Fluoroquinolone consumption and Escherichia coli resistance in Japan: an ecological study

Relationship between Antibiotic Consumption and Resistance: A Systematic Review

Background

Unreserved use of antibiotics exerted selective pressure on susceptible bacteria, resulting in the survival of resistant strains. Despite this, the relationship between antibiotic resistance (ABR) and antibiotic consumption (ABC) is rarely studied. This systematic review aims to review the relationship between ABC and ABR from 2016 to 2022.

Methods

Articles published over 7 years (2016-2022) were searched from December 23 to 31, 2022. The search strategy was developed by using keywords for ABC and ABR. From 3367 articles, 58 eligible articles were included in the final review.

Results

The pooled ABC was 948017.9 DPDs and 4108.6 DIDs where over 70% of antibiotics were from the Watch and Reserve category based on the WHO AWaRe classification. The average pooled prevalence of ABR was 38.4%. Enterococcus faecium (59.4%), A. baumannii (52.6%), and P. aeruginosa (48.6%) were the most common antibiotic-resistant bacteria. Cephalosporins (76.8%), penicillin (58.3%), and aminoglycosides (52%) were commonly involved antibiotics in ABR. The positive correlation between ABR and consumption accounted for 311 (81%). The correlation between ABR P. aeruginosa and ABC accounted for 87 (22.7%), followed by 78 (20.3%) and 77 (20.1%) for ABR E. coli and K. pneumoniae with ABCs, respectively. Consumption of carbapenems and fluoroquinolones was most commonly correlated with resistance rates of P. aeruginosa, K. pneumoniae, E. coli, and A. baumannii.

Conclusion

There is a positive correlation between ABC and the rate of ABR. The review also revealed a cross-resistance between the consumption of different antibiotics and ABR. Optimizing antibiotic therapy and reducing unnecessary ABC will prevent the emergence and spread of ABR. Thus, advocating the implementation of stewardship programs plays a pivotal role in containing ABR.

Spatial clusters of extended-spectrum beta-lactamase-producing Escherichia coli causing community-onset bacteriuria due to repeat infections: cluster analysis from a large urban medical center, San Francisco, 2014-2020

BACKGROUND

Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak.

METHODS

We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 h after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression.

RESULTS

Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001).

CONCLUSION

We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli. These findings may help better tailor clinical treatment of patients with recurrent urinary tract infections after an initial episode caused by ESBL-E. coli.

Spatial clusters of extended-spectrum beta-lactamase-producing Escherichia coli causing community-onset bacteriuria due to repeat infections: cluster analysis from a large urban medical center, San Francisco, 2014-2020

Background

Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak.

Methods

We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 hours after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression.

Results

Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001).

Conclusion

We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli.

Modelling Impact of High-Rise, High-Density Built Environment on COVID-19 Risks: Empirical Results from a Case Study of Two Chinese Cities

Characteristics of the urban environment (e.g., building density and road network) can influence the spread and transmission of coronavirus disease 2019 (COVID-19) within cities, especially in high-density high-rise built environments. Therefore, it is necessary to identify the key attributes of high-density high-rise built environments to enhance modelling of the spread of COVID-19. To this end, case studies for testing attributes for modelling development were performed in two densely populated Chinese cities with high-rise, high-density built environments (Hong Kong and Shanghai).The investigated urban environmental features included 2D and 3D urban morphological indices (e.g., sky view factor, floor area ratio, frontal area density, height to width ratio, and building coverage ratio), socioeconomic and demographic attributes (e.g., population), and public service points-of-interest (e.g., bus stations and clinics). The modelling effects of 3D urban morphological features on the infection rate are notable in urban communities. As the spatial scale becomes larger, the modelling effect of 2D built environment factors (e.g., building coverage ratio) on the infection rate becomes more notable. The influence of several key factors (e.g., the building coverage ratio and population density) at different scales can be considered when modelling the infection risk in urban communities. The findings of this study clarify how attributes of built environments can be applied to predict the spread of infectious diseases. This knowledge can be used to develop effective planning strategies to prevent and control epidemics and ensure healthy cities.

