Recognition and prevention of hospital-associated enteric infections in the intensive care unit

Quantitative Microbial Risk Assessment (QMRA) of Workers Exposure to Bioaerosols at MSW Open Dumpsites

The bioaerosol exposure data from the study by Akpeimeh, Fletcher, and Evans (2019) was used to compute the risk of infection from the exposure of dumpsite workers to Aspergillus fumigatus and Escherichia coli O157:H7. A stochastic (Markov Chain) model was used to model the transport of the inhaled dose though the human respiratory system and then integrated into the beta-Poisson dose-response model to estimate workers risks of respiratory and gastrointestinal (GI) infection. The infection risk was computed based on workers exposure to E. coli O157:H7 at 10-50% pathogen ingestion rate and pathogen-indicator ratio (P:I) of 1:10³ and 1:10⁴ , while exposure to A. fumigatus was based solely on the average initial exposure dose. The results showed that after 11 hours of exposure, workers engaged in scavenging, waste sorting, and site monitoring were at risk of respiratory and GI infection in the magnitude of 10^-1 . However, the risk estimates associated with specific areas of the dumpsite showed that, the risk of GI infection at the active area ranged between 3.23 × 10^-3 -1.56 × 10^-2 and 3.25 × 10^-4 -1.62 × 10^-3 ; dormant area 2.06 × 10^-3 -1.01 × 10^-2 and 2.09 × 10^-4 -1.04 × 10^-3 ; entrance 1.85 × 10^-3 -9.09 × 10^-3 and 1.87 × 10^-4 -9.27 × 10^-4 ; boundary 1.82 × 10^-3 -8.82 × 10^-3 and 2.09 × 10^-4 -8.94 × 10^-4 for P:I = 1:10³ and 1:10⁴ respectively, while the risk of respiratory infection risks were in the magnitude of 10^-1 for all four locations. The estimated risk of workers developing respiratory and gastrointestinal infections were high for all activities assessed at the dumpsite.

Animal Model To Study Klebsiella pneumoniae Gastrointestinal Colonization and Host-to-Host Transmission

An important yet poorly understood facet of the life cycle of a successful pathogen is host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae, a Gram-negative bacterium, is notorious for causing HAI, with many of these infections difficult to treat, as K. pneumoniae has become multidrug resistant. Epidemiological studies suggest that K. pneumoniae host-to-host transmission requires close contact and generally occurs through the fecal-oral route.

An important yet poorly understood facet of the life cycle of a successful pathogen is host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae, a Gram-negative bacterium, is notorious for causing HAI, with many of these infections difficult to treat, as K. pneumoniae has become multidrug resistant. Epidemiological studies suggest that K. pneumoniae host-to-host transmission requires close contact and generally occurs through the fecal-oral route. Here, we describe a murine model that can be utilized to study mucosal (oropharynx and gastrointestinal [GI]) colonization, shedding within feces, and transmission of K. pneumoniae through the fecal-oral route. Using an oral route of inoculation, and fecal shedding as a marker for GI colonization, we showed that K. pneumoniae can asymptomatically colonize the GI tract in immunocompetent mice and modifies the host GI microbiota. Colonization density within the GI tract and levels of shedding in the feces differed among the clinical isolates tested. A hypervirulent K. pneumoniae isolate was able to translocate from the GI tract and cause hepatic infection that mimicked the route of human infection. Expression of the capsule was required for colonization and, in turn, robust shedding. Furthermore, K. pneumoniae carrier mice were able to transmit to uninfected cohabitating mice. Lastly, treatment with antibiotics led to changes in the host microbiota and development of a transient supershedder phenotype, which enhanced transmission efficiency. Thus, this model can be used to determine the contribution of host and bacterial factors toward K. pneumoniae dissemination.

