Prospective evaluation of environmental contamination by Clostridium difficile in isolation side rooms.

We determined prospectively the frequency, persistence and molecular epidemiology of Clostridium difficile environmental contamination after detergent-based cleaning in side rooms used to isolate patients with C. difficile diarrhoea. Approximately one-quarter of all environmental sites in side rooms sampled over four-week periods were contaminated with C. difficile. The overall side room prevalence of environmental C. difficile declined from 35% initially, to 24% in week 2, 18% in week 3, and 16% in week 4. The bed frame was the most common site from which C. difficile was recovered, although the floor was the most contaminated site in terms of total numbers of colonies. C. difficile was recovered significantly more frequently from swabs plated directly on to C. difficile selective media containing lysozyme than from enrichment broth (P< 0.001), emphasizing the benefit of lysozyme supplementation. The great majority of C. difficile isolates (87% of all isolates, 84% of patient isolates) was indistinguishable from the UK epidemic strain (PCR ribotype 1). It thus could not be determined whether environmental contamination was a cause or a consequence of diarrhoea. Our findings highlight the need for improved approaches to hospital environmental hygiene, and call into question current UK guidelines that recommend detergent-based cleaning to remove environmental C. difficile. In particular, improved cleaning of frequently touched sites in the immediate bed space area is required.     

Molecular epidemiology of endemic Clostridium difficile infection

This is the first study to provide a comprehensive insight into the molecular epidemiology of endemic Clostridium difficile and particularly that associated with a recently recognized epidemic strain. We DNA fingerprinted all C. difficile isolates from the stools of patients with symptomatic antibiotic-associated diarrhoea and from repeated samples of the inanimate ward environment on two elderly medicine hospital wards over a 22-month period. Notably, C. difficile was not recoverable from either ward immediately before opening, but was found on both wards within 1-3 weeks of opening, and the level of environmental contamination rose markedly during the first 6 months of the study period. C. difficile infection (CDI) incidence data correlated significantly with the prevalence of environmental C. difficile on ward B (r = 0.76, P < 0.05) but not on ward A (r = 0.26, P > 0.05). We found that RAPD and RS-PCR typing had similar discriminatory power, although, despite fingerprinting over 200 C. difficile isolates, we identified only six distinct types. Only two distinct C. difficile strains were identified as causing both patient infection and ward contamination. Attempts to determine whether infected patients or contaminated environments are the prime source for cross-infection by C. difficile had limited success, as over 90% of C. difficile isolates were the UK epidemic clone. However, a non-epidemic strain caused a cluster of six cases of CDI, but was only isolated from the environment after the sixth patient became symptomatic. The initial absence of this strain from the environment implies patient-to-patient and/or staff-to-patient spread. In general, routine cleaning with detergent was unsuccessful at removing C. difficile from the environment. Understanding the epidemiology and virulence of prevalent strains is important if CDI is to be successfully controlled.     

Airborne hydrogen peroxide for disinfection of the hospital environment and infection control: a systematic review

We reviewed the effectiveness of airborne hydrogen peroxide as an environmental disinfectant and infection control measure in clinical settings. Systematic review identified ten studies as eligible for inclusion. Hydrogen peroxide was delivered in the form of vapour and dry mist in seven and three studies, respectively. Pathogens evaluated included meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile and multiple bacterial types, in five, three, and two studies, respectively. Before the application of any cleaning intervention, 187/480 (39.0%; range: 18.9-81.0%) of all sampled environmental sites were found to be contaminated by the studied pathogens in nine studies that reported specific relevant data. After application of terminal cleaning and airborne hydrogen peroxide, 178/630 (28.3%; range: 11.9-66.1%) of the sampled sites in six studies and 15/682 (2.2%; range: 0-4.0%) of the sampled sites in ten studies, respectively, remained contaminated. Four studies evaluated the use of hydrogen peroxide vapour for infection control. This was associated with control of a nosocomial outbreak in two studies, eradication of persistent environmental contamination with MRSA and decrease in C. difficile infection in each of the remaining two studies.     

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis((R))) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis((R)) hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.     

Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection

To determine how best to decontaminate the hospital environment of Clostridium difficile, we carried out a cross-over study on two elderly medicine wards to determine whether cleaning with a hypochlorite disinfectant was better than using neutral detergent in reducing the incidence of C. difficile infection (CDI). We examined 1128 environmental samples in two years, 35% of which grew C. difficile. There was a significant decrease of CDI incidence on ward X, from 8.9 to 5.3 cases per 100 admissions (P<0.05) using hypochlorite, but there was no significant effect on ward Y. On ward X the incidence of CDI was significantly associated with the proportion of culture-positive environmental sites (P<0.05). On ward Y the only significant correlation between CDI and C. difficile culture-positive environmental sites was in patient side-rooms (r=0.41, P<0.05). The total daily defined doses of cefotaxime, cephradine and aminopenicillins were similar throughout the trial. These results provide some evidence that use of hypochlorite for environmental cleaning may significantly reduce incidence of CDI, but emphasize the potential for confounding factors.     

Gaseous and air decontamination technologies for Clostridium difficile in the healthcare environment

The recent data for hospital-acquired infections suggest that infection rates for meticillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile are beginning to decrease. However, while there is still pressure to maintain this trend, the resistance of C. difficile spores to standard detergents continues to present a problem for many UK hospitals trying to prevent its spread or control outbreaks. Alternative disinfection technologies such as gaseous decontamination are currently being marketed to the healthcare sector as an alternative/supplement to manual disinfection, and have been shown to be effective in reducing environmental contamination. When used correctly, they offer a complementary technology to manual cleaning that increases the probability of an effective reduction in viability and provides a comparatively uniform distribution of disinfectant. Three gaseous decontamination technologies are examined for their suitability in reducing environmental contamination with C. difficile: gaseous hydrogen peroxide, chlorine dioxide and ozone. Air decontamination and UV-based technologies are also briefly described. We conclude that while there is a role to play for these new technologies in the decontamination of ward surfaces contaminated with C. difficile, the requirement for both a preclean before use and the limited 'in vivo' evidence means that extensive field trials are necessary to determine their cost-effectiveness in a healthcare setting.     

Value of lysozyme agar incorporation and alkaline thioglycollate exposure for the environmental recovery of Clostridium difficile

Clostridium difficile is an increasingly prevalent nosocomial pathogen. Environmental contamination by spores is believed to be a major factor propagating the spread of C. difficile. Various approaches including the use of bile salts have been described to enhance the recovery of C. difficile from clinical and environmental specimens. We found that lysozyme (5 mg/L) incorporated into a selective medium containing bile salts significantly increased the recovery of C. difficile from swabs of 197 environmental sites (11% versus 24% samples positive, P< 0.01). Furthermore, in a separate series of experiments additional use of cooked meat broth enrichment significantly enhanced the recovery of C. difficile (35% versus 45%, P = 0.009). Conversely, we found that pre-exposure to alkaline thioglycollate did not improve the yield of C. difficile. Lysozyme incorporation markedly increases the recovery of C. difficile from environmental samples probably by stimulation of spore germination. Our findings suggest that previous attempts to determine the level of environmental C. difficile contamination have markedly underestimated the true prevalence of this pathogen.     

Risk of bioaerosol contamination with Aspergillus species before and after cleaning in rooms filtered with high-efficiency particulate air filters that house patients with hematologic malignancy.

