Successful combat of an outbreak due to Clostridium difficile PCR ribotype 027 and recognition of specific risk factors

Risk Factors of Patients With Diarrhea for Having Clostridioides (Clostridium) difficile Infection

Nosocomial infections with Clostridioides (Clostridium) difficile have become an emergent health threat. We sought to define risk factors for a C. difficile infection (CDI) beyond the widely known ones, such as antibiotic use and prior hospital stay. We therefore focused on a group of patients with diarrhea in order to identify risk factors for C. difficile infection among this symptomatic cohort. A total of 121 hospitalized patients from Seesen/Germany with diarrhea were included who submitted a stool sample and were interviewed about their socio-demographic background, lifestyle and state of health using a standardized questionnaire. Antibiotic potential of diuretics was examined by agar diffusion test. C. difficile was identified in 29 patients resulting in a prevalence of 24.0%. The infection was hospital-acquired in most cases (p < 0.001, 82.1%; n = 23/28, versus 29/91, 31.9%). The generally accepted risk factor previous antibiotic use was confirmed in this study (p = 0.002, n = 23/28 CDI patients, 82.1%, versus n = 44/91 non-CDI patients, 48.4%). The following additional risk factors were identified: regular consumption of proton pump inhibitors; PPI (p = 0.011, n = 24/29, 82.8% vs. n = 52/92, 56.5%), CDI patients ate less vegetables (p = 0.001, n = 12/29, 41.4% vs. 69/92, 75.0%). The intake of the diuretic agent torasemid in patients with CDI (p = 0.005, n = 18/29, 62.1%) was higher than in patients without (n = 30/92, 32.6%). More patients with CDI had to undergo a surgery in the previous year (p = 0.022, n = 13/29, 44.8% vs. n = 21/92, 22.8%) and held more birds (p = 0.056, n = 4/29, 13.8%) than individuals of the negative group (n = 3/92, 3.3%). In conclusion, although no antibiotic potential was detected in diuretics, especially torasemid seems to have significant influence for the occurrence of a CDI as well as a nutrition poor in vegetables. A diet rich in vegetables represented a fourfold lower risk for a CDI (OR 0.240, CI (0.0720 - 0.796]).

A systematic review of the effectiveness of cohorting to reduce transmission of healthcare-associated C. difficile and multidrug-resistant organisms

BACKGROUND

Cohorting of patients and staff is a control strategy often used to prevent the spread of infection in healthcare institutions. However, a comprehensive evaluation of cohorting as a prevention approach is lacking.

METHODS

We performed a systematic review of studies that used cohorting as part of an infection control strategy to reduce hospital-acquired infections. We included studies published between 1966 and November 30, 2019, on adult populations hospitalized in acute-care hospitals.

RESULTS

In total, 87 studies met inclusion criteria. Study types were quasi-experimental "before and after" (n = 35), retrospective (n = 49), and prospective (n = 3). Case-control analysis was performed in 7 studies. Cohorting was performed with other infection control strategies in the setting of methicillin-resistant Staphylococcus aureus (MRSA, n = 22), Clostridioides difficile infection (CDI, n = 6), vancomycin-resistant Enterococcus (VRE, n = 17), carbapenem-resistant Enterobacteriaceae infections (CRE, n = 22), A. baumannii (n = 15), and other gram-negative infections (n = 5). Cohorting was performed either simultaneously (56 of 87, 64.4%) or in phases (31 of 87, 35.6%) to help contain transmission. In 60 studies, both patients and staff were cohorted. Most studies (77 of 87, 88.5%) showed a decline in infection or colonization rates after a multifaceted approach that included cohorting as part of the intervention bundle. Hand hygiene compliance improved in approximately half of the studies (8 of 15) during the respective intervention.

CONCLUSION

Cohorting of staff, patients, or both is a frequently used and reasonable component of an enhanced infection control strategy. However, determining the effectiveness of cohorting as a strategy to reduce transmission of MDRO and C. difficile infections is difficult, particularly in endemic situations.

The microbial diversity following antibiotic treatment of Clostridioides difficile infection

Background

Clostridioides difficile (C. difficile) is a major nosocomial pathogen that infects the human gut and can cause diarrheal disease. A dominant risk factor is antibiotic treatment that disrupts the normal gut microbiota. The aim of the study was to examine the correlation between antibiotic treatment received prior to C. difficile infection (CDI) onset and patient gut microbiota.

Methods

Stool samples were collected from patients with CDI, presenting at the Baruch Padeh Medical Center Poriya, Israel. Demographic and clinical information, including previous antibiotic treatments, was collected from patient charts, and CDI severity score was calculated. Bacteria were isolated from stool samples, and gut microbiome was analyzed by sequencing the 16S rRNA gene using the Illumina MiSeq platform and QIIME2.

Results

In total, 84 patients with CDI were enrolled in the study; all had received antibiotics prior to disease onset. Due to comorbidities, 46 patients (55%) had received more than one class of antibiotics. The most common class of antibiotics used was cephalosporins (n = 44 cases). The intestinal microbiota of the patients was not uniform and was mainly dominated by Proteobacteria. Differences in intestinal microbiome were influenced by the different combinations of antibiotics that the patients had received (p = 0.022)

Conclusions

The number of different antibiotics administered has a major impact on the CDI patients gut microbiome, mainly on bacterial richness.

Successful management of a Clostridioides difficile ribotype 027 outbreak with a lean intervention bundle

BACKGROUND

In a 2015 point-prevalence study, Clostridioides difficile 027, a hypervirulent ribotype, was absent from healthcare institutions in Switzerland. In late 2016, we detected an outbreak of C. difficile infection (CDI) with ribotype 027 occurring across several hospitals in the same hospital network.

METHODS

The first cases of CDI due to ribotype 027 triggered an outbreak investigation, including whole genome sequencing (WGS) to identify outbreak strains.

