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The relation of colonization of the perineum to bacteriuria and environmental contamination in spinally injured patients
Journal
of Hospital
Infection
(1990)
15, 229-234
The relation of colonization bacteriuria and environmental spinally injured P. J. Sanderson Royal
National
of the perineum contamination patients
to in
and S. Weissler
Orthopaedic Hospital, Brockley Middlesex HA 7 4LP
Accepted for publication
Hill,
Stanmore,
19 December 1989
Summary: We have examined the relation of perineal colonization by coliforms to bacteriuria and to contamination of bedclothes and other environmental sites with these organisms in spinally injured patients. Perineal colonization was significantly associated with bacteriuria and with contamination of bedclothes, but not with contamination of other sites. There was no association between bacteriuria and contamination of bedclothes or the environment. The perinea of these and other patients may be an important source of contamination of the environment and indirectly of the hands of the patients and staff. Keywords:
Perineum;
bacteriuria;
environmental
contamination.
Introduction It has been shown that the perinea and groins of spinally injured patients become stably colonized with coliforms (Montgomerie & Morrow, 1980; Gilmore et al., 1981, 1982; Fawcett et al., 1986). These patients suffer a high incidence of bacteriuria and urinary infection, and organisms recovered from the perineum of these patients have subsequently been found in the urine (Fawcett et al., 1986). We have previously shown that the environment of spinal injury patients, e.g. bed sheets, bath towels, locker surfaces and other sites, become contaminated with organisms indistinguishable from those causing bacteriuria (Sanderson & Rawal, 1987). In the present study we have examined the relationship between colonization by coliforms of the perineum and the incidence of bacteriuria and the contamination of bedclothes and other environmental sites with these organisms. Patients, Patients
of the
Correspondence 01954701/90/030229+06
London
materials
Spinal
and methods
Injuries
Unit
at the
Royal
National
to Dr P. J. Sanderson $03.00/O
0 1990 The Hospital
229
Infectmn
Society
230
P. J. Sanderson
and S. Weissler
Orthopaedic Hospital, Stanmore, took part in the study. The patients were undergoing rehabilitation, and were treated with sterile intermittent catheterization, usually on five occasions each day. If indwelling catheterization was required for more than a week, they were temporarily removed from the trial. Patients were washed daily on their beds or less often in a shower, using either non-medicated soap or chlorhexidine gluconate 4.0% (ICI, Macclesfield) applied to flannels. Appropriate antibiotics were given to patients on clinical evidence of urinary infection or of infection elsewhere. A variety of antibiotics were used, generally ‘first-line’ types, and for urinary infection a standard course of seven days was given. Bacteriology Urine was sampled daily by placing a ‘dip slide’ (Oxoid, UK) with CLED medium into pooled urine immediately after catheterization. A cfu count of > 10’ ml-’ was considered positive, i.e. indicating the presence of bacteriuria; lower numbers and mixed cultures were regarded as negative. Perineal colonization by coliforms was assessed at weekly intervals by rubbing a moistened cotton tipped swab along the groin into the fold between the base of the scrotum (or the vulva) and the thigh ending on the perineum, on both sides. The swab was inoculated onto CLED medium (Oxoid, UK), and the plates incubated aerobically for 24 h. Perineal colonization was assessed as positive when any coliform-type organism was recovered and as negative when no coliforms were found. Bedsheets were sampled after overnight use by sweep plates containing CLED medium; the bottom sheets (eight sweeps) and pillows (four sweeps) were each sampled by single plates and