Appropriate Antibiotic Selection during the in-hospital Waiting Period for Surgery for Appendicitis

Objectives

Acute appendicitis is a common disease that often requires emergency surgery. However, recently, not all cases are treated as an urgent operation, but surgery may be delayed to when medical resources are abundant to perform the operation safely. In such cases, preoperative antibiotics are administered during the waiting period. Though the choice is empiric, an appropriate choice is needed to avoid emergency surgery. Guidelines for the choice of antibiotics recognized as international standards cannot be applied in Asia due to the high rate of extended-spectrum β-lactamase (ESBL) producers or fluoroquinolone-resistant Escherichia coli. The purpose of this study was to determine the optimal antibiotic during the in-hospital waiting period for patients with appendicitis scheduled for surgery.

Methods

Bacterial culture results and antibiotic susceptibility were retrospectively examined in 106 cases who underwent surgery for appendicitis.

Results

Bacterial cultures were positive in 53 cases (50%). Twenty-six strains of E. coli were identified. Of these, four (15%) were ESBL producers, and seven (27%) were fluoroquinolone resistant. Twenty-two strains of anaerobic bacteria were identified. Carbapenems and tazobactam/piperacillin were effective for all. The rates of susceptibility to clindamycin (CLDM) and cefmetazole (CMZ) were 59% and 82%, respectively.

Conclusions

In Japan, from the point of view of reducing carbapenem use, CMZ must be considered a first-choice drug during the in-hospital waiting period for appendectomy.

Dynamic changes in antibiotic resistance genes and gut microbiota after Helicobacter pylori eradication therapies

BACKGROUND

Short-term antibiotics exposure is associated with alterations in microbiota and antibiotic resistance genes (ARGs) in the human gut. While antibiotics are critical in the successful eradication of Helicobacter pylori, the short-term and long-term impacts on the composition and quantity of antibiotics resistance genes after H. pylori eradication are unclear. This study used whole-genome shotgun metagenomic of stool samples to characterize the gut microbiota and ARGs, before and after H. pylori eradication therapy.

RESULTS

Forty-four H. pylori-infected patients were recruited, including 21 treatment naïve patients who received clarithromycin-based triple therapy (CLA group) and 23 patients who failed previous therapies, in which 10 received levofloxacin-based quadruple therapy (LEVO group) and 13 received other combinations (OTHER group). Stool samples were collected at baseline (before current treatment), 6 week and 6 month after eradication therapy. At baseline, there was only a slight difference among the three groups on ARGs and gut microbiota. After eradication therapy, there was a transient but significant increase in gut ARGs 6 week post-therapy, among which the LEVO group had the most significant ARGs alteration compared to other two groups. For treatment naïve patients, those with higher ErmF abundance were prone to fail CLA eradication and gain more ARGs after treatment. For gut microbiota, the bacteria richness decreased at 6 week and there was a significant difference in microbiota community among the three groups at 6 week.

CONCLUSIONS

Our findings demonstrated the dynamic alterations in gut microbiota and ARGs induced by different eradication therapies, which could influence the choices of antibiotics in eradication therapy.

Influence of Change of Full-Time Equivalents on Post-prescription Review with Feedback Interventions in an Antimicrobial Stewardship

Few studies have investigated the influence of more full-time equivalents (FTEs) of infectious disease (ID) pharmacists on the likelihood of a post-prescription review with feedback (PPRF) intervention. This study focused on this in community hospitals before and after the Japanese medical reimbursement system was revised to introduce antimicrobial stewardship (AS) fees. We collected data for two periods: before (April 2017 to March 2018) and after (April 2018 to March 2019) AS fee implementation. The efficacy of the PPRF by the ID pharmacist was assessed based on the usage of broad-spectrum antimicrobials in days of therapy (DOT) per 100 patient-days. Further, we generated the susceptibility rate for antimicrobial-resistant organisms. The number of PPRF drugs was 2336 (2596 cases) before AS fee implementation and 2136 (1912 cases) after implementation. The overall monthly FTE for AS for an ID pharmacist increased from [median (interquartile range; IQR)] 0.34 (0.33-0.36) to 0.63 (0.61-0.63) after AS fee implementation. The DOT of the broad-spectrum antibiotics decreased from 10.46 (9.61-12.48) to 8.68 (8.14-9.18). The DOT of carbapenems and quinolones decreased significantly from 4.11 (3.69-4.41) to 3.07 (2.79-3.22) and 0.96 (0.61-1.14) to 0.37 (0.19-0.46), respectively (p < 0.05). Furthermore, the rate of levofloxacin (LVFX)-susceptible Pseudomonas (P.) aeruginosa improved from 71.5 to 84.8% (p < 0.01). We observed that increasing the FTE of ID pharmacists influences the DOTs of broad-spectrum antibiotics; a higher FTE contributes to fewer DOTs. Further, the susceptibility of P. aeruginosa to meropenem and LVFX increased as the FTE increased.

