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Nosocomial infections — A continuing danger to patients at Lagos University Teaching Hospital
PubL lthh, Lond. (1980) 94,229-234
Nosocomial Infections -- A Continuing Danger to Patients at Lagos University Teaching Hospital C. E. Anyiwo M.D., M.Se
Infection Control Officer S. O. Daniel M.B.Ch.B., F.M.C.P.H., M.F.C.M., F.W.A.C.P.
Hospital Consultant Epidemiologist O. O. Ogunbi M.Sc.. M.B., Ch.B., F.M.C. Path
Chairman Hospital Infection Control Committee and G. O. Aromolaran S.R.N., S.C.M.
Hospital Infection Control Nurse Hospital Infection Control Unit/Department o f Community Health Lagos University Teaching Hospital & College of Medicine, P.M.B. 12003, Lagos, NiEeria
There were 693 nosocomial infections in the Lagos University Teaching Hospital between 1977 and 1978. The incidence dropped over this period. The lower incidence w a s mainly due to intensive infection control measures and the awareness engendered by the current surveillance programme. Surgical wound (58-7%) and the Urinary Tract (22%) still constitute the most frequently affected sites, with a preponderance o f Gram negative to Gram positive organisms in the ratio of 5 to !. It is suggested that the problem of hospital acquired infections in Lagos University Teaching Hospital should be met by appropriate preventive measures through a multi-d isciplinary approach.
Introduction Hosoital acquired infections (nosocomial infections) are by no means a new problem. They undoubtedly existed from the time sick people were first gathered for care. More complex medical procedures, new drugs as well as X-ray treatment may facilitate the development o f infections by increasing the suscel~tibility o f the patient. 1 Several factors have operated to stimulate both an awareness of and an intense research interest in nosocornial infections. Such factors have included antimicrobial therapy and the emergence of drug resistant bacteria. 0038-3506/80/040229+06 $01.0010
(~1980 The Society of Community Medicine
230
C. E, A n y i w o et M
Hospital patients may take home transmissible infections without apparently being ill, or their hospital acquired infection may not become a manifest disease until after disdlarge. Therefore it is quite clear that hospital infections are community health problem in the broad sense) Knowing the usual endemic rate o f infection in a hospital, iniection control personnel can anticipate a potential epidemic and identify areas in need o f more specific control measures. Such information could be utilized in a teaching programme within the hospital, as well as assisting the clinician in the selection of his therapeutic technique. Nosocornial infections are among the major causes of morbidity and mortality in institutionalized patients. 2 These unfortunate complications often prolong hospitalization, a d d appreciably to cost of treatment and also create new health hazards for the community. The population at risk o f nosoeomial infections include those undergoing surgery, being treated with broad spectrum amibiotics or on immunosuppresive or antineoplastic therapy. Others are debilitated or geriatric patients or those being treated in intensive care unitswhere instrumentation procedures are widely practiced, The prevention, surveillance and control of hospital-associated infections has become a major subject o f interest among clinicians, microbiologists, epidemiologists, environmental scientists, hospital administrators, and more recently - economists. With advances in biomedical engineering, such as the use o f complicated apparatus and devices there has been a certain relaxation in the application o f basic principles o f hygiene often accompanied b y drug abuse or underutiiization o f antiseptics or disin fectan ts. Consequently, the problem is still with us. Many countries are seeking a rational approach to its solution based on a rational surveillance programme. We feel that a prospective study o f nosocomial infections in the Lagos University Teaching Hospital, will provide valuable guidehnes for hospital infection control programme currently being initiated in other teaching hospitals in Nigeria. The objective was 1o ensure that any patient entering the hospital does not encounter still another disease during the period o f hospitalization.
