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Cross infection on a combined paediatric plastic surgery and burns unit: A clinical and microbiological audit1
Burns 25 (1999) 655±658
www.elsevier.com/locate/burns
Cross infection on a combined paediatric plastic surgery and burns unit: A clinical and microbiological audit1 I.G. Camilleri a,*, S.J. Pedler b, O. Murphy b, C.A. Reid a a
Department of Plastic and Reconstructive Surgery, Royal Victoria In®rmary, Newcastle-Upon-Tyne, NE1 4LP, UK b Department of Medical Microbiology, Royal Victoria In®rmary, Newcastle-Upon-Tyne, NE1 4LP, UK Accepted 26 February 1999
Abstract To try and determine any presence of cross-infection between patients, prospective screening of 226 consecutive admissions on our burns unit was performed by taking nose, throat and wound swabs. Infected wounds were also swabbed and a correlation was sought between the organisms cultured on screening swabs and those responsible for infection. We did not ®nd any evidence of cross infection occurring between the burns patients and the other categories of patients on the ward. Screening swabs were useful in detecting carriers, who were found to be more of a risk to themselves than to other patients on the unit. # 1999 Elsevier Science Ltd and ISBI. All rights reserved. Keywords: Burns; Cross infection
1. Introduction One of the major concerns on a combined plastic surgery and burns unit is the possibility that cross infection may occur between the two groups of patients. Children with burns may become colonised with a variety of potential pathogens, a proportion of which may originate in patients being admitted for other (non burn) diseases. On the other hand, patients admitted for elective and emergency plastic surgery operations are expected to have a low infection rate. The problem of cross-infection in burns units was ®rst reported by Cruickshank in 1935, where he described the acquisition of Streptococcus pyogenes in patients after admission to hospital [1]. This and other organisms spread by the airborne route, by direct contact between patients or indirectly via medical sta or rela-
* Corresponding author. Tel.: +44 191 2325231; Fax: +44 191 2733534. E-mail address: [email protected] (I.G. Camilleri) 1 Presented at Annual meeting, British Burns Association 1995 (preliminary report) European Congress for Paediatric Burns, Zurich, October 1996.
tives. Children in particular are dicult to keep apart on a combined burns and plastic surgery unit. This audit was done to evaluate the possibility of cross contamination between the two major groups of patients. 2. Materials and methods Patients were divided into three groups according to the type of admission: elective surgery, emergency (non-burn) and burns. Nose and throat swabs were taken from consecutive admissions on entry to the ward over a 6-month period. These were inserted into Stewart's transport medium and cultured according to standard laboratory methods. All the isolates were kept for future analysis. Sensitivity tests were performed according to standard microbiological protocols. Children admitted with burns older than 24 h also had swabs taken from the burn wound. Wounds were inspected routinely (Fig. 1) and if evidence of infection was present the appearance of the wound was noted and swabs taken. Infection was de®ned as bacterial numbers in excess of 105 gÿ1 or if there was clinical evidence of cellulitis, pus or systemic
0305-4179/99/$20.00+0.00 # 1999 Elsevier Science Ltd and ISBI. All rights reserved. PII: S 0 3 0 5 - 4 1 7 9 ( 9 9 ) 0 0 0 5 2 - 2
656
I.G. Camilleri et al. / Burns 25 (1999) 655±658
citated and stabilised before surgery. Tangential excision and graft harvesting is performed using a pneumatic dermatome. Except for the face and neck, all grafts are meshed, usually at 1:1.5 ratio. Grafts are secured with cyanoacrylate adhesive (Histoacryl), and covered with layers of povidone iodine soaked paran gauze followed by a wool dressing and crepe bandage. Donor sites are covered with alginate dressing followed by a semi-occlusive dressing and a crepe bandage. In large burns, temporary wound cover is achieved using Biobrane dressings until the donor areas can be recropped. None of our patients are treated by exposure. Skin grafts are checked after ®ve days and donor sites at 10 days post operatively (Fig. 1). Fig. 1. Review pattern of burn wounds on the unit showing peaks at 48 h (burn wound assessment), 5 days (graft checks) and 10 days (graft donor sites).