the results combined for analysis. Plates were incubated aerobically for 24 h and coliform-type colonies enumerated. Bedsheets were changed daily. Other environmental sites, i.e. bath towels, flannels, washing bowls, locker surfaces and wheelchair arms, were sampled once weekly, usually on the same day as the bedclothes, by moistened swabs as described previously (Sanderson & Rawal, 1987). Swabs were plated onto CLED medium and examined for coliform-type colonies after incubation. The recovery of any coliform-type organisms from any of the different sites was regarded as a positive result; a negative result was recorded when none was found. Statistics The results were analysed using the x2 test on 2 X 2 contingency tables. Yates’ correction was applied when any cell had less than 10 observations. Results
Relation of colonization of the perineum to bacteriuria One hundred and eleven pairs of perineal swabs
and ‘dip-slide’
urine
Perineal
colonization
231
and bacteriuria
cultures from the same patient were available for study. ‘I’he urine cultures were taken either on the same day as the perineal cultures or less often on the day preceding; none was taken after perineal culture. The patients were not receiving antibiotics and were washed in either soap or chlorhexidine. Ninety-eight perineal swabs and 81 ‘dip slide’ cultures yielded coliform organisms. The results are correlated in Table I. A significant association (P= 0.05) was found between positive perineal cultures for coliforms and the presence of bacteriuria. Table I. Correlation of perineal colonization by coliforms bacteriuria in the same patient, in a series of spinally injured
with the presence or absence of patients not receiving antibiotics Bacteriuria
P erineal
colonization
Absent
Negative Positive Total
Present
7 ii
x2= 3.9 (with Yates’ correction);
Total
6
13 98 111
2
P=O.OS.
Relation of colonization of the perineum to contamination of bedclothes There were 168 sets of perineal swabs and sweep plate cultures of bedsheets from the same patient available for study. Perineal swabs and sweep cultures were taken on the same day in individual patients and cultured for coliform organisms. Patients receiving antibiotics were included. The results are analysed in Table II. A significant association (PC 0.01) was found between coliform-positive perineal cultures and contamination of bedclothes by coliforms.
Table
II.
Correlation
of perineal
colonization by co&forms with contamination the same patient with coliforms Presence
Perineal
colonization
Negative Positive Total
Positive 15 107 122
of coliforms Negative 15 31 46
of bedclothes of
on bedclothes Total 30 138 168
x2=9.34; P
Kelation of colonization of the perineum to contamination of other environmental sites Table III demonstrates the relation between the results of perineal culture for the coliforms and the results of sampling bath towels, flannels, washing
232 Table
P. J. Sanderson III.
Correlation
and
of perineal colonization than bedclothes)
with contamination of the same patient
Presence Perineal
colonization
S. Weissler
of coliforms on towels, flannels, lockers and wheelchairs
Positive
Negative Positive Total
of environmental
Negative
1% 153
sites (other washbowls, Total
1: 14
1:‘: 167
x* = 0~0007; P= 0.98.
bowls, bedside lockers and wheelchair arms for these organisms on the same There were 167 sets of perineal swabs and day in the same patient. environmental swabs; of the latter, 153 yielded coliforms, often at more than one site. No statistical association was found between coliform positive perineal cultures and coliform contamination of the environmental sites sampled. Relation of bacteriuria to contamination of bedclothes and other environmental sites When the results of urine culture were correlated with coliform contamination of bedclothes and of the other environmental sites sampled, there appeared to be no association between bacteriuria and contamination at these sites. (Table IV). Table
IV.
