Section of Occupational Medicine
S
Laboratory Service and Blood Transfusion laboratories in England and Wales enquiring about health and safety in laboratories in general and 4 diseases in particular: tuberculosis, hepatitis, shigellosis and brucellosis. Phase 2: A mortality study of pathologists and technicians. Phase 3: A prospective enquiry over a twelvemonth period in 10% of the Phase 1 laboratories to determine the sickness absence and accident record in these laboratories. The data presented here represent the preliminary results from the accident returns of 36 of the laboratories (90 %) included in Phase 3 and from visits to all 40 pathology departments.
95
Table 4 Analysis of type in 602 laboratory accidents (90 % of Phase 3 laboratory returns) Type of accident Cuts (glassware) Cuts (others) Cuts (knives, needles)
Burns Leaks, splashes, spills Falls Contusions Mouth pipetting Animal bites Eyes Gassings Explosions Assaults
No. 247 100 93 44 36 24 16 9 9 8 6 5 4
Safety precautions: Although most laboratories No major differences in accident rates seem provided washing facilities in the laboratory only to distinguish the different pathology disciplines 54% formally instructed new starters in safety. (Table 3), though microbiology does experience Two-thirds of the laboratories permitted mouth a slightly higher accident rate. pipetting. Preliminary returns from Phase 1 Most of the injuries were caused by lacerations suggest that the servicing of safety cabinets and to of one type or another (Table 4) but it is disa lesser extent centrifuges is infrequent and in turbing to note that on 9 occasions mouth some cases is never done with the appropriate pipetting accidents resulted in injury, usually instruments or servicing agencies. from swallowing corrosive or infected material. The younger laboratory workers had higher Accidents: In a population of 2186 staff, 602 accident rates than the older ones but ethnic accidents resulting in injury occurred and although origin was of no significance. the figures for porters and morticians are probably REFERENCES erroneous due to inaccuracies in assessing the Antony H M & Thomas G M population at risk, over three-quarters of the (1970) Journal ofthe National Cancer Institute 45, 859-895 accidents occurred to two-thirds of the popula- Department of Health and Security (1970) Precautions against Tuberculous Infection in the Diagnostic Laboratory. HM(70) 60 tion, namely the technical staff (Table 2). Reid D D (1957) British MedicalJournal ii, 10-14 Sulkin S E & Pike R M (1951) American Journal ofPublic Health 41, 1-13, 769-781 Uldali A (1974) Scandinavian Journal of Clinical andLaboratory Investigation 33, 21-25
Table 2 Phase 3: accidents with injury by laboratory grade (90 % of laboratories)
Total Population Annual rate Staffgrade per 1000 injuries at risk Medical 19 163 116.5 Scientific qualified 5 75 66.6 Technical qualified 250 817 306.0 Technical junior/student 213 611 348.5 Clerical 19 226 84.2 Domestic Morticians Porters
Total
Domestic/porter
51 10 35
234 25 35
218.1 400.0 1000.0
602 86
2186 269
276.0 319.8
Table 3 Accident injury rates by laboratory division Laboratory division General duties
Hematology Morbid anatomy Microbiology Clinical chemistry Not stated
All types
Total
Laboratory Annual rate
injuries 37
population 327 485 334 571 469
per 1000 113.1 270.0 263.5 339.9 242.7
2186
276.0
131 88 194 115
37 602
Dr C H L Howells (Public Health Laboratory Service, University Hospital of Wales, Heath Park, Cardiff, CF4 4XW)
Infections in Hospitals Infection in hospitals has been a problem for many years. Pioneer work by Semmelweis, Lister and many others enabled preventive measures to be instituted and the incidence of such infection to be reduced to manageable proportions. Outside the laboratory, an area already covered by Dr Harrington, most preventive work has concerned patients rather than staff. In the University Hospital of Wales (UHW) the proportion of staff who are untrained in aseptic technique and
