- Email: [email protected]
SURVEY OF ANTIBIOTIC PRESCRIBING IN A DISTRICT GENERAL HOSPITAL I. PATTERN OF USE
349
Hospital Practice SURVEY OF ANTIBIOTIC PRESCRIBING IN A DISTRICT GENERAL HOSPITAL I. PATTERN OF USE
(1.) The anatomical site of infection. (2.) The clinical, radiological, and laboratory findings
M. W. MCNICOL D. L. MILLER
FIONA MOSS* D. A. MCSWIGGAN
Cardio-thoracic Department; Department of Microbiology and Public Health Laboratory; and Department of Community Medicine (Middlesex Hospital Medical School), Central Middlesex Hospital, London NW10
Summary
In
a
survey
of
of drug, dose, initial route of administration, and the date of starting the antibiotic were recorded. The age and sex of the patients, the type of admission (whether emergency or booked), and the admitting team were also noted. As soon as possible after the prescription, always within 48 hours, the prescriber was interviewed by F.M. using a standard questionnaire. Prescribers were first asked to state whether the antibiotic was given for therapeutic or prophylactic purposes. The prescribers of therapeutic antibiotics were asked: used as evidence of infection. (3.) Whether any bacteriological investigations had been requested. (4.) Whether the bacteria responsible for the infection had been isolated. (5.) If no organisms had been isolated, the suspected infecting agent. (6.) Any other features relevant to the diagnosis of infection (e.g., diabetes,
corticosteroid or cytotoxic therapy, indwelling urinary catheters).
The
all
antibiotic
pre-
scriptions in a district general hospital during November, 1978, the reason for each prescription was determined by a brief interview with the prescriber. 28% of all inpatients received antibiotics. Older patients were prescribed antibiotics more often than were younger patients. Ampicillin was the most frequently used antibiotic, accounting for over 40% of prescriptions. Over 70% of antibiotic courses were stated by the prescriber as being for the treatment of infection and the remainder were said to be prophylactic. Although 80% of the antibiotics were assessed as suitable treatment for the stated infection, most of the patients were treated without bacteriological evidence of the infecting agent and, for these patients, prescribers were unable to specify the pathogen against which treatment was intended in 50% of the courses they initiated. Only 7% of antibiotics prescribed for conventional surgical prophylaxis fulfilled all the criteria used to assess the suitability of choice of drug and the method and timing of its administration. INTRODUCTION
ANTIBIOTICS are one of the largest single groups of drugs prescribed. Knowledge about their use is important not only because of their cost but also because the price of their misuse, especially in hospital, may be unnecessary morbidity and mortality, high hospital infection rates and rapid
obsolescence of the most valuable drugs.Previous surveys of antibiotic use in hospital’-" have been based on indirectly derived information. Only one refers to the U.K. and that was restricted to patients in certain medical wards.13 A Lancet editorial 14 suggested antibiotic audit as a method of influencing antibiotic prescribing in hospital practice. We report a survey or "audit" of antibiotic use throughout a district general hospital based on interviews with the prescribers. Our findings suggest there is a need to reappraise antibiotic policies as a basis for influencing antibiotic
prescribers of prophylactic antibiotics were asked:
(1.) Whether the patient was exposed to any special risk of infection, such as an operative procedure and, if so, its nature and date. (2.) Any medical condition which might enhance susceptibility to infection (e.g., immunological deficiency, broken barriers such as CSF leak, rheumatic heart disease, corticosteroid therapy). (3) The potential infecting agents against which prophylaxis was mainly directed.
