Lack of evidence for the efficacy of enhanced surveillance compared to other specific interventions to control neonatal healthcare-associated infection outbreaks

Infection control measures against multidrug-resistant Gram-negative bacteria in children and neonates

The increase in infections caused by multidrug-resistant (MDR) Gram-negative bacteria in neonatal and pediatric intensive care units over recent years is alarming. MDR Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii have constituted the main causes of the MDR Gram-negative bacteria problem. The implementation of infection control measures such as hand hygiene, cohorting of patients, contact precautions, active surveillance and environmental cleaning could diminish their spread. Recently, water safety has been identified as a major component of infection control policies. The aim of the current review is to highlight the effectiveness of these infection control measures in managing outbreaks caused by MDR Gram-negative bacteria in neonatal and pediatric intensive care units and highlight future perspectives on the topic.

Prevalence and incidence of carbapenem-resistant K. pneumoniae colonization: systematic review and meta-analysis

BACKGROUND

Klebsiella pneumoniae is a gram-negative rod belonging to the order Enterobacterales and having a wide distribution in the environment, including the human colon. Recently, the bacterium is one of the known problems in the healthcare setting as it has become resistant to last-resort drugs like carbapenems. The colonized person can serve as a reservoir for his/herself and others, especially in the healthcare setting leading to nosocomial and opportunistic infections. Therefore, we aimed to quantitatively estimate the rate of prevalence and incidence of colonization with carbapenem-resistant K. pneumoniae.

METHODS

A literature search was conducted on PubMed/MEDLINE, Google Scholar, Science Direct, Cochrane Library, WHO Index Medicus, and university databases. The study includes all published and unpublished papers that addressed the prevalence or incidence of K. pneumoniae colonization. Data were extracted onto format in Microsoft Excel and pooled estimates with a 95% confidence interval calculated using Der-Simonian-Laird random-effects model. With the use of I² statistics and prediction intervals, the level of heterogeneity was displayed. Egger's tests and funnel plots of standard error were used to demonstrate the publication bias.

RESULTS

A total of 35 studies were included in the review and 32 records with 37,661 patients for assessment of prevalence, while ten studies with 3643 patients for incidence of colonization. The prevalence of carbapenem-resistant K. pneumoniae colonization varies by location and ranges from 0.13 to 22%, with a pooled prevalence of 5.43%. (3.73-7.42). Whereas the incidence of colonization ranges from 2 to 73% with a pooled incidence of 22.3% (CI 12.74-31.87), both prevalence and incidence reports are majorly from developed countries. There was a variation in the distribution of carbapenem resistance genes among colonizing isolates with KPC as a prominent gene reported from many studies and NDM being reported mainly by studies from Asian countries. A univariate meta-regression analysis indicated continent, patient type, study design, and admission ward do not affect the heterogeneity (p value>0.05).

CONCLUSION

The review revealed that colonization with K. pneumoniae is higher in a healthcare setting with variable distribution in different localities, and resistance genes for carbapenem drugs also have unstable distribution in different geographic areas.

Healthcare worker associated outbreak of Panton-Valentine Leucocidin producing meticillin-sensitive Staphylococcus aureus in a large Neonatal Unit in London: successful targeted suppression therapy following failure of mass suppression therapy

BACKGROUND

Staphylococcus aureus is a leading cause of healthcare associated infection and outbreaks have been associated with neonatal units and colonisation of healthcare workers.

AIM

To describe an outbreak of Panton-Valentine Leucocidin producing meticillin-sensitive Staphylococcus aureus (PVL-MSSA) in a Neonatal Intensive Care Unit (NICU).

METHODS

Multi-disciplinary outbreak control investigation RESULTS: Over a period of 16 months, 7 neonates were identified as positive for PVL-MSSA. Isolates were identified in blood cultures (2 patients), nasopharyngeal aspirate (1 patient) and rectal screening swabs (4 patients). Epidemiological and whole genome sequencing data suggested a long-term carrier as the most likely source. Despite two rounds of mass suppression therapy of staff, using chlorhexidine initially, then octenidine-based regimens, positive patients continued to be identified. Staff screening subsequently identified one healthcare worker colonised with the outbreak strain of PVL-MSSA who underwent enhanced screening and further suppression therapy. No further cases have been identified to date. Compliance with mass suppression therapy was >95% and a post administration staff satisfaction survey showed the majority of staff agreed with the steps taken with low rates of adverse reactions.