Materials and Methods Patients admitted into L.U.T.H. and its Ebute.Metta annexe from January 1977 to December t 9 7 8 were studied. Data collection Infections occuring in patients admitted into L.U.T.H. and its annexe were monitored through the surveillance programme o f L.U.T.H. infection control programme. Data were collected on several forms.* Cases o f hospital infections were studied to determine as far as possible tile aetiology, the source and mode o f transmission. The bacterial resistance to antibiotics was recorded and tlle prescribing habits of the clinician studied in relation to emergence of bacterial drug resistance. Measures aimed at preventing hospital-associated infections were evaluated. Ward rounds Weekly visits were made to the wards to discuss the quality o f asepsis, the effect o f antibiotics prescribed for patients and the criteria of surgical wound infections, together with the risk and chances o f recontamination. Environmental sampling The quantitative and qualitative characteristics of micro-organisms in the hospital environment were studied and information concerning relative microbial contamination and the sources o f such contamination obtained. *Available on request.
Nosocomial Infections
231
Results A total o f 693 nosocomial infections were recorded during the two year study period. Table 1 shows the distribution o f hospital acquired infections. The hospital infection rates for 1977 and 1978 were 3-4 and 2-7 per I00 discharges respectively. The sites o f infection mostly encountered were the surgical wound and the urinary tract. Fot~r hundred and one (58.8%) post-operative wound infections and 148 (21-8%) U.T.I. were recorded. Table 2 shows the pathogens involved and the percentage o f infection. The ratio o f Gram negative to Gram
TABLE 1 Cases ofnosocomial infection at L.U.T.H. and their distr~ulion (Jan. 1977 - Dec. 1978)
Period
Sites of Infection U.T.L
Jan. 1977 - Dec. 1977. Number Jan. 1978 - Dec. 1978 Total Percentage
84 64 148 21"8
Resp. Surgical Burns Skin Bacteraemia Genital Eye Ear Total Wound~System 17 224 6 177 23 401 3"4 58"8
8 20 28 4.1
19 6 25 3"8
2 2 0"3
24 6 30 4-4
15 1 3 4 18 5 2-7 0.7
394 286 680 100
positive organisms isolated in the study was 5 :I while 167 Gram positive organisms accounted for about 16-7% o f the nosoconfial infections. Coagulase positive Staphylococcus was resl~onsible for 146 (14-5%) infections. But the Gram negatives incriminated in order o f frequency were Klebsiella aerogenes 254 (25-3%) Esch. coli 224 (22-3%)Pseudomonas pyocyanae 142 (14-2%) Proteus mirabilis 129 (12-9%) and Enterobaeter'75 (7.5%). The least conunon organism was Peptostreptococcus (anaerobic Streptococcus) which was responsible for infection of one surgical wound.
Discussion
The first report on hospital acquired infections a t l a g o s University Teaching Hospital was made in 1976 in the first national symposium on nosocomial infections, x4 This prospective study is a continuation o f the research work undertaken since that report. The sites of infection mostly encountered still remain surgical wounds and the urinary tract. As shown in Table 1 a total o f 401 cases o f surgical wound infections (58-8%)and 148 o f Urinary Tract Infection (U.T.I.) 21-8% were recorded. Tiffs indicates that surgical wound infections were on the increase compared to a previous report in which 383 cases (35-2%) were recorded. 3 On the contrary the U.T.I. is declining. In 1976 302 cases (28-2%)were recorded. However, the ratio o f Gram negatives to Gram positives organisms incriminated in hospital infections has risen from 4:1 in 19764 to 5:1 indicating that the Gram negatiVe organisnts are still the principal agents in hospital accounting for 83-3% o f hospital associated infections.'~5 Table 2 shows that these Gram negatives have been the major causes o f post operative wound sepsis. For example 130 isolates of Esch. coil (21%); 159 isolates o f Klebsiella aerogenes (25-7%) 94 ofPs. aerugfnosa (15-2%) and 82 of Proteus mirabilis (13.2%)were the major isolates. Staphylococe~is aureus
192
1 3
22 2
15
65 57 16
11
U.T.t.
