Clinical and economic impact of meropenem resistance in Pseudomonas aeruginosa-infected patients

Prevalence of meropenem-resistant Pseudomonas Aeruginosa in Ethiopia: a systematic review and meta‑analysis

INTRODUCTION

Antimicrobial resistance (AMR) is a pressing global health concern, particularly pronounced in low-resource settings. In Ethiopia, the escalating prevalence of carbapenem-resistant Pseudomonas aeruginosa (P. aeruginosa) poses a substantial threat to public health.

METHODS

A comprehensive search of databases, including PubMed, Scopus, Embase, Hinari, and Google Scholar, identified relevant studies. Inclusion criteria encompassed observational studies reporting the prevalence of meropenem-resistant P. aeruginosa in Ethiopia. Quality assessment utilized JBI checklists. A random-effects meta-analysis pooled data on study characteristics and prevalence estimates, with subsequent subgroup and sensitivity analyses. Publication bias was assessed graphically and statistically.

RESULTS

Out of 433 studies, nineteen, comprising a total sample of 11,131, met inclusion criteria. The pooled prevalence of meropenem-resistant P. aeruginosa was 15% (95% CI: 10-21%). Significant heterogeneity (I2 = 83.6%) was observed, with the number of P. aeruginosa isolates identified as the primary source of heterogeneity (p = 0.127). Subgroup analysis by infection source revealed a higher prevalence in hospital-acquired infections (28%, 95% CI: 10, 46) compared to community settings (6%, 95% CI: 2, 11). Geographic based subgroup analysis indicated the highest prevalence in the Amhara region (23%, 95% CI: 8, 38), followed by Addis Ababa (21%, 95% CI: 11, 32), and lower prevalence in the Oromia region (7%, 95% CI: 4, 19). Wound samples exhibited the highest resistance (25%, 95% CI: 25, 78), while sputum samples showed the lowest prevalence. Publication bias, identified through funnel plot examination and Egger's regression test (p < 0.001), execution of trim and fill analysis resulted in an adjusted pooled prevalence of (3.7%, 95% CI: 2.3, 9.6).

CONCLUSION

The noteworthy prevalence of meropenem resistance among P. aeruginosa isolates in Ethiopia, particularly in healthcare settings, underscores the urgency of implementing strict infection control practices and antibiotic stewardship. Further research is imperative to address and mitigate the challenges posed by antimicrobial resistance in the country.

The economic burden of antibiotic resistance: A systematic review and meta-analysis

INTRODUCTION

Antibiotic resistance (ABR) has substantial global public health concerns. This systematic review aimed to synthesise recent evidence estimating the economic burden of ABR, characterised by study perspectives, healthcare settings, study design, and income of the countries.

METHODS

This systematic review included peer-reviewed articles from PubMed, Medline, and Scopus databases, and grey literature on the topic of the economic burden of ABR, published between January 2016 and December 2021. The study was reported in line with 'Preferred Reporting Items for Systematic Review and Meta-Analysis' (PRISMA). Two reviewers independently screened papers for inclusion first by title, then abstract, and then the full text. Study quality was assessed using appropriate quality assessment tools. Narrative synthesis and meta-analyses of the included studies were conducted.

RESULTS

A total of 29 studies were included in this review. Out of these studies, 69% (20/29) were conducted in high-income economies and the remainder were conducted in upper-and-middle income economies. Most of the studies were conducted from a healthcare or hospital perspective (89.6%, 26/29) and 44.8% (13/29) studies were conducted in tertiary care settings. The available evidence indicates that the attributable cost of resistant infection ranges from -US$2,371.4 to +US$29,289.1 (adjusted for 2020 price) per patient episode; the mean excess length of stay (LoS) is 7.4 days (95% CI: 3.4-11.4), the odds ratios of mortality for resistant infection is 1.844 (95% CI: 1.187-2.865) and readmission is 1.492 (95% CI: 1.231-1.807).

CONCLUSION

Recent publications show that the burden of ABR is substantial. There is still a lack of studies on the economic burden of ABR from low-income economies, and lower-middle-income economies, from a societal perspective, and in relation to primary care. The findings of this review may be of value to researchers, policymakers, clinicians, and those who are working in the field of ABR and health promotion.

SYSTEMATIC REVIEW REGISTRATION

CRD42020193886.