Correlation
of presence or absence of bacteriuria with contamination other environmental sites Contamination Bedclothes
Bacteriuria
Positive
Negative Positive Total
50
Negative
with
coliforms Other
Total
Positive
18
68
65
46 28
167 99
x2=0.11; 0.7
1::
of bedclothes and
of environmental Negative
sites Total
3 129
68 1z:
x2 = 0.78 (with Yates’ correction); 0.3
Our finding that the perineal skin of spinally injured patients is frequently colonized with coliforms agrees with the results of Fawcett et al. (1986) and Montgomerie et al. (1987). Such colonization might be explained by the use of antibiotics to treat or prevent infection after injury and subsequently for urinary infection. Alteration in the normal bowel flora and perineal skin
Perineal
colonization
and bacteriuria
233
flora, together with other possible changes e.g. in skin pH, humidity (Montgomerie et al., 1988) or other factors, may result in prolonged survival of coliforms on the perineum. The recovery of coliforms from patients’ bedclothes, even after only a single night’s use, and from towels, flannels, bedside lockers, bowls and wheelchair arms, confirms previous results from this unit (Sanderson & Rawal, 1987). We previously reported that the same strain of coliform causing urinary infection could be recovered from environmental sites related to the patient. However, urinary infection may originate from bowel organisms colonizing the perineum and the question arose as to whether the source of environmental contamination is the urine or the perineum itself. The large number of coliforms that can be recovered from the perineum of these patients and their direct contact with bedding, (patients did not wear pyjamas), suggest the perineum as the source. The good association we found (PzO.01) between perineal coliform colonization and contamination of the bedclothes with similar organisms, and the absence of an association with the presence of bacteriuria, confirms the perineum as the source. was no association between perineal colonization and There contamination with coliforms of the other environmental sites we examined. It is possible that these somewhat more remote sites were seeded from another source such as the hands of patients or staff, the cleaning fluids used (Werry, Lawrence & Sanderson, 1987), or the water supplies. However, our method of approach, using statistical analysis, may have been insensitive. The biotyping of individual strains of bacteria may reveal associations not shown by our technique. The colonization by coliforms of the perineal skin was also associated (PcO.05) with the presence of bacteriuria. This association provides further evidence for the pathway of urinary infection from bowel (Diafuku & Stamm, 1984) via perineum to bladder. These results also illustrate the high rate of bacteriuria in these patients and reflects our experience in this unit and that of others (Barkin et al., 1983). Our policy is not to treat bacteriuria unless symptoms or signs indicative of urinary infection are also present. We also examined whether there was an association between bacteriuria and contamination of bedding and the other environmental sites. None was found and we conclude that, although the urine will contain large numbers of organisms during bacteriuric episodes, perineal colonization is relatively more important as a source of contamination. It will have occurred earlier, with a large number of organisms in direct contact with bedclothes. Urinary spillage should be slight in most patients. These results demonstrate the importance of the perineum as a source of bacteria causing both urinary infection and contamination of bedding, at least in spinally injured patients. Contamination of bedclothes may lead to contamination of hands and cross-infection. These findings suggest that methods to reduce perineal colonization should be investigated, as well as whether this site is a source of contamination in other types of patients.
234
P. J. Sanderson
and S. Weissler
References Barkin, M., Dolfin, D., Herschorn, S., Bharatwal, N. & Comisarow, R. (1983). The urologic care of the spinal cord injury patient. Journal of Urology 129, 335-339. Daifuku, R. & Stamm, W. E. (1984). A ssociation of rectal and urethral colonization with urinary tract infection in patients with indwelling catheters. Journal of the American Medical Association 252, 2028-2030. Fawcett, C., Chawla, J. C., Quoraishi, A. & Stickler, D. J. (1986). A study of the skin flora of spinal cord injured patients. Journal of Hospital Infection 8, 149-1.58. Gilmore, D. S., Aeilts, G. D., Alldis, B. A. et al. (1981). Effects of bathing on pseudomonas and klebsiella colonization in patients with spinal cord injuries. Journal of Clinical Microbiology 14, 404407. Montgomerie, J. Z. & Morrow, J. W. (1980). Long-term pseudomonas colonization in 112, 508-517. spinal-cord injury patients. American Journal of Epidemiology Montgomerie, J. Z., Gilmore, D. S., Graham, I. E. & Schick, D. G. (1988). The effects of antiperspirant on the perineal skin flora of patients with spinal cord injury. Journal of Hospital Infection 12, 4349. Sanderson, P. J. & Rawal, P. (1987). Contamination of the environment of spinal cord injured patients by organisms causing urinary-tract infection. Journal of Hospital Infection 10, 173-178. Werry C., Lawrence, J. M. & Sanderson, P. J. (1988). Contamination of detergent cleaning solution during hospital cleaning. Journal of Hospital Infection 11, 4449.