Effect on Antimicrobial Resistance of a Policy Restricting Over-the-Counter Antimicrobial Sales in a Large Metropolitan Area, São Paulo, Brazil

Although restricting over-the-counter (OTC) antimicrobial drug sales is recommended globally, no data track its effect on antimicrobial resistance (AMR) in bacteria. We evaluated the effect of a national policy restricting OTC antimicrobial sales, put in place in November 2010, on AMR in a metropolitan region of São Paulo, Brazil. We reviewed associations between antimicrobial sales from private pharmacies and AMR in 404,558 Escherichia coli and 5,797 Streptococcus pneumoniae isolates using a dynamic regression model based on a Bayesian approach. After policy implementation, a substantial drop in AMR in both bacterial species followed decreased amoxicillin and trimethoprim/sulfamethoxazole sales. Conversely, increased ciprofloxacin sales were associated with increased ciprofloxacin resistance, and extended spectrum β-lactamases-positive E. coli isolates and azithromycin sales increases after 2013 were associated with increased erythromycin resistance in S. pneumoniae isolates. These findings suggest that restricting OTC antimicrobial sales may influence patterns of AMR, but multifaceted approaches are needed to avoid unintended consequences.

Estimating the Economic and Clinical Value of Reducing Antimicrobial Resistance to Three Gram-negative Pathogens in Japan

Background: Antimicrobial resistance (AMR) represents a significant global public health crisis. Despite ample availability of Gram-positive antibiotics, there is a distinct lack of agents against Gram-negative pathogens, including carbapenem-resistant Enterobacterales, which remains a real threat in Japan. The AMR Action Plans aim to mitigate the growing public health concern posed by AMR. Objective: This study aims to estimate the clinical and economic outcomes of drug-resistant Gram-negative pathogens forecasts for Japan to guide resource allocation defined within the upcoming National AMR Action Plan. Methods: A previously published and validated dynamic health economic model was adapted to the Japanese setting. The model used a 10-year time horizon with a willingness-to-pay threshold of ¥5 000 000 (US $46 827) and discounting was applied at a rate of 2% to costs and benefits. Clinical and economic outcomes were assessed as a function of varying AMR levels of three Gram-negative pathogens in Japan by up to 100% of the current level. Results: Reducing drug-resistant Gram-negative pathogens in Japan has the potential to save 4 249 096 life years, corresponding to 3 602 311 quality-adjusted life years. The associated maximum clinical and economic gains were estimated at up to 4 422 284 bed days saved, up to 3 645 480 defined daily doses of antibiotics avoided, up to ¥117.6 billion (US $1.1 billion) saved in hospitalization costs, and a net monetary benefit of up to ¥18.1 trillion (US $169.8 billion). Discussion: Learnings from this study can be used by the Japanese government to help inform decision-making on the strategies that may be included in the upcoming National AMR Action Plan and facilitate allocation of the required budget. Conclusions: This analysis demonstrated the considerable economic and clinical value of reducing AMR levels of three Gram-negative pathogens in Japan and could be utilized to support the valuation of antimicrobial treatment and resistance in Japan and more broadly.

Spatial, Ecologic, and Clinical Epidemiology of Community-Onset, Ceftriaxone-Resistant Enterobacteriaceae, Cook County, Illinois, USA

We performed a spatial and mixed ecologic study of community-onset Enterobacteriaceae isolates collected from a public healthcare system in Cook County, Illinois, USA. Individual-level data were collected from the electronic medical record and census tract–level data from the US Census Bureau. Associations between individual- and population-level characteristics and presence of ceftriaxone resistance were determined by logistic regression analysis. Spatial analysis confirmed nonrandom distribution of ceftriaxone resistance across census tracts, which was associated with higher percentages of Hispanic, foreign-born, and uninsured residents. Individual-level analysis showed that ceftriaxone resistance was associated with male sex, an age range of 35–85 years, race or ethnicity other than non-Hispanic Black, inpatient encounter, and percentage of foreign-born residents in the census tract of isolate provenance. Our findings suggest that the likelihood of community-onset ceftriaxone resistance in Enterobacteriaceae is influenced by geographic and population-level variables. The development of effective mitigation strategies might depend on better accounting for these factors.