96 Proc. roy. Soc. Med. Volume 68 February 1975 presumably unaware of possible dangers is surprisingly large (Table 1). They work in an atmosphere contaminated by infected patients and carriers resulting in dissemination of microorganisms in dust, linen and fomites. The micro-organisms concerned include Grampositive cocci (Staphylococcus aureus, Streptococcus pyogenes), various Gram-negative rods, some Gram-positive rods, acid-fast bacilli and viruses. (1) Staphylococcus aureus infections in patients include wound sepsis, pemphigus, enterocolitis, breast abscess and pneumonia. Infections in staff are not widely reported. Davies (1960) described 146 cases in 725 nurses at the London Hospital and noted a nuisance value out of proportion to the severity, the nurses concerned having to be removed from contact with patients. Again, Behrendt (1969) found 700 pyodermas in 501 staff over seven years; 73 % were caused by Staphylococcus aureus. Local findings at UHW are shown in Table 2; the incidence amongst housekeeping staff is noteworthy. (2) Streptococcus pyogenes, once the organism most feared in puerperal infections, was a cause of septicemia amongst morbid anatomists. Semmelweis himself, although an obstetrician, frequently worked in the autopsy room and is thought to have died from such infection. The organism can still be found causing sore throats amongst staff. A few girls become carriers with adverse effects on their careers. (3) Gram-negative rods are also important. They enter the hospital environment via infected patients and on contaminated food. Thus Shooter et al. (1971) found various Gram-negative rods in washing-up water in hospital kitchens. Although there have been no outbreaks in UHW, evidence of infection is often revealed by gastroenteritis amongst residents. Even in the absence of such infections, however, there is colonization in the bowel of hospital staff. Many of these organisms are resistant to antibiotics and carry R. factors. It is possible that urinary infections might result and surveillance of such infections Table 1 Distribution of staff at University Hospital of Wales, May 1974
Staff Nursing Housekeeping Catering Medical Administrative and clerical Portering Para-medical Engineering and building
37 17 13 9 9 8 4
3
6 Table 2 Distribution of University Hospital of Wales stafl presenting with septic lesions, 1 October 1973 to 31 March 1974
Staff Housekeeping staff Clerical staff Catering staff Technicians Porters Stores Nursing staff Security Operating theatre staff Carpenters Resident gymnast
% 28 18 16 12 10 4 4 2 2 2 2
amongst hospital staff would be an interesting exercise. Catering staff are often screened to detect Salmonella spp. The organisms have also been isolated from chicken giblets in our kitchens with no adverse effects to date (R W S Harvey 1974, personal communication). (4) Infections with Gram-positive rods are uncommon. C. diphtherie infections have occurred in a neighbouring mental hospital, however, which underlines the desirability of Schick testing and giving toxoid if necessary. Spore bearing rods rarely cause problems. (5) M. tuberculosis: It is important that the official recommendation of initial X-ray, Mantoux and BCG if required should be followed by an annual X-ray. This is particularly so where the staff concerned are from countries with a high incidence of tuberculosis. There have been 4 unexpected cases of tuberculosis in patients at UHW but no infections in staff. (6) 'Australia antigen' infection: This is transmitted to susceptible subjects by blood, either from carriers or from blood for transfusion. Since 1965 there have been 120 cases in the staff of British hospitals with 6 deaths. Preventive measures include the education of all staff in the dangers of handling blood carelessly and of accidents with used syringes and needles. The identification of patients who are a special risk is also important, i.e. those with chronic liver disease, on immunosuppressive therapy, with polyarteritis nodosa, with a history of blood transfusion or who are immigrants from Africa or Asia. Routine monitoring of staff in dialysis units, of blood for transfusion and of the above patients should be initiated. Special care should be exercised when any of them have blood taken. The specimens should be placed in sealed polythene bags identified with a yellow label before being sent to the laboratory. During 1973 there were 6 infected patients in the dialysis unit at UHW and 3 non-laboratory staff were infected. From the Blood Transfusion Service, 8 bottles were found to be antibody positive and 8 antigen positive. In
97
7
Section of Occupational Medicine
Table 3
particularly amongst those with no special knowledge and not trained in asepsis. As mentioned before, the proportion of such staff is surprisingly large. Of the 273 housekeeping staff 174 individuals (63.7%) presented 638 medical certificates between 1 October 1973 and 31 March 1974. Table 3 shows that well over half this illness was caused by infection as well as the distribution of such infections. A planned prospective trial would be interesting with non-hospital staff used as controls.