prescribers were asked to state the intended duration of although the actual duration was not recorded. Results of bacteriological tests carried out on the patients were recorded from the laboratory copies of the reports sent to prescribers. All
treatment
The suitability of each antibiotic for its stated purpose was reviewed by two ofus (M.W.McN. and D.A.McS.). For therapeutic prescriptions the antibiotics used were classified as "appropriate" or "inappropriate" having regard to the site of infection, the presumed/known infecting organisms, and known antibiotic hypersensitivity. Prophylactic courses were considered appropriately administered if the antibiotic(s) was given just before the surgical procedure, if the intended duration of the course was 24 h, if the antibiotic(s) was given parenterally (or rectally also for metronidazole), and if the drug(s) chosen was suitable "cover" for the procedure. We use the term prescription to indicate every time that an individual antibiotic was prescribed and the term antibiotic course to describe the use of either a single antibiotic or a combination of antibiotics prescribed together. RESULTS
366 patients were prescribed antibiotics during the period of the survey. This represents 28% of all patients admitted to hospital during that period. The proportion of patients receiving these drugs increased with age, ranging from 24% of those aged under 11years to 63% of those aged 81 years or more (table I). The median age for patients prescribed antibiotics for a therapeutic purpose was 61 years and for TABLE I-AGES OF PATIENTS ADMITTED TO HOSPITAL AND OF THOSE
PRESCRIBED ANTIBIOTICS DURING THE SURVEY PERIOD
prescribing practices. METHOD
The survey
was
done
28 days in November, 1978, at the (CMH), a district general hospital in hospital has 480 beds for acute services
over
Central Middlesex Hospital
north-west London. The and has a neurosurgical unit, an eye surgery unit, an intensive therapy unit, and a special care baby unit. The survey entailed inquiry into all antibiotic prescriptions (except anti-tuberculous therapy) for inpatients. All prescriptions were written by junior medical staff. All wards were visited daily by F.M. For all prescriptions the type ’P-esent address.
Department of Medicine, Whittington Hospital,
London N 19 5NF.
"Obstetric patients not included because their ages were not available. Difference between the proportion of patients <61 years and those >61 received antibiotics was significant (x2 41.5; p<0.001).
years who
350 TABLE 11-MEDICAL AND SURGICAL PATIENTS ADMITTED TO HOSPITAL AND WHO WERE PRESCRIBED ANTIBIOTICS
*X=1
-37
(p= >0 10).
TABLE III-ANTIBIOTIC COURSES AND PRESCRIPTIONS FOR THERAPY AND FOR PROPHYLAXIS I
prescriptions and 33% of prophylactic prescriptions). More than 60% of all prescriptions were for one of the penicillin drugs. The cephalosporins accounted for only 5% of the antibiotics used. Therapeutic Antibiotic Prescriptions 261 patients, about a fifth of all patients admitted during the period of the survey, received at least one course of antibiotics for a condition considered by the prescriber to be due to infection. 43 patients received multiple courses. The sites of the infection identified by the prescribers are shown in table V. The most frequent were lower respiratory (39%), and urinary tract (20%). Surgical wound infection accounted for 6% of cases. Of the 309 courses prescribed therapeutically, the choice of antibiotics was considered "appropriate" in 251 (81%) and
*Combination
courses
significantly more common in prophylaxis (X’ =21’5j p<0’001).
those prescribed antibiotics prophylactically it was 49 years. The frequency of prescriptions for antimicrobial agents did not differ significantly between surgical and medical services.
(table II). 437 courses of antibiotics were prescribed, of which 309 (71%) were therapeutic and 128 (29%) were prophylactic. Nearly a fifth (18%) of prescriptions were for a combination of antibiotics; combinations were significantly more frequently prescribed for prophylaxis than for therapy (table III). The antibiotics used, in rank order of frequency of prescription, are shown in table IV. The ampicillin antibiotics accounted for 41% of all prescriptions (44% of therapeutic TABLE IV-TYPES
OF ANTIBIOTICS USED BY MAJOR SPECIALTIES 4H I7
Fig. I-Microbiological investigations. *Isolates thought
T = therapeutic. P = prophylactic Other antibiotics used were: nystatin 9, cefuroxime 7, amphotericin 6, neomycin 6, sulphadimidine 4, sodium fusidate 3, oxytetracycline 3, nitrofurantoin 3, doxycycline 1, nahdixic acid 1, tobramycin 1. *Includes amoxycillin. t includes flucloxacillin. * includes cephradine. TABLE V- SITES OF INFECTION FOR WHICH ANTIBIOTICS WERE
PRESCRIBED BY MAJOR SPECIALTIES
to
be relevant
to
symptoms.
"inappropriate" in 58 (19%). The most frequent errors were: (a) seriously inadequate cover against the likely infecting organism (e.g., peritoneal or intrauterine infection treated with ampicillin alone); (b) an inappropriate drug for the stated infecting agent (e.g., ampicillin for staphylococcal sepsis); and (c) unsuitable combinations ofdrugs. Specimens (including blood cultures) for microbiological tests were taken from 186 (67%) of the identified sites of infection for which therapeutic antibiotic courses were prescribed. Bacteria, thought to be responsible for the infection, were isolated from 88 (47%) of these. In 29 the laboratory results led to no change in treatment but in 59 the laboratory findings resulted in either the initiation or change of therapy (fig. 1). 250 (80%) of the therapeutic antibiotic courses were started without the prescriber knowing the results of the microbiological tests. For almost half of these, the prescribers stated that they did not suspect any particular infecting agent as the cause of the infection (fig. 2). Prophylactic Antibiotic Prescriptions
*Includes 17
surgical wounds.