37
7 7 14 3 3 2 1
619
90 130 159 45 94 82 5 2 1 1 6 2 2
55
1
I1 8 6 5 16 7 1
36
I
6 6 5 2 8 8
3
1
1
1
34
1
1
4 7 11 3 t 6
20
1
I 1
t5 1 1
7
Resp. Surgical Burns Skin Bacteraemia Reproductive Eye Ear wounds
Gram negativeorganisms: 836 (83"3%). Gram positive organisms: 167 (16.7%), Ratio of Gram negative to Gram positive 5:1.
To~al
Streptococcus
Non haemolyti¢
Streptococcus vk~dans Anaerobic Streptococcus Candida albieans Streptococcus faecalis Beta Hae. Streptococcus Ilaernophilus influenzae
AtypicalColiform
Staphylococcus attreus Eseh. Coil Klebsiella aerogenes Enterobacter Pseudomonas pyocyanae Proteus specoes
Pathogens
TABLE 2. Organi.~ms esponszblefor nosooomial infectionsJan. 1977 Dec.1978
14'6 22'5 25'5 7'5 14'2 12'9 1'0 0'2 0'1 0'2 I'1 0'3 0'2 0'2
%
1003 100
146 224 254 75 142 129 10 2 1 2 11 3 2 2
Total
Nosocomial hrfections
233
(coagulase positive) was isolated from 90 cases o f wound sepsis (14-5%). The phage group pattern remains predonfinantly 1 and 3. Anaerobes which are usually major isolates in wound infections were almost conspiciously absent .in our records - a situation attribuled to inadequate collection of specimens for anaerobic bacteriol,)gy and infrequent submission to the laboratory of post-treatment specimens. The overall infection rate o f 7.5 per 1O0 discharges during the period January 1974 - J u n e 1975 recorded at L.U.T.H. 4 is higher than the 0-5 - 5 per IO0 discharges recorded by tile U.S. Centre of Disease Control (1973) 6 in their National Nosocomial Infections Study. However, the statistical studies from various 'hospitals in different countries have shown that nosocomial infections may develop in an average of 7% o f patients, the range being from 3% to 15%.: The percentage always tends to be higher whenever the susceptible group of patients (as was observed in this study) sudl as the debilitated, the neonates or those undergoing surgery or in labour are hospitalized. On the contrary, our low figures (3.4% and 2-7% ofhospitaI infection rates for 1977 and 1978 respectively) may be due in part to the intensive hospital infection control system and vigilant surveillance programme of Lagos University Teaching Hospital. The low isolation rate for anaerobes suggests, however, that under reporting may also be a factor. As in our earlier report, a our findings in the present prospective study compare favourably with the f'mdings in other hospitals, where U.T.I. and post-operative wound infections are also the predominant nosocomial infections,za Data from the University o f Minnesota showed that a sharp increa~ o f G~am negative infections in hospitals due to U.T.I. occurred in patients whose resistance was compromised by serious underlying disease. 9 The incidence of hospital-associated infections in developing countries (such as Nigeria) is difficult to assess on a national basis. This may be partly due to the fact that clinicians are Iess interested in nosocon-,ial irffections and fail to record relevant statistics and partly because epidemiologists are too preoccupied with other ¢onmmnicable diseases, it must be stressed that nosocomial infections in both endemic and epidemic form are among the major causes o f morbidity and mortality. It is therefore imperative for similar sludies to be conducted in all government and private hospitals. A multi-disciplinary approach is essential when any research projects are envisaged. From our experience these research activities should be centred around four cardinal points: (a) The patient (specia! risk groups and application o f vaccination). (b) The microorganism (improvement and epidemiological assessment o f typing schemes, resistance patterJ~s and evaluation o f diagnostic techniques)J ° (c) The environment (control o f methods o f sterilization and disinfection processes, studies o f hospital design, isolation facilities and development o f efficient disinfectants). (d) The adminislration (economic aspects, cost effectiveness, hospital formulary and legal aspects). Conclusion
From this study we conclude that hospital-acquired infections at Lagos University T e n t i n g Hospital is a continuing'danger and a vigilant surveillance programme is required to remove it. Acknowledgements The co-operation of many ConsuRants, Paediatricians, Obstertricians and Gynaecologists, Surgeons and Physicians under whose care in the various wards the patients were, and Nurses o f the Lagos University Teaching Hospital and College o f Medicine is gratefully acknowledged. For technical assistance we .are indebted to faculty and staff of the Department of Microbiology L.U.T.H.