Detection of norovirus infections in Denmark, 2011-2018

Norovirus (NoV) infections occur very frequently yet are rarely diagnosed. In Denmark, NoV infections are not under surveillance. We aimed to collect and describe existing laboratory-based NoV data. National NoV laboratory data were collected for 2011–2018, including information on patient identification number, age and sex, requesting physician, analysis date and result. We defined positive patient-episodes by using a 30-day time window and performed descriptive and time series analysis. Diagnostic methods used were assessed through a survey. We identified 15 809 patient-episodes (11%) out of 142 648 tested patients with an increasing trend, 9366 in 2011 vs. 32 260 in 2018. This corresponded with a gradual introduction of polymerase chain reaction analysis in laboratories. The highest positivity rate was in patients aged <5 years (15%) or >85 years (17%). There was a large difference in test performance over five Danish geographical regions and a marked seasonal variation with peaks from December to February. This is the first analysis of national NoV laboratory data in Denmark. A future laboratory-based surveillance system may benefit public health measures by describing trend, burden and severity of seasons and possibly pinpoint hospital outbreaks.

Probiotics and Paraprobiotics in Viral Infection: Clinical Application and Effects on the Innate and Acquired Immune Systems

Recently, the risk of viral infection has dramatically increased owing to changes in human ecology such as global warming and an increased geographical movement of people and goods. However, the efficacy of vaccines and remedies for infectious diseases is limited by the high mutation rates of viruses, especially, RNA viruses. Here, we comprehensively review the effectiveness of several probiotics and paraprobiotics (sterilized probiotics) for the prevention or treatment of virally-induced infectious diseases. We discuss the unique roles of these agents in modulating the cross-talk between commensal bacteria and the mucosal immune system. In addition, we provide an overview of the unique mechanism by which viruses are eliminated through the stimulation of type 1 interferon production by probiotics and paraprobiotics via the activation of dendritic cells. Although further detailed research is necessary in the future, probiotics and/or paraprobiotics are expected to be among the rational adjunctive options for the treatment of various viral diseases.

Guidelines for Antibiotic Prescription in Intensive Care Unit

How to cite this article: Khilnani GC, Zirpe K, Hadda V, Mehta Y, Madan K, Kulkarni A, Mohan A, Dixit S, Guleria R, Bhattacharya P. Guidelines for Antibiotic Prescription in Intensive Care Unit. Indian Journal of Critical Care Medicine 2019;23 (Suppl 1):1-63.

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.

Nosocomial Infections in Intensive Care Unit: Pattern of Antibiotic-resistance in Iranian Community

Background:

Bacterial infections are responsible for great number of mortality in Intensive Care Unit (ICU). Knowledge about prevalence of bacterial infections and their antibiotic-resistance pattern would be a great step for their treatment and management.

Materials and Methods:

Data about nosocomial infections in ICUs of Alzahra Hospital (referral hospital in Isfahan, center of Iran) were gathered during the years 2007–2010. A questionnaire was fulfilled for any specific patient with nosocomial infection containing demographic data of patient and also characteristics of the infection.

Results:

Out of all patients, 707 individuals (65.6%) were male and 370 (34.4%) were female. Our data revealed that Pseudomonas aeruginosa (13.9%), Klebsiella (11%), and Escherichia coli (6.4%) were the most prevalent bacterial infections. The most common sites of nosocomial infections in the ICU were respiratory system (399 cases, 37%), urinary system (230 cases, 21.4%), and blood (102 cases, 9.5%). The antibiotic-resistance of each bacteria in ICU ward was assessed and data were categorized in a table. There were less documentary about bacterial cultures in the year 2007 when compared with the next years.

Conclusion:

We found some differences (such as bacterial prevalence in ICU wards which caused nosocomial infections) in our local prevalence of nosocomial infections and also in their resistance pattern compared to other centers. Knowing about our data will help physicians to administer the most suitable antibiotics for treatment of nosocomial infections in our area.

Proton Pump Inhibitors Do Not Increase Risk for Clostridium difficile Infection in the Intensive Care Unit

OBJECTIVES

Patients in the intensive care unit (ICU) frequently receive proton pump inhibitors (PPIs) and have high rates of Clostridium difficile infection (CDI). PPIs have been associated with CDI in hospitalized patients, but ICU patients differ fundamentally from non-ICU patients and few studies have focused on PPI use exclusively in the critical care setting. We performed a retrospective cohort study to determine the associations between PPIs and health-care facility-onset CDI in the ICU.