Recovery of antimicrobial susceptibility in methicillin-resistant Staphylococcus aureus (MRSA): a retrospective, epidemiological analysis in a secondary care hospital, Sapporo, Japan

Anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs are critical final options for treating MRSA infection. This study investigated the percentage of all S. aureus isolates that are resistant to methicillin and also MRSA susceptibility to other antimicrobial agents in the JR Sapporo Hospital inpatient service. The inpatient service MRSA percentages for Japan, Hokkaido, and JR Sapporo Hospital from 2010-2019 were compared, exploring the annual rate of change in the MRSA percentage. We also investigated the antimicrobial use density (AUD) and its relationship with MRSA antimicrobial susceptibility in the JR Sapporo Hospital during 2019. The MRSA percentage in JR Sapporo Hospital was 61.5% (95% CI [52.6-69.7]) in 2010 but was only 51.6% (95% CI [41.6-61.5]) in 2019, which is a 1.43% (95% CI [0.42-2.43]) annual decrease (p = 0.05). Regarding the MRSA antimicrobial susceptibility rate in JR Sapporo Hospital, the highest rates of annual increase were seen for minocycline (3.11% (95% CI [2.25-3.94])) followed by fosfomycin (2.85% (95% CI [1.83-3.85])). Positive correlations with the AUD of anti-MRSA drugs were identified for susceptibility to erythromycin (p < 0.01), clindamycin (p = 0.002), and levofloxacin (p = 0.0005). A recovery of MRSA antimicrobial susceptibility was observed in our antibiogram dataset. Our study supports the potential for appropriate antimicrobial agent use in reviving MRSA antimicrobial susceptibility.

Clinical Impact of the Revised 2019 CLSI Levofloxacin Breakpoints in Patients with Enterobacterales Bacteremia

The Clinical and Laboratory Standards Institute (CLSI) revised the fluoroquinolone MIC breakpoints for Enterobacterales in 2019, based on pharmacokinetic/pharmacodynamic analyses. However, clinical evidence supporting these breakpoint revisions is limited. A retrospective study was conducted at 3 hospitals in Taiwan between January 2017 and March 2019. Patients treated with levofloxacin for bacteremia caused by members of the Enterobacterales with high MICs (1 or 2 μg/ml; levofloxacin susceptible by pre-2019 CLSI breakpoints) were compared with those with low-MIC bacteremia (≤0.5 μg/ml; levofloxacin susceptible by 2019 CLSI breakpoints) to assess therapeutic effectiveness by multivariable logistic regression. The primary outcome was 30-day mortality, and the secondary outcome was the emergence of levofloxacin-resistant isolates within 90 days after levofloxacin initiation. A total of 308 patients were eligible for the study. Kaplan-Meier analysis showed that patients infected with high-MIC isolates (n = 63) had a significantly lower survival rate than those infected with low-MIC isolates (n = 245) (P = 0.001). Multivariable logistic regression revealed that high levofloxacin MIC was a predictor of 30-day mortality (odds ratio [OR], 6.05; 95% confidence interval [CI], 1.51 to 24.18; P = 0.011). We consistently found similar results in a propensity score-matched cohort (OR, 5.38; 95% CI, 1.06 to 27.39; P = 0.043). The emergence of levofloxacin-resistant isolates was more common in the high-MIC group than the low-MIC group (25.0% versus 7.5%; P = 0.065). An estimated area under the concentration-time curve/MIC ratio of ≥87 was significantly associated with better survival (P = 0.002). In conclusion, patients infected with isolates with levofloxacin MICs within the pre-2019 CLSI susceptible range of 1 or 2 μg/ml exhibited higher mortality than those infected with isolates with MICs of ≤0.5 μg/ml.