Diagnosis on medical certificates in housekeeping staff, 1 October 1973 to 31 March 1974 No. Infections: Respiratory Gastrointestinal Other Non-infections Illegible/no diagnosis
219 63 359 77 222 57
Total
638
°/ 34.3 9.9 .56.3 12.1 J 34.7 9 100
the Renal Transplant Unit 8 antigen positive cases were found. (7) Herpetic whitlow: This infectious skin lesion, due to the herpes simplex virus, occurs in staff nursing patients on tracheostomy. A deepseated vesicle is found on the hand, especially on the middle finger subsiding in 14 days leaving a painful, dry, crusted vesicle. The condition can be prevented by wearing gloves. There have been few cases at UHW. (8) Rubella: Nursing staff are in danger of infection from infants with congenital rubella or from infected fetal material. Those with low immunity should be identified and offered vaccine. At UHW 10% of our nurses required vaccination. (9) Influenza: Large scale immunization is probably not justified in the absence of a definite pandemic. Ffrench & Ellison (1970) described a reduced rate of upper respiratory illness in vaccinated nurses and suggested that nurses of African and Indian origin might need more protection. At UHW a limited trial of zonally purified vaccine showed that only 2 of 37 vaccinated nurses developed upper respiratory illness as compared with 9 non-vaccinated controls. (10) Smallpox: Although smallpox is a rarity, hospital staff should all be vaccinated and carry a record of such vaccinations.
Some improvement in the situation might result when plans for the provision of an adequately staffed Occupational Health Service materialize. There are obvious advantages in undertaking pre-employment medical examination, ensuring a clean environment, correct immunization, and giving education and advice to those whose knowledge of infection and asepsis is rudimentary. In addition, bacteriological investigation of infections in hospital staff would add to our knowledge of the epidemiology of these conditions. REFERENCES Behrendt F B (1969) Danish Medical Bulletin 16, 4 Davies D M (1960) Lancet i, 644-645 Ffrench G E & Ellison S E (1970) Practitioner 205, 346-350 Shooter R A, Cooke E M, Faiers M C, Breaden A L & O'Farrell S M (1971) Lancet ii, 390-392
The following papers were also read: Work of a Hospital Safety and Occupational Health Committee Dr J R Glover (Welsh National School ofMedicine, Cardiff, CF4 4XN)
Other conditions such as glandular fever and 'Royal Free disease' also occur. In the latter condition the presentation is vague with malaise, Unsuspected Electrical Hazards in a Hospital sore throat, increasing headache, neck ache, back Mr J P McCarthy ache, limb pains and dizziness. Few physical (Welsh National School of Medicine, signs are found. Symptoms persist for many Cardiff, CF4 4XN) months. T'hermal Stress in Hospital Kitchens It appears that hospital staff can suffer infection Mr J Mason-Williams and Dr R L Kell from a variety of pathogens. In the University (Welsh National School of Medicine, Hospital of Wales the situation seems reflected Cardiff, CF4 4XN)
S
Laboratory Service and Blood Transfusion laboratories in England and Wales enquiring about health and safety in laboratories in general and 4 diseases in particular: tuberculosis, hepatitis, shigellosis and brucellosis. Phase 2: A mortality study of pathologists and technicians. Phase 3: A prospective enquiry over a twelvemonth period in 10% of the Phase 1 laboratories to determine the sickness absence and accident record in these laboratories. The data presented here represent the preliminary results from the accident returns of 36 of the laboratories (90 %) included in Phase 3 and from visits to all 40 pathology departments.
95
Table 4 Analysis of type in 602 laboratory accidents (90 % of Phase 3 laboratory returns) Type of accident Cuts (glassware) Cuts (others) Cuts (knives, needles)
Burns Leaks, splashes, spills Falls Contusions Mouth pipetting Animal bites Eyes Gassings Explosions Assaults
No. 247 100 93 44 36 24 16 9 9 8 6 5 4
Safety precautions: Although most laboratories No major differences in accident rates seem provided washing facilities in the laboratory only to distinguish the different pathology disciplines 54% formally instructed new starters in safety. (Table 3), though microbiology does experience Two-thirds of the laboratories permitted mouth a slightly higher accident rate. pipetting. Preliminary returns from Phase 1 Most of the injuries were caused by lacerations suggest that the servicing of safety cabinets and to of one type or another (Table 4) but it is disa lesser extent centrifuges is infrequent and in turbing to note that on 9 occasions mouth some cases is never done with the appropriate pipetting accidents resulted in injury, usually instruments or servicing agencies. from swallowing corrosive or infected material. The younger laboratory workers had higher Accidents: In a population of 2186 staff, 602 accident rates than the older ones but ethnic accidents resulting in injury occurred and although origin was of no significance. the figures for porters and morticians are probably REFERENCES erroneous due to inaccuracies in assessing the Antony H M & Thomas G M population at risk, over three-quarters of the (1970) Journal ofthe National Cancer Institute 45, 859-895 accidents occurred to two-thirds of the popula- Department of Health and Security (1970) Precautions against Tuberculous Infection in the Diagnostic Laboratory. HM(70) 60 tion, namely the technical staff (Table 2). Reid D D (1957) British MedicalJournal ii, 10-14 Sulkin S E & Pike R M (1951) American Journal ofPublic Health 41, 1-13, 769-781 Uldali A (1974) Scandinavian Journal of Clinical andLaboratory Investigation 33, 21-25