234
Arosocomial htfections
Referenoes 1. Goddard, J. L. (1970). Epidemiology. Proceedings National Conference on Institutionally Acquired Infections. 2. Wahba, A. H. W. (1977). Itospital infections - a continuing danger 1o patients and staff. W.H.O. chronicle 3 I , 63--6. 3. Ogunbi, O. & Anyiwo C. E. (1977). Lagos University Teaching Hospilat: Infection Control l~rogramme-a review o f two years activities 1974/75. Proceedings o f First National Symposium o f Nosocomial Infections (1976). 4. Daniel, S. O. (197-7). An epidemiological study o f nosocomial infections at Lagos University Teaching Hospital. Public Health 91, 1 3 - 1 8 . 5. Itunponu~Wusu, 0. 0 . & Daniel, S. O. (1977). Klebsiella infection as agents of nosocomial infections. Proceedings o f First National Symposium on Nosocomial Infections held in i976. 6. Centre o f Disease Control (1973). Centre o f Disease Control's National Nosoeomial Infections Stud),. Second Quarter 1972. Washington D.C. 7. Altermeir, W. A. (1970). Current infection problem in surgery. International Conference on Nosocomiat Infections pp. 8 2 - 8 7 . 8. Shaffer, J. G. (1963). Proceedings National Conference on Institutionally Acquired Infections. pp. 6 - I 9. 9_ Kunin, C. M. ( I 970). Nosoeomial Infections International Conference. pp. 8 8 - 9 4 . i0. Hnll, L. B. (1970). Air sampling techniques. Proceedings National Conference on Institutionally A cquired Infections.
Nosocomial Infections -- A Continuing Danger to Patients at Lagos University Teaching Hospital C. E. Anyiwo M.D., M.Se
Infection Control Officer S. O. Daniel M.B.Ch.B., F.M.C.P.H., M.F.C.M., F.W.A.C.P.
Hospital Consultant Epidemiologist O. O. Ogunbi M.Sc.. M.B., Ch.B., F.M.C. Path
Chairman Hospital Infection Control Committee and G. O. Aromolaran S.R.N., S.C.M.
Hospital Infection Control Nurse Hospital Infection Control Unit/Department o f Community Health Lagos University Teaching Hospital & College of Medicine, P.M.B. 12003, Lagos, NiEeria
There were 693 nosocomial infections in the Lagos University Teaching Hospital between 1977 and 1978. The incidence dropped over this period. The lower incidence w a s mainly due to intensive infection control measures and the awareness engendered by the current surveillance programme. Surgical wound (58-7%) and the Urinary Tract (22%) still constitute the most frequently affected sites, with a preponderance o f Gram negative to Gram positive organisms in the ratio of 5 to !. It is suggested that the problem of hospital acquired infections in Lagos University Teaching Hospital should be met by appropriate preventive measures through a multi-d isciplinary approach.