Immune responses and protective efficacy of a trivalent combination DNA vaccine based on oprL, oprF and flgE genes of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an infectious pathogenic bacteria infecting many different species of animals. Currently, it lacks a commercial vaccine. In this study, three monovalent DNA vaccines (poprL, poprF, and pflgE), three bivalent combination DNA vaccines (poprL+poprF, poprL+pflgE, poprF+pflgE), and a trivalent DNA vaccine (poprL+poprF+pflgE) were constructed. Consequently, we immunised chickens with these DNA vaccines and used inactivated vaccines as the positive controls. Then, the immune efficacy was evaluated through serum antibody detection, a lymphocyte proliferation assay, and cytokine concentration determination. Lastly, we assessed the protection rate through a challenge experiment. Following vaccination, the serum antibody levels induced using these DNA vaccines were different due to the different coating antigens. In the trivalent combination DNA vaccine group, we established that the lymphocyte proliferation (SI values), IFN-γ, IL-2, and IL-4 levels were significantly higher than those of the other six DNA vaccine groups and the inactivated vaccine group. However, the protection provided was slightly lower than that of the inactivated vaccine and higher than those of other DNA vaccines. The protection rate of poprL, poprF, pflgE, poprL+poprF, poprL+pflgE, poprF+pflgE, poprL+poprF+pflgE, and the inactivated vaccine were 50, 45, 60, 75, 80, 80, 90, and 95%, respectively. The results of this study indicated the trivalent DNA vaccine based on oprL, oprF and flgE genes represents a promising approach for the prevention of Pseudomonas aeruginosa infections.

Graphene materials: Armor against nosocomial infections and biofilm formation - A review

Graphene has revolutionized the field of energy and storage sectors. Out of the total number of nosocomial infections diagnosed all around the world, the majority of the cases (around 70%) are found to be due to the medical device or assistance utilized while treating the patient. Combating these diseases is vital as they cause a nuisance to the patients and medical practitioners. Coatings of graphene and its derivatives hold the key to the formation of special surfaces that can rupture microbial cells using their sharp edges, ultimately leading to nuclear and cellular fragmentation. Their incorporation as a whole or as a part in the hospital apparel and the medical device has aided medical practitioners to combat many nosocomial diseases. Graphene is found to be highly virulent with broad-spectrum antimicrobial activity against nosocomial strains and biofilm formation. Their alternate mode of action like trapping and charge transfer has also been discussed well in the present review. The various combinational forms of graphene with its conjugates as a suitable agent to combat nosocomial infections and a potential coating for newer challenges like COVID-19 infections has also been assessed in the current study. Efficiency of graphene sheets has been found to be around 89% with a reaction time as less as 3 h. Polymers with graphene seem to have a higher potency against biofilm formation. When combined with graphene oxide, silver nanoparticles provide 99% activity against nosocomial pathogens. In conclusion, this review would be a guiding light for scientists working with graphene-based coatings to unfold the potentials of this marvelous commodity to tackle the present and future pandemics to come.

Carbapenem-resistant Pseudomonas aeruginosa strains: a worrying health problem in intensive care units

Pseudomonas aeruginosa is one of the most common bacterium with a broad spectrum of human-associated infections. It is intrinsically resistant to many antimicrobial drugs, making carbapenems crucial in clinical management. The emergence and dissemination of carbapenemases among P. aeruginosa clinical isolates is a serious public health concern as it limits the options for the treatment of bacterial infections. Here, we described the molecular and epidemiological characteristics of 28 carbapenem-resistant P. aeruginosa strains isolated from patients hospitalized in an intensive care unit (ICU). The antimicrobial susceptibility of carbapenem-resistant P. aeruginosa strains was determined by broth microdilution. The presence of resistance genes was evaluated by PCR and DNA sequencing. Additionally, alterations in genes encoding P. aeruginosa outer membrane proteins were analyzed by PCR as well as SDS-PAGE. Clinical characteristics of the patients and the economic impact of hospitalization on the public health system were evaluated. PCR amplification showed that the blaKPC-2 and blaTEM genes were identified in three isolates (11%) and blaSHV gene in two isolates (7%). Outer membrane profiles obtained by SDS-PAGE indicated that the OprD porin was either absent or was produced at very low levels. A PCR assay using oprD-specific primers failed to show the presence of mutations in this gene. P. aeruginosa strains were isolated from 28 patients, among whom 43% (12/28) had sepsis, 31% (9/28) had respiratory failure, and 31% (9/28) had systemic arterial hypertension. A high mortality rate (39%) was observed in these patients, with an average duration of hospitalization of 34.6 days and a median cost of 3.275 dollars per patient. The production of carbapenemase was not the main mechanism of resistance in these strains. All carbapenem-resistant P. aeruginosa were isolated from patients hospitalized in the ICU. Besides the high mortality rate, many patients remained hospitalized for several days, resulting in a high cost of hospitalization for the public health system. Therefore, the evolution of this resistance and its dissemination should be actively monitored among critically ill patients to improve their health conditions.