METHODS

We analyzed data from all adult ICU patients at three affiliated hospitals (14 ICUs) between 2010 and 2013. Patients were excluded if they had recent CDI or an ICU stay of <3 days. We parsed electronic medical records for ICU exposures, focusing on PPIs and other potentially modifiable exposures that occurred during ICU stays. Health-care facility-onset CDI in the ICU was defined as a newly positive PCR for the C. difficile toxin B gene from an unformed stool, with subsequent receipt of anti-CDI therapy. We analyzed PPIs and other exposures as time-varying covariates and used Cox proportional hazards models to adjust for demographics, comorbidities, and other clinical factors.

RESULTS

Of 18,134 patients who met the criteria for inclusion, 271 (1.5%) developed health-care facility-onset CDI in the ICU. Receipt of antibiotics was the strongest risk factor for CDI (adjusted HR (aHR) 2.79; 95% confidence interval (CI), 1.50-5.19). There was no significant increase in risk for CDI associated with PPIs in those who did not receive antibiotics (aHR 1.56; 95% CI, 0.72-3.35), and PPIs were actually associated with a decreased risk for CDI in those who received antibiotics (aHR 0.64; 95% CI, 0.48-0.83). There was also no evidence of increased risk for CDI in those who received higher doses of PPIs.

CONCLUSIONS

Exposure to antibiotics was the most important risk factor for health-care facility-onset CDI in the ICU. PPIs did not increase risk for CDI in the ICU regardless of use of antibiotics.

Developing professional habits of hand hygiene in intensive care settings: An action-research intervention

OBJECTIVES

To explore perceptions and unconscious psychological processes underlying handwashing behaviours of intensive care nurses, to implement organisational innovations for improving hand hygiene in clinical practice.

RESEARCH METHODOLOGY

An action-research intervention was performed in 2012 and 2013 in the intensive care unit of a public hospital in Italy, consisting of: structured interviews, semantic analysis, development and validation of a questionnaire, team discussion, project design and implementation. Five general workers, 16 staff nurses and 53 nurse students participated in the various stages.

RESULTS

Social handwashing emerged as a structured and efficient habit, which follows automatically the pattern "cue/behaviour/gratification" when hands are perceived as "dirty". The perception of "dirt" starts unconsciously the process of social washing also in professional settings. Professional handwashing is perceived as goal-directed. The main concern identified is the fact that washing hands requires too much time to be performed in a setting of urgency. These findings addressed participants to develop a professional "habit-directed" hand hygiene procedure, to be implemented at beginning of workshifts.

CONCLUSIONS

Handwashing is a ritualistic behaviour driven by deep and unconscious patterns, and social habits affect professional practice. Creating professional habits of hand hygiene could be a key solution to improve compliance in intensive care settings.

The knowledge of intensive care professionals about diarrhea

Objective

To assess the opinions and practices of intensive care professionals with regard to diarrhea in critically ill patients.

Methods

A multicenter cross-sectional study was conducted among health care professionals working at three adult intensive care units. Participants responded individually to a self-administered questionnaire about their length of work experience in intensive care; the definition, characterization, and causes of diarrhea; types of records in the patient's medical record; and training received.

Results

A total of 78 professionals participated in this study, of whom 59.0% were nurse technicians, 25.7% were nurses, and 15.3% were physicians; 77.0% of them had worked in intensive care for over 1 year. Only 37.2% had received training on this topic. Half of the interviewees defined diarrhea as "liquid and/or pasty stools" regardless of frequency, while the other 50.0% defined diarrhea based on the increased number of daily bowel movements. The majority of them mentioned diet as the main cause of diarrhea, followed by "use of medications" (p<0.001). Distinct nutritional practices were observed among the analyzed professionals regarding episodes of diarrhea, such as discontinuing, maintaining, or reducing the volume of enteral nutrition; physicians reported that they do not routinely communicate the problem to other professionals (for example, to a nutritionist) and do not routinely record and quantify diarrhea events in patients' medical records.

Conclusion

Different opinions and practices were observed in intensive care professionals with regard to diarrhea.