Table 2 Phase 3: accidents with injury by laboratory grade (90 % of laboratories)
Total Population Annual rate Staffgrade per 1000 injuries at risk Medical 19 163 116.5 Scientific qualified 5 75 66.6 Technical qualified 250 817 306.0 Technical junior/student 213 611 348.5 Clerical 19 226 84.2 Domestic Morticians Porters
Total
Domestic/porter
51 10 35
234 25 35
218.1 400.0 1000.0
602 86
2186 269
276.0 319.8
Table 3 Accident injury rates by laboratory division Laboratory division General duties
Hematology Morbid anatomy Microbiology Clinical chemistry Not stated
All types
Total
Laboratory Annual rate
injuries 37
population 327 485 334 571 469
per 1000 113.1 270.0 263.5 339.9 242.7
2186
276.0
131 88 194 115
37 602
Dr C H L Howells (Public Health Laboratory Service, University Hospital of Wales, Heath Park, Cardiff, CF4 4XW)
Infections in Hospitals Infection in hospitals has been a problem for many years. Pioneer work by Semmelweis, Lister and many others enabled preventive measures to be instituted and the incidence of such infection to be reduced to manageable proportions. Outside the laboratory, an area already covered by Dr Harrington, most preventive work has concerned patients rather than staff. In the University Hospital of Wales (UHW) the proportion of staff who are untrained in aseptic technique and
96 Proc. roy. Soc. Med. Volume 68 February 1975 presumably unaware of possible dangers is surprisingly large (Table 1). They work in an atmosphere contaminated by infected patients and carriers resulting in dissemination of microorganisms in dust, linen and fomites. The micro-organisms concerned include Grampositive cocci (Staphylococcus aureus, Streptococcus pyogenes), various Gram-negative rods, some Gram-positive rods, acid-fast bacilli and viruses. (1) Staphylococcus aureus infections in patients include wound sepsis, pemphigus, enterocolitis, breast abscess and pneumonia. Infections in staff are not widely reported. Davies (1960) described 146 cases in 725 nurses at the London Hospital and noted a nuisance value out of proportion to the severity, the nurses concerned having to be removed from contact with patients. Again, Behrendt (1969) found 700 pyodermas in 501 staff over seven years; 73 % were caused by Staphylococcus aureus. Local findings at UHW are shown in Table 2; the incidence amongst housekeeping staff is noteworthy. (2) Streptococcus pyogenes, once the organism most feared in puerperal infections, was a cause of septicemia amongst morbid anatomists. Semmelweis himself, although an obstetrician, frequently worked in the autopsy room and is thought to have died from such infection. The organism can still be found causing sore throats amongst staff. A few girls become carriers with adverse effects on their careers. (3) Gram-negative rods are also important. They enter the hospital environment via infected patients and on contaminated food. Thus Shooter et al. (1971) found various Gram-negative rods in washing-up water in hospital kitchens. Although there have been no outbreaks in UHW, evidence of infection is often revealed by gastroenteritis amongst residents. Even in the absence of such infections, however, there is colonization in the bowel of hospital staff. Many of these organisms are resistant to antibiotics and carry R. factors. It is possible that urinary infections might result and surveillance of such infections Table 1 Distribution of staff at University Hospital of Wales, May 1974
Staff Nursing Housekeeping Catering Medical Administrative and clerical Portering Para-medical Engineering and building
37 17 13 9 9 8 4
3
6 Table 2 Distribution of University Hospital of Wales stafl presenting with septic lesions, 1 October 1973 to 31 March 1974
Staff Housekeeping staff Clerical staff Catering staff Technicians Porters Stores Nursing staff Security Operating theatre staff Carpenters Resident gymnast
% 28 18 16 12 10 4 4 2 2 2 2
