Persistent microbial contamination of incubators despite disinfection.

BACKGROUND: In neonatal intensive care units (NICUs), hygiene and disinfection measures are pivotal to protect neonates from nosocomial infections. This study aimed to evaluate the efficacy of the classical incubators disinfection procedure and to follow-up neonates housed in the incubators for the development of late-onset sepsis (LOS). METHODS: In a tertiary NICU, 20 incubators were monitored for bacterial contamination at three times: before disinfection, after disinfection, and 24 h after turning on and housing a new neonate. Clinical data of neonates housed in these incubators were retrieved from the medical records. RESULTS: All 20 incubators were contaminated at the 3 times of the study, mainly on mattresses and balances. Coagulase-negative Staphylococci, Enterococcus, and Bacillus-resisted disinfection while enterobacteria and Staphylococcus aureus were eradicated. After 24 h, the bacterial colonisation was similar to the one observed before disinfection. The bacteria isolated on incubators were also found on the caregivers' hands. During the study, two preterm neonates developed a LOS involving a bacterial species that has been previously isolated in their incubator. CONCLUSION: Pathogenic contaminants persist on incubators despite disinfection and represent a risk for subsequent infection in preterm neonates. Improvements are needed concerning both the disinfection process and incubator design. IMPACT: Procedures of disinfection that are usually recommended in NICUs do not allow for totally eradicating bacteria from incubators. Preterm neonates are housed in incubators colonised with potentially pathogenic bacteria. The control of nosocomial infections in NICUs requires further researches concerning mechanisms of bacterial persistence and ways to fight against environmental colonisation.

Sources and reservoirs of Staphylococcus capitis NRCS-A inside a NICU.

Background: The methicillin-resistant clone Staphylococcus capitis NRCS-A, involved in sepsis in neonatal intensive care units (NICUs) worldwide, is able to persist and spread in NICUs, suggesting the presence of reservoirs inside each setting. The purpose of the present study was to identify these reservoirs and to investigate the cycle of transmission of NRCS-A in one NICU. Methods: In a single institution study, NRCS-A was sought in 106 consecutive vaginal samples of pregnant women to identify a potential source of NRCS-A importation into the NICU. Additionally NICU caregivers and environmental including incubators were tested to identify putative secondary reservoirs. Finally, the efficacy of disinfection procedure in the elimination of NRCS-A from incubators was evaluated. Results: No S. capitis was isolated from vaginal samples of pregnant women. Three of the 21 tested caregivers (14%) carried S. capitis on their hands, but none remain positive after a five-day wash-out period outside NICU. Moreover, the clone NRCS-A persisted during six consecutive weeks in the NICU environment, but none of the sampled sites was constantly contaminated. Finally in our before/after disinfection study, all of 16 incubators were colonized before disinfection and 10 (62%) incubators remained colonized with NRCS-A after the disinfection procedure. Conclusions: The partial ineffectiveness of incubators' disinfection procedures is responsible for persistence of NRCS-A inside a NICU, and the passive hand contamination of caregivers could be involved in the inter-patient transmission of S. capitis.

Public Health since the beginning: Neonatal incubators safety in a clinical setting.

BACKGROUND: The role of environmental cleaning as an effective measure to contain the diffusion of Healthcare Associated Infections (HAIs) has already been demonstrated. Among medical devices, neonatal incubators have been recognized as a source of pathogens involved in the spread of HAIs. Aim of the study was to assess the efficacy of a disinfection protocol for neonatal incubators. METHODS: The cross sectional study took place in the "Neonatal Pediatric Unit" of the Teaching Hospital of Siena: twenty incubators, used for critical newborns, were swabbed in 13 sampling points before and after the implementation of the disinfection protocol. Sanitation procedures were performed by trained staff, implementing the product Umonium38® Neutralis as disinfectant. Different culture media for the identification of the microbial contamination were adopted: plates were incubated for the proper time and the results were referred to Colony Forming Units (CFUs)/swab per point. Descriptive statistical analysis was performed. It was also evaluated the 95% confidence interval (C.I.) of the mean and the percentage of CFUs reduction by the bootstrap bias corrected and accelerated resampling method. RESULTS: Matched points analyzed were 313. The average CFUs percentage of reduction was 93.5% [C.I. 90.6-95.9%]: it was higher, 97.0% [C.I. 94.1-99.1%], in points placed inside the incubators structure compared to the 88.4% [C.I. 83.6-93.0%] obtained outside. CONCLUSION: The disinfection protocol achieved good results. Routine surveillance and supervision of the various aspects of the disinfection processes (procedures, staff and disinfectants) could guarantee a safe environment during the first days of babies' life, avoiding harmful conditions for the newborns' health.