FINDINGS

Twenty-eight patients with CDI caused by ribotype 027 between December 2016 and December 2017 were identified, out of which 20 were caused by a single clone. Commonalities among these patients were hospitalization in the same room or on the same ward, receiving care from the same healthcare workers, and shared toilet areas. In addition to the epidemiological links suggesting possible transmission pathways between cases, WGS confirmed the clonality of this C. difficile 027 outbreak. The outbreak was contained by isolation precautions, raising awareness among healthcare workers, harmonizing diagnostic algorithms, and switching to a sporicidal agent for environmental disinfection. Of note, neither default gowning and gloving nor hand washing with water and soap were implemented.

CONCLUSION

This C. difficile 027 outbreak was recognized belatedly due to lack of screening for this ribotype in some hospitals, and was contained by a swift response with simple infection prevention measures and adapting the laboratory approach. In order to have a better understanding of C. difficile epidemiology, diagnostic approaches should be standardized, CDI declared notifiable, and longitudinal data on prevalent ribotypes collected in countries where this is not established.

Examining the association between hospital-onset Clostridium difficile infection and multiple-bed room exposure: a case-control study

OBJECTIVE

To determine whether assignment to a multiple-bed room increased the risk of hospital-onset C. difficile diarrhea (HO-CDI).

DESIGN

Case-control study.

SETTING

San Francisco General Hospital and Trauma Center.PopulationAdult general medical and surgical inpatients.

METHODS

Consecutive cases of HO-CDI were identified between January 1, 2010, and December 31, 2015. To investigate the effect of multiple-bed room exposure both at admission and at the time of symptom onset, 2 sets of controls were selected from the general medical/surgical inpatient population using incidence density sampling. Conditional logistic regression was used to estimate the relationship between room assignment (single bed vs multiple beds) and the development of HO-CDI.

RESULTS

In total, 187 cases were identified and matched with 512 and 515 controls for the admission and at-diagnosis analyses, respectively. The adjusted rate ratio (RR) associated with the development HO-CDI associated with multiple-bed room exposure during the 7 and 14 days immediately prior to HO-CDI diagnosis were 1.08 (95% confidence interval [CI], 0.93-1.25; P=.31) and 0.96 (95% CI, 0.93-1.18; P=.12), respectively. Furthermore, no significant association was detected in the analysis of the first 7 and 14 days after case admission or among patients with Charlson comorbidity scores ≥4 in either period.

CONCLUSION

Assignment of patients to multiple-bed rooms on general medical and surgical wards was not associated with an increased risk in the development of HO-CDI. Future investigation should be performed with larger cohorts in multiple sites to more definitively address the question because this issue could have implications for patient room assignment and hospital design.

Sensitivity of Single-Molecule Array Assays for Detection of Clostridium difficile Toxins in Comparison to Conventional Laboratory Testing Algorithms

Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile toxins cannot be used as standalone tests due to suboptimal sensitivity, and molecular tests suffer from nonspecificity by detecting colonization.

Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile toxins cannot be used as standalone tests due to suboptimal sensitivity, and molecular tests suffer from nonspecificity by detecting colonization. Sensitive immunoassays have recently been developed to improve and simplify CDI diagnosis. Assays detecting CD toxins have been developed using single-molecule array (SIMOA) technology. SIMOA performance was assessed relative to a laboratory case definition of CDI defined by positive glutamate dehydrogenase (GDH) screen and cell cytotoxicity neutralizing assay (CCNA). Samples were tested with SIMOA assays and a commercial toxin EIA to compare performance, with discrepancy resolution using a commercial nucleic acid-based test and a second cell cytotoxicity assay. The SIMOA toxin A and toxin B assays showed limits of detection of 0.6 and 2.9 pg/ml, respectively, and intra-assay coefficients of variation of less than 10%. The optimal clinical thresholds for the toxin A and toxin B assays were determined to be 22.1 and 18.8 pg/ml, respectively, with resultant sensitivities of 84.8 and 95.5%. In contrast, a high-performing EIA toxin test had a sensitivity of 71.2%. Thus, the SIMOA assays detected toxins in 24% more samples with laboratory-defined CDI than the high performing toxin EIA (95% [63/66] versus 71% [47/66]). This study shows that SIMOA C. difficile toxin assays have a higher sensitivity than currently available toxin EIA and have the potential to improve CDI diagnosis.

Magnitude and direction of the association between Clostridium difficile infection and proton pump inhibitors in adults and pediatric patients: a systematic review and meta-analysis

BACKGROUND

Clostridium difficile infection (CDI) is a cause of increased morbidity and health care costs among hospitalized patients. Proton pump inhibitors (PPIs) are mainly used for the treatment of acid-related upper gastrointestinal diseases. The aim of the study was to assess the risks associated with initial and recurrent CDI in adult and pediatric patients treated with PPIs.

METHODS

A systematic search was performed using PubMed (Medline), Embase, and Web of Science with the following search terms: ("proton pump inhibitor," "PPI," or "acid suppression") AND ("infection," "diarrhea," "diarrhoea," "colitis," or "disease") AND ("Clostridium difficile"). Meta-analysis was performed using Revman5.3 software. Pooled odds ratios (ORs) presented as standard plots with 95% confidence intervals (CIs) were determined.

RESULTS

Sixty-seven eligible studies were selected. PPI use was significantly associated with risk of CDI (OR 2.34, 95% CI 1.94-2.82; P < 0.00001). Pooled data from twelve studies demonstrated a significant association between PPI use and recurrent CDI (OR 1.73, 95% CI 1.39-2.15; P = 0.02). Subgroup analysis revealed significant associations between PPI use and an increased incidence of CDI among adult (OR 2.30, 95% CI 1.89-2.80; P < 0.00001) and pediatric (OR 3.00, 95% CI 1.44-6.23; P < 0.00001) patients.

CONCLUSIONS

PPI use was associated with CDI in adult and pediatric patients, and with recurrent CDI. Although many risk factors are associated with the occurrence and recurrence of CDI, consideration should be given to not administering PPIs at any age if they are unnecessary.