CONCLUSION

Staphylococcus aureus outbreaks are commonly associated with colonisation of healthcare workers and are challenging to manage within environments such as neonatal units. Our study highlights the utility of whole genome sequencing in identifying and mapping an outbreak. We recommend that targeted staff screening should be considered early in similar outbreaks. In our setting mass suppression therapy was not an effective strategy despite a high level of staff engagement and compliance.

A cost analysis of active surveillance culture in a neonatal intensive care unit

Active surveillance culture (ASC) in neonatal intensive care units (NICUs) has been implemented to monitor horizontal transmission and choose appropriate antimicrobials when neonates experience late-onset infections (LOIs). To perform a cost analysis of ASC in the NICU, we evaluated data from a NICU ward in a Japanese community hospital. This was a retrospective study of neonates admitted to the NICU of Nara Prefecture General Medical Center, Nara City, Japan, from April 2012 to May 2017. We implemented biweekly ASC (nasal, stool and umbilical cultures) during this period. We assessed the detection rate for methicillin-sensitive and -resistant S. aureus (MSSA and MRSA) in each culture and reviewed the cases of LOI. Among the 785 cases, MSSA and MRSA were detected in 158 and 75 cases, respectively. Nasal culture was the most sensitive method for detecting MSSA and MRSA. Three cases benefitted from changing the empiric treatment based on previous ASC results, with an annual cost of ¥808,331 (£5773.80 or $7282.30) for ASC. The total cost per one benefited case during the study period was calculated as ¥1,392,126 (£9943.80 or $12,541.70). The total cost per benefited case in risk factor targeted ASC, nasal culture targeted ASC and MRSA-targeted ASC was ¥1,332,264 (£9516.20 or $12,002.30), ¥692,222 (£4944.40 or $6236.20) and ¥858,547 (£6132.50 or $7734.70), respectively. Considering the frequency of S. aureus detection and the cost of each culture, our ASC was modified to use only nasal cultures. This study suggests that the cost performance of ASC should be evaluated with consideration of the characteristics of each NICU.

Role of viral bioaerosols in nosocomial infections and measures for prevention and control

The presence of patients with diverse pathologies in hospitals results in an environment that can be rich in various microorganisms including respiratory and enteric viruses, leading to outbreaks in hospitals or spillover infections to the community. All hospital patients are at risk of nosocomial viral infections, but vulnerable groups such as older adults, children and immuno-compromised/-suppressed patients are at particular risk of severe outcomes including prolonged hospitalization or death. These pathogens could transmit through direct or indirect physical contact, droplets or aerosols, with increasing evidence suggesting the importance of aerosol transmission in nosocomial infections of respiratory and enteric viruses. Factors affecting the propensity to transmit and the severity of disease transmitted via the aerosol route include the biological characteristics affecting infectivity of the viruses and susceptibility of the host, the physical properties of aerosol particles, and the environmental stresses that alter these properties such as temperature and humidity. Non-specific systematic and individual-based interventions designed to mitigate the aerosol route are available although empirical evidence of their effectiveness in controlling transmission of respiratory and enteric viruses in healthcare settings are sparse. The relative importance of aerosol transmission in healthcare setting is still an on-going debate, with particular challenge being the recovery of infectious viral bioaerosols from real-life settings and the difficulty in delineating transmission events that may also be a result of other modes of transmission. For the prevention and control of nosocomial infections via the aerosol route, more research is needed on identifying settings, medical procedures or equipment that may be associated with an increased risk of aerosol transmission, including defining which procedures are aerosol-generating; and on the effectiveness of systematic interventions on aerosol transmission of respiratory and enteric viruses in healthcare settings.

Whole-Genome Sequencing of Bacterial Pathogens: the Future of Nosocomial Outbreak Analysis

