Effectiveness of deep cleaning followed by hydrogen peroxide decontamination during high Clostridium difficile infection incidence.

BACKGROUND: Clostridium difficile infection (CDI) remains an infection control challenge, especially when environmental spore contamination and suboptimal cleaning may increase transmission risk. AIM: To substantiate the long-term effectiveness throughout a stroke rehabilitation unit (SRU) of deep cleaning and hydrogen peroxide decontamination (HPD), following a high incidence of CDI. METHODS: Extensive environmental sampling (342 sites on each occasion) for C. difficile using sponge wipes was performed: before and after deep cleaning with detergent/chlorine agent; immediately following HPD; and on two further occasions, 19 days and 20 weeks following HPD. C. difficile isolates underwent polymerase chain reaction ribotyping and multi-locus variable repeat analysis (MLVA). FINDINGS: C. difficile was recovered from 10.8%, 6.1%, 0.9%, 0% and 3.5% of sites at baseline, following deep cleaning, immediately after HPD, and 19 days and 20 weeks after HPD, respectively. C. difficile ribotypes recovered after deep cleaning matched those from CDI cases in the SRU during the previous 10 months. Similarly, 10/12 of the positive sites identified at 20 weeks post-HPD harboured the same C. difficile ribotype (002) and MLVA pattern as the isolate from the first post-HPD CDI case. CDI incidence [number of cases on SRU per 10 months (January-October 2011)] declined from 20 before to seven after the intervention. CONCLUSION: HPD, after deep cleaning with a detergent/chlorine agent, was highly effective for removing environmental C. difficile contamination. Long-term follow-up demonstrated that a CDI symptomatic patient can rapidly recontaminate the immediate environment. Determining a role for HPD should include long-term cost-effectiveness evaluations.

Effectiveness of topical chlorhexidine powder as an alternative to hexachlorophane for the control of Staphylococcus aureus in neonates.

We routinely phage-type Staphylococcus aureus isolates from high-risk inpatients each week. This surveillance approach previously identified a five-year outbreak of a methicillin-susceptible S. aureus strain (MSSA, PT 53,85), which affected 202 babies on a regional neonatal unit. We previously reported this outbreak and the multiple staged infection control measures that were required to end it. These included strict emphasis on hand hygiene, environmental and staff surveillance sampling, application of topical triclosan solution and hexachlorophane powder, aseptic handling of a skin protectant material, and use of topical mupirocin for staff nasal carriers of the endemic MSSA strain and for babies colonized or infected with S. aureus. In summer 2000 topical hexachlorophane powder became unavailable and we therefore substituted topical 1% chlorhexidine powder as part of routine umbilical decontamination. We have continued prospective S. aureus surveillance for the past five years to monitor the effect of this practice change. We observed a continued decline in the numbers of monthly MSSA isolates from neonatal unit babies. Since the substitution of chlorhexidine for hexachlorophane, the median monthly number of MRSA isolates has been 0.5 (range 0-4). Only sporadic S. aureus PT 53,85 isolates were recovered. Control of S. aureus in our regional neonatal unit, in particular an endemic MSSA strain, was maintained when topical umbilical hexachlorophane powder was substituted with 1% chlorhexidine powder.

Use of perioperative mupirocin to prevent methicillin-resistant Staphylococcus aureus (MRSA) orthopaedic surgical site infections.

We have examined whether topical perioperative prophylaxis can reduce the incidence of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infections (SSIs). Using a controlled before and after approach on patients from four orthopaedic wards, undergoing orthopaedic surgery involving insertion of metal prostheses and/or fixation, received perioperative prophylaxis with nasal mupirocin for five days, and a shower or bath with 2% (v/v) triclosan before surgery (PPNMT). After introduction of PPNMT there was a marked decrease in incidence of MRSA SSIs (per 1000 operations) from 23 in the six months beforehand (period A) to 3.3 (P<0.001) and 4 (P<0.001) in subsequent consecutive six-month periods (B and C, respectively). Of 11 MRSA SSI cases that occurred during periods B and C, only one had actually received PPNMT, and 10 occurred after acute, as opposed to elective, surgery (P<0.001). Point prevalence nasal MRSA carriage decreased from 38% before PPNMT to 23% immediately after, and 20%, 7%, 10% and 8% (P<0.001) at six-monthly intervals post-intervention. Conversely, the prevalence of nasal MRSA carriage in a control elderly medicine ward did not change significantly. Vancomycin usage, in terms of defined daily doses, declined by 23%. Low-level mupirocin resistance was found in 2.3% of S. aureus isolates from orthopaedic patients before PPNMT, and in 3.9%, 6.1%, 10% and 0% in subsequent six month periods. No S. aureus isolates with high-level mupirocin resistance were found. PPNMT can reduce the incidence of MRSA SSls after orthopaedic surgery, probably by reducing nasal MRSA carriage in the endemic setting, without selecting for mupirocin resistance.

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.

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.

Diversity and detection of nitrate assimilation genes in marine bacteria.

A PCR approach was used to construct a database of nasA genes (called narB genes in cyanobacteria) and to detect the genetic potential for heterotrophic bacterial nitrate utilization in marine environments. A nasA-specific PCR primer set that could be used to selectively amplify the nasA gene from heterotrophic bacteria was designed. Using seawater DNA extracts obtained from microbial communities in the South Atlantic Bight, the Barents Sea, and the North Pacific Gyre, we PCR amplified and sequenced nasA genes. Our results indicate that several groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments.

Burn injuries in children. The emotional and psychological effects on child and family.

Attention to the total care of the patient and family is needed to promote emotional as well as physical healing. This paper looks at the grief process as experienced by the parents of a burn injured child. Mention is made of non-accidental injuries, accident prevention and the rehabilitation stage of a burn injury. Emphasis is on scalds to toddlers between the ages of 1 to 2 years.