Infection Control in real life

Transcription

1 Infection Control in real life Safe Credible Practical Acceptable Users Outside agencies Often means compromise Precautionary principle and evidence based

2 What to balance? Infectious disease Severity Infectivity

3 In comparison to common, sensible strains, drug resistance pathogens (i.e. MDR-TB, MRSA, ecc) can influence infection control measures and PPE because of higher severity (and infectivity?) despite the same route of transmission

4 What to balance? Infectious disease Social impact Severity Infectivity How general population perceive (and accept) the risk

5 DIRECTIVE 2000/54/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the protection of workers from risks related to exposure to biological agents at work - of 18 September 2000 Artcle 2: Definition Biological agents shall be classified into four risk groups, according to their level of risk of infection: 1. group 1 biological agent means one that is unlikely to cause human disease: 2. group 2 biological agent means one that can cause human disease and might be a hazard to workers; it is unlikely to spread to the community; there is usually effective prophylaxis or treatment available; 3. group 3 biological agent means one that can cause severe human disease and present a serious hazard to workers; it may present a risk of spreading to the community, but there is usually effective prophylaxis or treatment available; 4. group 4 biological agent means one that causes severe human disease and is a serious hazard to workers; it may present a high risk of spreading to the community; there is usually no effective prophylaxis or treatment available to protect workers' health when workers are or may be exposed to such a biological agent as a result of their work;

6 ANNEX III COMMUNITY CLASSIFICATION Group 3 Y. pestis F. Tularensis A B. anthracis M. TB HIV ** Group 4 VHF Variola Certain biological agents classified in group 3 which are indicated in the appended list by two asterisks (**), may present a limited risk of infection for workers because they are not normally infectious by the airborne route.

7 Biological and Chemical Terrorism: Strategic Plan for Preparedness and Response CDC Classification BOX 3. Critical biological agents Category A High-priority agents include organisms that pose a risk to national security because they _ can be easily disseminated or transmitted person-to-person; _ cause high mortality, with potential for major public health impact; _ might cause public panic and social disruption; and _ require special action for public health preparedness (Box 2). Category A agents include _ Variola major (smallpox); _ Bacillus anthracis (anthrax); _ Yersinia pestis (plague); _ Clostridium botulinum toxin (botulism); _ Francisella tularensis (tularaemia); _ VHF

8 National Institute of Allergy and Infectious Diseases Strategic Plan for Biodefense Research The Strategic Plan should not be limited to preexisting lists of agents but should remain flexible and based on characteristics that make an agent a feasible threat against civilian populations. We recognize that these select agents have characteristics in common with other pathogens, especially those recognized as causing naturally occurring emerging o reemerging diseases. Biologic agents that have potential to become civilian bioterrorist agents have many of the following characteristics: High morbidity and mortality Potential for person-to-person transmission, directly or by vector Low infective dose and high infectivity by aerosol, with a commensurate ability to cause large outbreaks Ability to contaminate food and water supplies Lack of a specific diagnostic test and/or effective treatment Lack of a safe and effective vaccine Potential to cause anxiety in the public and in health care workers Potential to be weaponized

9 Category A Bacillus anthracis (anthrax) Bacillus anthracis, has several characteristics that make it a formidable bioterrorist threat: its stability in spore form, its ease of culture and production, its ability to be aerosolized, the seriousness of the disease it causes, and the lack of sufficient vaccine for widespread use. Variola major (smallpox) and other pox viruses Smallpox, which is caused by the virus Variola major, is considered one of the most dangerous potential biological weapons because it is easily transmitted from person to person, no effective therapy exists, and few people carry full immunity to the virus. Viral hemorrhagic fevers These viruses pose a risk from intentional exposure because, with very few exceptions, no vaccines or proven treatments exist, and many of the diseases are highly fatal.