OBJECTIVE: To examine the impact of cleaning and directional airflow on environmental contamination with Aspergillus species in hospital rooms filtered with high-efficiency particulate air (HEPA) filters that house patients with hematologic malignancy. DESIGN: Detailed environmental assessment. SETTING: A 475-bed tertiary cancer center in the southern United States. METHODS: From April to October 2004, 1,258 surface samples and 627 bioaerosol samples were obtained from 74 HEPA-filtered rooms (in addition, 88 outdoor bioaerosol samples were obtained). Samples were collected from rooms cleaned within 1 hour after patient discharge and from rooms before cleaning. Positive and negative airflows were evaluated using air-current tubes at entrances to patient rooms. RESULTS: Of 1,258 surface samples, 3.3% were positive for Aspergillus species. Univariate analysis showed no relationship between cleaning status and occurrence of Aspergillus species. Of 627 bioaerosol samples, 7.3% were positive for Aspergillus species. Multiple logistic analysis revealed independently significant associations with detection of Aspergillus species. Cleaned rooms positive for Aspergillus species had a higher geometric mean density of colonies than that of rooms sampled before cleaning (18.9 vs 5.5 colony-forming units [cfu] per cubic meter; P=.0047). Rooms with positive airflow had a detection rate for bioaerosol samples equivalent to that of rooms with negative airflow (7.3% vs 7.8%; P=.8). There was no significant difference in the density of Aspergillus species between rooms with negative airflow and rooms with positive airflow (12.5 vs 8.4 cfu/m(3); P=.33). CONCLUSIONS: Concentration of bioaerosol contamination with Aspergillus species was increased in rooms sampled 1 hour after cleaning compared with rooms sampled before cleaning, suggesting a possible correlation between re-entrained bioaerosols (ie, those suspended by activity in the room) after cleaning and the risk of nosocomial invasive aspergillosis.     

Emergence and control of fluoroquinolone-resistant, toxin A-negative, toxin B-positive Clostridium difficile.

BACKGROUND: Clostridium difficile is a major cause of infectious diarrhea in hospitalized patients. Between August 2003 and January 2004, we experienced an increase in the incidence of C. difficile-associated disease. We describe the investigation into and management of the outbreak in this article. METHODS: A total of 73 consecutive patients with nosocomial C. difficile-associated diarrhea were identified. C. difficile isolates were characterized using toxin-specific enzyme immunoassays, a tissue-culture fibroblast cytotoxicity assay, polymerase chain reaction (PCR), and antimicrobial susceptibility tests. Rates of recurrence and of C. difficile colitis were recorded. Changes in antibiotic use and infection control policies were documented. RESULTS: The incidence of C. difficile-associated diarrhea peaked at 21 cases per 1,000 patient admissions. Of the C. difficile isolates recovered, 85 (95%) were identical toxin A-negative and toxin B-positive strains, corresponding to toxinotype VIII and PCR ribotype 017. All clonal isolates were resistant to multiple antibiotics, including ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin (minimum inhibitory concentrations [MICs] of greater than 32 micro g/mL) and erythromycin, clarithromycin, and clindamycin (MICs of greater than 256 micro g/mL). Recurrent C. difficile-associated disease occurred in 26 (36%) of the patients. At least 10 (14%) of the patients developed C. difficile colitis. Additional infection control measures introduced included the use of ward memos, a hand-hygiene awareness campaign, increased environmental cleaning, attention to prescribing practices for antibiotics, increased awareness of diarrheal illness, and early isolation of affected patients. Total use of fluoroquinolones did not change throughout the study period. Despite persistence of this toxin-variant strain, the incidence of C. difficile-associated disease in our institution decreased to fewer than 5 cases per 1,000 admissions. CONCLUSIONS: We report on the emergence of a fluoroquinolone- and clindamycin-resistant, toxin A-negative, and toxin B-positive strain of C. difficile associated with an outbreak of C. difficile-associated disease in our institution during a 6-month period. We found that careful attention to improvement of infection control interventions was the most important means of controlling this nosocomial pathogen.     