3. Results signs of infection such as temperature and leucocytosis. Bacterial colonisation was taken to be a bacterial count of <105 gÿ1 and no clinical evidence of sepsis. Otherwise the condition of the wound was noted at the ®rst dressing change and a swab taken only if clinically indicated. Pathogens were identi®ed and stored for further typing to determine whether infection was exogenous or endogenous in origin. 2.1. Analysis Each study group was analysed for the number of patients colonised with potential pathogens on admission, the interval between surgery or burn and inspection of wound, the infection rate and whether there was evidence of cross infection. 2.2. Wound dressing protocol Our current policy in the management of paediatric burns includes the routine inspection of the majority of burn wounds 48 h following injury to determine accurate assessment of burn depth and therefore the need for grafting (Fig. 1). Initial dressings consist of paran gauze (Jelonet), gauze, wool and cotton crepe. If the decision is made not to graft, a topical antimicrobial agent (Silver sulfadiazine) is used as dressing and the patient usually treated on an outpatient basis. 2.3. Technique for excision and grafting for burns Our unit follows a policy of early tangential excision and split skin grafting. After a 48-h assessment, burns patients are put on the next available operating list (within 48 h). Patients with major burns are ®rst resus-
A total of 226 consecutive admissions were admitted over a 6-month period. Microbiology request forms were incomplete in 34 cases and not returned for analysis in another 18 cases. 174 patients were therefore included in the study. The overall ®gures for screening swabs showed a predominance of Staphylococcus aureus colonisation in 30 nasal and 3 throat swabs. Other pathogens occurred much less frequently (Table 1). The overall infection rate was 4.6% (8 patients). S. aureus was again the predominant organism, being cultured in 5 cases (Table 1). The one infection that occurred in the elective surgery group was due to S. aureus, following surgery for excision of a lesion on the cheek. Phage typing revealed that the patient was a carrier of the same strain of S. aureus. In the emergency (non-burn) group infection occurred in two cases. In the ®rst case this occurred 12 days following ¯exor tendon repair. S. aureus was again cultured from the wound but in this case the patient was not a carrier and phage typing failed to match any other carrier on the unit. In the second case infection occurred 2 days following a dog bite to the face. No pathogens were isolated from this wound and the patient was not a carrier of any pathogen. In the burns group (mean TBSA=5%) there were ®ve wounds that were colonised on admission (Table 1), all from the patients' own ¯ora. However none of these patients demonstrated any systemic signs of infection. There were 4 clinically overt infections in this group. Two (S. aureus ) were present on admission and therefore could not have been acquired on the unit. One S. aureus infection did come from the patient's own ¯ora and in the other case the patient was not a carrier and the organisms did not match any type cultured from the other two groups of patients.
I.G. Camilleri et al. / Burns 25 (1999) 655±658
657
Table 1 Distribution of pathogens in the dierent subgroups
No. of Patients Screening swabs S. aureus Strep. pneumoniae H. in¯uenzae b haemolytic Strep. Infection rate S. aureus b haemolytic Strep. Multiple pathogensa No growth a
Elective Surgery
Emergency (non burn)
Burns group
Total (%)
95
36
43
28 3 0 1
0 2 1 0
5 0 0 0
33 5 1 1
(19%) (2.8%) (0.6%) (0.6%)
1 0 0 0
1 0 0 1
3 0 1 0
5 1 1 1
(2.8%) (0.6%) (0.6%) (0.6%)
174
Enterococci, coliforms.
4. Discussion The overall infection rate in paediatric patients is signi®cantly lower than that in adult burns [2,3]. Despite this, infections remain as serious complications in paediatric burns with signi®cant morbidity and mortality in particular in those with severe burns, both due to lack of skin resistance and immunocompromise. Predisposing factors include more than 20% full thickness burn and indwelling devices [3]. Burn injury destroys the natural barrier mechanisms of the skin and contamination invariably occurs despite the use of topical antimicrobial agents. Although infections are most commonly acquired from the patient's own ¯ora [4,5], children may become infected from other patients, frequently in the hospital for elective operations. Other areas of concern are sta carriers and occult contamination of agents such as disinfectants [6]. Our original policy included screening, by means of nose and throat swabs, of all patients admitted to the unit in order to detect any potential pathogen carriers. The medical and paramedical sta is regularly screened but this is not the case for patients' relatives or visitors. In this study we found that of the 40 patients with positive screening swabs, 32 patients (82.5%) came from the elective surgery group while only 5 (12.5%) were burns patients. The most common organism encountered was S. aureus (33 patients, 19%) while Strep. Pneumoniae, H. in¯uenzae and b haemolytic streptococci were less frequently encountered. The high frequency of S. aureus encountered was in keeping with other studies [7,8]. Methicillin and aminoglycoside-resistant S. aureus is becoming a signi®cant problem [7] in many burn centres although none featured in our study. It was interesting to note that none of our cases featured Pseudomonas species or yeasts although outbreaks of these infections had been reported on our ward previously.