[Impact of an active surveillance program and infection control measures on the incidence of carbapenem-resistant Gram-negative bacilli in an intensive care unit]

Hospital-acquired infections caused by carbapenem-resistant Gram-negative bacteria (CRGNB) have been increasingly reported worldwide and are associated with high rates of mortality especially in intensive care units(ICUs). Early identification through rectal surveillance cultures and implementation of infection control measures(ICM) including contact precautions, staff education on cleaning and hand hygiene may reduce the spread of these microorganisms. The aim of this work was to assess the impact of enhanced ICM on CRGNB colonization and to describe the molecular epidemiology of these bacteria in a polyvalent ICU in a tertiary level hospital. A prospective study including audits and active surveillance culture program, with molecular characterization, was conducted before and after the implementation of prevention programs and infection control measures. Microbiological screening was performed in chromogenic media; PCR targeting β-lactamases genes (bla_KPC, bla_NDM, bla_VIM and bla_OXA-48, bla_SHV and bla_CTX-M), molecular typing by PFGE; and MLST in K. pneumoniae were performed. CRGNB colonization was reduced from 16.92% to 9.67% upon implementing the infection control measures. In K. pneumoniae the most frequent carbapenemase type was KPC-2 associated with SHV-2 and CTX-M-15, and was disseminated in various STs (ST17, ST13, ST2256, ST353); there was no persistence of particular clones and virulence factors showed no association with hypervirulence. IMP-1 carbapenemase predominated in A. baumannii and the PFGE analysis individualized 3 clusters, assuming that the dissemination in the ICU was clonal. The early detection of patients colonized with CRBGN by using epidemiological surveillance cultures and the implementation of prophylactic measures are key to reducing the incidence of these microorganisms.

Socioeconomic burden of bloodstream infections caused by carbapenem-resistant and carbapenem-susceptible Pseudomonas aeruginosa in China

OBJECTIVES

Drug resistance in Pseudomonas aeruginosa (PAE) is a serious health threat. Additionally, it is important to understand the associated socioeconomic burden.

METHODS

Clinical information and hospital cost data for patients with PAE bloodstream infections (BSIs) in a tertiary teaching hospital (2011-2016) were collected retrospectively to estimate the direct economic burden. Socioeconomic loss incurred by patients was calculated using the human capital approach combined with estimating disability-adjusted life years (DALYs). Differences in socioeconomic burden between BSIs caused by carbapenem-resistant (CR) and carbapenem-susceptible (CS) PAE were compared.

RESULTS

This study included data for 220 patients, of which were 29.5% (65/220) CR-PAE BSIs. The median direct economic burden of patients following CR-PAE BSI was significantly higher than following CS-PAE BSI ($5005.94 vs. $1462.86; P < 0.001). The median DALY loss was significantly higher in the CR-PAE group compared with CS-PAE group (0.024 vs. 0.008; P = 0.001). The median indirect socioeconomic loss of patients in the CR-PAE group tended to be significantly higher than in the CS-PAE group ($64.06 vs. $29.71; P = 0.011). The annual economic burden of CR-PAE is higher (up to >1.5 times) than the Chinese annual per capita GDP.

CONCLUSION

The economic burden of PAE BSIs is significant, irrespective of carbapenem resistance. The direct economic burden of CR-PAE BSI was at least three-fold that of CS-PAE BSI. The DALY loss caused by CR-PAE BSI is three-fold that caused by CS-PAE BSI. The indirect socioeconomic loss caused by CR-PAE BSI is more than twice that of CS-PAE BSI.

Evaluating the emergence of nonsusceptibility among Pseudomonas aeruginosa respiratory isolates from a phase-3 clinical trial for treatment of nosocomial pneumonia (ASPECT-NP)

OBJECTIVES

The emergence of nonsusceptibility to ceftolozane/tazobactam and meropenem was evaluated among Pseudomonas aeruginosa (P. aeruginosa) lower respiratory tract isolates obtained from participants in the ASPECT-NP clinical trial.

METHODS

ASPECT-NP was a phase-3, randomised, double-blind, multicentre trial that demonstrated noninferiority of 3 g ceftolozane/tazobactam q8h versus 1 g meropenem q8h for treatment of ventilated hospital-acquired/ventilator-associated bacterial pneumonia. Molecular resistance mechanisms among postbaseline nonsusceptible P. aeruginosa isolates and clinical outcomes associated with participants with emergence of nonsusceptibility were examined. Baseline susceptible and postbaseline nonsusceptible P. aeruginosa isolate pairs from the same participant underwent molecular typing.