Microbial contamination of nebulizers in the home treatment of cystic fibrosis

BACKGROUND: Home nebulizers are in widespread use in cystic fibrosis (CF) and other chronic pulmonary diseases. Bacterial contamination may be a source of respiratory tract colonization. OBJECTIVES: To investigate microbial contamination of home nebulizers in CF patients, compare with sputum cultures and relate to cleaning practices. METHODS: A total of 29 home nebulizers of CF patients were cultured. Families were interviewed regarding cleaning routines and patients had sputum cultures for bacteria and fungi. RESULTS: In total, 19/29 (65%) nebulizers were contaminated: 18 reservoir cups, 14 mouthpieces and five filters. Pseudomonas spp. were isolated from 10 nebulizers (35%) and all 10 had Pseudomonas aeruginosa airway infection although without genetic typing we could not be sure this was the same bacteria as that from their nebulizer unit. An additional 7/29 had Pseudomonas aeruginosa airway infection without a contaminated nebulizer (P=0.001). No nebulizers were contaminated with Aspergillus. Only 4/19 contaminated nebulizers (22%) had been cleaned after every use, compared with seven of the 10 (70%) uncontaminated nebulizers (P=0.017). Only 7/19 patients with contaminated nebulizers (37%) and 5/10 with clean nebulizers (50%) recalled receiving cleaning instructions (not significant). CONCLUSIONS: Home nebulizers are frequently contaminated, particularly when cleaning instructions are inadequate, and may be a source of airway infection or reinfection especially following contamination from a patient chronically colonized with P. aeruginosa. Simple oral and written cleaning instructions should be offered.     

Assessing the biological efficacy and rate of recontamination following hydrogen peroxide vapour decontamination

The inanimate hospital environment can become contaminated with nosocomial pathogens. Hydrogen peroxide vapour (HPV) decontamination has proven effective for the eradication of persistent environmental contamination. We investigated the extent of meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and gentamicin-resistant Gram-negative rod (GNR) contamination in a ward side-room occupied by a patient with a history of MRSA, VRE and GNR infection and colonisation and investigated the impact of HPV decontamination. Fifteen standardised sites in the room were sampled using a selective broth enrichment protocol to culture MRSA, VRE and GNR. Sampling was performed before cleaning, after cleaning, after HPV decontamination and at intervals over the subsequent 19 days on two separate occasions. Environmental contamination was identified before cleaning on 60, 30 and 6.7% of sites for MRSA, GNR and VRE, respectively, and 40, 10 and 6.7% of sites after cleaning. Only one site (3.3%) was contaminated with MRSA after HPV decontamination. No recontamination with VRE was identified and no recontamination with MRSA and GNR was identified during the two days following HPV decontamination. Substantial recontamination was identified approximately one week after HPV decontamination towards post-cleaning levels for GNR and towards pre-cleaning levels for MRSA. HPV is more effective than standard terminal cleaning for the eradication of nosocomial pathogens. Recontamination was not immediate for MRSA and GNR but contamination returned within a week in a room occupied by a patient colonised with MRSA and GNR. This finding has important implications for the optimal deployment of HPV decontamination in hospitals.     

Role of environmental cleaning in controlling an outbreak of Acinetobacter baumannii on a neurosurgical intensive care unit

An outbreak of Acinetobacter baumannii colonization and infection occurred in 19 patients over a 14-month period during 1998-1999 on a neurosurgical intensive care unit. During efforts to control the outbreak a significant correlation was observed between the number of environmental isolates of A. baumannii obtained during each monthly screening and the number of patients with A. baumannii colonization/infection in the same calendar month (P < 0.004). Use of 1000 ppm hypochlorite solution and the introduction of new cleaning protocols reduced the number of environmental isolates. Failure to maintain low levels of environmental contamination with A. baumannii resulted in increases in patient colonization. This study showed that high standards of cleaning play an integral role in controlling outbreaks of A. baumannii in the intensive care unit setting.     

Acquisition of Clostridium difficile from the hospital environment

An outbreak of antibiotic-associated colitis that occurred on a ward of a Michigan hospital during February-April, 1984, was studied by bacteriophage-bacteriocin typing. Stools from the seven involved patients yielded Clostridium difficile isolates of types B1537 or Cld7;B1537. C. difficile was recovered from 31.4% of environmental cultures obtained on the ward, and the majority of isolates were types B1537 or Cld7;B1537. When the ward was disinfected with unbuffered hypochlorite (500 parts per million (ppm) available chlorine), surface contamination decreased to 21% of initial levels and the outbreak subsequently ended. Phosphate buffered hypochlorite (1,600 ppm available chlorine, pH 7.6) was even more effective; its use resulted in a 98% reduction in surface contamination. These findings suggest that environmental contamination with C. difficile is important in the epidemiology of antibiotic-associated colitis, and that hypochlorite is effective in eliminating C. difficile from the hospital environment.     

