@AikoHIRAKI:f820e5c342b0e3ce1af0905b69ebea927865a809_add JSONTXT

The main infection control measures are droplet and contact precautions. Practices in paediatric and neonatal wards in Hong Kong that were utilised during the outbreak were well described. 23, 24 It is important that strict hand hygiene and adequate decontamination be performed after each direct or potential exposure to patients and at any time that body parts are perceived to be contaminated by patients' bodily fluids. A shower after high-risk procedures and before leaving duty would have been most desirable. The employment of a 'policing nurse' had been found to be very effective in ensuring compliance to infection control precautions and procedures during the SARS epidemic. While N95 masks have higher filtration efficiency compared with surgical masks, they have lower breathability, higher thermal stress, more discomfort and cause more fatigue. 25 CDC recommended the use of N95 (95% filtration of 0.1 mm sodium chloride particles at a flow rate of 85 l/min), 26 the EU recommended the use of FFP2 or FFP3 masks (which had a filtering efficiency of 92% and 98% respectively, tested at 95 l/min with 0.1 mm sodium chloride particles) and Canada N100 respirators (filtering efficiency of 99.97% for mono-dispersed particles of size 0.12 mm). 27 A full face respirator with an ultra-low penetrating air filter has also been recommended for its higher efficiency, good fit and protection of the mucous membranes but the disadvantage is cost, cleaning, disinfection and maintenance. 28 N95 masks should be test-fitted and the same model used whenever possible. A check fit should be performed each time one puts on the respirator and before entering the patient's room. In a study looking into factors affecting nosocomial infection in Hong Kong, it was found that all HCWs consistently used N95s or surgical masks and perceived that the inadequacy of personal protective equipment (PPE) supply, infection control training <2 h and inconsistent use of goggles, gowns, gloves and caps were significant independent risk factors for SARS infection. 29 The wearing of masks, gowns and goggles does pose considerable stress and fatigue to HCWs. Comfort and usability are other important issues to be considered. Masks can also affect visibility and patient rapport. The psychological impact of masking on children has not been studied. In low-risk times and areas, surgical masks would probably be sufficient. It would be useful to have children wearing a surgical mask of appropriate size when they have respiratory symptoms, though the risk of transmission is considered to be lower than in adults. The associated discomfort may make it difficult to continue wearing the masks for a long period of time. With education, most children can be taught to put on a mask, at least when being examined or nursed and when outside the room. Prescribed eye glass is not sufficient to protect against splashes. Face shields should be sufficient for most pro-cedures unless excess splashes or direct coughing is expected, in these cases goggles should be worn. Full face masks and hoods are more cumbersome alternatives. PPC are essential elements of infection control precautions, but which type of the available PPC provide better protection in terms of water repellency, water resistance, risk of environmental contamination, usability and comfort has not been determined. It is important to identify risk factors for non-compliance and design interventions and routines that are sustainable and practicable. In a study comparing different types of PPC available in Hong Kong, the use of a surgical gown in ordinary work procedures was recommended. When heavy splashes or droplets are expected, an additional plastic apron should be worn to protect the trunk. 30 It is important that PPC should be removed when soiled. Due care should be taken to avoid contamination of the environment and PPC should only be worn when needed and removed immediately on leaving isolation rooms. Great care should be taken when removing PPC. Lack of appropriate PPC removal procedures can lead to lapses in infection control measures. This should be done outside the patient's area and with adequate spacing to avoid cross contamination and contamination of the environment. Mirrors would be helpful so that one can observe the whole procedure. One must avoid contamination of the nose, mouth and eyes while removing the cap, gown, gloves, mask and eye protectors. There are several sets of recommendations on the sequence of removing PPC. The one recommended by the National Institute for Infectious Diseases in Italy is probably the safest. 31 The essentials are that the procedures are clear, consistent and simple to follow. The use of shoe covers is controversial and was not used in several hospitals in Hong Kong during the epidemics. Stringent infection precautions, especially for high-risk procedures, appropriate triage and prompt isolation of potential SARS patients will contribute to the control of nosocomial spread and acquisition of HCW in hospital settings. 23, 24, 32 In a retrospective case control study of 91 intubations, risk factors for infection included difficult intubation (OR 8.8), extensive bagging (OR 25.9), intubation in a general ward environment (OR 8.2) and extensive droplet contamination. 33 Before performing high-risk pro-cedures including CPR, intubation etc, one must ensure adequate protection in appropriate and properly equipped isolation facilities. Call for help if alone and choose the right technique before embarking on the procedure. 34 The analogy of putting on your own oxygen mask before attending to others while in air flight emergencies should be remembered. Neubulisation, bronchoscopy induced sputum collection and face mask ventilation should be avoided as far a possible. If medically indicated, they should be undertaken in a negative pressure room with minimal but adequate staffing. All staff should be in PPC covering the torso, arms and hands as well as eyes, nose and mouth. N95s, N-99s or N-100s are adequate but full face masks are desirable. However, the use of powered air purifying respirators is not recommended because of risk to self and environmental contamination. The use of a face mask with a good fit and attached valved manifold may reduce the risk of transmission. 