The process of burn wound colonisation is a dynamic one. In some studies [2], initial dominance of S. aureus, and a haemolytic streptococci species was followed by a rise in the count of enterococci, Pseudomonas and Candida species. The average hospital stay for our patients was 12 days, which may explain the dominance of the former organisms in the wound swabs. Even if cross infection can be prevented, the patient's burns may become colonised from his/her own intestinal tract. Non absorbable antibiotics are not used routinely in the UK but maintenance of bowel ¯ora by early enteral feeding is the key to prevent bacterial translocation across the gastrointestinal tract and systemic sepsis. In most units the prevention of contact spread is all that is required to reduce crossinfection. The major source of infection is the patient and every eort should be made to reduce microbial dissemination. One way of achieving this is by the use of topical antimicrobials. Good aseptic techniques are necessary during dressing changes, although most of the protective clothing for dressing postoperative wounds on the ward has been discarded over the years [9]. The discontinuation of facemasks on wards during dressing changes has not been associated with an increase in infection [9]. It would seem to be rational for sta changing dressings to wear disposable aprons and gloves, but caps, masks, or overshoes probably contribute very little to the reduction of cross-infection. Hands should be disinfected before and after a dressing change. Work surfaces associated should be wiped with alcoholic solution between patients. Similar precautions are necessary for isolation nursing and all patient contact including bedmaking and hands should be disinfected even if gloves are worn. Excessive or topical use of antibiotics will not necessarily increase cross-infection but will select resistant strains which makes treatment more dicult as resistance is associated with more virulent strains [10]. The use of antibiotics in infected cases may decrease the patient's stay
658
I.G. Camilleri et al. / Burns 25 (1999) 655±658
in hospital, thus reducing the opportunities for cross infection. Similarly early tangential excision of a burn and grafting reduces the risks of spread of pathogens by reducing the size of the source. Finally regular surveillance plays a major role in the prevention of crossinfection. Some larger burns are re-admitted for grafting, often over periods of several years. If the patient carries an undesirable strain, case notes should be clearly marked. Rapid identi®cation of these patients enables them to be promptly moved to isolation facilities [10]. Much of the information about cross-infection is available and although further research is helpful, it is well documented that aseptic discipline by sta is a major requirement.
5. Conclusions From this audit there are several conclusions that can be drawn. S. aureus is the dominant organism found in carriers and caused the majority of infections in this study. Our present management strategy of mixing burns and general plastic surgery patients does not appear to compromise either group of patients. Burn wounds tended to become colonised from the patients' own ¯ora rather than from other patients. In this study screening swabs were useful in detecting carriers of potential pathogens and alerting the ward sta of
potential cross infection between patients, although this did not occur signi®cantly in our study. References [1] Cruickshank R. The bacterial infection of burns. Journal of Pathology and Bacteriology 1935;41:367±9. [2] Heggers J, Linares HA, Edgar P, Villareal C, Herndon D Treatment of infections in burns. In: Herndon D, editors. Total burn care. Philadelphia: Saunders. p. 98±135. [3] Schlager T, Sadler J, Weber D, Donowitz L, Lohr J. Hospital acquired infections in paediatric burns patients. Southern Medical Journal 1994;87:481±4. [4] Heggers JP, Robson MC, Ko F, et al. Transient and resident micro¯ora of burn unit personnel and its in¯uence on burn wound sepsis. Infec Control 1982;3:471±4. [5] Pruitt B, McManus AT. Opportunistic infections in severely burned patients. Am J Med 1984;76:146±53. [6] Pandit DV, Gore MA, Saileshwar N, Deodhar LP. Laboratory data from the surveillance of a burns ward for the detection of hospital infection. Burns 1993;19:52±5. [7] Taylor GD, Kibsey P, Kirkland T, Burroughs E, Tredget E. Predominance of staphylococcal organisms in infections occurring in a burns intensive care unit. Burns 1992;18:332±5. [8] Farrington M, Ling T, French GL. Outbreaks of infection with methicillin-resistant Staphylococcus aureus on neonatal and burns units of a new hospital. Epidemiology and Infection 1990;105:215±28. [9] Taylor LJ. Are face masks necessary in operating theatres and wards? Journal of Hospital Infection 1980;1:173±5. [10] Ayclie GA, Lilly HA. Cross-infection and its prevention. Journal of Hospital Infection 1985;6:47±57.