A targeted strategy to wipe out Clostridium difficile

This study evaluated daily cleaning with germicidal bleach wipes on wards with a high incidence of hospital-acquired Clostridium difficile infection (CDI). The intervention reduced hospital-acquired CDI incidence by 85%, from 24.2 to 3.6 cases per 10,000 patient-days, and prolonged the median time between hospital-acquired CDI cases from 8 to 80 days.     

Efficacy of hospital cleaning agents and germicides against epidemic Clostridium difficile strains.

OBJECTIVE: To compare the effects of hospital cleaning agents and germicides on the survival of epidemic Clostridium difficile strains. METHODS: We compared the activity of and effects of exposure to 5 cleaning agents and/or germicides (3 containing chlorine, 1 containing only detergent, and 1 containing hydrogen peroxide) on vegetative and spore forms of epidemic and non-epidemic C. difficile strains (3 of each). We carried out in vitro exposure experiments using a human fecal emulsion to mimic conditions found in situ. RESULTS: Cleaning agent and germicide exposure experiments yielded very different results for C. difficile vegetative cells, compared with those for spores. Working-strength concentrations of all of the agents inhibited the growth of C. difficile in culture. However, when used at recommended working concentrations, only chlorine-based germicides were able to inactivate C. difficile spores. C. difficile epidemic strains had a greater sporulation rate than nonepidemic strains. The mean sporulation rate, expressed as the proportion of a cell population that is in spore form, was 13% for all strains not exposed to any cleaning agent or germicide, and it was significantly increased by exposure to cleaning agents or germicides containing detergent alone (34%), a combination of detergent and hypochlorite (24%), or hydrogen peroxide (33%). By contrast, the mean sporulation rate did not change substantially after exposure to germicides containing either a combination of detergent and dichloroisocyanurate (9%) or dichloroisocyanurate alone (15%). CONCLUSIONS: These results highlight differences in the activity of cleaning agents and germicides against C. difficile spores and the potential for some of these products to promote sporulation.     

Widespread environmental contamination associated with patients with diarrhea and methicillin-resistant Staphylococcus aureus colonization of the gastrointestinal tract.

OBJECTIVE: Patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) may contaminate their immediate environment with this organism. However, the extent to which gastrointestinal colonization with MRSA affects environmental contamination is not known. We investigated the frequency of environmental contamination in the rooms of patients with diarrheal stools and heavy gastrointestinal colonization with MRSA. DESIGN: Prospective observational study. SETTING: A 500-bed teaching hospital. METHODS: Stool specimens submitted for Clostridium difficile toxin assays were inoculated onto colistin-naladixic acid agar. MRSA was identified with standard methods. Samples from a standardized list of 10 environmental surfaces were cultured, from the rooms of 8 patients who had diarrhea that yielded heavy growth of MRSA (case patients) and from the rooms of 6 MRSA-positive patients with stool cultures negative for MRSA (control patients). MRSA isolates from 13 patients (8 case patients and 5 control patients) and 64 of the environmental isolates recovered from their rooms were compared by pulsed-field gel electrophoresis (PFGE). One clinical isolate from a control patient was excluded because there was no corresponding environmental MRSA isolate with which to compare it. RESULTS: Overall, MRSA were recovered from 47 (58.8%) of 80 surfaces in the rooms of case patients, compared with 14 (23.3%) of 60 surfaces in the rooms of control patients (58.8% [95% CI, 47.8-68.9] vs 23.3% [95% CI, 14.3-35.5]; P<.0001). The items most commonly contaminated were bedside rails, blood pressure cuffs, television remote controls, and toilet seats. Seventy-eight percent of the environmental isolates in patients' rooms had PFGE types that were indistinguishable or closely related to those recovered from the patients' clinical specimens. CONCLUSIONS: Patients who have diarrheal stools and heavy gastrointestinal colonization with MRSA are associated with significantly greater environmental MRSA contamination than patients without MRSA in their stool, and they are likely to be the source of that contamination.     