Introduction Hosoital acquired infections (nosocomial infections) are by no means a new problem. They undoubtedly existed from the time sick people were first gathered for care. More complex medical procedures, new drugs as well as X-ray treatment may facilitate the development o f infections by increasing the suscel~tibility o f the patient. 1 Several factors have operated to stimulate both an awareness of and an intense research interest in nosocornial infections. Such factors have included antimicrobial therapy and the emergence of drug resistant bacteria. 0038-3506/80/040229+06 $01.0010
(~1980 The Society of Community Medicine
230
C. E, A n y i w o et M
Hospital patients may take home transmissible infections without apparently being ill, or their hospital acquired infection may not become a manifest disease until after disdlarge. Therefore it is quite clear that hospital infections are community health problem in the broad sense) Knowing the usual endemic rate o f infection in a hospital, iniection control personnel can anticipate a potential epidemic and identify areas in need o f more specific control measures. Such information could be utilized in a teaching programme within the hospital, as well as assisting the clinician in the selection of his therapeutic technique. Nosocornial infections are among the major causes of morbidity and mortality in institutionalized patients. 2 These unfortunate complications often prolong hospitalization, a d d appreciably to cost of treatment and also create new health hazards for the community. The population at risk o f nosoeomial infections include those undergoing surgery, being treated with broad spectrum amibiotics or on immunosuppresive or antineoplastic therapy. Others are debilitated or geriatric patients or those being treated in intensive care unitswhere instrumentation procedures are widely practiced, The prevention, surveillance and control of hospital-associated infections has become a major subject o f interest among clinicians, microbiologists, epidemiologists, environmental scientists, hospital administrators, and more recently - economists. With advances in biomedical engineering, such as the use o f complicated apparatus and devices there has been a certain relaxation in the application o f basic principles o f hygiene often accompanied b y drug abuse or underutiiization o f antiseptics or disin fectan ts. Consequently, the problem is still with us. Many countries are seeking a rational approach to its solution based on a rational surveillance programme. We feel that a prospective study o f nosocomial infections in the Lagos University Teaching Hospital, will provide valuable guidehnes for hospital infection control programme currently being initiated in other teaching hospitals in Nigeria. The objective was 1o ensure that any patient entering the hospital does not encounter still another disease during the period o f hospitalization.
Materials and Methods Patients admitted into L.U.T.H. and its Ebute.Metta annexe from January 1977 to December t 9 7 8 were studied. Data collection Infections occuring in patients admitted into L.U.T.H. and its annexe were monitored through the surveillance programme o f L.U.T.H. infection control programme. Data were collected on several forms.* Cases o f hospital infections were studied to determine as far as possible tile aetiology, the source and mode o f transmission. The bacterial resistance to antibiotics was recorded and tlle prescribing habits of the clinician studied in relation to emergence of bacterial drug resistance. Measures aimed at preventing hospital-associated infections were evaluated. Ward rounds Weekly visits were made to the wards to discuss the quality o f asepsis, the effect o f antibiotics prescribed for patients and the criteria of surgical wound infections, together with the risk and chances o f recontamination. Environmental sampling The quantitative and qualitative characteristics of micro-organisms in the hospital environment were studied and information concerning relative microbial contamination and the sources o f such contamination obtained. *Available on request.
Nosocomial Infections
231
Results A total o f 693 nosocomial infections were recorded during the two year study period. Table 1 shows the distribution o f hospital acquired infections. The hospital infection rates for 1977 and 1978 were 3-4 and 2-7 per I00 discharges respectively. The sites o f infection mostly encountered were the surgical wound and the urinary tract. Fot~r hundred and one (58.8%) post-operative wound infections and 148 (21-8%) U.T.I. were recorded. Table 2 shows the pathogens involved and the percentage o f infection. The ratio o f Gram negative to Gram
TABLE 1 Cases ofnosocomial infection at L.U.T.H. and their distr~ulion (Jan. 1977 - Dec. 1978)
Period
Sites of Infection U.T.L
Jan. 1977 - Dec. 1977. Number Jan. 1978 - Dec. 1978 Total Percentage
84 64 148 21"8
Resp. Surgical Burns Skin Bacteraemia Genital Eye Ear Total Wound~System 17 224 6 177 23 401 3"4 58"8
8 20 28 4.1
19 6 25 3"8
2 2 0"3
24 6 30 4-4
15 1 3 4 18 5 2-7 0.7
394 286 680 100
positive organisms isolated in the study was 5 :I while 167 Gram positive organisms accounted for about 16-7% o f the nosoconfial infections. Coagulase positive Staphylococcus was resl~onsible for 146 (14-5%) infections. But the Gram negatives incriminated in order o f frequency were Klebsiella aerogenes 254 (25-3%) Esch. coli 224 (22-3%)Pseudomonas pyocyanae 142 (14-2%) Proteus mirabilis 129 (12-9%) and Enterobaeter'75 (7.5%). The least conunon organism was Peptostreptococcus (anaerobic Streptococcus) which was responsible for infection of one surgical wound.