of Hospital
Infection
(1990)
15, 229-234
The relation of colonization bacteriuria and environmental spinally injured P. J. Sanderson Royal
National
of the perineum contamination patients
to in
and S. Weissler
Orthopaedic Hospital, Brockley Middlesex HA 7 4LP
Accepted for publication
Hill,
Stanmore,
19 December 1989
Summary: We have examined the relation of perineal colonization by coliforms to bacteriuria and to contamination of bedclothes and other environmental sites with these organisms in spinally injured patients. Perineal colonization was significantly associated with bacteriuria and with contamination of bedclothes, but not with contamination of other sites. There was no association between bacteriuria and contamination of bedclothes or the environment. The perinea of these and other patients may be an important source of contamination of the environment and indirectly of the hands of the patients and staff. Keywords:
Perineum;
bacteriuria;
environmental
contamination.
Introduction It has been shown that the perinea and groins of spinally injured patients become stably colonized with coliforms (Montgomerie & Morrow, 1980; Gilmore et al., 1981, 1982; Fawcett et al., 1986). These patients suffer a high incidence of bacteriuria and urinary infection, and organisms recovered from the perineum of these patients have subsequently been found in the urine (Fawcett et al., 1986). We have previously shown that the environment of spinal injury patients, e.g. bed sheets, bath towels, locker surfaces and other sites, become contaminated with organisms indistinguishable from those causing bacteriuria (Sanderson & Rawal, 1987). In the present study we have examined the relationship between colonization by coliforms of the perineum and the incidence of bacteriuria and the contamination of bedclothes and other environmental sites with these organisms. Patients, Patients
of the
Correspondence 01954701/90/030229+06
London
materials
Spinal
and methods
Injuries
Unit
at the
Royal
National
to Dr P. J. Sanderson $03.00/O
0 1990 The Hospital
229
Infectmn
Society
230
P. J. Sanderson
and S. Weissler
Orthopaedic Hospital, Stanmore, took part in the study. The patients were undergoing rehabilitation, and were treated with sterile intermittent catheterization, usually on five occasions each day. If indwelling catheterization was required for more than a week, they were temporarily removed from the trial. Patients were washed daily on their beds or less often in a shower, using either non-medicated soap or chlorhexidine gluconate 4.0% (ICI, Macclesfield) applied to flannels. Appropriate antibiotics were given to patients on clinical evidence of urinary infection or of infection elsewhere. A variety of antibiotics were used, generally ‘first-line’ types, and for urinary infection a standard course of seven days was given. Bacteriology Urine was sampled daily by placing a ‘dip slide’ (Oxoid, UK) with CLED medium into pooled urine immediately after catheterization. A cfu count of > 10’ ml-’ was considered positive, i.e. indicating the presence of bacteriuria; lower numbers and mixed cultures were regarded as negative. Perineal colonization by coliforms was assessed at weekly intervals by rubbing a moistened cotton tipped swab along the groin into the fold between the base of the scrotum (or the vulva) and the thigh ending on the perineum, on both sides. The swab was inoculated onto CLED medium (Oxoid, UK), and the plates incubated aerobically for 24 h. Perineal colonization was assessed as positive when any coliform-type organism was recovered and as negative when no coliforms were found. Bedsheets were sampled after overnight use by sweep plates containing CLED medium; the bottom sheets (eight sweeps) and pillows (four sweeps) were each sampled by single plates and the results combined for analysis. Plates were incubated aerobically for 24 h and coliform-type colonies enumerated. Bedsheets were changed daily. Other environmental sites, i.e. bath towels, flannels, washing bowls, locker surfaces and wheelchair arms, were sampled once weekly, usually on the same day as the bedclothes, by moistened swabs as described previously (Sanderson & Rawal, 1987). Swabs were plated onto CLED medium and examined for coliform-type colonies after incubation. The recovery of any coliform-type organisms from any of the different sites was regarded as a positive result; a negative result was recorded when none was found. Statistics The results were analysed using the x2 test on 2 X 2 contingency tables. Yates’ correction was applied when any cell had less than 10 observations. Results
Relation of colonization of the perineum to bacteriuria One hundred and eleven pairs of perineal swabs
and ‘dip-slide’
urine
Perineal
colonization
231
and bacteriuria
cultures from the same patient were available for study. ‘I’he urine cultures were taken either on the same day as the perineal cultures or less often on the day preceding; none was taken after perineal culture. The patients were not receiving antibiotics and were washed in either soap or chlorhexidine. Ninety-eight perineal swabs and 81 ‘dip slide’ cultures yielded coliform organisms. The results are correlated in Table I. A significant association (P= 0.05) was found between positive perineal cultures for coliforms and the presence of bacteriuria. Table I. Correlation of perineal colonization by coliforms bacteriuria in the same patient, in a series of spinally injured
with the presence or absence of patients not receiving antibiotics Bacteriuria
P erineal
colonization
Absent
Negative Positive Total
Present
7 ii
x2= 3.9 (with Yates’ correction);
Total
6
13 98 111
2
P=O.OS.