Outbreaks of multidrug-resistant bacteria present a frequent threat to vulnerable patient populations in hospitals around the world. Intensive care unit (ICU) patients are particularly susceptible to nosocomial infections due to indwelling devices such as intravascular catheters, drains, and intratracheal tubes for mechanical ventilation. The increased vulnerability of infected ICU patients demonstrates the importance of effective outbreak management protocols to be in place. Understanding the transmission of pathogens via genotyping methods is an important tool for outbreak management. Recently, whole-genome sequencing (WGS) of pathogens has become more accessible and affordable as a tool for genotyping. Analysis of the entire pathogen genome via WGS could provide unprecedented resolution in discriminating even highly related lineages of bacteria and revolutionize outbreak analysis in hospitals. Nevertheless, clinicians have long been hesitant to implement WGS in outbreak analyses due to the expensive and cumbersome nature of early sequencing platforms. Recent improvements in sequencing technologies and analysis tools have rapidly increased the output and analysis speed as well as reduced the overall costs of WGS. In this review, we assess the feasibility of WGS technologies and bioinformatics analysis tools for nosocomial outbreak analyses and provide a comparison to conventional outbreak analysis workflows. Moreover, we review advantages and limitations of sequencing technologies and analysis tools and present a real-world example of the implementation of WGS for antimicrobial resistance analysis. We aimed to provide health care professionals with a guide to WGS outbreak analysis that highlights its benefits for hospitals and assists in the transition from conventional to WGS-based outbreak analysis.

The relationship between Gram-negative colonization and bloodstream infections in neonates: a systematic review and meta-analysis

OBJECTIVES

Neonates admitted to neonatal intensive care units (NICU) are at significant risk of developing bloodstream infections (BSIs). Gram-negative bacteria (GNB) both colonize and infect, but the association between these entities is unclear. By conducting a systematic literature review, we aimed to explore the impact of factors on the association between GN colonization and GN-BSI at both baby-level and unit-level.

METHODS

We searched Medline, Embase, and Cochrane Library. Observational cohort studies published after 2000 up to June 2016 reporting data on the total number of neonates (0-28 days) colonized with GNB assessed by rectal/skin swab culture and the total number of neonates with GN-BSI (same bacteria) were included. Studies were excluded if data on skin/rectal colonization, neonates, and GNB could not be identified separately. Meta-analyses along with multivariate meta-regression with a random-effect model were performed to investigate factors associated with the GN colonization and GN-BSI at baby-level and unit-level.

RESULTS

Twenty-seven studies fulfilled our inclusion criteria, 15 for the baby-level and 12 for the unit-level analysis. Study heterogeneity was high, with suboptimal overall quality of reporting assessed by the STROBE-NI statement (44.8% of items adequately reported). In 1984 colonized neonates, 157 (7.9%) developed GN-BSI compared with 85 of 3583 (2.4%) non-colonized neonates. Considerable heterogeneity was observed across studies. Four factors were included in the meta-regression model: gross domestic product (GDP), pathogen, outbreak, and frequency of screening. There was no statistically significant impact of these factors on GN colonization and GN-BSI in baby-level. We were unable to perform the multivariate meta-regression because of insufficient reported data for unit-level.

CONCLUSIONS

Study limitations include the small number and the high heterogeneity of the included studies. While this report shows a correlation between colonization and BSI risk, these data currently do not support routine screening for GNB. Analysis of large cohorts of colonized neonates with clinical outcomes is still needed to define the major determinants leading from colonization to infection.

Infectious disease exposures and outbreaks at a South African neonatal unit with review of neonatal outbreak epidemiology in Africa

BACKGROUND

Hospitalized neonates are vulnerable to infection, with pathogen exposures occurring in utero, intrapartum, and postnatally. African neonatal units are at high risk of outbreaks owing to overcrowding, understaffing, and shared equipment.

METHODS

Neonatal outbreaks attended by the paediatric infectious diseases and infection prevention (IP) teams at Tygerberg Children's Hospital, Cape Town (May 1, 2008 to April 30, 2016) are described, pathogens, outbreak size, mortality, source, and outbreak control measures. Neonatal outbreaks reported from Africa (January 1, 1996 to January 1, 2016) were reviewed to contextualize the authors' experience within the published literature from the region.

RESULTS

Thirteen outbreaks affecting 148 babies (11 deaths; 7% mortality) over an 8-year period were documented, with pathogens including rotavirus, influenza virus, measles virus, and multidrug-resistant bacteria (Serratia marcescens, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci). Although the infection source was seldom identified, most outbreaks were associated with breaches in IP practices. Stringent transmission-based precautions, staff/parent education, and changes to clinical practices contained the outbreaks. From the African neonatal literature, 20 outbreaks affecting 524 babies (177 deaths; 34% mortality) were identified; 50% of outbreaks were caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae.

CONCLUSIONS

Outbreaks in hospitalized African neonates are frequent but under-reported, with high mortality and a predominance of Gram-negative bacteria. Breaches in IP practice are commonly implicated, with the outbreak source confirmed in less than 50% of cases. Programmes to improve IP practice and address antimicrobial resistance in African neonatal units are urgently required.