Antibiotic susceptibility guided reuse of levofloxacin-based therapy in a penicillin-allergic patient for Helicobacter pylori infection: A case report

RATIONALE

Antibiotic resistance poses a challenge for Helicobacter pylori eradication treatment. Current guidelines strongly recommend avoiding repeated treatments with the same antibiotic to prevent the emergence of drug resistance. However, for penicillin-allergic patients with recurrent H. pylori eradication failures, avoiding repeated treatments with the same antibiotic severely limits the choice of treatment.

PATIENT CONCERNS

A 47-year-old woman with a penicillin allergy for whom 2 previous levofloxacin and bismuth-based therapies had failed.

DIAGNOSIS

H. pylori infection.

INTERVENTIONS

Agar dilution susceptibility testing and gene sequence analysis was performed to confirm levofloxacin susceptibility again. Therefore, we treated her with a 14-day regimen consisting of levofloxacin (500 mg once daily), furazolidone (100 mg twice daily), colloidal bismuth pectin (220 mg twice daily), and esomeprazole (20 mg twice daily).

OUTCOMES

The patient was successfully treated with a third levofloxacin and bismuth-based regimen.

LESSONS

Antibiotics included in previous failed therapies need not be eliminated if no antibiotic resistance is found on antimicrobial susceptibility testing.

Impact of Geographical Variations on the Prevalence of Multidrug-Resistant Organisms in Japan

Emergence and spread of multidrug-resistant organisms (MDRO) is an urgent social and public health problem. Here, we carried out an epidemiological survey to clarify the geographical characteristics and factors influencing the prevalence of MDRO. Data on the prevalence of MDRO in 47 prefectures in Japan were extracted from the Japanese Nosocomial Infection Surveillance, a nationwide database for infection control. Potential factors for MDRO were analyzed using data selected from the pharmacological, medical service, infection control, environmental, social, and food-related categories, based on the characteristics of each organism and the correlations between them and MDRO prevalence. Statistical data for potential factors were obtained from public domains. The use of antibiotics was found to be correlated with the prevalence of penicillin-resistant Streptococcus pneumoniae, 3rd-generation cephalosporin- and fluoroquinolone-resistant Escherichia coli, and methicillin-resistant Staphylococcus aureus. Negative correlation between the consumption of food such as kelp and fermented soybeans that facilitate the growth of lactic acid bacteria and the prevalence of 3rd-generation cephalosporin- and fluoroquinolone-resistant E. coli suggested an association between the intestinal microflora and MDRO colonization. In addition to the use of antibiotics, lifestyle, food culture, and social factors such as tobacco smoking, average atmospheric temperature, prevalence of three-generation households, ratio of elderly population, average duration of tourist stay, chicken and fermented soybean consumption, and the competency of healthcare services may also affect MDRO prevalence.

Escherichia coli Resistance to Fluoroquinolones in Community-Acquired Uncomplicated Urinary Tract Infection in Women: a Systematic Review

Antibiotic resistance is a threat to public health, and uncomplicated urinary tract infections (uUTIs) are an example of this concern. This systematic review (International Prospective Register of Systematic Reviews [PROSPERO] ID: CRD42020156674) is the first to determine the prevalence of Escherichia coli resistance to fluoroquinolones in women with community-acquired uUTI. PubMed and Embase searches were conducted; 38 studies fulfilled eligibility criteria and were included in the systematic review. Within Europe, ciprofloxacin resistance in E. coli isolates varied between countries and increased in some from 2006 to 2008 and 2014 to 2016, specifically in the United Kingdom (0.5% to 15.3%), Germany (8.7% to 15.1%), and Spain (22.9% to 30.8%), although methodologies and settings were often not comparable. In Asia, there was a substantial increase in ciprofloxacin resistance during 2008 to 2014 from 25% to more than 40%. In North America, resistance to ciprofloxacin also increased between 2008 and 2017, from 4% to 12%. Data exploring different age groups did not show a consistent relationship with resistance, whereas two studies found that fluoroquinolone resistance was higher in postmenopausal women than premenopausal women. One study indicated a link between fluoroquinolone resistance and uUTI recurrence. These findings may have implications for the empirical treatment of uUTI with fluoroquinolones globally, but more data are needed to fully understand regional situations and impact patient management.