RESULTS

Emergence of nonsusceptibility was not observed among the 59 participants with baseline susceptible P. aeruginosa isolates in the ceftolozane/tazobactam arm. Among 58 participants with baseline susceptible P. aeruginosa isolates in the meropenem arm, emergence of nonsusceptibility was observed in 13 (22.4%). Among participants who received ceftolozane/tazobactam and meropenem, 5.1% and 3.4% had a new infection with a nonsusceptible strain, respectively. None of the isolates with emergence of nonsusceptibility to meropenem developed co-resistance to ceftolozane/tazobactam. The molecular mechanisms associated with emergence of nonsusceptibility to meropenem were decreased expression or loss of OprD and overexpression of MexXY.

CONCLUSIONS

Among participants with emergence of nonsusceptibility to meropenem, clinical outcomes were similar to overall clinical outcomes in the ASPECT-NP meropenem arm. Ceftolozane/tazobactam was more stable to emergence of nonsusceptibility versus meropenem; emergence of nonsusceptibility was not observed in any participants with baseline susceptible P. aeruginosa who received ceftolozane/tazobactam in ASPECT-NP.

Burden of carbapenem non-susceptible infections in high-risk patients: systematic literature review and meta-analysis

Background

Owing to their resistance to an important class of antibiotics, the prevention and treatment of carbapenem-resistant (CR)/non-susceptible Gram-negative (GN) infections has become an important public health objective. We conducted a systematic review and meta-analysis of published literature to evaluate the burden of CR GN infections, focusing on high-risk patients such as transplant recipients, or patients with cancer, renal impairment, or sepsis.

Methods

MEDLINE®, Cochrane Central, and Embase® were searched between 2010 and March 2019. Abstracts and full-text articles were screened in duplicate. Random effects meta-analysis was conducted when reported outcomes were sufficiently similar.

Results

Twenty-six publications were eligible. Meta-analyses found increased mortality associated with CR infections among high-risk patients in both unadjusted analysis (8 studies; summary unadjusted odds ratio [OR]: 5.85; 95% confidence interval [CI]: 3.69, 9.26; I² = 19.8%) and adjusted analysis (5 studies; summary hazard ratio [HR]: 4.67; 95% CI: 2.18, 9.99; I² = 77.7%), compared to patients with carbapenem-susceptible (CS) infections or no infection. Increased mortality was also seen in subgroup analyses by length of follow-up (either short-term or long-term) or causative pathogen. A limited number of studies found that CR GN infections increased the risk for mechanical ventilation, adverse events such as graft failure or acute rejection in solid organ transplant recipients, increased renal failure or nephrotoxicity, and an increase in readmissions and costs, though the findings reported in the literature were not consistent.

Conclusion

This systematic literature review and meta-analysis indicates that CR GN infections in high-risk patients are associated with increased mortality, emphasizing the need for antimicrobial stewardship and infection control in hospitals which treat high-risk patients and for the development of effective antimicrobials with favorable efficacy and safety profiles for the treatment of CR GN infections.

A "Single-Use" Ceramic-Based Electrochemical Sensor Chip Using Molecularly Imprinted Carbon Paste Electrode

An inexpensive disposable electrochemical drug sensor for the detection of drugs (vancomycin, meropenem, theophylline, and phenobarbital) is described. Molecularly imprinted polymer (MIP) templated with the target drugs was immobilized on the surface of graphite particles using a simple radical polymerization method and packed into the working electrode of a three-electrode ceramic-based chip sensor. Differential pulse voltammetry (DPV) was used to determine the relationship between the response current and the concentration of the targeted drug while using one sensor chip for one single operation. The time required for each DPV measurement was less than 2 min. Concentrations corresponding to the therapeutic range of these drugs in plasma were taken into account while performing DPV. In all the cases, the single-used MIP sensor showed higher sensitivity and linearity than non-imprinted polymer. The selectivity test in drugs with a structure similar to that of the target drugs was performed, and it was found that MIP-based sensors were more selective than the untreated ones. Additionally, the test in whole blood showed that the presence of interfering species had an insignificant effect on the diagnostic responses of the sensor. These results demonstrate that the disposable MIP-sensor is promising for quick and straightforward therapeutic drug monitoring to prevent the toxic side effects and the insufficient therapeutic effect due to the overdose and underdose, respectively.