Discussion
The first report on hospital acquired infections a t l a g o s University Teaching Hospital was made in 1976 in the first national symposium on nosocomial infections, x4 This prospective study is a continuation o f the research work undertaken since that report. The sites of infection mostly encountered still remain surgical wounds and the urinary tract. As shown in Table 1 a total o f 401 cases o f surgical wound infections (58-8%)and 148 o f Urinary Tract Infection (U.T.I.) 21-8% were recorded. Tiffs indicates that surgical wound infections were on the increase compared to a previous report in which 383 cases (35-2%) were recorded. 3 On the contrary the U.T.I. is declining. In 1976 302 cases (28-2%)were recorded. However, the ratio o f Gram negatives to Gram positives organisms incriminated in hospital infections has risen from 4:1 in 19764 to 5:1 indicating that the Gram negatiVe organisnts are still the principal agents in hospital accounting for 83-3% o f hospital associated infections.'~5 Table 2 shows that these Gram negatives have been the major causes o f post operative wound sepsis. For example 130 isolates of Esch. coil (21%); 159 isolates o f Klebsiella aerogenes (25-7%) 94 ofPs. aerugfnosa (15-2%) and 82 of Proteus mirabilis (13.2%)were the major isolates. Staphylococe~is aureus
192
1 3
22 2
15
65 57 16
11
U.T.t.
37
7 7 14 3 3 2 1
619
90 130 159 45 94 82 5 2 1 1 6 2 2
55
1
I1 8 6 5 16 7 1
36
I
6 6 5 2 8 8
3
1
1
1
34
1
1
4 7 11 3 t 6
20
1
I 1
t5 1 1
7
Resp. Surgical Burns Skin Bacteraemia Reproductive Eye Ear wounds
Gram negativeorganisms: 836 (83"3%). Gram positive organisms: 167 (16.7%), Ratio of Gram negative to Gram positive 5:1.
To~al
Streptococcus
Non haemolyti¢
Streptococcus vk~dans Anaerobic Streptococcus Candida albieans Streptococcus faecalis Beta Hae. Streptococcus Ilaernophilus influenzae
AtypicalColiform
Staphylococcus attreus Eseh. Coil Klebsiella aerogenes Enterobacter Pseudomonas pyocyanae Proteus specoes
Pathogens
TABLE 2. Organi.~ms esponszblefor nosooomial infectionsJan. 1977 Dec.1978
14'6 22'5 25'5 7'5 14'2 12'9 1'0 0'2 0'1 0'2 I'1 0'3 0'2 0'2
%
1003 100
146 224 254 75 142 129 10 2 1 2 11 3 2 2
Total
Nosocomial hrfections
233
(coagulase positive) was isolated from 90 cases o f wound sepsis (14-5%). The phage group pattern remains predonfinantly 1 and 3. Anaerobes which are usually major isolates in wound infections were almost conspiciously absent .in our records - a situation attribuled to inadequate collection of specimens for anaerobic bacteriol,)gy and infrequent submission to the laboratory of post-treatment specimens. The overall infection rate o f 7.5 per 1O0 discharges during the period January 1974 - J u n e 1975 recorded at L.U.T.H. 4 is higher than the 0-5 - 5 per IO0 discharges recorded by tile U.S. Centre of Disease Control (1973) 6 in their National Nosocomial Infections Study. However, the statistical studies from various 'hospitals in different countries have shown that nosocomial infections may develop in an average of 7% o f patients, the range being from 3% to 15%.: The percentage always tends to be higher whenever the susceptible group of patients (as was observed in this study) sudl as the debilitated, the neonates or those undergoing surgery or in labour are hospitalized. On the contrary, our low figures (3.4% and 2-7% ofhospitaI infection rates for 1977 and 1978 respectively) may be due in part to the intensive hospital infection control system and vigilant surveillance programme of Lagos University Teaching Hospital. The low isolation rate for anaerobes suggests, however, that under reporting may also be a factor. As in our earlier report, a our findings in the present prospective study compare favourably with the f'mdings in other hospitals, where U.T.I. and post-operative wound infections are also the predominant nosocomial infections,za Data from the University o f Minnesota showed that a sharp increa~ o f G~am negative infections in hospitals due to U.T.I. occurred in patients whose resistance was compromised by serious underlying disease. 