www.elsevier.com/locate/burns
Cross infection on a combined paediatric plastic surgery and burns unit: A clinical and microbiological audit1 I.G. Camilleri a,*, S.J. Pedler b, O. Murphy b, C.A. Reid a a
Department of Plastic and Reconstructive Surgery, Royal Victoria In®rmary, Newcastle-Upon-Tyne, NE1 4LP, UK b Department of Medical Microbiology, Royal Victoria In®rmary, Newcastle-Upon-Tyne, NE1 4LP, UK Accepted 26 February 1999
Abstract To try and determine any presence of cross-infection between patients, prospective screening of 226 consecutive admissions on our burns unit was performed by taking nose, throat and wound swabs. Infected wounds were also swabbed and a correlation was sought between the organisms cultured on screening swabs and those responsible for infection. We did not ®nd any evidence of cross infection occurring between the burns patients and the other categories of patients on the ward. Screening swabs were useful in detecting carriers, who were found to be more of a risk to themselves than to other patients on the unit. # 1999 Elsevier Science Ltd and ISBI. All rights reserved. Keywords: Burns; Cross infection
1. Introduction One of the major concerns on a combined plastic surgery and burns unit is the possibility that cross infection may occur between the two groups of patients. Children with burns may become colonised with a variety of potential pathogens, a proportion of which may originate in patients being admitted for other (non burn) diseases. On the other hand, patients admitted for elective and emergency plastic surgery operations are expected to have a low infection rate. The problem of cross-infection in burns units was ®rst reported by Cruickshank in 1935, where he described the acquisition of Streptococcus pyogenes in patients after admission to hospital [1]. This and other organisms spread by the airborne route, by direct contact between patients or indirectly via medical sta or rela-
* Corresponding author. Tel.: +44 191 2325231; Fax: +44 191 2733534. E-mail address: [email protected] (I.G. Camilleri) 1 Presented at Annual meeting, British Burns Association 1995 (preliminary report) European Congress for Paediatric Burns, Zurich, October 1996.
tives. Children in particular are dicult to keep apart on a combined burns and plastic surgery unit. This audit was done to evaluate the possibility of cross contamination between the two major groups of patients. 2. Materials and methods Patients were divided into three groups according to the type of admission: elective surgery, emergency (non-burn) and burns. Nose and throat swabs were taken from consecutive admissions on entry to the ward over a 6-month period. These were inserted into Stewart's transport medium and cultured according to standard laboratory methods. All the isolates were kept for future analysis. Sensitivity tests were performed according to standard microbiological protocols. Children admitted with burns older than 24 h also had swabs taken from the burn wound. Wounds were inspected routinely (Fig. 1) and if evidence of infection was present the appearance of the wound was noted and swabs taken. Infection was de®ned as bacterial numbers in excess of 105 gÿ1 or if there was clinical evidence of cellulitis, pus or systemic
0305-4179/99/$20.00+0.00 # 1999 Elsevier Science Ltd and ISBI. All rights reserved. PII: S 0 3 0 5 - 4 1 7 9 ( 9 9 ) 0 0 0 5 2 - 2
656
I.G. Camilleri et al. / Burns 25 (1999) 655±658
citated and stabilised before surgery. Tangential excision and graft harvesting is performed using a pneumatic dermatome. Except for the face and neck, all grafts are meshed, usually at 1:1.5 ratio. Grafts are secured with cyanoacrylate adhesive (Histoacryl), and covered with layers of povidone iodine soaked paran gauze followed by a wool dressing and crepe bandage. Donor sites are covered with alginate dressing followed by a semi-occlusive dressing and a crepe bandage. In large burns, temporary wound cover is achieved using Biobrane dressings until the donor areas can be recropped. None of our patients are treated by exposure. Skin grafts are checked after ®ve days and donor sites at 10 days post operatively (Fig. 1). Fig. 1. Review pattern of burn wounds on the unit showing peaks at 48 h (burn wound assessment), 5 days (graft checks) and 10 days (graft donor sites).