128 courses of antibiotics were stated by the prescribers to be for prophylaxis (fig. 3). 90 (70%) were prescribed to cover an operative or non-operative surgical procedure. Of these only 55 were for conventional surgical prophylaxis. Of the
351
antibiotics in patients over 81 years of age was greater than has been previously recorded. This reflects the policy of the geriatric unit where 60% of all patients received antibiotics. All of these prescriptions were classified as therapeutic. These patients also accounted for the higher median age for therapeutic as opposed to prophylactic antibiotic use. In previous studies ampicillin has been the most frequently prescribed drug, accounting for up to 22% of antibiotics used,8but in our survey ampicillin accounted for 41% of antibiotic prescriptions. The cephalosporins (cephaloridine+ TABLE VI-FREQUENCY OF "CORRECT" FEATURES IN 55 COURSES OF "CONVENTIONAL SURGICAL PROPHYLAXIS"
Fig. 2-Relation between microbiological forecast, laboratory tests, and therapeutic courses.
non-surgical
courses
of prophylactic antibiotics,
most were
for trauma.
Only 4 (7%) of the 55 courses of conventional surgical prophylaxis fulfilled all four criteria used for assessment, and 12 (22%) fulfilled none (table vi). The most frequent error was excessive intended duration of prophylaxis, over 80% of courses being planned to continue for longer than 24 hours. Over 66% of courses were started too early (before the day of the operation) or too late (after the procedure). Of the antibiotics prescribed, only 45% were judged as suitable for the stated procedure (table VII). DISCUSSION
The results of this survey, based on an interview with the prescriber rather than pharmacy records or retrospective review of case-notes, are similar to those previously reported from North America. The proportion of patients prescribed antibiotics in our survey was 28% compared with a range of 23% to 36% previously reported.2-12 The proportion. prescribed to medical and surgical patients was also similar, as was the trend to increased prescribing rates of antibiotics in the older patient8,1I although in our study the use of
Fig.
TABLE VII-ASSESSMENT OF
55
COURSES OF
"CONVENTIONAL
SURGICAL PROPHYLAXIS
cefuroxime) were used very infrequently (5%). It seems probable that this pattern of usage is the consequence of the type of antibiotic policy operating in the hospital which depends on indirect influences rather than directive. The sensitivity of organisms to ampicillin is reported routinely but, in contrast, sensitivity to cephalosporins is reported only when the organism is resistant to other commonly used antibiotics. The infrequent use of other antibiotics probably also reflects the laboratories policy of selective reporting rather than any policy of deliberate abstention.
3-Reasons for antibiotic
prophylaxis.
352
Two features arise from this survey which
we
find
particularly disturbing. Although most antibiotics used therapeutically were assessed as appropriate, many prescribers were unable to say what particular microbial agents they wished to treat. Most of them based therapy only on the anatomical site of putative infection. Rational prescribing can only be expected if the prescriber is aware of the most likely infective agents. Only one antibiotic course was subsequently stopped or amended by a member of the consultant staff-in whose name treatment is administered. The second disturbing feature concerned the prescribing of antibiotics for surgical prophylaxis. There seemed to be no coherent policy. Since there is no clear consensus about the efficacy of and indications for prophylaxis for many surgical proceduresls we made no judgment about whether or not antibiotic prophylaxis was justified but confined our assessment to the specific features of timing, drug administration and choice. Only 7% of prophylactic prescriptions satisfied the four criteria we have applied,and 22% met none. The reasons for
(what we consider to be) this poor prophylactic usage entirely clear but may relate to the informal antibiotic policy practised in our hospital. This depends heavily for its effect on contact with the laboratory mainly through the submission of specimens. Prescribing antibiotics for surgical prophylaxis generates much less with the laboratory than does therapeutic contact prescribing. Our informal antibiotic policy therefore seems to be an unsatisfactory mechanism for influencing prophylactic prescribing. Two other matters of concern emerged from this study. These related to the poor use of laboratory data in antibiotic prescribing and the unsatisfactory basis for the diagnosis of infection resulting in many patients receiving antibiotics unnecessarily. Both these aspects will be dealt with in subsequent reports. are not
We thank the senior and junior medical staff of the Central Middlesex Hospital for their cooperation; Miss M. Fielding, Miss A. Etherington, and Miss J. Steward for secretarial services; and Miss V. Musgrove for retrieval of chest X-rays. F. M. was in receipt of a grant from the C.M.H. Research and Teaching Fund.