10 US Army Medical Research Academy for Infectious Disease USAMRIID s MEDICAL MANAGEMENT OF BIOLOGICAL CASUALTIES HANDBOOK Aug 2004 Bioengineered Threats 1) microorganisms resistant to antibiotics, standard vaccines and/or therapeutics. 2) innocuous microorganisms genetically altered to produce a toxin, poisonous substance, or endogenous bioregulator. 3) microorganisms possessing enhanced aerosol and environmental stability characteristics. 4) immunologically altered microorganisms which are able to defeat standard threat identification, and / or diagnostic methods. 5) combinations of the above with improved delivery systems.

11 USAMRIID s MEDICAL MANAGEMENT OF BIOLOGICAL CASUALTIES HANDBOOK Aug 2004 Biothreat Diseases requiring Airborne Precautions: Smallpox. Biothreat Diseases requiring Droplet precautions: Pneumonic Plague. Biothreat Diseases requiring Contact Precautions: Viral Hemorrhagic Fevers. Airborne Precautions Standard Precautions plus: Place the patient in a private room that has monitored negative air pressure, a minimum of six air changes/hour, and appropriate filtration of air before it is discharged from the room. Wear respiratory protection when entering the room. Limit movement and transport of the patient. Place a mask on the patient if need to be moved.

12 Modes of Transmission Contact Droplet Airborne Respiratory secretions and largest droplets in which pathogens can survive Small-medium size droplets can be propelled 2 or more meters (6 to 10 feet) from the source

13 Airborne transmission of communicable infection The elusive pathway Roy e Milton N Engl J Med 2004; 350: (modified) Obligate M. Tuberculosis Preferential VZV, Measles Opportunistic SARS Occasional/rare Smallpox, HFV Influenza

14 What to balance? Infectious disease Social impact Severity Infectivity Infection control measures Environmental impact Resources and costs Efficacy and effectiveness

15 Council Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work Article 6 General obligations on employers (e) adapting to technical progress; (h) giving collective protective measures priority over individual protective measures;

16 DIRECTIVE 2000/54/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the protection of workers from risks related to exposure to biological agents at work - of 18 September 2000 Article 3 Scope Determination and assessment of risks Article 6 Reduction of risks., the risk of exposure must be reduced to as low a level as necessary in order to protect adequately the health and safety of the workers. In particular the following measures are to be applied : (b) design of work processes and engineering control measures so as to avoid or minimise the release of biological agents into the place of work; (c) collective protection measures and/or, where exposure cannot be avoided by other means, individual protection measures; Collective measures can be implemented only for airborne isolation

17 Laboratory biosafety manual

18 Patient care and isolation

19 Draft Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. Recommendations of the Healthcare Infection Control Practices Advisory Committee, Draft CDC Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, Draft American Institute of Architects (AIA) Guidelines for Design and Construction of Hospital and Health Care Facilities CDC-Hospital Infection Control Practices Advisory Committee (HICPAC). Guidelines For Prevention of Healthcare-Associated Pneumonia, 2003 HICPAC Guideline for infection control in health care personnel, 1998 CDC - HICPAC Guidelines for Environmental Infection Control in Health-Care Facilities, 2003

20 Hospital Infection Control Guidance for Severe Acute Respiratory Syndrome (SARS) Revised 24 April 2003 Inpatient setting Care for probable SARS cases Probable SARS cases should be isolated and accommodated as follows in descending order of preference: 1.negative pressure rooms with the door closed 2.single rooms with their own bathroom facilities 3.cohort placement in an area with an independent air supply, exhaust system and bathroom facilities

21 Last updated: 10 March 2004 Influenza A (H5N1): WHO Interim Infection Control Guidelines for Health Care Facilities 2-2. Infection control precautions Infection control for influenza A (H5N1) involves a two-level approach: Standard precautions which apply to ALL patients at ALL times, including those who have influenza A (H5N1) infection and Additional precautions which should include:. droplet precautions,. contact precautions,. airborne precautions (including the use of high efficiency masks negative pressure rooms if available) A combination of these precautions will give the appropriate infection control. Strict adherence to these precautions is required to break the chain of infection transmission

22 Collettive measures: level of infection contol measures in lab Lab Biological safety Level BSL 1 BSL 2 BSL 3 BSL 4 suit or cabinet Biological safety cabinets Class I Class II type A, B1, B2 Class III Defined characteristics and procedures