Phenotypic and genotypic characterization of clinical carbapenem-resistant Enterobacteriaceae isolates from Sokoto, northwest Nigeria

Emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) are two of the major problems currently threatening global public health. In Nigeria, interest in CPE is recent. In Sokoto, northwest Nigeria, there are no data on the prevalence and mechanism underlying carbapenem resistance. In this study, we aimed to investigate the presence of clinical carbapenems-resistant Enterobacteriaceae isolates in two leading hospitals in Sokoto, northwest Nigeria. A total of 292 non-duplicate Enterobacteriaceae isolated from clinical specimens processed in the diagnostic laboratories of two hospitals between January and June 2019 were collected. Of these, 129 (44.2 %) and 19 (6.5%) were resistant to third-generation cephalosporin and carbapenems, respectively. RT-PCR revealed that 10 (7.8%), 19 (14.7%) and 46 (35.7%) of the third-generation cephalosporin-resistant isolates harboured bla SHV, bla TEM and bla CTX-M genes, respectively. The modified Carba NP test result showed that only 7 (36.8 %) of the 19 carbapenem-resistant isolates were carbapenemase producing; among them, bla NDM-5 and bla OXA-181 genes were identified in five and two isolates, respectively. However, none of the carbapenemase genes investigated, including bla VIM, bla KPC and bla IMP, was detected in the remaining carbapenem-resistant isolates, suggesting a non-enzymatic mechanism. This study reports for the first time, the emergence of CPE in Sokoto state and the detection of NDM-producing Citrobacter freundii in Nigeria. The observed CPE in this study is a concern in a country where alternative antibiotics are rarely available.

Effect of Graphene Oxide and Silver Nanoparticles Hybrid Composite on P. aeruginosa Strains with Acquired Resistance Genes

BACKGROUND

In the last decades, nosocomial infections caused by drug-resistant Pseudomonas aeruginosa became a common problem in healthcare facilities. Antibiotics are becoming less effective as new resistant strains appear. Therefore, the development of novel enhanced activity antibacterial agents becomes very significant. A combination of nanomaterials with different physical and chemical properties enables us to generate novel multi-functional derivatives. In this study, graphene oxide and polyvinylpyrrolidone-stabilized silver nanoparticles hybrid nanocomposite (GO-Ag HN) were synthesized. The relation between antibiotic resistance and GO-Ag HN potential toxicity to clinical P. aeruginosa strains, their antibiotic resistance, and molecular mechanisms were assessed.

METHODS

Chemical state, particle size distribution, and morphology of synthesized GO-Ag NH were investigated using spectroscopy and microscopy techniques (UV-Vis, FTIR, XPS, TEM, SEM, AFM). Broad-spectrum antibiotic resistance of P. aeruginosa strains was determined using E-test. Antibiotic resistance genes were identified using polymerase chain reaction (PCR).

RESULTS

In this study, the toxicity of the GO-Ag NH to the isolated clinical P. aeruginosa strains has been investigated. A high antibiotic resistance level (92%) was found among P. aeruginosa strains. The most prevalent antibiotic resistance gene among tested strains was the AMPC beta-lactamase gene (65.6%). UV-vis, FTIR, and XPS studies confirmed the formation of the silver nanoparticles on the GO nanosheets. The functionalization process occurred through the interaction between Ag nanoparticles, GO, and polyvinylpyrrolidone used for nanoparticle stabilization. SEM analysis revealed that GO nanosheets undergo partial fragmentation during hybrid nanocomposite preparation, which remarkably increases the number of sharp edges and their mediated cutting effect. TEM analysis showed that GO-Ag HN spherical Ag nanoparticles mainly 9-12 nm in size were irregularly precipitated on the GO nanosheet surface. A higher density of Ag NPs was observed in the sheets' wrinkles, corrugations, and sharp edges. This hybrid nanocomposite poses enhanced antibacterial activity against carbapenem-resistant P. aeruginosa strains through a possible synergy between toxicity mechanisms of GO nanosheets and Ag nanoparticles. With incubation time increasing up to 10 minutes, the survival of P. aeruginosa decreased significantly.

CONCLUSION

A graphene oxide and silver nanoparticles hybrid composite has been shown to be a promising material to control nosocomial infections caused by bacteria strains resistant to most antibiotics.

Evaluation of Renal Safety Between Imipenem/Relebactam and Colistin Plus Imipenem in Patients With Imipenem-Nonsusceptible Bacterial Infections in the Randomized, Phase 3 RESTORE-IMI 1 Study

Background

In the randomized controlled RESTORE-IMI 1 clinical trial (NCT02452047), imipenem/cilastatin (IMI) with relebactam (IMI/REL) was as effective as colistin plus IMI for the treatment of imipenem-nonsusceptible gram-negative infections. Differences in nephrotoxicity were observed between treatment arms. As there is no standard definition of nephrotoxicity used in clinical trials, we conducted analyses to further understand the renal safety profile of both treatments.