Requests for reprints should be addressed to F. M.
Public Health WATERBORNE OUTBREAKS OF CAMPYLOBACTER ENTERITIS IN CENTRAL SWEDEN
LARS-OLOF MENTZING
Länsläkarorganisationen,
651 86 Karlstad, Sweden
In an outbreak of enteritis affecting about 2000 people in central Sweden Campylobacter jejuni was isolated from the faeces of 221 of 263 patients whose stools were cultured. Among the patients who consulted general practitioners the highest attack rate was in children under five years old but a sample survey of the community showed that all age groups were equally affected. There was strong circumstantial evidence pointing to tap water as the source of the infection, although this was not bacteriologically confirmed. This is only the second major waterborne outbreak of campylobacter enteritis that has been
Summary
reported. INTRODUCTION
THE first Swedish cases of campylobacter enteritis were reported in January, 1978,’ after Skirrow had described his method of selective culture. Most infections in Sweden are sporadic. The proportion in travellers from abroad is unusually high.3 Nearly all major outbreaks of campylobacter enteritis reported have been caused by unpasteurised milk.4 The exceptions are an outbreak due to undercooked chickens and a waterborne outbreak in the United States.6 What follows is the first full report ofa major waterborne outbreak of campylobacter enteritis. OUTBREAK
During the first two weeks of October, 1980, over 380 people with diarrhoea consulted general practitioners in Grums, a community 30 km west of Karlstad in central Sweden. Another community, Valberg, situated nearer Karlstad, was also affected but to a lesser extent.
REFERENCES 1. Jackson G. Antibiotic policies, practices and pressures. J Antimicrob Chemother 1979; 5: 1-5. 2. Scheckler WE, Bennett JV. Antibiotic usage in seven community hospitals. JAMA 1970; 213: 264-67. 3. McGowan JE, Finland M. Infection and antiobiotic use at Boston City Hospital during the decade 1964-1973. J Infect Dis 1974; 129: 421-28. 4. Moody ML, Burke JP. Infections and antibiotic use in a large private hospital, January, 1971. Arch Intern Med 1972; 130: 261-66. 5. Roberts AW, Visconti JA. The rational and irrational use of systemic antimicrobial drugs. Am J Hosp Pharm 1972; 29: 828-32. 6. Carruthers MM, Grant K. A practical method of antimicrobial surveillance. Health Lab. Sci 1978; 15: 44-49. 7. Kunin CM, Tupasi T, Craig WA. Use of antibiotics: a brief exposition and some tentative solutions. Ann Intern Med 1973; 79: 555-60. 8. Shapiro M, Townsend TR, Rosner B, Kass EH. Use of antimicrobial drugs in general hospitals II. Analysis of patterns of use. J Infect Dis 1979; 139: 698-706. 9. Edwards LD. Infections and use of antimicrobials in an 800 bed hospital. Publ Health Rep 1969; 84: 451-57. 10. Kistler SB, Kough RH. Antibiotic acquisitions in a 387 bed general hospital. Am J Hosp Pharm 1969; 26: 681-85. 11. Ruedy J. A method of determining pattern of use of antimicrobial drugs. Can Med Assoc J 1966; 95: 807-12. 12 Rebecca K, Blair JA. A ten month study of the use of antibiotics in a 175 bedded hospital. Am J Hosp Pharm 1965; 22: 502-07. 13. Lawson DH, MacDonald S. Antibacterial therapy in general medical wards. Postgrad Med J 1977; 53: 306-09. 14. Editorial. Antibiotic audit. Lancet 1981; i: 310-11. 15. Prophylactic antimicrobial drug therapy at five London teaching hospitals: a report by the study group on the use of antimicrobial drugs. Lancet 1977; i: 1351-53.
Campylobacterjejuni was isolated from the faeces of 221 of patients for whom cultures were done. 45 specimens
263
Fig.