amongst hospital staff would be an interesting exercise. Catering staff are often screened to detect Salmonella spp. The organisms have also been isolated from chicken giblets in our kitchens with no adverse effects to date (R W S Harvey 1974, personal communication). (4) Infections with Gram-positive rods are uncommon. C. diphtherie infections have occurred in a neighbouring mental hospital, however, which underlines the desirability of Schick testing and giving toxoid if necessary. Spore bearing rods rarely cause problems. (5) M. tuberculosis: It is important that the official recommendation of initial X-ray, Mantoux and BCG if required should be followed by an annual X-ray. This is particularly so where the staff concerned are from countries with a high incidence of tuberculosis. There have been 4 unexpected cases of tuberculosis in patients at UHW but no infections in staff. (6) 'Australia antigen' infection: This is transmitted to susceptible subjects by blood, either from carriers or from blood for transfusion. Since 1965 there have been 120 cases in the staff of British hospitals with 6 deaths. Preventive measures include the education of all staff in the dangers of handling blood carelessly and of accidents with used syringes and needles. The identification of patients who are a special risk is also important, i.e. those with chronic liver disease, on immunosuppressive therapy, with polyarteritis nodosa, with a history of blood transfusion or who are immigrants from Africa or Asia. Routine monitoring of staff in dialysis units, of blood for transfusion and of the above patients should be initiated. Special care should be exercised when any of them have blood taken. The specimens should be placed in sealed polythene bags identified with a yellow label before being sent to the laboratory. During 1973 there were 6 infected patients in the dialysis unit at UHW and 3 non-laboratory staff were infected. From the Blood Transfusion Service, 8 bottles were found to be antibody positive and 8 antigen positive. In
97
7
Section of Occupational Medicine
Table 3
particularly amongst those with no special knowledge and not trained in asepsis. As mentioned before, the proportion of such staff is surprisingly large. Of the 273 housekeeping staff 174 individuals (63.7%) presented 638 medical certificates between 1 October 1973 and 31 March 1974. Table 3 shows that well over half this illness was caused by infection as well as the distribution of such infections. A planned prospective trial would be interesting with non-hospital staff used as controls.
Diagnosis on medical certificates in housekeeping staff, 1 October 1973 to 31 March 1974 No. Infections: Respiratory Gastrointestinal Other Non-infections Illegible/no diagnosis
219 63 359 77 222 57
Total
638
°/ 34.3 9.9 .56.3 12.1 J 34.7 9 100
the Renal Transplant Unit 8 antigen positive cases were found. (7) Herpetic whitlow: This infectious skin lesion, due to the herpes simplex virus, occurs in staff nursing patients on tracheostomy. A deepseated vesicle is found on the hand, especially on the middle finger subsiding in 14 days leaving a painful, dry, crusted vesicle. The condition can be prevented by wearing gloves. There have been few cases at UHW. (8) Rubella: Nursing staff are in danger of infection from infants with congenital rubella or from infected fetal material. Those with low immunity should be identified and offered vaccine. At UHW 10% of our nurses required vaccination. (9) Influenza: Large scale immunization is probably not justified in the absence of a definite pandemic. Ffrench & Ellison (1970) described a reduced rate of upper respiratory illness in vaccinated nurses and suggested that nurses of African and Indian origin might need more protection. At UHW a limited trial of zonally purified vaccine showed that only 2 of 37 vaccinated nurses developed upper respiratory illness as compared with 9 non-vaccinated controls. (10) Smallpox: Although smallpox is a rarity, hospital staff should all be vaccinated and carry a record of such vaccinations.
Some improvement in the situation might result when plans for the provision of an adequately staffed Occupational Health Service materialize. There are obvious advantages in undertaking pre-employment medical examination, ensuring a clean environment, correct immunization, and giving education and advice to those whose knowledge of infection and asepsis is rudimentary. In addition, bacteriological investigation of infections in hospital staff would add to our knowledge of the epidemiology of these conditions. REFERENCES Behrendt F B (1969) Danish Medical Bulletin 16, 4 Davies D M (1960) Lancet i, 644-645 Ffrench G E & Ellison S E (1970) Practitioner 205, 346-350 Shooter R A, Cooke E M, Faiers M C, Breaden A L & O'Farrell S M (1971) Lancet ii, 390-392
The following papers were also read: Work of a Hospital Safety and Occupational Health Committee Dr J R Glover (Welsh National School ofMedicine, Cardiff, CF4 4XN)
Other conditions such as glandular fever and 'Royal Free disease' also occur. In the latter condition the presentation is vague with malaise, Unsuspected Electrical Hazards in a Hospital sore throat, increasing headache, neck ache, back Mr J P McCarthy ache, limb pains and dizziness. Few physical (Welsh National School of Medicine, signs are found. Symptoms persist for many Cardiff, CF4 4XN) months. T'hermal Stress in Hospital Kitchens It appears that hospital staff can suffer infection Mr J Mason-Williams and Dr R L Kell from a variety of pathogens. In the University (Welsh National School of Medicine, Hospital of Wales the situation seems reflected Cardiff, CF4 4XN)