35 No infection has been attributed to the taking of nasopharyngeal aspirate from SARS patients in Hong Kong. When performed it should be taken in a single room while wearing full PPC. A new upper respiratory tract irrigation method has been devised to replace nasopharyngeal aspirate testing, which should be safer. 36 The disadvantage of this method is that it cannot be used in young children. Early recognition followed by prompt initiation of isolation and infection control precautions are the most important strategies for controlling SARS and other emerging infectious diseases. Clinical features alone cannot reliably distinguish SARS from other respiratory illnesses. Having an epidemiological linkage was the most consistent finding (95.5%) in children infected with SARS in Hong Kong. 37 Combining clinical findings and epidemiological linkage or clustering of cases and interpreting clinical findings with key epidemiological risk factors serves as a good framework for triage, especially for children. Precise and timely information about these epidemiological risks should be provided, coupled with proper training of frontline healthcare professionals on its interpretation. A predictive model basing on a four-item clinical score of cough before or concomitant with fever, myalgia, diarrhoea and rhinorrhoea or sore throat had a 100% sensitivity and 75.9% specificity of early detection of probable SARS. The addition of lymphopaenia and thrombocytopaenia increased the specificity to 86.2%. 38 In another model, a scoring system of attributing 11, 10, 3, 3 and 3 points to the presence of independent risk factors of epidemiological link, radiographic deterioration, myalgia, lymphopaenia and elevated ALT respectively, generated high- (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) and low-(0-10) risk scores for SARS. The sensitivity and specificity of this prediction rule in positively identifying a SARS patient were 97.7% and 81.3% respectively. 39 The prediction rule could be useful at the bedside. However, these studies were conducted in adult patients and would need to be validated in paediatric patients. Other clinical guidance has also been developed but again is probably only applicable to the adult population. 40 The case definition for clinical SARS used by Leung et al. in Hong Kong was: fever (rectal temperature of 38.58C or oral temperature of 388C); chest radiograph (CXR) findings of pulmonary infiltrates or acute respiratory distress syndrome; and suspected or probable contact with a person under investigation for SARS or exposure to a locality with suspected or documented community transmission of SARS through either travel or residence within 10 days of the onset of symptoms, as well as 1 of the following: chills, malaise, myalgia, muscle fatigue, cough, dyspnoea, tachypnoea, hypoxia, lymphopenia, decreasing lymphocyte count, or failure to respond, in terms of fever and general well-being, to antibiotics covering the usual pathogens of community-acquired pneumonia (e.g. a broad-spectrum lactam plus a macrolide) after 2 days of therapy. This case definition had a sensitivity and specificity of 97.8% and 92.7% respectively in identifying paediatric SARS during the SARS outbreak. 36 While almost all reported patients with laboratory evidence of SARS have radiographic evidence of pneumonia at some point during their illness, paediatric SARS have non-specific radiographic features, making it difficult for radiological differentiation. 41 A private general clinic participating in the SARS-screening programme in Hong Kong during the SARS epidemic -by using telephone triage followed by chest radiograph of cases with 'flu-like' illness, the author successfully and safely screened 1161 attendees, X-rayed 151 patients and diagnosed one case of SARS. Therefore, a chest X-ray (CXR) would be a useful screening tool during outbreaks. 42 A SARS and avian influenza algorithm for early recognition and investigation of potential paediatric cases, modified from the UK Health Protection Agency's algorithm, is suggested in the Appendix. 40 Negative pressure rooms are recommended for the isolation of patients with SARS. However, it should be noted that negative pressure rooms only prevent the virus from travelling outside the room and may not reduce viral load or environmental contamination inside the room. Several designs such as low level suction and laminar flow have tried to reduce the viral load inside the room but the effectiveness is unproven. 43 Various devices such as portable/mobile local exhaust ventilation devices, tents and personal isolation systems have been designed and tested but the usability, risk of contamination of staff and effectiveness are still under study. 44, 45 A rethink on the best design for effective infection control which also improves clinical and psychological care of patients is very much needed. No matter how good the design this cannot replace preparedness, a good clinical routine and appropriate personal protection. Elaborate ventilation designs and negative pressure systems would be difficult in most clinical settings. Exhaust fans and mobile local exhaust ventilation devices with HEPA filters have been used in hospitals and clinics in Hong Kong. Their efficacy has not been tested. Several ingenious barrier precaution designs have been made by local medical practitioners: a torch mounted to a face shield for throat examination; cling film wrapping of telephones, keyboards and medical instrument to facilitate cleaning; and home-made air powered helmet hoods or tents for high-risk patients. These have not been tested and cannot replace hand hygiene, appropriate PPC and regular decontamination. While having adequate infection control equipment and facilities are important, overcrowding or inadequate bed/ clinic spacing or triage rooms and insufficient manpower are two major risk factors for hospital cross infection. Having clear clinical guidelines and timely information are essential but it is it even more important that everyone has adequate information and proper training, practice and enforcement on infections and infection control starting in schools and in the community. Panic and fear can be more harmful than the disease itself. SARS and avian flu have taught us that infections are not just a problem for healthcare professionals, they involve everyone of all ages within communities throughout the world.