Proton pump inhibitors therapy and risk of Clostridium difficile infection: Systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis on proton pump inhibitors (PPIs) therapy and the risk of Clostridium difficile infection (CDI).

METHODS

We conducted a systematic search of MEDLINE/PubMed and seven other databases through January 1990 to March 2017 for published studies that evaluated the association between PPIs and CDI. Adult case-control and cohort studies providing information on the association between PPI therapy and the development of CDI were included. Pooled odds ratios (ORs) estimates with 95% confidence intervals (CIs) were calculated using the random effect. Heterogeneity was assessed by I² test and Cochran’s Q statistic. Potential publication bias was evaluated via funnel plot, and quality of studies by the Newcastle-Otawa Quality Assessment Scale (NOS).

RESULTS

Fifty-six studies (40 case-control and 16 cohort) involving 356683 patients met the inclusion criteria and were analyzed. Both the overall pooled estimates and subgroup analyses showed increased risk for CDI despite substantial statistical heterogeneity among studies. Meta-analysis of all studies combined showed a significant association between PPI users and the risk of CDI (pooled OR = 1.99, CI: 1.73-2.30, P < 0.001) as compared with non-users. The association remained significant in subgroup analyses: by design-case-control (OR = 2.00, CI: 1.68-2.38, P < 0.0001), and cohort (OR = 1.98, CI: 1.51-2.59, P < 0.0001); adjusted (OR = 1.95, CI: 1.67-2.27, P < 0.0001) and unadjusted (OR = 2.02, CI: 1.41-2.91, P < 0.0001); unicenter (OR = 2.18, CI: 1.72-2.75, P < 0.0001) and multicenter (OR = 1.82, CI: 1.51-2.19, P < 0.0001); age ≥ 65 years (OR = 1.93, CI: 1.40-2.68, P < 0.0001) and < 65 years (OR = 2.06, CI: 1.11-3.81, P < 0.01). No significant differences were found in subgroup analyses (test for heterogeneity): P = 0.93 for case-control vs cohort, P = 0.85 for adjusted vs unadjusted, P = 0.24 for unicenter vs multicenter, P = 0.86 for age ≥ 65 years and < 65 years. There was significant heterogeneity across studies (I² = 85.4%, P < 0.001) as well as evidence of publication bias (funnel plot asymmetry test, P = 0.002).

CONCLUSION

This meta-analysis provides further evidence that PPI use is associated with an increased risk for development of CDI. Further high-quality, prospective studies are needed to assess whether this association is causal.

Association between omeprazole use and Clostridium difficile infection among hospitalized patients: A case-control study of the Saudi population

Background: While few international studies have assessed the association between omeprazole use and the risk of Clostridium difficile infection (CDI), research into this is lacking in Saudi Arabia and the Middle East region. The aim of this study was to determine whether exposure to omeprazole is associated with the risk of Clostridium difficile infection in a sample of hospitalized Saudi patients. Methodology: A retrospective matched case–control study was conducted at the King Abdulaziz Medical City in Riyadh, Saudi Arabia, from 1 August 2010 through 31 July 2015. The analysis included a total of 200 patients: 100 CDI cases and 100 matched controls. Results: The majority (60%, 120 out of 200) of patients had received proton pump inhibitors (PPIs), and a minority (18.5%, 37 out of 200) had received omeprazole. The PPI use was insignificantly higher in CDI cases than in controls. However, the use of omeprazole was significantly higher in CDI cases compared with controls. Specifically, patients receiving omeprazole were two times more likely to develop CDI compared with controls (aOR = 2.1, 95% confidence interval (CI) = (1.007–4.437)). After adjusting for potential predictors of CDI, watery diarrhea (aOR = 59.1, 95% CI = 19.831–175.974) and abdominal pain (aOR = 7.5, 95% CI = 2.184–25.445) were found to be independent predictors of CDI. Conclusions: The data suggests that PPIs were commonly used in patients admitted to King Abdulaziz Medical City in Riyadh: six out of ten patients received PPIs. The findings support a possible association between the use of omeprazole and a high risk of CDI. To confirm causality, the link between omeprazole and CDI should be assessed in a large interventional study.

Strategies to enhance rational use of antibiotics in hospital: a guideline by the German Society for Infectious Diseases

Introduction

In the time of increasing resistance and paucity of new drug development there is a growing need for strategies to enhance rational use of antibiotics in German and Austrian hospitals. An evidence-based guideline on recommendations for implementation of antibiotic stewardship (ABS) programmes was developed by the German Society for Infectious Diseases in association with the following societies, associations and institutions: German Society of Hospital Pharmacists, German Society for Hygiene and Microbiology, Paul Ehrlich Society for Chemotherapy, The Austrian Association of Hospital Pharmacists, Austrian Society for Infectious Diseases and Tropical Medicine, Austrian Society for Antimicrobial Chemotherapy, Robert Koch Institute.

Materials and methods

A structured literature research was performed in the databases EMBASE, BIOSIS, MEDLINE and The Cochrane Library from January 2006 to November 2010 with an update to April 2012 (MEDLINE and The Cochrane Library). The grading of recommendations in relation to their evidence is according to the AWMF Guidance Manual and Rules for Guideline Development.

Conclusion

The guideline provides the grounds for rational use of antibiotics in hospital to counteract antimicrobial resistance and to improve the quality of care of patients with infections by maximising clinical outcomes while minimising toxicity. Requirements for a successful implementation of ABS programmes as well as core and supplemental ABS strategies are outlined. The German version of the guideline was published by the German Association of the Scientific Medical Societies (AWMF) in December 2013.