Methods

Nephrotoxicity was retrospectively evaluated using 2 acute kidney injury assessment criteria (Kidney Disease Improving Global Outcomes [KDIGO] and Risk, Injury, Failure, Loss, and End-stage Kidney Disease [RIFLE]). Additional outcomes included time to onset of protocol-defined nephrotoxicity and incidence of renal adverse events.

Results

Of 47 participants receiving treatment, 45 had sufficient data to assess nephrotoxicity (IMI/REL, n = 29; colistin plus IMI, n = 16). By KDIGO criteria, no participants in the IMI/REL but 31.3% in the colistin plus IMI group experienced stage 3 acute kidney injury. No IMI/REL-treated participants experienced renal failure by RIFLE criteria, vs 25.0% for colistin plus IMI. Overall, the time to onset of nephrotoxicity varied considerably (2–22 days). Fewer renal adverse events (12.9% vs 37.5%), including discontinuations due to drug-related renal adverse events (0% vs 12.5%), were observed in the IMI/REL group compared with the colistin plus IMI group, respectively.

Conclusions

Our analyses confirm the findings of a preplanned end point and provide further evidence that IMI/REL had a more favorable renal safety profile than colistin-based therapy in patients with serious, imipenem-nonsusceptible gram-negative bacterial infections.

ClinicalTrials.gov Identifier

NCT02452047.

In-hospital Medical Costs of Infections Caused by Carbapenem-resistant Klebsiella pneumoniae

Background

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a major health threat, but the economic impact of carbapenem resistance in K. pneumoniae infections remains largely uninvestigated.

Methods

We constructed a retrospective cohort of all patients hospitalized at West China Hospital in 2017 who had CRKP- or carbapenem-susceptible K. pneumoniae (CSKP)-positive clinical samples. Propensity score matching (PSM) was used to control the impact of potential confounding variables, including demographics, comorbidities, and treatment, and to observe the impact of factors other than length of stay (LOS). Patients who survived were subjected to subgroup analyses stratified by infection type.

Results

There were 267 patients with CRKP and 1328 with CSKP. Patients with CRKP had a higher crude in-hospital mortality rate (14.61% vs 5.65%, P < .05) and longer LOS (median, 31 vs 19 days; P < .05). PSM for demographics, comorbidities, and treatment generated 237 pairs. Patients with CRKP had higher medical costs than those with CSKP during the entire hospitalization (median, in US dollars, $22962 vs $11755, respectively; P < .05) and during the period after infection (median, $9215 vs $6904, respectively; P < .05). When LOS was matched, patients with CRKP still had high excess costs compared to those with CSKP (median, $22917 vs $13851, respectively, for the entire hospitalization, P < .05; $9101 vs $7001, respectively, after infection, P < .05). For infection type, the sample size generated sufficient power to compare only the patients with pneumonia. For surviving patients, high excess costs were observed in those with pneumonia caused by CRKP as compared to CSKP ($21890 vs $11698, respectively, for the entire hospitalization, P < .05; $9773 vs $5298, respectively, after infection, P < .05). Medicines other than antibacterial agents and nonmedicinal therapies contributed most (57.8%) of the excess costs associated with CRKP.

Conclusions

Carbapenem resistance in K. pneumoniae was associated with increased medical costs not accounted for by the cost of antimicrobial therapy.

Influence of Preoperative Oropharyngeal Microflora on the Occurrence of Postoperative Pneumonia and Survival in Patients Undergoing Esophagectomy for Esophageal Cancer

OBJECTIVE

The aim of this study was to clarify the correlation between oropharyngeal microflora and postoperative complications as well as long-term survival after esophagectomy.

BACKGROUND

Although the oral cavity is known to be a potential reservoir for pathogens, the influence of abnormal oropharyngeal microflora on the outcomes of patients undergoing esophagectomy remains unknown.

METHODS

This study included 675 patients who underwent esophagectomy between 2007 and 2014. Saliva samples from the oropharynx were collected 2 days before the operation. There were 442 patients with indigenous flora (Ind group) and 233 with allopatric flora. Among the patients with allopatric flora, 140 had antibiotic-sensitive microbes only (Allo-S group) while 93 had different types of antibiotic-resistant microbes (Allo-R group). We investigated the correlation between the types of oropharyngeal microflora and the incidence of postoperative complications as well as long-term outcomes.

