HEPATITIS IN LABORATORY WORKERS: RISKS AND PRIORITIES

HEPATITIS IN LABORATORY WORKERS: RISKS AND PRIORITIES

956 claiming serious attention. These sceptical juniors can cite supporters both literary and scientific to back them. CICERO wrote: "The authority o...

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956

claiming serious attention. These sceptical juniors can cite supporters both literary and scientific to back them. CICERO wrote: "The authority of those who teach is very often a hindrance to those who wish to learn," 10 and the Royal Society’s motto Nullius in verba means that no one’s say-so will do by itself. Not even in medical education.

enough to suggest that the procedure properly belongs to a hospital setting. Whether desensitised or not, it seems prudent for all persons to carry adrenaline with them when at risk. This can be in aerosol form, but for serious anaphylaxis adrenaline 1 :1000 is needed parenterally: 1 ml can be given slowly subcutaneously for a moderate reaction, intramuscularly in a serious emergency. The trouble in the U.K. is that adrenaline is not available in convenient preloaded syringes as in the U.S.A. This might be corrected by the pharmaceutical industry with considerable benefit to some very frightened people.

seriously sting-sensitive

NEXT YEAR’S BEE AND WASP STINGS As the last wasps crawl away to hibernation this is a good think about what to do for patients who have become seriously sensitised to hymenoptera stings. The subject is in the limelight because desensitising injections made from bee and wasp venom are now commercially available, offering considerable advantages in efficacy and safety over the previously popular whole-body extracts. The best controlled trials of these new venom preparations have been conducted in Lichtenstein’s department in Baltimore, and arduous they must have been. 1,2 Double-blind trials were not possible, but the efficacy of desensitisation was tested by the only convincing method-namely, by arranging for the subject’s to be stung after completion of treatment, and showing either no reaction or at most a trivial one. Before deciding what to do for a patient with a story of sting sensitivity, several factors need careful thought. The first, often difficult, clinical decision is whether to recommend any special treatment at all. Accounts of sting reactions are often exaggerated and with repeated stings the severity of the reaction is much more likely to decrease than to increase. Children with severe reactions tend to become less sensitive with age, and most bee-keepers scarcely bat an eyelid at their inevitable stings. Clinical pointers to potentially serious or fatal sensitisation are a history of shock, unconsciousness, wheezing, or facial and laryngeal oedema immediately after stings. Skin-prick tests with bee or wasp venom are positive in most seriously sensitised subjects. Such people are nearly always terrified of the hymenoptera, but none of these pointers predicts the degree of future risk with precision. If special treatment is decided upon, should this consist simply in providing adrenaline to be carried at times of risk, or should desensitisation be attempted? If desensitisation is favoured, should it be performed in a general practice setting, or is it better left to hospital or specialised centre? In favour of desensitisation is its now proven efficacy; against it are its cost (in money and in time), its side-effects, and the fact that it offers no guarantee of lasting efficacy. Hearsay evidence suggests that, for lasting protection, -it has to be given indefinitely. In immunological terms, it may also be a questionable treatment, since specific IgE to hymenoptera venom will rise during treatment (along with desirable "blocking" IgG), and might conceivably leave the subject more sensitive than before. Although side-effects are not usually severe when venom desensitisation is done carefully, some systemic reactions have been reported-certainly moment to

10. Cicero. De natura deorum I, 5. 1. Hunt KJ, Valentine MD, Sobotka AK, Benton AW, Amodio FJ, Lichtenstein LM. A controlled trial of immunotherapy in insect hypersensitivity. N engl J Med 1978;

299: 157-61. 2.

Chipps BE, Valentine MD, Sobotka AK, Schuberth KC, Lichtenstein LM. Diagnosis and treatment of anaplylactic reactions to Hymenoptera Stings in Children. J Pediatr 1980; 97:1 177-84.