9 The incidence of hospital-associated infections in developing countries (such as Nigeria) is difficult to assess on a national basis. This may be partly due to the fact that clinicians are Iess interested in nosocon-,ial irffections and fail to record relevant statistics and partly because epidemiologists are too preoccupied with other ¢onmmnicable diseases, it must be stressed that nosocomial infections in both endemic and epidemic form are among the major causes o f morbidity and mortality. It is therefore imperative for similar sludies to be conducted in all government and private hospitals. A multi-disciplinary approach is essential when any research projects are envisaged. From our experience these research activities should be centred around four cardinal points: (a) The patient (specia! risk groups and application o f vaccination). (b) The microorganism (improvement and epidemiological assessment o f typing schemes, resistance patterJ~s and evaluation o f diagnostic techniques)J ° (c) The environment (control o f methods o f sterilization and disinfection processes, studies o f hospital design, isolation facilities and development o f efficient disinfectants). (d) The adminislration (economic aspects, cost effectiveness, hospital formulary and legal aspects). Conclusion
From this study we conclude that hospital-acquired infections at Lagos University T e n t i n g Hospital is a continuing'danger and a vigilant surveillance programme is required to remove it. Acknowledgements The co-operation of many ConsuRants, Paediatricians, Obstertricians and Gynaecologists, Surgeons and Physicians under whose care in the various wards the patients were, and Nurses o f the Lagos University Teaching Hospital and College o f Medicine is gratefully acknowledged. For technical assistance we .are indebted to faculty and staff of the Department of Microbiology L.U.T.H.
234
Arosocomial htfections
Referenoes 1. Goddard, J. L. (1970). Epidemiology. Proceedings National Conference on Institutionally Acquired Infections. 2. Wahba, A. H. W. (1977). Itospital infections - a continuing danger 1o patients and staff. W.H.O. chronicle 3 I , 63--6. 3. Ogunbi, O. & Anyiwo C. E. (1977). Lagos University Teaching Hospilat: Infection Control l~rogramme-a review o f two years activities 1974/75. Proceedings o f First National Symposium o f Nosocomial Infections (1976). 4. Daniel, S. O. (197-7). An epidemiological study o f nosocomial infections at Lagos University Teaching Hospital. Public Health 91, 1 3 - 1 8 . 5. Itunponu~Wusu, 0. 0 . & Daniel, S. O. (1977). Klebsiella infection as agents of nosocomial infections. Proceedings o f First National Symposium on Nosocomial Infections held in i976. 6. Centre o f Disease Control (1973). Centre o f Disease Control's National Nosoeomial Infections Stud),. Second Quarter 1972. Washington D.C. 7. Altermeir, W. A. (1970). Current infection problem in surgery. International Conference on Nosocomiat Infections pp. 8 2 - 8 7 . 8. Shaffer, J. G. (1963). Proceedings National Conference on Institutionally Acquired Infections. pp. 6 - I 9. 9_ Kunin, C. M. ( I 970). Nosoeomial Infections International Conference. pp. 8 8 - 9 4 . i0. Hnll, L. B. (1970). Air sampling techniques. Proceedings National Conference on Institutionally A cquired Infections.