RESULTS

Sixteen microbes could be cultivated from the saliva samples. The incidence of postoperative pneumonia in the Allo-S and Allo-R groups was significantly higher than in the Ind group (P < 0.001). In addition, acute respiratory distress syndrome was more often observed in the Allo-R group than in the other groups (P = 0.002). A significantly higher rate of antibiotic use and longer hospital stays were observed in the Allo-R group compared with the Ind group. Multivariate logistic regression analysis revealed that the presence of allopatric antibiotic-resistant microbes in the oropharynx was an independent risk factor for postoperative pneumonia (odds ratio, 3.93; 95% confidence interval, 2.41-6.42). The overall survival was significantly poorer in the Allo-R group than in the other groups.

CONCLUSIONS

Preoperative oropharyngeal culture is a simple and low-cost method that can predict both the occurrence of postoperative pneumonia and poor prognosis after esophagectomy.

A multi-center nested case-control study on hospitalization costs and length of stay due to healthcare-associated infection

Background

In 2018, the Chinese government demanded nationwide implementation of medical insurance payment methods based on Single-Disease Payment (SDP), but during the operation process the medical insurance system did not fully consider the extra economic burden caused by healthcare-associated infection (HAI). HAIs can prolong the length of stay and increase the hospitalization costs, but only a few studies have been conducted in Sichuan province, China. We evaluated the hospitalization costs and length of stay due to HAI in Sichuan province based on the prevalence survey, and provided data reference for China’s medical insurance reform.

Methods

In the hospitals surveyed on the prevalence of HAI, a multi-center nested case-control study was performed by a paired method. The study period was from 6 September 2016 to 30 November 2016. Binary outcomes were tested using χ2 test, continuous outcomes were tested using Wilcoxon matched-pairs signed rank test, intra-group comparisons were tested using multiple linear regression analysis.

Results

A total of 225 pairs/450 patients were selected in 51 hospitals, and 170 pairs/350 patients were successfully matched. The case fatality rate was 5.14% for the HAIs patients and 3.43% for non-HAs patients, there was no significant difference (χ² = 0.627, P = 0.429); the median length of stay in patients with HAIs was 21 days, longer than that of patients with non-HAI 16 days, the median of the difference between matched-pairs was 5 days, the difference was statistically significant (Z = 4.896, P = 0.000). The median hospitalization costs of patients with HAI were €1732.83, higher than that of patients with non-HAI €1095.29, the median of the difference between matched-pairs were €431.34, the difference was statistically significant (Z = 6.413, P = 0.000). Multiple linear regression results showed that HAIs at different sites have caused different economic burdens, but in different economic regions, the difference was not statistically significant.

Conclusions

In Sichuan, the hospitalization costs and length of stay caused by HAI should be given special attention in the current medical insurance reform. The proportion and scope of medical payment for patients with HAI at different sites should be different. Efforts need to be taken to incentivize reduction of HAI rates which will reduce hospitalization costs and length of stay.

Impact of active surveillance and infection control measures on carbapenem-resistant Gram-negative bacterial colonization and infections in intensive care

BACKGROUND

Carbapenem-resistant Gram-negative bacteria (CRGNB) infections constitute a global threat for critically ill patients and the outcome of their hospitalization. Early identification of CRGNB through rectal surveillance cultures and routine infection control measures including contact precautions, use of appropriate disinfectants, staff education on cleaning, and hand hygiene may reduce the dissemination of CRGNB.

AIM

To assess the impact of enhanced infection control measures on CRGNB infections in a nine-bed polyvalent intensive care unit in a tertiary level hospital in an endemic area.

METHODS

A quasi-experimental study, which included patients with CRGNB infection retrospectively for six months and those participating in an active surveillance programme prospectively for the subsequent 22 months. Active surveillance programme (weekly rectal swabs) was implemented including two sub-periods with infection control measures and enhanced infection control measures. CRGNB incidence, prevalence, colonization pressure, infections and compliance with infection control measures and enhanced infection control measures were recorded. Analysis was performed through time-series and interrupted time-series.

FINDINGS

During the active surveillance programme, enhanced infection control measures led to a steeper downwards trend in incidence, prevalence, and colonization pressure for CRGNB compared to the infection control measures sub-period. The linear trend was for carbapenem-resistant Klebsiella pneumoniae (CRKP) and Pseudomonas aeruginosa (CRPA) infections to decrease from 19.6 to 8.1 infections per 1000 bed-days (IBD) (P = 0.001) and from 5.1 to 1.79 IBD (P = 0.043), respectively. By contrast, carbapenem-resistant Acinetobacter baumannii infections increased from 5.2 to 15.3 IBD (P = 0.001).