HEPATITIS IN LABORATORY WORKERS: RISKS AND PRIORITIES THE British public could easily be getting the impression, from various pronouncements, that clinical laboratories are pest-houses, a danger both to their staff and to the world at large. This is scarcely the impression of those who work in them, and a useful opportunity to review the evidence was provided by a symposium on laboratory-acquired infection organised by the Royal College of Pathologists early this month. First, Dr J. M. Harrington summarised the surveys of morbidity and mortality in British medical laboratory workers done between 1971 and 1974 from the T.U.C. Centenary Institute of Occupational Health. 1-3 These revealed a pattern of sickness absence and accidents similar to that in other working populations, though with excess rates for tuberculosis, diarrhoea, dermatitis, and possibly hepatitis and shigellosis. Then Prof N. R. Grist and Dr S. Polakoff presented data on hepatitis in British laboratories up to the end of 1979. Both the continuing survey of hepatitis in clinical laboratories by the Association of Clinical Path010gists4-7 and the analysis of hepatitis B infections reported to the Public Health Laboratory Service8 had shown a sharp absolute and relative decline in the incidence of infection in laboratory staff since the end of 1974, for which the most likely explanation was improved safety-consciousness after the outbreaks associated with dialysis units in the 1960s and several consequent reports.9-12 This explanation fits the known properties of hepatitis B virus, which in laboratories is spread parenterally, either through tissue penetration by 1. 2. 3.

4.

Harrington JM, Shannon HS. Mortality study of pathologists and medical laboratory technicians. Br Med J 1975; ii: 329-32. Harrington JM, Shannon HS. Incidence of tuberculosis, hepatitis, brucellosis, and shigellosis in British medical laboratory workers. Br Med J 1976, i: 759-62. Harrington JM, Shannon HS. Survey of safety and health care in British medical laboratories. Br Med J 1977; i: 626-28. Grist NR. Hepatitis in clinical laboratories: a three-year survey. J Clin Path 1975, 28: 255-59.

5. Grist NR. 6. Grist NR. 7. Grist NR.

Hepatitis in clinical laboratories 1973-74. J Clin Path 1976, 29: 480-83 Hepatitis in clinical laboratories 1975-76. JClin Path 1978, 31: 415-17. Hepatitis in clinical laboratories 1977-78 J Clin Path 1980, 33: 471-73 8. Acute hepatitis B in laboratory staff: reports to the CDR during seven epidemiological years, mid 1972-1979. Commun Dis Rep 1979, 79/48. 9. Working Party of Central Pathology Committee, Department of Health and Social Security and Welsh Office, chairman J.G. Heggie, Safety in pathology laboratories London: D.H.S S., 1972. 10. Hepatitis and the treatment of chronic renal failure: Report of Advisory Group 1970-72, Chairman Lord Rosenheim. Department of Health and Social Security, Scottish Home and Health Department and Welsh Office, 1972. 11. Revised report of the Advisory Group on Testing for the Presence of Australia (Hepatitis Associated) Antigen and its Antibody, Chairman W d’A. Maycock, Department of Health and Social Security, Scottish Home and Health Department and Welsh Office, 1972. 12. Collins CH, Hartley EG, Pilsworth R The prevention of laboratory-acquired infection. Publ Health Lab Serv Monog Ser no.6. London: H.M Stationery Office, 1974.

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accidents with infected "sharps" or by contagion of broken skin from contaminated apparatus or surfaces. 13 These mechanisms of infection are easily interrupted by the high standards of microbiological technique and safety recommended in 1978 by the "Howie Code" for category C organisms.14 Category C corresponds to the American class

2, in which hepatitis-associated-antigen material is termed an agent of ordinary potential hazard: this class includes agents which may produce disease of varying degrees of severity from accidental inoculation or injection or other means of cutaneous penetration but which are contained by ordinary laboratory techniques. Unfortunately, to avoid a minority report, the Howie Code divided hepatitis between category B 1, requiring both special accommodation and conditions for containment (to include materials known to contain hepatitis B virus) and category B2 requiring special conditions for containment but not special accommodation (category B2, including materials known to contain hepatitis B surface antigen and specimens from patients with defined conditions having strong association with hepatitis B infection). This recommendation, from which Sir James Howie and another member of the working-party now dissent,16 has generated considerable alarm among those who feel that such inconvenient and expensive recommendations imply that there must be a commensurate danger, and despondency in those whose task is to provide an efficient and speedy laboratory service. In an attempt to put things right, a working-party of clinical pathologists and biochemists with the Institute of Medical Laboratory Sciences and the Royal College of Pathologists has produced a case for downgrading hepatitis B specimens from category B2 to category C. 17 This is based on consideration of the practical difficulties-the delays and limitations of testing specimens from patients labelled B2 (possibly for inadequate reasons) and the impossibility of recognising every carrier. Even if every blood sample could be pretested for hepatitis B, why single out this infection for special attention ? The Association of Scientific, Technical and Managerial Staffs (ASTMS) disagrees and has published its argument against the "attempt to downgrade safety standards in laboratories testing hepatitis B virus specimens".18 The Association denounces the Department of Health and its shadowy committees of "experts", whose guidance is criticised as inadequate and badly drafted. One valid point is that those who advise the Department and those who speak for the pathologists should be different people: in a specialised area, supposedly separate committees are apt to have members in common. But when it comes to facts, the Association’s document is on boggy ground, as emerges from comparison of the text with original documents4-’’6 provided as appendices. Data have been misunderstood and misinterpreted. In the power-play between the crusading trade-union and those 13. Lauer JL, Van Drunen NA, Washburn JW, Balfour HH. Transmission of hepatitis B virus in clinical laboratory areas. JInfect Dis 1979; 140: 513-16 14. Working Party to formulate a Code of Practice for the Prevention of Infection in Clinical laboratories, Chairman J. W. Howie. London: H.M.S.O., 1978. 15. UnitedStatesDepartmentof Health,EducationandWelfare.Classificationof etiologic agents on the basis of hazard. Atlanta: Center for Disease Control, 1974. 16. Howie JW, Collins CH. The Howie code for preventing infection in clinical laboratories comments on some general criticisms and specific complaints. Br Med J 1980; 280: 1071-74. 17. Joint Working Party of the Association of Clinical Biochemists, Association of Clinical Pathologists, Institute of Medical Laboratory Sciences and Royal College of Pathologists. Stated case for downgrading hepatitis B virus specimens(B2)to Category C.