3. Results signs of infection such as temperature and leucocytosis. Bacterial colonisation was taken to be a bacterial count of <105 gÿ1 and no clinical evidence of sepsis. Otherwise the condition of the wound was noted at the ®rst dressing change and a swab taken only if clinically indicated. Pathogens were identi®ed and stored for further typing to determine whether infection was exogenous or endogenous in origin. 2.1. Analysis Each study group was analysed for the number of patients colonised with potential pathogens on admission, the interval between surgery or burn and inspection of wound, the infection rate and whether there was evidence of cross infection. 2.2. Wound dressing protocol Our current policy in the management of paediatric burns includes the routine inspection of the majority of burn wounds 48 h following injury to determine accurate assessment of burn depth and therefore the need for grafting (Fig. 1). Initial dressings consist of paran gauze (Jelonet), gauze, wool and cotton crepe. If the decision is made not to graft, a topical antimicrobial agent (Silver sulfadiazine) is used as dressing and the patient usually treated on an outpatient basis. 2.3. Technique for excision and grafting for burns Our unit follows a policy of early tangential excision and split skin grafting. After a 48-h assessment, burns patients are put on the next available operating list (within 48 h). Patients with major burns are ®rst resus-
A total of 226 consecutive admissions were admitted over a 6-month period. Microbiology request forms were incomplete in 34 cases and not returned for analysis in another 18 cases. 174 patients were therefore included in the study. The overall ®gures for screening swabs showed a predominance of Staphylococcus aureus colonisation in 30 nasal and 3 throat swabs. Other pathogens occurred much less frequently (Table 1). The overall infection rate was 4.6% (8 patients). S. aureus was again the predominant organism, being cultured in 5 cases (Table 1). The one infection that occurred in the elective surgery group was due to S. aureus, following surgery for excision of a lesion on the cheek. Phage typing revealed that the patient was a carrier of the same strain of S. aureus. In the emergency (non-burn) group infection occurred in two cases. In the ®rst case this occurred 12 days following ¯exor tendon repair. S. aureus was again cultured from the wound but in this case the patient was not a carrier and phage typing failed to match any other carrier on the unit. In the second case infection occurred 2 days following a dog bite to the face. No pathogens were isolated from this wound and the patient was not a carrier of any pathogen. In the burns group (mean TBSA=5%) there were ®ve wounds that were colonised on admission (Table 1), all from the patients' own ¯ora. However none of these patients demonstrated any systemic signs of infection. There were 4 clinically overt infections in this group. Two (S. aureus ) were present on admission and therefore could not have been acquired on the unit. One S. aureus infection did come from the patient's own ¯ora and in the other case the patient was not a carrier and the organisms did not match any type cultured from the other two groups of patients.
I.G. Camilleri et al. / Burns 25 (1999) 655±658
657
Table 1 Distribution of pathogens in the dierent subgroups
No. of Patients Screening swabs S. aureus Strep. pneumoniae H. in¯uenzae b haemolytic Strep. Infection rate S. aureus b haemolytic Strep. Multiple pathogensa No growth a
Elective Surgery
Emergency (non burn)
Burns group
Total (%)
95
36
43
28 3 0 1
0 2 1 0
5 0 0 0
33 5 1 1
(19%) (2.8%) (0.6%) (0.6%)
1 0 0 0
1 0 0 1
3 0 1 0
5 1 1 1
(2.8%) (0.6%) (0.6%) (0.6%)
174
Enterococci, coliforms.
4. Discussion The overall infection rate in paediatric patients is signi®cantly lower than that in adult burns [2,3]. Despite this, infections remain as serious complications in paediatric burns with signi®cant morbidity and mortality in particular in those with severe burns, both due to lack of skin resistance and immunocompromise. Predisposing factors include more than 20% full thickness burn and indwelling devices [3]. Burn injury destroys the natural barrier mechanisms of the skin and contamination invariably occurs despite the use of topical antimicrobial agents. Although infections are most commonly acquired from the patient's own ¯ora [4,5], children may become infected from other patients, frequently in the hospital for elective operations. Other areas of concern are sta carriers and occult contamination of agents such as disinfectants [6]. Our original policy included screening, by means of nose and throat swabs, of all patients admitted to the unit in order to detect any potential pathogen carriers. The medical and paramedical sta is regularly screened but this is not the case for patients' relatives or visitors. In this study we found that of the 40 patients with positive screening swabs, 32 patients (82.5%) came from the elective surgery group while only 5 (12.5%) were burns patients. The most common organism encountered was S. aureus (33 patients, 19%) while Strep. Pneumoniae, H. in¯uenzae and b haemolytic streptococci were less frequently encountered. The high frequency of S. aureus encountered was in keeping with other studies [7,8]. Methicillin and aminoglycoside-resistant S. aureus is becoming a signi®cant problem [7] in many burn centres although none featured in our study. It was interesting to note that none of our cases featured Pseudomonas species or yeasts although outbreaks of these infections had been reported on our ward previously.