Rapid recontamination with MRSA of the environment of an intensive care unit after decontamination with hydrogen peroxide vapour

Meticillin-resistant Staphylococcus aureus (MRSA) persists in the hospital environment and conventional cleaning procedures do not necessarily eliminate contamination. A prospective study was conducted on an intensive care unit to establish the level of environmental contamination with MRSA, assess the effectiveness of hydrogen peroxide vapour (HPV) decontamination and determine the rate of environmental recontamination. MRSA was isolated from 11.2% of environmental sites in the three months preceding the use of HPV and epidemiological typing revealed that the types circulating within the environment were similar to those colonising patients. After patient discharge and terminal cleaning using conventional methods, MRSA was isolated from five sites (17.2%). After HPV decontamination but before the readmission of patients, MRSA was not isolated from the environment. Twenty-four hours after readmitting patients, including two colonized with MRSA, the organism was isolated from five sites. The strains were indistinguishable from a strain with which a patient was colonized but were not all confined to the immediate vicinity of the colonized patient. In the eight weeks after the use of HPV, the environment was sampled on a weekly basis and MRSA was isolated from 16.3% sites. Hydrogen peroxide vapour is effective in eliminating bacteria from the environment but the rapid rate of recontamination suggests that it is not an effective means of maintaining low levels of environmental contamination in an open-plan intensive care unit.     

The disinfection of baths and shower trolleys in hospitals

The contamination level of bath tubs and shower trolleys has been studied after use by hospital patients and following either disinfection with a phenolic disinfectant-detergent or cleaning with a detergent. After use the surfaces were contaminated with 0.5 x 10(3) - 1.7 x 10(3) colony-forming units/dm2. Cleaning and disinfection reduced the contamination level approximately tenfold. As disinfection is not more efficient than cleaning the latter procedure should routinely be preferred after each use of a bath or a shower trolley. However, disinfection may be more effective than cleaning after bathing or showering a patient with a major wound or skin infection.     

Intensive care unit environmental cleaning: an evaluation in sixteen hospitals using a novel assessment tool

Despite isolation precautions and enhanced hand hygiene product use, the transmission of healthcare-associated pathogens remains a major problem. Recent studies have confirmed that microbial contamination of the environment in intensive care units (ICUs) can lead to colonisation and infection of patients. Although environmental disinfectants have been used to minimise the spread of microbial pathogens, suboptimal cleaning may limit the effectiveness of such activities. In order to evaluate the thoroughness of cleaning near-patient surfaces, a transparent, easily cleanable and environmentally stable solution was developed that fluoresces when exposed to UV light. The solution was used to mark a standardised group of frequently touched objects in ICU patient rooms following discharge cleaning. These sites were then evaluated after at least two patients had occupied the room and at least two terminal cleanings had been completed. Evaluation of 2320 objects in 197 patient areas disclosed that 57.1% of the standardised sites were cleaned following discharge of the room's occupant in the 16 ICUs studied. Although high rates of cleaning (>80%) were found for toilet seats, sinks and tray tables, consistently low rates of cleaning (<30%) were documented for several objects at high risk of becoming contaminated with nosocomial pathogens, including bedpan cleaners, toilet area handholds, doorknobs and light switches.     

Microbiological conditions of hospital beds before and after terminal cleaning

INTRODUCTION: The hospital's environment keeps a close relationship with hospital infection, which may promote focus of contact and transmission. The terminal cleaning of patient unit represents one way to control microbiological environmental contamination. The study has as its main objective to evaluate the microbiological conditions of hospital mattresses before and after cleaning. METHODS: Rodac plates were utilized for specimen collection with culture medium - blood agar plate. The patients beds were chosen by criteria established before hand and the places for specimen collection in the mattress were chosen by aleatory drawing. To the study of numerical alteration related to the positivity of plates before and after cleaning, Goodman' statistics tests were used. RESULTS: From 52 mattress investigated, 520 culture plates were done from which 514 (98,8%) had a positive culture, 259 before cleaning and 255 after cleaning showing a reduction of positive cultures in only 4 plates after cleaning. CONCLUSIONS: The number of plates with countable and countless colonies suggests that the cleaning, as it is done, instead of reducing the microorganism is dislocating it to other areas of the mattress keeping the microbiological condition as it was before the cleaning process.