CONCLUSION

Enhanced infection control measures including enhanced hand hygiene, active surveillance combined with contact precautions, education, audits and feedback policies and interventions could reduce CRKP and CRPA in endemic areas.

Effect of multiple drug resistance on total medical costs among patients with intra-abdominal infections in China

Background

Multiple drug resistant (MDR) intra-abdominal infections (IAIs) are associated with notable direct and societal costs. As previous studies have not considered the impact of MDR on the total medical costs (TMCs) of IAIs, the present one examines this, as well as further estimates the additional costs at a national level.

Methods

This is a retrospective study. Firstly, we randomly selected a sample of 40% of all inpatients discharged between 2014 and 2015 from a teaching hospital, due to limits in budget and the large number of patients. Then, we manually selected 254 patients with IAIs according to the International Classification of Disease, 10^th revision, using electronic medical records. Eventually, 101 patients with IAIs (64 MDR patients and 37 non-MDR patients) were included after excluding cases without laboratory test results, any pathogens detected, or antimicrobial resistant pathogens. Univariate analysis and a generalized linear model were applied to assess the parameters associated with TMCs.

Results

Compared to non-MDR patients, those with MDR pathogens were significantly associated with higher TMCs, higher antimicrobial costs, higher antimicrobial usage, larger number of pathogens, and longer length of stay and were more likely to have insurance and combination antimicrobial therapy. In addition, the average TMC among patients with MDR pathogens was ¥ 131801, which is ¥ 90201 higher than those without MDR pathogens. If our results are applied to the whole country, the sum of all attributable TMCs was ¥ 37 billion. The societal costs, furthermore, were ¥111 billion in 2015.

Conclusion

Our results provide information that should lead to increased efforts to reduce inappropriate antimicrobial therapy, in order to decrease the emergence of MDR pathogens and to reduce their economic burden.

High excess costs of infections caused by carbapenem-resistant Gram-negative bacilli in an endemic region

The financial burden of antibiotic resistance is a serious concern worldwide. The aim of this study was to describe the excess costs associated with pneumonia, bacteraemia, surgical site infections and intra-abdominal infections (IAIs) caused by carbapenem-resistant Gram-negative bacilli in Medellín, Colombia, an endemic region for carbapenem resistance. A cohort study was conducted in a third-level hospital from 2014-2015. All patients with carbapenem-resistant and carbapenem-susceptible Gram-negative bacterial infections were included. Pharmaceutical, medical and surgical direct costs were described from the health system perspective. Excess costs were estimated from generalised linear models with gamma distribution and adjusted for variables that could affect the cost difference. A total of 218 patients were enrolled, 48 (22.0%) of whom were infected with carbapenem-resistant bacteria. IAIs were the most frequent. The adjusted total excess cost was US$3966 [95% confidence interval (CI) US$1684-6249], with a significantly higher cost for antibiotics, followed by hospital stay, laboratory tests and interconsultation. The highest excess cost was attributed mainly to the use of broad-spectrum antibiotics (US$1827, 95% CI US$1005-2648), followed by length of hospital stay (US$1015, 95% CI US$163-1867). The results of this study highlight the importance of designing antimicrobial stewardship programmes and infection control strategies in endemic regions to reduce the financial threat of antimicrobial resistance to health systems.

The difference in medical costs between carbapenem-resistant Acinetobacter baumannii and non-resistant groups: a case study from a hospital in Zhejiang province, China

This retrospective study aims to compare differences in the medical costs between inpatients infected/colonised with carbapenem-resistant (CRAB) and carbapenem-susceptible (CSAB) Acinetobacter baumannii in a hospital in Zhejiang province, China. Because the patient population was large, we randomly selected 60% of all inpatients with clinical specimens between 2013 and 2015. We classified the A. baumannii cases as CRAB or CSAB based on antibiotic susceptibility testing. Univariate and multivariate analyses were used to identify factors associated with the total medical cost (TMC). Those included in the study totalled 2980 inpatients, 71.3% of whom had CRAB infection/colonisation. Differences in the TMC between the CRAB and CSAB groups were lower by multivariate analyses than the differences obtained by univariate analyses. Carbapenem resistance was significantly associated with an approximately 1.5-fold increase in the TMC after accounting for confounding factors. Our study highlights the heavy financial burden imposed by A. baumannii and carbapenem resistance on the Chinese healthcare system.