I-Date of onset of illness in
practitioners.
patients consulting their general
Hospital Practice SURVEY OF ANTIBIOTIC PRESCRIBING IN A DISTRICT GENERAL HOSPITAL I. PATTERN OF USE
(1.) The anatomical site of infection. (2.) The clinical, radiological, and laboratory findings
M. W. MCNICOL D. L. MILLER
FIONA MOSS* D. A. MCSWIGGAN
Cardio-thoracic Department; Department of Microbiology and Public Health Laboratory; and Department of Community Medicine (Middlesex Hospital Medical School), Central Middlesex Hospital, London NW10
Summary
In
a
survey
of
of drug, dose, initial route of administration, and the date of starting the antibiotic were recorded. The age and sex of the patients, the type of admission (whether emergency or booked), and the admitting team were also noted. As soon as possible after the prescription, always within 48 hours, the prescriber was interviewed by F.M. using a standard questionnaire. Prescribers were first asked to state whether the antibiotic was given for therapeutic or prophylactic purposes. The prescribers of therapeutic antibiotics were asked: used as evidence of infection. (3.) Whether any bacteriological investigations had been requested. (4.) Whether the bacteria responsible for the infection had been isolated. (5.) If no organisms had been isolated, the suspected infecting agent. (6.) Any other features relevant to the diagnosis of infection (e.g., diabetes,
corticosteroid or cytotoxic therapy, indwelling urinary catheters).
The
all
antibiotic
pre-
scriptions in a district general hospital during November, 1978, the reason for each prescription was determined by a brief interview with the prescriber. 28% of all inpatients received antibiotics. Older patients were prescribed antibiotics more often than were younger patients. Ampicillin was the most frequently used antibiotic, accounting for over 40% of prescriptions. Over 70% of antibiotic courses were stated by the prescriber as being for the treatment of infection and the remainder were said to be prophylactic. Although 80% of the antibiotics were assessed as suitable treatment for the stated infection, most of the patients were treated without bacteriological evidence of the infecting agent and, for these patients, prescribers were unable to specify the pathogen against which treatment was intended in 50% of the courses they initiated. Only 7% of antibiotics prescribed for conventional surgical prophylaxis fulfilled all the criteria used to assess the suitability of choice of drug and the method and timing of its administration. INTRODUCTION
ANTIBIOTICS are one of the largest single groups of drugs prescribed. Knowledge about their use is important not only because of their cost but also because the price of their misuse, especially in hospital, may be unnecessary morbidity and mortality, high hospital infection rates and rapid
obsolescence of the most valuable drugs.Previous surveys of antibiotic use in hospital’-" have been based on indirectly derived information. Only one refers to the U.K. and that was restricted to patients in certain medical wards.13 A Lancet editorial 14 suggested antibiotic audit as a method of influencing antibiotic prescribing in hospital practice. We report a survey or "audit" of antibiotic use throughout a district general hospital based on interviews with the prescribers. Our findings suggest there is a need to reappraise antibiotic policies as a basis for influencing antibiotic
prescribers of prophylactic antibiotics were asked:
(1.) Whether the patient was exposed to any special risk of infection, such as an operative procedure and, if so, its nature and date. (2.) Any medical condition which might enhance susceptibility to infection (e.g., immunological deficiency, broken barriers such as CSF leak, rheumatic heart disease, corticosteroid therapy). (3) The potential infecting agents against which prophylaxis was mainly directed.