23 Types of patient containment isolation Single-room isolation Negative-pressure rooms High-security rooms (disposal unit included) Cohort isolation (cases with the same infection) Prevents access of uninfected individuals Outward airflow dilutes & removes airborne pathogens Sealed rooms, airflow control, HEPA filters Any of the above, with multiple occupants/room

24 BSL 2-3 lab PRIMARY PROTECTION BARRIER The primary barrier system is the laboratory worker's first line of defense. It consists of laboratory equipment such as Class I and II biological safety cabinets, and aerosal containing centrifuges, which are designed to aid in containing infectious agents. It also consists of the protective clothing worn by anyone entering into the facility; solid front, water resistant gowns, gloves, head and shoe covers, and respirator

25 Airborne isolation Ventilatory system exterior Controled air-flow Direction of leakage - 50 Pa - 50 Pa - 25 Pa

26 Engineering Controls: Isolation Rooms Patients housed in rooms under negative pressure compared to hall. At least 6 to12 air changes/hour. Air not recirculated to other rooms. Source: CDC, 1994

27 Draft CDC Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, Many of the activities and recommendations for the prevention and control of TB will also be useful for preventing transmission of agents of bioterrorism and diseases such as smallpox and SARS. Since agents of smallpox and SARS, for example, are transmitted by air, implementation of a comprehensive infection-control program, including environmental control measures (e.g., AII rooms) and a respiratory protection program, potentially will enhance health-care settings preparedness for many agents that are transmitted by the airborne route.

28 Because the biological aerosols likely to contain Mycobacterium tuberculosis range in size from 1 to 3 micron, N95/FFP2 respirators are considered sufficient and recommended in the care of patients with pulmonary tuberculosis MDR-TB, SARS, VHF, Smallpox need stronger and safer measures???

29 BSL 4 Cabinet Lab Class III Biological Safety Cabinet A. glove ports,with O-ring for attaching arm-length gloves to cabinet. B. sash, C. exhaust HEPA filter, D. supply HEPA filter, E. double -ended autoclave or passthrough box. Note: A chemical tank may be installed which would be located beneath the work surface of the BSC with access from above.

30 Patient isolators Protect against all routes of infection, but need daily inspection Only suitable for individual patients Demand high staffing ratios Require special waste disposal systems

31 Stretcher isolator for initial patient retrieval

32 High containment ambulance

33 High-security suit rooms BSL 4 Suit lab

34 The relative efficacy of respirators and room ventilation in preventing occupational tuberculosis. Fennelly KP,Nardell EA.Infect Control Hosp Epidemiol 1998;19:754-9 The relative efficacy of personal respiratory protection decreases as room ventilation rates increase or as the concentrations of infectious aerosols decrease. The risk of occupational tuberculosis probably can be lowered considerably by using relatively simple respirators combined with modest room ventilation rates for the infectious aerosols likely to be present in isolation rooms of patients. More sophisticated respirators may be needed to achieve a comparable risk reduction for exposures to more highly concentrated aerosols, such as may be generated during cough-inducing procedures or autopsies involving infectious patients.

35 Personal respiratory protection against Mycobacterium tuberculosis. Fennelly KP. Clin Chest Med. 1997;18:1-17 Respirator selection should be based on anticipated exposures. The concentration of infectious aerosols in well-ventilated respiratory isolation rooms is likely to be very low, and the new N95 respirators offer a reasonable balance of comfort, cost, practicality, and protection. High-risk exposures to TB are often associated with cough-inducing procedures or with aerosolization of infected tissues during autopsies. For such high-risk situations in health care settings is a PAPR hood recommended.