Relation of colonization of the perineum to contamination of bedclothes There were 168 sets of perineal swabs and sweep plate cultures of bedsheets from the same patient available for study. Perineal swabs and sweep cultures were taken on the same day in individual patients and cultured for coliform organisms. Patients receiving antibiotics were included. The results are analysed in Table II. A significant association (PC 0.01) was found between coliform-positive perineal cultures and contamination of bedclothes by coliforms.
Table
II.
Correlation
of perineal
colonization by co&forms with contamination the same patient with coliforms Presence
Perineal
colonization
Negative Positive Total
Positive 15 107 122
of coliforms Negative 15 31 46
of bedclothes of
on bedclothes Total 30 138 168
x2=9.34; P
Kelation of colonization of the perineum to contamination of other environmental sites Table III demonstrates the relation between the results of perineal culture for the coliforms and the results of sampling bath towels, flannels, washing
232 Table
P. J. Sanderson III.
Correlation
and
of perineal colonization than bedclothes)
with contamination of the same patient
Presence Perineal
colonization
S. Weissler
of coliforms on towels, flannels, lockers and wheelchairs
Positive
Negative Positive Total
of environmental
Negative
1% 153
sites (other washbowls, Total
1: 14
1:‘: 167
x* = 0~0007; P= 0.98.
bowls, bedside lockers and wheelchair arms for these organisms on the same There were 167 sets of perineal swabs and day in the same patient. environmental swabs; of the latter, 153 yielded coliforms, often at more than one site. No statistical association was found between coliform positive perineal cultures and coliform contamination of the environmental sites sampled. Relation of bacteriuria to contamination of bedclothes and other environmental sites When the results of urine culture were correlated with coliform contamination of bedclothes and of the other environmental sites sampled, there appeared to be no association between bacteriuria and contamination at these sites. (Table IV). Table
IV.