A Regional Outbreak of Clostridium difficile PCR-Ribotype 027 Infections in Southeastern France from a Single Long-Term Care Facility

OBJECTIVE To describe and analyze a large outbreak of Clostridium difficile 027 (CD-027) infections. METHODS Confirmed CD-027 cases were defined as CD infection plus real-time polymerase chain reaction assay (PCR) positive for CD-027. Clinical and microbiological data on patients with CD-027 infection were collected from January 2013 to December 2015 in the Provence-Alpes-Côte-d'Azur region (southeastern France). RESULTS In total, 19 healthcare facilities reported 144 CD-027 infections (112 confirmed and 32 probable CD-027 infections) during a 22-month period outbreak. Although the incidence rate per 10,000 bed days was lower in long-term care facilities (LTCFs) than in acute care facilities (0.05 vs 0.14; P<.001), cases occurred mainly in LTCFs, one of which was the probable source of this outbreak. After centralization of CD testing, the rate of confirmed CD-027 cases from LTCFs or residential-care homes increased significantly (69% vs 92%; P<.001). Regarding confirmed CD-027 patients, the sex ratio and the median age were 0.53 and 84.2 years, respectively. The 30-day crude mortality rate was 31%. Most patients (96%) had received antibiotics within 3 months prior to the CD colitis diagnosis. During the study period, the rate of patients with CD-027 (compared with all patients tested in the point-of-care laboratories) decreased significantly (P=.03). CONCLUSIONS A large CD-027 outbreak occurred in southeastern France as a consequence of an initial cluster of cases in a single LTCF. Successful interventions included rapid isolation and testing of residents with potentially infectious diarrhea and cohorting of case patients in a specialized infectious diseases ward to optimize management. Infect Control Hosp Epidemiol 2016;1-5.

Dissimilar Fitness Associated with Resistance to Fluoroquinolones Influences Clonal Dynamics of Various Multiresistant Bacteria

Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae. The resulting dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major international clone (ribotype 027) of Clostridium difficile. Furthermore, several additional international clones of various multiresistant bacteria are suspect to have been selected by an analogous process. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Since, the consumption of other "non-fluoroquinolone" groups of antibiotics have also contributed to the rise in resistance rates a more judicious use of antibiotics in general and of fluoroquinolones in particular could ameliorate the international resistance situation.

Fluoroquinolone and Macrolide Exposure Predict Clostridium difficile Infection with the Highly Fluoroquinolone- and Macrolide-Resistant Epidemic C. difficile Strain BI/NAP1/027

Antibiotics have been shown to influence the risk of infection with specific Clostridium difficile strains as well as the risk of C. difficile infection (CDI). We performed a retrospective case-control study of patients infected with the epidemic BI/NAP1/027 strain in a U.S. hospital following recognition of increased CDI severity and culture of stools positive by C. difficile toxin immunoassay. Between 2005 and 2007, 72% (103/143) of patients with first-episode CDIs were infected with the BI strain by restriction endonuclease analysis (REA) typing. Most patients received multiple antibiotics within 6 weeks of CDI onset (median of 3 antibiotic classes). By multivariate analysis, fluoroquinolone and macrolide exposure was more frequent among BI cases than among non-BI-infected controls (odds ratio [OR] for fluoroquinolones, 3.2; 95% confidence interval [CI], 1.3 to 7.5; (P < 0.001; OR for macrolides, 5.2; 95% CI, 1.1 to 24.0; P = 0.04)). In contrast, clindamycin use was less frequent among the BI cases than among the controls (OR, 0.1; 95% CI, 0.03 to 0.4; P = 0.001). High-level resistance to moxifloxacin and azithromycin was more frequent among BI strains (moxifloxacin, 49/102 [48%] BI versus 0/40 non-BI, P = 0.0001; azithromycin, 100/102 [98%] BI versus 22/40 [55%] non-BI, P = 0.0001). High-level resistance to clindamycin was more frequent among non-BI strains (22/40 [55%] non-BI versus 7/102 [7%] BI, P = 0.0001). Fluoroquinolone use, macrolide use, and C. difficile resistance to these antibiotic classes were associated with infection by the epidemic BI strain of C. difficile in a U.S. hospital during a time when CDI rates were increasing nationally due to the highly fluoroquinolone-resistant BI/NAP1/027 strain.

Clostridium difficile infection (CDI) severity and outcome among patients infected with the NAP1/BI/027 strain in a non-epidemic setting

OBJECTIVE

Determine whether the NAP1 strain identified by polymerase chain reaction (PCR)-based stool assay is correlated with CDI severity and clinical outcomes.

METHODS

Medical records of adult patients with positive stool Xpert® Clostridium difficile PCR assay for an initial episode of CDI between January 2012 and January 2013 at a tertiary care hospital in Chicago were reviewed. Two patients diagnosed with CDI caused by a non-NAP1 strain (positive Xpert® C. difficile assay but negative Xpert® C. difficile Epi assay) were included for each patient diagnosed with CDI caused by a NAP1 strain (positive Epi assay). Patient charts were reviewed for markers of severity, risk factors, treatment regimens, and outcomes.

RESULTS

Of 494 stool specimens, 90 (18%) that were positive for C. difficile by PCR were positive for NAP1 strain. In total, 37 patients with CDI due to NAP1 were matched with 74 patients with CDI due to non-NAP1 strains. Multivariable model revealed individuals ≥65 years old were 3 times more likely to have NAP1 strain than individuals <65 (P=.02). Residents of a nursing home prior to hospitalization were 10 times more likely to have NAP1 strain than patients residing in their homes (P=.001). More NAP1 cases had a change in treatment from metronidazole to oral vancomycin plus intravenous metronidazole (P=.01). The severity of CDI, incidence of mortality and recurrent CDI were similar between groups.

CONCLUSIONS

In a nonepidemic setting, NAP1 strains were more common in older patients and individuals admitted from nursing homes. Identification of NAP1 by PCR of stool specimens was associated in a change of therapy but did not predict worse outcomes. Reporting strain results may not be clinically useful in routine settings.