36 The proper selection of control measures is based on a hierarchy of elimination and minimization by engineering controls, followed last by personal protective equipment when exposures cannot be eliminated. Once it is decided that personal protective equipment is needed, the process of selecting an appropriate PPE requires an understanding of the work activities associated with potential exposure

37 Once it is decided that personal protective equipment is needed, consideration must be given to whether wearing a certain type of PPE will adversely affect a HCW s ability to perform his/her tasks without create a risk to the safety of HCW or patients

38 VHF and accidental needlesticks Ebola, 1976, Zaire: 85 (26.7%) of 318 cases Bull World Health Organ 1978;56: BMJ 1977;2:

39 HCW Adherence

40 Eck EK, Vannier A. The effect of high-efficiency particulate air respirator design on occupational health: a pilot study balancing risks in the real world Communication, visibility, and range of motion were found to affect contaminated sharps injuries significantly. HEPA respirators, because of their design, potentially increase the risk of bloodborne pathogen exposure through sharps injuries. Mandating respirators may be counterproductive to HCW safety, because they may increase, rather than decrease, overall occupational risk to HCWs Infect Control Hosp Epidemiol 1997 Feb;18(2):122-7

41 Many workers occasionally remove respirators when their use is required or are reluctant to wear them at all Thermal discomfort has been suggested as a common reason for not wearing air-purifying respirators General Discomfort and burden Physiological impact on respiratory and cardiovascular apparatus Psycological impact Claustrophobia Patient s Psycological impact Altered Patient/provider relationship

42 Healthcare Worker Perceptions of Mask Use during a Nosocomial Pertussis Outbreak Pennsylvania, 2003 Oral presentation at APIC 2004 Forty-three (45%) HCWs perceived obstacles to using mask. Masks were considered a barrier to a trusting provider-patient relationship: 20 HCWs felt that a provider in a mask increased worries among patients, and 26 thought that the mask was a barrier to communicating with patients. Thirty respondents indicated that wearing a mask was uncomfortable and/or a burden. The physiological impact of wearing an N95 mask during hemodialysis as a precaution against SARS in patients with endstage renal disease. J Formos Med Assoc 2004 Aug;103(8):624-8 Wearing an N95 mask significantly reduced the PaO2 level ( / to / mm Hg, p = 0.006), increased the respiratory rate (16.8 +/- 2.8 to /- 2.7/min, p < 0.001), and increased the occurrence of chest discomfort (3 to 11 patients, p = 0.014) and respiratory distress (1 to 17 patients, p < 0.001).

43 The N-95 masks (in combination with face shields and goggles) are likely equivalent to PAPRs in protection in the health care setting. We recommend that clinicians caring for patients with a VHF use either N-95 masks or PAPRs, depending on their familiarity with one or the other, the suitability for the individual, and availability at a given institution Hemorrhagic Fever Viruses as Biological Weapons: Medical and Public Health Management JAMA. 2002;287:

44 Impact on patient care and well being

45 Safety of patients isolated for infection control JAMA 2003;290: Patients isolated for infection control precautions experience more preventable adverse events, express greater dissatisfaction with their treatment, and have less documented care. Do physicians examine patients in contact isolation less frequently? A brief report AJIC 2003; 31: Physicians are about half as likely to examine patients in contact isolation compared with patients not in contact isolation. Adverse effects of contact isolation. Lancet 1999; 354: Health-care workers are half as likely to enter the rooms of patients in contact isolation, but are more likely to wash their hands after caring for them than after caring for patients not in isolation.

46 Stop the ritual of tracing colonised people BMJ 1997;314:665 Patients in isolation may receive less attention. Isolation is psychologically detrimental and may delay progress and discharge. Anxiety and depression in hospitalized patients in resistant organism isolation South Med J. 2003;96:141-5 Placement in resistant organism isolation may increase hospitalized patients' levels of anxiety and depression MRSA: psychological impact of hospitalization and isolation in an older adult population. J Hosp Infect. 2001;49:250-4 Isolation has a negative impact on mood in addition to that resulting from hospitalization Contact isolation in surgical patients: a barrier to care? Surgery 2003, 134: Isolated patients were visited fewer times than nonisolated patients, had less contact time overall in the ICU and on the floor in spite of higher mean APACHE II scores

47 Personal Protective Equipment

48 AirMate PAPR hood (HEPA filter)

49 Stryker T4 Personal Protection System Before putting Stryker suit on Put helmet on and Get battery