Correlation
of presence or absence of bacteriuria with contamination other environmental sites Contamination Bedclothes
Bacteriuria
Positive
Negative Positive Total
50
Negative
with
coliforms Other
Total
Positive
18
68
65
46 28
167 99
x2=0.11; 0.7
1::
of bedclothes and
of environmental Negative
sites Total
3 129
68 1z:
x2 = 0.78 (with Yates’ correction); 0.3
Our finding that the perineal skin of spinally injured patients is frequently colonized with coliforms agrees with the results of Fawcett et al. (1986) and Montgomerie et al. (1987). Such colonization might be explained by the use of antibiotics to treat or prevent infection after injury and subsequently for urinary infection. Alteration in the normal bowel flora and perineal skin
Perineal
colonization
and bacteriuria
233
flora, together with other possible changes e.g. in skin pH, humidity (Montgomerie et al., 1988) or other factors, may result in prolonged survival of coliforms on the perineum. The recovery of coliforms from patients’ bedclothes, even after only a single night’s use, and from towels, flannels, bedside lockers, bowls and wheelchair arms, confirms previous results from this unit (Sanderson & Rawal, 1987). We previously reported that the same strain of coliform causing urinary infection could be recovered from environmental sites related to the patient. However, urinary infection may originate from bowel organisms colonizing the perineum and the question arose as to whether the source of environmental contamination is the urine or the perineum itself. The large number of coliforms that can be recovered from the perineum of these patients and their direct contact with bedding, (patients did not wear pyjamas), suggest the perineum as the source. The good association we found (PzO.01) between perineal coliform colonization and contamination of the bedclothes with similar organisms, and the absence of an association with the presence of bacteriuria, confirms the perineum as the source. was no association between perineal colonization and There contamination with coliforms of the other environmental sites we examined. It is possible that these somewhat more remote sites were seeded from another source such as the hands of patients or staff, the cleaning fluids used (Werry, Lawrence & Sanderson, 1987), or the water supplies. However, our method of approach, using statistical analysis, may have been insensitive. The biotyping of individual strains of bacteria may reveal associations not shown by our technique. The colonization by coliforms of the perineal skin was also associated (PcO.05) with the presence of bacteriuria. This association provides further evidence for the pathway of urinary infection from bowel (Diafuku & Stamm, 1984) via perineum to bladder. These results also illustrate the high rate of bacteriuria in these patients and reflects our experience in this unit and that of others (Barkin et al., 1983). Our policy is not to treat bacteriuria unless symptoms or signs indicative of urinary infection are also present. We also examined whether there was an association between bacteriuria and contamination of bedding and the other environmental sites. None was found and we conclude that, although the urine will contain large numbers of organisms during bacteriuric episodes, perineal colonization is relatively more important as a source of contamination. It will have occurred earlier, with a large number of organisms in direct contact with bedclothes. Urinary spillage should be slight in most patients. These results demonstrate the importance of the perineum as a source of bacteria causing both urinary infection and contamination of bedding, at least in spinally injured patients. Contamination of bedclothes may lead to contamination of hands and cross-infection. These findings suggest that methods to reduce perineal colonization should be investigated, as well as whether this site is a source of contamination in other types of patients.
234
P. J. Sanderson
and S. Weissler
References Barkin, M., Dolfin, D., Herschorn, S., Bharatwal, N. & Comisarow, R. (1983). The urologic care of the spinal cord injury patient. Journal of Urology 129, 335-339. Daifuku, R. & Stamm, W. E. (1984). A ssociation of rectal and urethral colonization with urinary tract infection in patients with indwelling catheters. Journal of the American Medical Association 252, 2028-2030. Fawcett, C., Chawla, J. C., Quoraishi, A. & Stickler, D. J. (1986). A study of the skin flora of spinal cord injured patients. Journal of Hospital Infection 8, 149-1.58. Gilmore, D. S., Aeilts, G. D., Alldis, B. A. et al. (1981). Effects of bathing on pseudomonas and klebsiella colonization in patients with spinal cord injuries. Journal of Clinical Microbiology 14, 404407. Montgomerie, J. Z. & Morrow, J. W. (1980). Long-term pseudomonas colonization in 112, 508-517. spinal-cord injury patients. American Journal of Epidemiology Montgomerie, J. Z., Gilmore, D. S., Graham, I. E. & Schick, D. G. (1988). The effects of antiperspirant on the perineal skin flora of patients with spinal cord injury. Journal of Hospital Infection 12, 4349. Sanderson, P. J. & Rawal, P. (1987). Contamination of the environment of spinal cord injured patients by organisms causing urinary-tract infection. Journal of Hospital Infection 10, 173-178. Werry C., Lawrence, J. M. & Sanderson, P. J. (1988). Contamination of detergent cleaning solution during hospital cleaning. Journal of Hospital Infection 11, 4449.