Clostridium difficile colitis: review of the therapeutic approach

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated and nosocomial infectious diarrhea. Presenting as clostridium difficile colitis, it is a significant cause of morbidity and mortality. Metronidazole is regarded as the agent of choice for CDl therapy and also for the first recurrence in most patients with mild to moderate CDI. Vancomycin is recommended as an initial therapy for patients with severe CDI. With recent Food and Drug Administration-approval fidaxomicin is available for clinical use and is as effective as vancomycin with lower relapse rates. Rifaximin and fecal bacteriotherapy are alternative approaches in patients with severe or refractory CDI, before surgical intervention. Antibiotic research is ongoing to add potential new drugs such as teicoplanin, ramoplanin, fusidic acid, nitazoxanide, rifampin, bacitracin to our armamentarium. Role of toxin-binding agents is still questionable. Monoclonal antibody and intravenous immunoglobulin are still investigational therapies that could be promising options. The ongoing challenges in the treatment of CDI include management of recurrence and presence of resistance strains such as NAP1/BI/027, but early recognition of surgical candidates can potentially decrease mortality in CDI.

Association between Clostridium difficile infection and antimicrobial usage in a large group of English hospitals

AIMS

This study aimed to determine the association between the reduction in the number of Clostridium difficile infection (CDI) cases reported by the English National Health Service (NHS) hospitals and concurrent antimicrobial use.

METHODS

A retrospective ecological study for January 2005 to December 2008 was conducted using data from 26 of the 29 NHS trusts (i.e. a trust manages one or more hospitals) located in the North West Strategic Health Authority of England. Antimicrobial use data, for patients of all ages, were provided by IMS Health, and CDI case data for patients aged ≥65 years were provided by the Health Protection Agency. Antimicrobial use was converted into defined daily doses (DDDs). The overall association between antimicrobial use and CDI for the trusts was investigated using multilevel models.

RESULTS

Our study shows a positive significant association between the CDI cases and the use of the following antimicrobials: ‘third-generation cephalosporins’ [11.62 CDI cases per 1000 DDDs; 95% confidence interval (CI), 5.92–17.31]; ‘fluoroquinolones’ (4.79 CDI cases per 1000 DDDs; 95% CI, 2.83–6.74); and ‘second-generation cephalosporins’ (4.25 CDI cases per 1000 DDDs; 95% CI, 1.66–6.83). The strength of this association was not significantly different (95% CI) among the antimicrobial groups.

CONCLUSIONS

This study shows that the reduction in the number of CDI cases reported by the English NHS hospitals is associated with concurrent reductions in antimicrobial use. This means that the number of CDI cases over time decreased in a similar fashion to the usage of various antimicrobials.

Outbreak of Clostridium difficile PCR ribotype 027--the recent experience of a regional hospital

Background

Clostridium difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, and several outbreaks with increased severity and mortality have been reported. In this study we report a C. difficile PCR ribotype 027 outbreak in Portugal, aiming to contribute to a better knowledge of the epidemiology of this agent in Europe.

Methods

Outbreak report with retrospective study of medical records and active surveillance data of all inpatients with the diagnosis of CDI, from 1^st January to 31^th December 2012, in a Portuguese hospital. C. difficile isolates were characterized regarding ribotype, toxin genes and moxifloxin resistance. Outbreak control measures were taken, concerning communication, education, reinforcement of infection control measures, optimization of diagnosis and treatment of CDI, and antibiotic stewardship.

Results

Fifty-three inpatients met the case definition of C. difficile-associated infection: 55% males, median age was 78.0 years (interquartile range: 71.0-86.0), 75% had co-morbidities, only 15% had a nonfatal condition, 68% had at least one criteria of severe disease at diagnosis, 89% received prior antibiotherapy, 79% of episodes were nosocomial. CDI rate peak was 13.89/10,000 bed days. Crude mortality rate at 6 months was 64.2% while CDI attributable cause was 11.3%. Worse outcome was related to older age (P = 0.022), severity criteria at diagnosis (leukocytosis (P = 0.008) and renal failure), and presence of fatal underlying condition (P = 0.025). PCR ribotype 027 was identified in 16 of 22 studied samples.

Conclusions

This is the first report of a 027-CDI outbreak in Portugal. We emphasize the relevance of the measures taken to control the outbreak and highlight the importance of implementing a close and active surveillance of CDI.

The impact of cefepime as first line therapy for neutropenic fever on Clostridium difficile rates among hematology and oncology patients

After changing empiric treatment of febrile neutropenia from meropenem to cefepime, the effect on Clostridium difficile infection (CDI) was investigated. The change was assessed using an autoregressive model. A significant increase in CDI rates occurred following the introduction of cefepime. There may be an association between increased cefepime usage and CDI.

Management and prevention of recurrent clostridium difficile infection in patients after total joint arthroplasty: a review

Clostridium difficile infection (CDI) is the most common infectious cause of nosocomial diarrhea in elderly patients, accounting for 15% to 25% of all cases of antibiotic-induced diarrhea in those patients. Virulent forms of this organism have developed, increasing the associated morbidity, mortality, and complication rates. The average patient undergoing total joint arthroplasty is at particular risk of CDI because of advanced age, the use of prophylactic antibiotic coverage in the perioperative period, multiple comorbid conditions, and length of hospital stay. In addition, patients who have had one CDI are at risk of another; the rate of recurrent CDI (RCDI) is 15% to 30%. To review the available information on RCDI, we conducted an extensive literature search, focusing on its epidemiology and the management strategies for its treatment and prevention. We found the management of RCDI is a controversial topic, with as yet no consensus regarding specific treatment guidelines. Several experienced clinicians have published suggested treatment algorithms, but they are based on anecdotal experience. With regard to the prevention of RCDI, the literature is scarce, and currently, the only effective strategies remain judicious use of perioperative antibiotics and appropriate implementation of infection control procedures. There are several vaccination medications that are currently being studied but are not yet ready for clinical use. We agree with the approach to management of RCDI that has been proposed in several articles, that is, on confirmation of a first recurrence of CDI by a stool toxin assay and clinical symptoms, a 14-day course of metronidazole or vancomycin; for a second recurrence, a tapered-pulsed course of vancomycin; and, for 3 or more recurrences, a repeat course of the tapered-pulsed vancomycin and adjunctive Saccharomyces boulardii or cholestyramine.