Role of noroviruses as aetiological agents of diarrhoea in developing countries

Diarrhoea is considered to be the second leading cause of death due to infections among children  < 5 years of age worldwide that may be caused by bacteria, parasites, viruses and non-infectious agents. The major causative agents of diarrhoea in developing countries may vary from those in developed countries. Noroviruses are considered to be the most common cause of acute diarrhoea in both children and adults in industrialized countries. On the other hand, there is a lack of comprehensive epidemiological evidence from developing countries that norovirus is a major cause of diarrhoea. In these regions, asymptomatic norovirus infections are very common, and similar detection rates have been observed in patients with diarrhoea and asymptomatic persons. This review summarizes the current knowledge of norovirus infection in developing countries and seeks to position infections with noroviruses among those of other enteropathogens in terms of disease burden in these regions.

New Drugs and Strategies for Management of Clostridium difficile Colitis

Approaches for management of Clostridium difficile infection continually evolve as research reveals shifts in epidemiology, microbial pathogenesis, disease severity states, and response to therapy. These new discoveries significantly impact diagnostic and therapeutic strategies, given the high morbidity associated with this common nosocomial infectious diarrhea. Critically ill patients are at an increased risk of developing diarrheal illness like C. difficile and succumbing to potentially fatal complications of this infection. Early diagnosis of severe disease state may improve patient outcomes. In this article, we review treatment strategies and new approaches for the management of C. difficile in critically ill patients.

Unrecognized norovirus infections in health care institutions and their clinical impact

Noroviruses (NoVs) have emerged as the leading cause of acute viral gastroenteritis (GE) in humans. Although diagnostic facilities have greatly improved, significant underdiagnosis of NoV in hospitals may still occur, thereby increasing clinical burden and nosocomial spread. We evaluated the underdiagnosis of sporadic NoV infections in a tertiary care hospital and estimated its clinical impact. From December 2008 until July 2009, fecal samples specifically referred for bacterial but not viral examination were retrospectively tested for NoV by real-time PCR. The clinical and virological data from patients with undiagnosed NoV infection (missed patients) were evaluated and compared with those from patients with recognized NoV. During the study period, 45 patients with undiagnosed NoV were detected, whereas 50 patients were regularly diagnosed. The missed NoV cases were more frequently adults than children (80% versus 46%; P < 0.001). The viral load levels did not differ between the diagnosed and missed patients, but missed patients more frequently presented without diarrhea (20% versus 4%; P < 0.07). The newly admitted missed NoV cases with GE underwent more diagnostic imaging (24% versus 4%; P < 0.01) and tended to be hospitalized longer. When missed-NoV patients were included, the number of nosocomial clusters doubled and missed patients were index cases in 5 of the 6 clusters. These data indicate that NoV infections are frequently missed despite routine laboratory testing and demonstrate that underdiagnosis of NoV patients is associated with costly abdominal imaging and nosocomial clustering. Awareness of NoV infection in adult patients and education about the importance of viral GE should be increased.

Clostridium difficile in the ICU: the struggle continues

Clostridium difficile infection (CDI) management has become more daunting over the past decade because of alarming increases in CDI incidence and severity both in the hospital and in the community. This increase has concomitantly caused significant escalation of the health-care economic burden caused by CDI, and it will likely be translated to increased ICU admission and attributable mortality. Some possible causes for difficulty in management of CDI are as follows: (1) inability to predict and prevent development of severe/complicated or relapsing CDI in patients who initially present with mild symptoms; (2) lack of a method to determine who would have benefited a priori from initiating vancomycin treatment first instead of treatment with metronidazole; (3) lack of sensitive and specific CDI diagnostics; (4) changing epidemiology of CDI, including the emergence of a hypervirulent, epidemic C difficile strain associated with increased morbidity and mortality; (5) association of certain high-usage nonantimicrobial medications with CDI; and (6) lack of treatment regimens that leave the normal intestinal flora undisturbed while treating the primary infection. The objective of this article is to present current management and prevention guidelines for CDI based on recommendations by the Society for Healthcare Epidemiology of America and Infectious Diseases Society of America and potential new clinical management strategies on the horizon.