The process of burn wound colonisation is a dynamic one. In some studies [2], initial dominance of S. aureus, and a haemolytic streptococci species was followed by a rise in the count of enterococci, Pseudomonas and Candida species. The average hospital stay for our patients was 12 days, which may explain the dominance of the former organisms in the wound swabs. Even if cross infection can be prevented, the patient's burns may become colonised from his/her own intestinal tract. Non absorbable antibiotics are not used routinely in the UK but maintenance of bowel ¯ora by early enteral feeding is the key to prevent bacterial translocation across the gastrointestinal tract and systemic sepsis. In most units the prevention of contact spread is all that is required to reduce crossinfection. The major source of infection is the patient and every eort should be made to reduce microbial dissemination. One way of achieving this is by the use of topical antimicrobials. Good aseptic techniques are necessary during dressing changes, although most of the protective clothing for dressing postoperative wounds on the ward has been discarded over the years [9]. The discontinuation of facemasks on wards during dressing changes has not been associated with an increase in infection [9]. It would seem to be rational for sta changing dressings to wear disposable aprons and gloves, but caps, masks, or overshoes probably contribute very little to the reduction of cross-infection. Hands should be disinfected before and after a dressing change. Work surfaces associated should be wiped with alcoholic solution between patients. Similar precautions are necessary for isolation nursing and all patient contact including bedmaking and hands should be disinfected even if gloves are worn. Excessive or topical use of antibiotics will not necessarily increase cross-infection but will select resistant strains which makes treatment more dicult as resistance is associated with more virulent strains [10]. The use of antibiotics in infected cases may decrease the patient's stay
658
I.G. Camilleri et al. / Burns 25 (1999) 655±658
in hospital, thus reducing the opportunities for cross infection. Similarly early tangential excision of a burn and grafting reduces the risks of spread of pathogens by reducing the size of the source. Finally regular surveillance plays a major role in the prevention of crossinfection. Some larger burns are re-admitted for grafting, often over periods of several years. If the patient carries an undesirable strain, case notes should be clearly marked. Rapid identi®cation of these patients enables them to be promptly moved to isolation facilities [10]. Much of the information about cross-infection is available and although further research is helpful, it is well documented that aseptic discipline by sta is a major requirement.
5. Conclusions From this audit there are several conclusions that can be drawn. S. aureus is the dominant organism found in carriers and caused the majority of infections in this study. Our present management strategy of mixing burns and general plastic surgery patients does not appear to compromise either group of patients. Burn wounds tended to become colonised from the patients' own ¯ora rather than from other patients. In this study screening swabs were useful in detecting carriers of potential pathogens and alerting the ward sta of
potential cross infection between patients, although this did not occur signi®cantly in our study. References [1] Cruickshank R. The bacterial infection of burns. Journal of Pathology and Bacteriology 1935;41:367±9. [2] Heggers J, Linares HA, Edgar P, Villareal C, Herndon D Treatment of infections in burns. In: Herndon D, editors. Total burn care. Philadelphia: Saunders. p. 98±135. [3] Schlager T, Sadler J, Weber D, Donowitz L, Lohr J. Hospital acquired infections in paediatric burns patients. Southern Medical Journal 1994;87:481±4. [4] Heggers JP, Robson MC, Ko F, et al. Transient and resident micro¯ora of burn unit personnel and its in¯uence on burn wound sepsis. Infec Control 1982;3:471±4. [5] Pruitt B, McManus AT. Opportunistic infections in severely burned patients. Am J Med 1984;76:146±53. [6] Pandit DV, Gore MA, Saileshwar N, Deodhar LP. Laboratory data from the surveillance of a burns ward for the detection of hospital infection. Burns 1993;19:52±5. [7] Taylor GD, Kibsey P, Kirkland T, Burroughs E, Tredget E. Predominance of staphylococcal organisms in infections occurring in a burns intensive care unit. Burns 1992;18:332±5. [8] Farrington M, Ling T, French GL. Outbreaks of infection with methicillin-resistant Staphylococcus aureus on neonatal and burns units of a new hospital. Epidemiology and Infection 1990;105:215±28. [9] Taylor LJ. Are face masks necessary in operating theatres and wards? Journal of Hospital Infection 1980;1:173±5. [10] Ayclie GA, Lilly HA. Cross-infection and its prevention. Journal of Hospital Infection 1985;6:47±57.