Loss of cutaneous microbial diversity during first 3 weeks of life in very low birthweight infants.

Neonatal sepsis (NS) is a frequent problem in neonatal intensive care, especially in preterm and very low birthweight (VLBW) infants. The objective of the study was to characterize the cutaneous bacterial microbiome in VLBW infants treated in the neonatal intensive care unit (NICU). Non-invasive skin microbiome specimens were taken repeatedly from 12 VLBW infants during treatment in NICU starting on the first day of life. All infants received benzylpenicillin and netilmicin during the first 1-5 postnatal days. Samples were also collected from incubators. High cutaneous microbial diversity was present at birth in 11 of 12 of the infants, but the diversity decreased substantially after the first weeks of life in all infants regardless of their infection status. After the loss of diversity, one Staphylococcus operational taxonomic unit dominated the skin microbiome. Recovery of microbial diversity was seen in six of 12 neonates. The microbiome of incubators showed typical environmental bacterial genera. Maternal antibiotic treatment, the aetiology of the preterm birth or being born by C-section did not appear to affect the diversity of skin microbiota at birth, and no correlation was found between cutaneous microbiome and NS.

Bacterial contamination in a special care baby unit of a tertiary hospital in Jos, Nigeria.

Background: Nosocomial infections pose a great challenge on healthcare systems. Although surfaces in neonatal wards, umbilical stump wounds and catheter are responsible for a high number of nosocomial infections due to bacteria. The aim of this study was to determine the bacterial profile of air and surface contamination in the special care baby unit of a tertiary hospital in Jos, Nigeria. Methods: Surface and air samples were cultured and antibiotic susceptibility of isolated bacteria were determined. Results: The bacterial profile of air and surface samples showed that Klebsiella was the most common bacteria followed by Staphyllococcus; while the least was Escherichia. Most of the bacteria were isolated from the out-born term area of the special care baby unit. All the bacteria isolated were susceptible to ceftriaxone and meropenem. Conclusion: This study showed that all areas of the special care baby unit of the hospital have bacterial, indicating that these are a potential source of cross-infection from healthcare workers to the neonatal patients.

Cold spots in neonatal incubators are hot spots for microbial contamination.

Thermal stability is essential for the survival and well-being of preterm neonates. This is achieved in neonatal incubators by raising the ambient temperature and humidity to sufficiently high levels. However, potentially pathogenic microorganisms also can thrive in such warm and humid environments. We therefore investigated whether the level of microbial contamination (i.e., the bacterial load) inside neonatal incubators can be predicted on the basis of their average temperature and relative humidity settings, paying special attention to local temperature differences. Swab samples were taken from the warmest and coldest spots found within Caleo incubators, and these were plated to determine the number of microbial CFU per location. In incubators with high average temperature (≥ 34°C) and relative humidity (≥ 60%) values, the level of microbial contamination was significantly higher at cold spots than at hot spots. This relates to the fact that the local equilibrium relative humidity at cold spots is sufficiently high to sustain microbial growth. The abundance of staphylococci, which are the main causative agents of late-onset sepsis in preterm neonates, was found to be elevated significantly in cold areas. These findings can be used to improve basic incubator hygiene.

Transmission of vancomycin-resistant enterococcus in a neonatal intensive care unit.

An outbreak of vancomycin-resistant Enterococcus transmission in our neonatal intensive care unit persisted despite strict contact precautions and cohorting of colonized neonates and their caregivers. After terminal cleaning was performed, incubators were found to harbor the neonates' clone of vancomycin-resistant Enterococcus. Transmission ceased after cohorting of incubators, suggesting the effectiveness of infection control measures targeting environmental contamination.

Neonatal intensive care unit: reservoirs of nosocomial pathogens.