April 29,

1980

18. Association of Scientific, Technical and Managerial Staffs. The risks of hepatitis to laboratory workers: the case against the attempt to downgrade safety standards in laboratories testing Hepatitis B virus specimens. Health and Safety Office Special Report, August, 1980.

despised "medics", let us hope that interests of patients will prevail.

commonsense

and the

EPIDEMIOLOGY AND THE CLINICIAN EPIDEMIOLOGY and its place in medicine is attracting much attention nowadays.1It was the subject ofaremarkable meeting in London on Oct. 16 under the chairmanship of Prof. Donald Acheson, attended by more than a hundred medical men and women from every branch of the profession. Two weeks previously a seminar on the same topic, for senior academic clinicians from the Third World, took place at the University of Cambridge and was heavily oversubscribed. To judge by the scale of support at the meeting and the strength of the opinions expressed, doctors with interests as different as ophthalmic surgery, gynaecology, and general practice now see epidemiology as an essential element in the framework of medicine without which their efforts are diminished or rendered fruitless. Several of the younger speakers voiced their frustration at the inflexibility of the British postgraduate system which makes it virtually impossible for them to gain skills in epidemiology and continue in clinical practice; some felt that a barbed-wire entanglement had been erected between the two, to the detriment of both. Several contributions from the floor showed that the plight of the would-be full-time epidemiologist is at least as serious. It is ironic that the Faculty of Community Medicine, which claims epidemiology as a major role but seldom practises it, cannot fill its ranks while a substantial number of able men and women who wish to practise epidemiology are dissuaded from entering the specialty because they do not want to spend most of the their time in administration.2,3 (No-one at the meeting spoke officially for the Faculty.) In such circumstances the setting up of a national epidemiological service with strong links with clinical medicine, along the lines suggested by Galbraith,4seems worthy of serious consideration. In the experience of Dr R. B. Cole at the North Staffordshire Medical Institute, facilities for research into epidemiology and preventive medicine can act as a focus for doctors in hospital, general practice, and industry as well as community medicine and can attract financial support from

private sources. Epidemiological surveys are the essential means by which the community’s needs for health care are determined and by which the benefits of health care are measured. Such data, together with information about costs, are the only national basis for the assignment of priorities between conflicting claims for resources; and, as populations grow and resources shrink, their importances increases. Dr John Evans, director of the Department of Population, Health and Nutrition of the World Bank, and other speakers from overseas, emphasised that in the Third World the efforts of full-time experts in community health are largely ineffective if, as is generally the case, the medical profession lacks understanding of the issues. Therefore the urgent need for a wider comprehension of the techniques of epidemiology and its closer involvement with medical practice, is not confined to the United

Kingdom. 1. Orchard TJ. Epidemiology in the 1980s-Need for a change? Lancet 1980; ii: 845-46. 2. Joint Working Group. Recruitment to community medicine. London- HMSO, 1980. 3. Hall DJ, Donaldson RJ. A note on differences between the work undertaken by area

medical officers of single-district and multi-district health authority areas in England and between district community physicians in England who are and who are not "proper officers". 4. Galbraith NS. Presidential address to the Royal Society of Health, 1980.