Comparison of five assays for detection of Clostridium difficile toxin

Performance characteristics of five assays for detection of Clostridium difficile toxin were compared using fresh stool samples from patients with C. difficile infection (CDI). Assays were performed simultaneously and according to the manufacturers' instructions. Patients were included in the study if they exhibited clinical symptoms consistent with CDI. Nonmolecular assays included glutamate dehydrogenase antigen tests, with positive findings followed by the Premier Toxin A and B Enzyme Immunoassay (GDH/EIA), and the C. Diff Quik Chek Complete test. Molecular assays (PCR) included the BD GeneOhm Cdiff Assay, the Xpert C. difficile test, and the ProGastro Cd assay. Specimens were considered true positive if results were positive in two or more assays. For each method, the Youden index was calculated and cost-effectiveness was analyzed. Of 81 patients evaluated, 26 (32.1%) were positive for CDI. Sensitivity of the BD GeneOhm Cdiff assay, the Xpert C. difficile test, the ProGastro Cd assay, C. Diff Quik Chek Complete test, and two-step GDH/EIA was 96.2%, 96.2%, 88.5%, 61.5%, and 42.3%, respectively. Specificity of the Xpert C. difficile test was 96.4%, and for the other four assays was 100%. Compared with nonmolecular methods, molecular methods detected 34.7% more positive specimens. Assessment of performance characteristics and cost-effectiveness demonstrated that the BD GeneOhm Cdiff assay yielded the best results. While costly, the Xpert C. difficile test required limited processing and yielded rapid results. Because of discordant results, specimen processing, and extraction equipment requirements, the ProGastro Cd assay was the least favored molecular assay. The GDH/EIA method lacked sufficient sensitivity to be recommended.

Diabetes mellitus as a risk factor for recurrence of Clostridium difficile infection in the acute care hospital setting

BACKGROUND

Clostridium difficile-associated diarrhea (CDAD) is increasingly encountered in the acute care setting with rates of infection increasing dramatically since 2001. Reoccurring episodes are being seen with increasing frequency. The purpose of this study was to examine risk factors specifically associated with CDAD recurrence in an urban medical center.

METHODS

This study was conducted in a 651-bed, acute care teaching hospital in an urban community in northeastern New Jersey. We examined the medical records of subjects discharged from the institution with a diagnosis of CDAD over the 6-year period January 1, 2003, to December 31, 2008. Inclusion in the study required clinical signs and symptoms of CDAD and the presence of C difficile toxins A/B. This cohort of 247 subjects was divided into 2 groups: those who were not readmitted with CDAD within 6 months (n = 171) and those who required readmission for CDAD within 6 months of discharge from their last admission (n = 76).

RESULTS

Both hypoalbuminemia (odds ration [OR], 1.74, 95% confidence interval [CI]: 1.10-2.77; P = .02) and diabetes (P < .0001; OR, 3.04; 95% CI: 1.84-5.03; P < .0001) were considered as independent risk factors. After adjustment for potential confounders, hypoalbuminemia was found to be race dependent (OR, adjusted for black race: 1.62; 95% CI: 0.93-2.82; P = .09); however, diabetes was found to be a significant independent risk factor for CDAD recurrence (adjusted OR ranged from 3.79 to 5.46, minimum lower 95% confidence level: 2.01, all P values <.0001).

CONCLUSION

We have demonstrated that diabetes is an important risk factor for recurrence of CDAD. Although previous have concluded that hypoalbuminemia is associated with CDAD recurrence, our data suggest that this association may have some dependence on race or ethnicity.

Infection control in the intensive care unit: progress and challenges in systems and accountability

Attention to the improvement of safety in healthcare lately has focused on healthcare-associated infections, including many that occur in the intensive care unit, such as catheter-related bloodstream infections and ventilator-associated pneumonias. Great strides have been made in decreasing the rates of intensive care unit hospital-acquired infections in the past decade. This is attributable to a number of factors, including standardization of care, technological advances, provider payment reform, and consumer activism. Teamwork and communication remain the most important facets in patient safety. The papers in this supplement examine the roles of human factors and process engineering, survey a spectrum of infection control and safety challenges encountered by critical care practitioners, and assess the future challenges for continued improvement in our systems of care.