Improvement in the care and treatment of neonates had contributed to their increased survival. Nosocomial infection remains an important problem in intensive care units. Hospital wards had been shown to act as reservoirs of pathogenic microorganisms associated with infection. To assess the prevalence of pathogenic organisms in the environment of the neonatal unit, 92 swabs were randomly collected from cots, incubators and various equipments in the unit and were cultured on Blood agar and MacConkey agar plates. Air contamination was detected by exposing the same types of agar plates for 3 hours in several areas of the unit. After 48 hours incubation, isolates were identified biochemically. There is marked congestion in the unit. Ninety one percent of swabs yielded growth, with coagulase negative Staphylococcus being the predominant organism (44%), followed by Bacillus species (20%), E. coli (12.5%), and Klebsiella (8.5%), Pseudomonas species (3.6%) and moulds (3.6%). Sedimentation plates had colony counts of from 10 - 100 per plate and the majority of the cultures were polymicrobial cultures. The presence of various Gram-negative bacili including known neonatal pathogens (like E. Coli and Pseudomonas) especially on ward equipment and congestion in the ward has the potential to cause nosocomial infection.

[Unusual sources of L. pneumophila in hospital environment]. / Sorgenti inusuali di L. pneumophila in ambiente ospedaliero.

Owing to the very frequent reports of Legionella's cases arising in italian hospitals we have done a microbiologic monitoring on some equipments utilized in a several ward, what represent a potential source of diffusion of germ. It has been analysed water collected from 135 bubblers for oxygen-therapy, 11 pediatric incubators and 10 dental chairs. The isolated strains ware 31 (19.23%), of which: 3 L. Pneumophila sgr. 1; 11 sgr. 3; 8 sgr. 6; 2 sgr. 7. For 6 strains identified as Legionella, have not been possible to establish sgr.

Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens infection in a neonatal intensive care unit.

Serratia marcescens is a well-recognized hospital-acquired pathogen, which has been associated with a number of specific outbreaks, particularly in critically ill neonates. We used pulsed-field gel electrophoresis (PEGE) typing to analyse an outbreak in a neonatal intensive care unit (NICU). We included samples from nine patients, three handwashes and ten environmental isolates from an outbreak (February to August 1999) in addition to four patient isolates from different wards of our hospital during the same time period. The clinical presentations of the outbreak included bacteraemia (four cases), pneumonia (three cases), umbilical wound infection (one case) and conjunctivitis (one case). Nine outbreak isolates exhibited an identical PFGE fingerprint, while the epidemiologically unrelated strains demonstrated distinct patterns. Epidemiological investigation failed to reveal a common source of the outbreak, although the epidemic S. marcescens strain was isolated from hand-washes and doors of incubators. We concluded that cross-transmission via transient contamination of hands was the major route for this outbreak. Strict handwashing practices, the cohorting and isolation of colonized and infected patients, and the regular dis-infection of incubators are crucial steps for preventing the transmission of S. marcescens in an NICU. This PFGE method is highly discriminatory for the thorough epidemiological investigation of an outbreak of S. marcescens.

Bacterial colonization of toys in neonatal intensive care cots.

OBJECTIVES: To investigate the bacteria and fungi contaminating toys in neonatal intensive care unit (NICU) cots, the colonization rates, and factors that influence them. METHODS: A cross-sectional, longitudinal bacteriologic survey of all toys in the cots of infants in an NICU. All the toys in an infant's cot were cultured weekly for 4 weeks. Data were collected on the infant's postnatal age, the type of cot, whether humidity was added, characteristics of the toy, and any infant infections. RESULTS: Over the 4-week period, there were 86 cultures from 34 toys of 19 infants. Bacteria were grown from 84/86 (98%): 84 of the cultures grew coagulase-negative Staphylococcus, 50 Micrococcus sp, 21 Bacillus sp, 13 methicillin-resistant Staphylococcus aureus, 12 diphtheroids, 4 group B streptococcus, 3 S aureus, 3 nonhemolytic streptococci, 3 group D streptococci, 4 alpha-hemolytic streptococci, and 2 coliforms. None grew fungi. The colonization rate did not differ with cot type, presence of humidity, size of the toy, toy fiber length, or the fluffiness score. Eight (42%) of the infants had positive blood culture results and 5/8 of the isolates (63%) were of the same type as that colonizing their corresponding toy. IMPLICATIONS: With time, all the toys in NICU cots became colonized with bacteria. Many were potentially pathogenic. Toys may be reservoirs for potential infantile nosocomial sepsis. infant, newborn, toys, infection, neonatal intensive care.