prescribers were asked to state the intended duration of although the actual duration was not recorded. Results of bacteriological tests carried out on the patients were recorded from the laboratory copies of the reports sent to prescribers. All
treatment
The suitability of each antibiotic for its stated purpose was reviewed by two ofus (M.W.McN. and D.A.McS.). For therapeutic prescriptions the antibiotics used were classified as "appropriate" or "inappropriate" having regard to the site of infection, the presumed/known infecting organisms, and known antibiotic hypersensitivity. Prophylactic courses were considered appropriately administered if the antibiotic(s) was given just before the surgical procedure, if the intended duration of the course was 24 h, if the antibiotic(s) was given parenterally (or rectally also for metronidazole), and if the drug(s) chosen was suitable "cover" for the procedure. We use the term prescription to indicate every time that an individual antibiotic was prescribed and the term antibiotic course to describe the use of either a single antibiotic or a combination of antibiotics prescribed together. RESULTS
366 patients were prescribed antibiotics during the period of the survey. This represents 28% of all patients admitted to hospital during that period. The proportion of patients receiving these drugs increased with age, ranging from 24% of those aged under 11years to 63% of those aged 81 years or more (table I). The median age for patients prescribed antibiotics for a therapeutic purpose was 61 years and for TABLE I-AGES OF PATIENTS ADMITTED TO HOSPITAL AND OF THOSE
PRESCRIBED ANTIBIOTICS DURING THE SURVEY PERIOD
prescribing practices. METHOD
The survey
was
done
28 days in November, 1978, at the (CMH), a district general hospital in hospital has 480 beds for acute services
over
Central Middlesex Hospital
north-west London. The and has a neurosurgical unit, an eye surgery unit, an intensive therapy unit, and a special care baby unit. The survey entailed inquiry into all antibiotic prescriptions (except anti-tuberculous therapy) for inpatients. All prescriptions were written by junior medical staff. All wards were visited daily by F.M. For all prescriptions the type ’P-esent address.
Department of Medicine, Whittington Hospital,
London N 19 5NF.
"Obstetric patients not included because their ages were not available. Difference between the proportion of patients <61 years and those >61 received antibiotics was significant (x2 41.5; p<0.001).
years who
350 TABLE 11-MEDICAL AND SURGICAL PATIENTS ADMITTED TO HOSPITAL AND WHO WERE PRESCRIBED ANTIBIOTICS
*X=1
-37
(p= >0 10).
TABLE III-ANTIBIOTIC COURSES AND PRESCRIPTIONS FOR THERAPY AND FOR PROPHYLAXIS I
prescriptions and 33% of prophylactic prescriptions). More than 60% of all prescriptions were for one of the penicillin drugs. The cephalosporins accounted for only 5% of the antibiotics used. Therapeutic Antibiotic Prescriptions 261 patients, about a fifth of all patients admitted during the period of the survey, received at least one course of antibiotics for a condition considered by the prescriber to be due to infection. 43 patients received multiple courses. The sites of the infection identified by the prescribers are shown in table V. The most frequent were lower respiratory (39%), and urinary tract (20%). Surgical wound infection accounted for 6% of cases. Of the 309 courses prescribed therapeutically, the choice of antibiotics was considered "appropriate" in 251 (81%) and
*Combination
courses
significantly more common in prophylaxis (X’ =21’5j p<0’001).
those prescribed antibiotics prophylactically it was 49 years. The frequency of prescriptions for antimicrobial agents did not differ significantly between surgical and medical services.
(table II). 437 courses of antibiotics were prescribed, of which 309 (71%) were therapeutic and 128 (29%) were prophylactic. Nearly a fifth (18%) of prescriptions were for a combination of antibiotics; combinations were significantly more frequently prescribed for prophylaxis than for therapy (table III). The antibiotics used, in rank order of frequency of prescription, are shown in table IV. The ampicillin antibiotics accounted for 41% of all prescriptions (44% of therapeutic TABLE IV-TYPES
OF ANTIBIOTICS USED BY MAJOR SPECIALTIES 4H I7
Fig. I-Microbiological investigations. *Isolates thought
T = therapeutic. P = prophylactic Other antibiotics used were: nystatin 9, cefuroxime 7, amphotericin 6, neomycin 6, sulphadimidine 4, sodium fusidate 3, oxytetracycline 3, nitrofurantoin 3, doxycycline 1, nahdixic acid 1, tobramycin 1. *Includes amoxycillin. t includes flucloxacillin. * includes cephradine. TABLE V- SITES OF INFECTION FOR WHICH ANTIBIOTICS WERE
PRESCRIBED BY MAJOR SPECIALTIES
to
be relevant
to
symptoms.
"inappropriate" in 58 (19%). The most frequent errors were: (a) seriously inadequate cover against the likely infecting organism (e.g., peritoneal or intrauterine infection treated with ampicillin alone); (b) an inappropriate drug for the stated infecting agent (e.g., ampicillin for staphylococcal sepsis); and (c) unsuitable combinations ofdrugs. Specimens (including blood cultures) for microbiological tests were taken from 186 (67%) of the identified sites of infection for which therapeutic antibiotic courses were prescribed. Bacteria, thought to be responsible for the infection, were isolated from 88 (47%) of these. In 29 the laboratory results led to no change in treatment but in 59 the laboratory findings resulted in either the initiation or change of therapy (fig. 1). 250 (80%) of the therapeutic antibiotic courses were started without the prescriber knowing the results of the microbiological tests. For almost half of these, the prescribers stated that they did not suspect any particular infecting agent as the cause of the infection (fig. 2). Prophylactic Antibiotic Prescriptions
*Includes 17
surgical wounds.