The association between histamine 2 receptor antagonist use and Clostridium difficile infection: a systematic review and meta-analysis

BACKGROUND

Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI.

PURPOSE

We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H2RAs) and CDI.

DATA SOURCE

We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H2RAs and CDI.

STUDY SELECTION

Two authors independently reviewed the studies for eligibility.

DATA EXTRACTION

Data about studies characteristics, adjusted effect estimates and quality were extracted.

DATA SYNTHESIS

Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H2RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22-1.7), I(2) = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15-1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H2RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097).

CONCLUSION

In this rigorous systematic review and meta-analysis, we observed an association between H2RAs and CDI. The absolute risk of CDI associated with H2RAs is highest in hospitalized patients receiving antibiotics.

Clostridium difficile infection and proton pump inhibitors

PURPOSE OF REVIEW

Clostridium difficile is an intestinal infection associated with antibiotic use, commonly seen in patients with chronic medical issues. The purpose of this review is to discuss the association of C. difficile-associated diarrhea with use of proton pump inhibitors.

RECENT FINDINGS

Multiple medical factors predispose patients to C. difficile-associated diarrhea. Proton pump inhibitors, commonly used for gastric acid suppression, have been shown to have an association with C. difficile-associated diarrhea in both the outpatient and hospital setting. C. difficile-associated diarrhea also has been reported in the pediatric age range linked with proton pump inhibitor use.

SUMMARY

An association exists between C. difficile infection and proton pump inhibitor use. Treatment options exist for C. difficile-associated diarrhea, although judicious use of proton pump inhibitors and antibiotics, emphasis on hand washing, and appropriate use of patient isolation should be implemented as well.

Risk factors for development of Clostridium difficile infection due to BI/NAP1/027 strain: a meta-analysis

OBJECTIVE

To identify risk factors for the development of Clostridium difficile infection (CDI) due to C. difficile BI/NAP1/027 strain.

METHODS

PubMed and Scopus databases were searched for studies that sought to identify risk factors for CDI due to the BI/NAP1/027 strain. The technique of meta-analysis was applied.

RESULTS

Five studies compared CDI BI/NAP1/027 patients to CDI patients infected with non-BI/NAP1/027 strains, one compared CDI BI/NAP1/027 patients to non-CDI patients, and one provided data for both comparisons. The meta-analysis showed that fluoroquinolones were associated with a higher risk of CDI due to BI/NAP1/027 when compared to non-BI/NAP1/027 CDI (odds ratio (OR) 1.96, 95% confidence interval (95% CI) 1.37-2.80). A trend towards a lower risk for CDI due to BI/NAP1/027 was observed with cephalosporins when compared to non-BI/NAP1/027 CDI (OR 0.70, 95% CI 0.46-1.07). Prior macrolides were not associated with a higher risk for CDI BI/NAP1/027 when compared with non-BI/NAP1/027 CDI controls (OR 0.88, 95% CI 0.44-1.78). Clindamycin administration was associated with a lower risk for CDI due to BI/NAP1/027 when compared to non-BI/NAP1/027 CDI (OR 0.24, 95% CI 0.12-0.48). Age over 65 years was associated with an increased risk of CDI BI/NAP1/027 compared to non-BI/NAP1/027 CDI (OR 1.77, 95% CI 1.31-2.38).

CONCLUSIONS

Fluoroquinolones and age over 65 years were associated with a higher risk of CDI due to the BI/NAP1/027 strain. Clindamycin was associated with a lower risk of CDI due to BI/NAP1/027.

Risk of Clostridium difficile infection with acid suppressing drugs and antibiotics: meta-analysis

OBJECTIVES

Several studies have raised concern regarding the possible association between proton-pump inhibitors (PPIs) and Clostridium difficile infection (CDI). We aimed to perform a systematic review of incident and recurrent CDI in PPI users, and to evaluate the relative impact of concurrent antibiotic use, or switching acid suppression to histamine-2-receptor antagonists (H2RAs).

METHODS

We searched MEDLINE and EMBASE from inception to December 2011 for controlled observational studies that reported on the risk of CDI with and without PPI use. We performed random effects meta-analysis and assessed statistical heterogeneity using the I(2) statistic.

RESULTS

We included 42 observational studies (30 case-control, 12 cohort) totalling 313,000 participants overall. Pooled analysis of 39 studies showed a statistically significant association between PPI use and risk of developing CDI, odds ratio (OR) 1.74 (95% confidence interval (CI) 1.47-2.85, P<0.001, I(2)=85%) compared with non-users. A pooled analysis of three studies showed a significant associated risk of recurrent CDI associated with PPIs, OR 2.51 (95% CI 1.16-5.44, P=0.005, I(2)=78%). Subgroup analysis failed to fully clarify the source of the substantial statistical heterogeneity. Adjusted indirect comparison demonstrated that use of H2RAs as an alternative carried a lower-risk OR 0.71 (95% CI 0.53-0.97) compared with PPIs. Conversely, concomitant use of PPI and antibiotics conferred a greater-risk OR 1.96 (95% CI 1.03-3.70) above that of PPIs alone. For PPI and antibiotics, the Rothman's synergy index was 1.36 and attributable proportion of risk from interaction 0.19, indicating an increased risk from interaction beyond the effects of each drug alone.

CONCLUSIONS

Despite the substantial statistical and clinical heterogeneity, our findings indicate a probable association between PPI use and incident and recurrent CDI. This risk is further increased by concomitant use of antibiotics and PPI, whereas H2RAs may be less harmful.

