operating rooms and aseptic units. Masks protect staff against airborne pathogens and must be used when working in the operating room, to care for immunocompromised patients, to puncture body cavities or perform procedures such as bronchoscopy. Patients with air-borne pathogens wear masks when outside their isolation room.

25. PREVENTION OF NOSOCOMIAL INFECTIONS PROTECTIVE CLOTHING (GLOVES) Sterile gloves for surgery, care for immuno- compromised patients, and invasive procedures. Non-sterile gloves should be worn for all patient contacts where hands are likely to be contaminated. Hands must be washed when gloves are removed or changed. Disposable gloves should not be reused. Latex or polyvinyl-chloride are the materials most frequently used for gloves. Quality and duration of use vary considerably from one glove type to another.

26. PREVENTION OF NOSOCOMIAL INFECTIONS ARCHITECTURAL SEGREGATION According to the WHO guidelines on infection control, four areas of a healthcare facility are defined: Administrative sections considered as low-risk areas. Regular patient wards as moderate-risk areas. Intensive care units, burn units, or isolation units as high- risk areas. Operating rooms as very high-risk areas. WHO and others have recommended that traffic flow should be limited in higher risk areas.

27. PREVENTION OF NOSOCOMIAL INFECTIONS ROLE OF THE MICROBIOLOGIST The microbiologist is responsible for: Handling patient and staff specimens to maximize the likelihood of a microbiological diagnosis. Developing guidelines for appropriate collection, transport, and handling of specimens. Ensuring laboratory practices meet appropriate standards. Ensuring safe laboratory practice to prevent infections in staff.

28. PREVENTION OF NOSOCOMIAL INFECTIONS ROLE OF THE MICROBIOLOGIST Performing antimicrobial susceptibility testing following internationally recognized methods, and providing summary reports of prevalence of resistance. Monitoring sterilization, disinfection and the environment where necessary. Timely communication of results to the Infection Control Committee or the hygiene officer. Epidemiological typing of hospital microorganisms when necessary.