128 courses of antibiotics were stated by the prescribers to be for prophylaxis (fig. 3). 90 (70%) were prescribed to cover an operative or non-operative surgical procedure. Of these only 55 were for conventional surgical prophylaxis. Of the
351
antibiotics in patients over 81 years of age was greater than has been previously recorded. This reflects the policy of the geriatric unit where 60% of all patients received antibiotics. All of these prescriptions were classified as therapeutic. These patients also accounted for the higher median age for therapeutic as opposed to prophylactic antibiotic use. In previous studies ampicillin has been the most frequently prescribed drug, accounting for up to 22% of antibiotics used,8but in our survey ampicillin accounted for 41% of antibiotic prescriptions. The cephalosporins (cephaloridine+ TABLE VI-FREQUENCY OF "CORRECT" FEATURES IN 55 COURSES OF "CONVENTIONAL SURGICAL PROPHYLAXIS"
Fig. 2-Relation between microbiological forecast, laboratory tests, and therapeutic courses.
non-surgical
courses
of prophylactic antibiotics,
most were
for trauma.
Only 4 (7%) of the 55 courses of conventional surgical prophylaxis fulfilled all four criteria used for assessment, and 12 (22%) fulfilled none (table vi). The most frequent error was excessive intended duration of prophylaxis, over 80% of courses being planned to continue for longer than 24 hours. Over 66% of courses were started too early (before the day of the operation) or too late (after the procedure). Of the antibiotics prescribed, only 45% were judged as suitable for the stated procedure (table VII). DISCUSSION
The results of this survey, based on an interview with the prescriber rather than pharmacy records or retrospective review of case-notes, are similar to those previously reported from North America. The proportion of patients prescribed antibiotics in our survey was 28% compared with a range of 23% to 36% previously reported.2-12 The proportion. prescribed to medical and surgical patients was also similar, as was the trend to increased prescribing rates of antibiotics in the older patient8,1I although in our study the use of
Fig.
TABLE VII-ASSESSMENT OF
55
COURSES OF
"CONVENTIONAL
SURGICAL PROPHYLAXIS
cefuroxime) were used very infrequently (5%). It seems probable that this pattern of usage is the consequence of the type of antibiotic policy operating in the hospital which depends on indirect influences rather than directive. The sensitivity of organisms to ampicillin is reported routinely but, in contrast, sensitivity to cephalosporins is reported only when the organism is resistant to other commonly used antibiotics. The infrequent use of other antibiotics probably also reflects the laboratories policy of selective reporting rather than any policy of deliberate abstention.
3-Reasons for antibiotic
prophylaxis.
352
Two features arise from this survey which
we
find
particularly disturbing. Although most antibiotics used therapeutically were assessed as appropriate, many prescribers were unable to say what particular microbial agents they wished to treat. Most of them based therapy only on the anatomical site of putative infection. Rational prescribing can only be expected if the prescriber is aware of the most likely infective agents. Only one antibiotic course was subsequently stopped or amended by a member of the consultant staff-in whose name treatment is administered. The second disturbing feature concerned the prescribing of antibiotics for surgical prophylaxis. There seemed to be no coherent policy. Since there is no clear consensus about the efficacy of and indications for prophylaxis for many surgical proceduresls we made no judgment about whether or not antibiotic prophylaxis was justified but confined our assessment to the specific features of timing, drug administration and choice. Only 7% of prophylactic prescriptions satisfied the four criteria we have applied,and 22% met none. The reasons for
(what we consider to be) this poor prophylactic usage entirely clear but may relate to the informal antibiotic policy practised in our hospital. This depends heavily for its effect on contact with the laboratory mainly through the submission of specimens. Prescribing antibiotics for surgical prophylaxis generates much less with the laboratory than does therapeutic contact prescribing. Our informal antibiotic policy therefore seems to be an unsatisfactory mechanism for influencing prophylactic prescribing. Two other matters of concern emerged from this study. These related to the poor use of laboratory data in antibiotic prescribing and the unsatisfactory basis for the diagnosis of infection resulting in many patients receiving antibiotics unnecessarily. Both these aspects will be dealt with in subsequent reports. are not
We thank the senior and junior medical staff of the Central Middlesex Hospital for their cooperation; Miss M. Fielding, Miss A. Etherington, and Miss J. Steward for secretarial services; and Miss V. Musgrove for retrieval of chest X-rays. F. M. was in receipt of a grant from the C.M.H. Research and Teaching Fund.