Clinical and economic burden of Clostridium difficile infection in Europe: a systematic review of healthcare-facility-acquired infection

PubMed, EMBASE and conference abstracts were reviewed systematically to determine the clinical and economic burden associated with Clostridium difficile infection (CDI) acquired and treated in European healthcare facilities. Inclusion criteria were: published in the English language between 2000 and 2010, and study population of at least 20 patients with documented CDI acquired/treated in European healthcare facilities. Data collection was completed by three unblinded reviewers using the Cochrane Handbook and PRISMA statement. The primary outcomes were mortality, recurrence, length of hospital stay (LOS) and cost related to CDI. In total, 1138 primary articles and conference abstracts were identified, and this was narrowed to 39 and 30 studies, respectively. Data were available from 14 countries, with 47% of studies from UK institutions. CDI mortality at 30 days ranged from 2% (France) to 42% (UK). Mortality rates more than doubled from 1999 to 2004, and continued to rise until 2007 when reductions were noted in the UK. Recurrent CDI varied from 1% (France) to 36% (Ireland); however, recurrence definitions varied between studies. Median LOS ranged from eight days (Belgium) to 27 days (UK). The incremental cost of CDI was £4577 in Ireland and £8843 in Germany, after standardization to 2010 prices. Country-specific estimates, weighted by sample size, ranged from 2.8% to 29.8% for 30-day mortality and from 16 to 37 days for LOS. CDI burden in Europe was most commonly described using 30-day mortality, recurrence, LOS and cost data. The continued spread of CDI and resultant healthcare burden underscores the need for judicious use of antibiotics.

Clostridium: transmission difficile?

Stephan Harbarth and Matthew Samore discuss the implications, and the limitations, of new research that might indicate that most Clostridium difficile cases are imported into hospitals.

Biology of Clostridium difficile: implications for epidemiology and diagnosis

Clostridium difficile is an anaerobic, spore-forming, gram-positive rod that causes a spectrum of antibiotic-associated colitis through the elaboration of two large clostridial toxins and other virulence factors. Since its discovery in 1978 as the agent responsible for pseudomembranous colitis, the organism has continued to evolve into an adaptable, aggressive, hypervirulent strain. Advances in molecular methods and improved animal models have facilitated an understanding of how this organism survives in the environment, adapts to the gastrointestinal tract of animals and humans, and accomplishes its unique pathogenesis. The advances in microbiology have been accompanied by some important clinical observations including increased rates of C. difficile infection, increased virulence, and multiple outbreaks. The major new risk is fluoroquinolone use; there is also an association with proton pump inhibitors and increased recognition of cases in outpatients, pediatric patients, and patients without recent antibiotic use. The combination of more aggressive strains with mobile genomes in a setting of an expanded pool of individuals at risk has refocused attention on and challenged assumptions regarding diagnostic gold standards. Future research is likely to build upon the advancements in phylogenetics to create novel strategies for diagnosis, treatment, and prevention.

Systematic review: the use of proton pump inhibitors and increased susceptibility to enteric infection

The use of proton pump inhibitors (PPIs) is increasing worldwide. Suppression of gastric acid alters the susceptibility to enteric bacterial pathogens. AIM  This systematic review was undertaken to examine the relationship between PPI use and susceptibility to enteric infections by a specific pathogen based on published literature and to discuss the potential mechanisms of PPI enhanced pathogenesis of enteric infections. METHODS  PubMed, OVID Medline Databases were searched. Search terms included proton pump inhibitors and mechanisms of, actions of, gastric acid, enteric infections, diarrhoea, Clostridium difficile, Salmonella, Shigella and Campylobacter. RESULTS The use of PPIs increases gastric pH, encourages growth of the gut microflora, increases bacterial translocation and alters various immunomodulatory and anti-inflammatory effects. Enteric pathogens show variable gastric acid pH susceptibility and acid tolerance levels. By multiple mechanisms, PPIs appear to increase susceptibility to the following bacterial enteropathogens: Salmonella, Campylobacter jejuni, invasive strains of Escherichia coli, vegetative cells of Clostridium difficile, Vibrio cholerae and Listeria. We describe the available evidence for enhanced susceptibility to enteric infection caused by Salmonella, Campylobacter and C. difficile by PPI use, with adjusted relative risk ranges of 4.2-8.3 (two studies); 3.5-11.7 (four studies); and 1.2-5.0 (17 of 27 studies) for the three respective organisms. CONCLUSIONS Severe hypochlorhydria generated by PPI use leads to bacterial colonisation and increased susceptibility to enteric bacterial infection. The clinical implication of chronic PPI use among hospitalized patients placed on antibiotics and travellers departing for areas with high incidence of diarrhoea should be considered by their physicians.

Antibiotic Collateral Damage: Resistance and Antibiotic-Associated Diarrhea

The purpose of this review is to describe dilemmas associated with antibiotic collateral damage and provide clinical pharmacists with information to improve antibiotic utilization. The clinical use of antibiotics has been associated with acquisition and spread of nosocomial pathogens and multidrug-resistant strains, such as extended-spectrum beta-lactamases, AmpC hyper-producers, carbapenemases, and resistant gram-positive organisms. The mobility of plasmid-mediated resistance, such as extended-spectrum beta-lactamases and the more recently isolated Klebsiella pneumoniae carbapenemases, have been well-demonstrated with worldwide distribution across several different species. The challenges surrounding antibiotic-associated diarrhea, particularly Clostridium difficile infection (CDI), continue to evolve with outbreaks of hypervirulent strains linked to the use of less commonly implicated antibiotics. Published literature was searched and reviewed using PubMed. Undesirable attributes related to antibiotic use can have broad consequences in addition to their effect on individual patients. This collateral damage can evolve over time, and prescribers must be aware of current concerns and be diligent in their judicious use of antibiotics.