Requests for reprints should be addressed to F. M.
Public Health WATERBORNE OUTBREAKS OF CAMPYLOBACTER ENTERITIS IN CENTRAL SWEDEN
LARS-OLOF MENTZING
Länsläkarorganisationen,
651 86 Karlstad, Sweden
In an outbreak of enteritis affecting about 2000 people in central Sweden Campylobacter jejuni was isolated from the faeces of 221 of 263 patients whose stools were cultured. Among the patients who consulted general practitioners the highest attack rate was in children under five years old but a sample survey of the community showed that all age groups were equally affected. There was strong circumstantial evidence pointing to tap water as the source of the infection, although this was not bacteriologically confirmed. This is only the second major waterborne outbreak of campylobacter enteritis that has been
Summary
reported. INTRODUCTION
THE first Swedish cases of campylobacter enteritis were reported in January, 1978,’ after Skirrow had described his method of selective culture. Most infections in Sweden are sporadic. The proportion in travellers from abroad is unusually high.3 Nearly all major outbreaks of campylobacter enteritis reported have been caused by unpasteurised milk.4 The exceptions are an outbreak due to undercooked chickens and a waterborne outbreak in the United States.6 What follows is the first full report ofa major waterborne outbreak of campylobacter enteritis. OUTBREAK
During the first two weeks of October, 1980, over 380 people with diarrhoea consulted general practitioners in Grums, a community 30 km west of Karlstad in central Sweden. Another community, Valberg, situated nearer Karlstad, was also affected but to a lesser extent.
REFERENCES 1. Jackson G. Antibiotic policies, practices and pressures. J Antimicrob Chemother 1979; 5: 1-5. 2. Scheckler WE, Bennett JV. Antibiotic usage in seven community hospitals. JAMA 1970; 213: 264-67. 3. McGowan JE, Finland M. Infection and antiobiotic use at Boston City Hospital during the decade 1964-1973. J Infect Dis 1974; 129: 421-28. 4. Moody ML, Burke JP. Infections and antibiotic use in a large private hospital, January, 1971. Arch Intern Med 1972; 130: 261-66. 5. Roberts AW, Visconti JA. The rational and irrational use of systemic antimicrobial drugs. Am J Hosp Pharm 1972; 29: 828-32. 6. Carruthers MM, Grant K. A practical method of antimicrobial surveillance. Health Lab. Sci 1978; 15: 44-49. 7. Kunin CM, Tupasi T, Craig WA. Use of antibiotics: a brief exposition and some tentative solutions. Ann Intern Med 1973; 79: 555-60. 8. Shapiro M, Townsend TR, Rosner B, Kass EH. Use of antimicrobial drugs in general hospitals II. Analysis of patterns of use. J Infect Dis 1979; 139: 698-706. 9. Edwards LD. Infections and use of antimicrobials in an 800 bed hospital. Publ Health Rep 1969; 84: 451-57. 10. Kistler SB, Kough RH. Antibiotic acquisitions in a 387 bed general hospital. Am J Hosp Pharm 1969; 26: 681-85. 11. Ruedy J. A method of determining pattern of use of antimicrobial drugs. Can Med Assoc J 1966; 95: 807-12. 12 Rebecca K, Blair JA. A ten month study of the use of antibiotics in a 175 bedded hospital. Am J Hosp Pharm 1965; 22: 502-07. 13. Lawson DH, MacDonald S. Antibacterial therapy in general medical wards. Postgrad Med J 1977; 53: 306-09. 14. Editorial. Antibiotic audit. Lancet 1981; i: 310-11. 15. Prophylactic antimicrobial drug therapy at five London teaching hospitals: a report by the study group on the use of antimicrobial drugs. Lancet 1977; i: 1351-53.
Campylobacterjejuni was isolated from the faeces of 221 of patients for whom cultures were done. 45 specimens
263
Fig.
I-Date of onset of illness in
practitioners.
patients consulting their general