Evaluation of automated repetitive-sequence-based PCR (DiversiLab) compared to PCR ribotyping for rapid molecular typing of community- and nosocomial-acquired Clostridium difficile

Automated repetitive PCR (rep-PCR; DiversiLab) was compared to PCR ribotyping of the 16S-23S RNA intergenic spacer of Clostridium difficile (CD) as the "gold standard" method for CD typing. PCR products were separated on DiversiLab LabChips (bioMérieux, St. Laurent, Quebec, Canada) utilizing a 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA) operating the DiversiLab v1.4 assay. Bioanalyzer data were exported to a secure DiversiLab website and analyzed with DiversiLab v3.4 software. Replicability of each method was verified by confirming that the 5 CD reference strains (RS) formed distinct clusters (CD4, CD6, VL0047, VL0013 [ribotype 027], VL0018 [ribotype 001]) by both typing methods. Ninety randomly selected clinical isolates (CS) were analyzed by both methods: 49 from community-acquired and 41 from hospital-acquired cases. A similarity index (SI) of ≥90% was used to define clusters when comparing the known RS cluster to the PCR ribotyping and rep-PCR patterns of CS. Fourteen different PCR-ribotype clusters were identified, but most CS formed 4 major clusters (i.e., CD4 [15/90; 17%], CD6 [17%], 027 [12%], and 001 [9%]). A total of 7 rep-PCR types were identified, but most CS formed 2 major rep-PCR clusters (i.e., CD4 [29/90; 32%] and CD6 [23%]); several PCR ribotypes occurred within a single rep-PCR cluster. Rep-PCR did not distinguish 027 or 001 isolates; i) 027 RS strain did not cluster, ii) eleven 027 CS strains clustered as CD4, iii) no 027 CS strains clustered with the 027 RS, and iv) only 2 001 CS clustered with the RS. Agreement between the PCR-ribotype and rep-PCR clusters only occurred for 35/90 (39%) of the CS using a rep-PCR SI of ≥90%. Rep-PCR time to results was similar, but the annual costs of routinely using this method are 32% higher than PCR ribotyping. Routine use of rep-PCR for CD typing is limited by its lack of definitive separation of the hypertoxigenic 027 or 001 outbreak CD strains.

Multihospital outbreak of Clostridium difficile ribotype 027 infection: epidemiology and analysis of control measures

OBJECTIVE

To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak.

DESIGN

Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland.

INTERVENTIONS

Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene.

RESULTS

A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, -0.054; lag time, 4 months; P = .003).

CONCLUSION

These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillance.

Use of antibacterial prophylaxis for patients with neutropenia. Australian Consensus Guidelines 2011 Steering Committee

The use of oral prophylactic antibiotics in patients with neutropenia is controversial and not recommended by this group because of a lack of evidence showing a reduction in mortality and concerns that such practice promotes antimicrobial resistance. Recent evidence has demonstrated non-significant but consistent, improvement in all-cause mortality when fluoroquinolones (FQs) are used as primary prophylaxis. However, the consensus was that this evidence was not strong enough to recommend prophylaxis. The evidence base for FQ prophylaxis is presented alongside current consensus opinion to guide the appropriate and judicious use of these agents. Due consideration is given to patient risk, as it pertains to specific patient populations, as well as the net effect on selective pressure from antibiotics if FQ prophylaxis is routinely used in a target population. The potential costs and consequences of emerging FQ resistance, particularly among Escherichia coli, Clostridium difficile and Gram-positive organisms, are considered. As FQ prophylaxis has been advocated in some chemotherapy protocols, specific regard is given to whether FQ prophylaxis should be used to support these regimens. The group also provides recommendations for monitoring and surveillance of emerging resistance in those centres that have adopted FQ prophylaxis.

Global epidemiology of Clostridium difficile infection in 2010

The past decade has been characterized by an epidemic of Clostridium difficile infection in North America and Europe that threatens to extend to the rest of the world. The epidemic is due in part to the emergence of a previously rare and now more lethal C. difficile strain variously named group BI, ribotype 027, and North American pulsed&#x2010;field gel electrophoresis type 1.

The epidemiology of Clostridium difficile in Scotland

The objective of this study was to characterise the epidemiology of Clostridium difficile in Scotland by determining the distribution of PCR ribotypes and antimicrobial susceptibility in 1613 isolates collected from all healthboard areas of Scotland in the period November 2007-December 2009. Three PCR ribotypes predominated amongst the Scottish isolates of C. difficile; ribotype 106 (29.4%), ribotype 001 (22%) and ribotype 027 (12.6%) followed by the less prevalent ribotypes including 002, 015, 014, 078, 005, 023 and 020. The distribution of ribotypes varied between healthboard areas. Ribotype 106 or 001 was the predominant ribotype in 10 healthboard areas, while ribotype 027 was the predominant type in two neighbouring areas. Antimicrobial susceptibility testing of C. difficile isolates showed high frequencies of resistance to moxifloxacin, levofloxacin, erythromycin and cefotaxime in the epidemic C. difficile ribotypes 001, 027 and 106 compared to other less common ribotypes. Furthermore, reduced susceptibility to metronidazole was found only in the epidemic strains. These findings are compatible with the hypothesis that fluoroquinolones, macrolides and cephalosporins may play a role in the spread of C. difficile in Scotland (while the role of metronidazole needs further investigations), and highlights the role of antimicrobial stewardship in preventing and controlling C. difficile infection (CDI).

Clostridium difficile infection: epidemiology, risk factors and management

The epidemiology of Clostridium difficile infection (CDI) has changed over the past decade. There has been a dramatic worldwide increase in its incidence, and new CDI populations are emerging, such as those with community-acquired infection and no previous exposure to antibiotics, children, pregnant women and patients with IBD. Diagnosis of CDI requires identification of C. difficile toxin A or B in diarrheal stool. The accuracy of current diagnostic tests remains inadequate and the optimal diagnostic testing algorithm has not been defined. The first-line agents for CDI treatment are metronidazole and vancomycin, with the latter being the preferred agent in patients with severe disease as it has significantly superior efficacy. The incidence of metronidazole treatment failures has increased, emphasizing the need to find alternative treatment options. Disease recurrence continues to occur in 20-40% of patients and its treatment remains challenging. In patients with CDI who develop fulminant colitis, early surgical consultation is essential. Intravenous immunoglobulin and tigecycline have been used in patients with severe refractory disease but delaying surgery may be associated with worse outcomes. Infection control measures are key to prevent horizontal transmission of infection. Ongoing research into effective treatment protocols and prevention is essential.