Comparative Genome Analyses of Wild Type- and Quinolone Resistant Escherichia coli Indicate Dissemination of QREC in the Norwegian Broiler Breeding Pyramid

Quinolones are important antimicrobials for both humans and animals, and resistance toward these compounds is a serious threat to public health. In Norway, quinolone resistant E. coli (QREC) have been detected at low levels in a high proportion of broiler flocks, even without the use of quinolones in rearing of broilers. Due to the pyramidal structure of broiler breeding, QREC isolates may be disseminated from grandparent animals down through the pyramid. However, quinolone resistance can also develop in wild type E. coli through specific chromosomal mutations, and by horizontal acquisition of plasmid-mediated quinolone resistance genes. The goal of this study was to determine whether QREC is disseminated through the broiler breeding pyramid or developed locally at some stage in the broiler production chain. For this purpose, we whole genome sequenced wild type- and QREC isolates from broiler and parent flocks that had been isolated in the Norwegian monitoring program for antimicrobial resistance in feed, food and animals (NORM-VET) between 2006 and 2017, from 22 different production sites. The sequencing data was used for typing of the isolates, phylogenetic analysis and identification of relevant resistance mechanisms. Highly similar QREC isolates were identified within major sequence types from multiple production sites, suggesting dissemination of QREC isolates in the broiler production chain. The occurrence of potential resistance development among the WT E. coli was low, indicating that this may be a rare phenomenon in the Norwegian broiler production. The results indicate that the majority of the observed QREC at the bottom of the broiler production pyramid originates from parent or grandparent animals. These results highlight the importance of surveillance at all levels of the broiler production pyramid and of implementation of proper biosecurity measures to control dissemination of QREC.

Carbapenem-resistant Pseudomonas aeruginosa and carbapenem use in Japan: an ecological study

Objective

This study focused on carbapenem resistance in Pseudomonas aeruginosa and examined potential ecological correlations with carbapenem use in Japan.

Methods

The proportion of carbapenem-resistant P. aeruginosa isolates from 2015 and 2016 by prefecture was obtained from the Japan Nosocomial Infections Surveillance system. Data on carbapenem use was obtained from the National Database of Health Insurance Claims. The correlation between the proportion of carbapenem-resistant isolates and carbapenem consumption was assessed in a cross-sectional manner. The study also collected information on other variables including the numbers of physicians, nurses and medical facilities per 100 000 individuals by prefecture.

Results

Both the proportion of carbapenem-resistant P. aeruginosa isolates and levels of carbapenem use were higher in western Japan. Using a multivariate model, only carbapenem use remained significantly associated with the proportion of carbapenem-resistant isolates.

Conclusions

Carbapenem use and the proportion of carbapenem-resistant P. aeruginosa isolates were positively correlated. By longitudinal data collection, this approach offers an avenue to establish causal links as the frequency of carbapenem-resistant P. aeruginosa isolates starts to change in the future.

Spatial epidemiological determinants of severe fever with thrombocytopenia syndrome in Miyazaki, Japan: a GWLR modeling study

Background

Cases of severe fever with thrombocytopenia syndrome (SFTS) have increasingly been observed in Miyazaki, southwest Japan. It is critical to identify and elucidate the risk factors of infection at community level. In the present study, we aimed to identify areas with a high risk of SFTS virus infection using a geospatial dataset of SFTS cases in Miyazaki.

Methods

Using 10 × 10-km mesh data and a geographically weighted logistic regression (GWLR) model, we examined the statistical associations between environmental variables and spatial variation in the risk of SFTS. We collected geospatial and population census data as well as forest and agriculture mesh information. Altitude and farmland were selected as two specific variables for predicting the presence of SFTS cases in a given mesh area.

Results

Using GWLR, the area under the receiver operating characteristic curve (AUC) was estimated at 73.9%, outperforming the classical logistic regression model (72.4%). The sensitivity and specificity of the GWLR model were estimated at 90.9 and 58.7%, respectively. We identified altitude (odds ratio (OR) = 0.996, 95% confidence interval (CI): 0.994–0.999 per one-meter elevation) and farmland (OR = 0.999, 95% CI: 0.998–1.000 per % increase) as useful negative predictors of SFTS cases in Miyazaki.

Conclusions

Our study findings revealed that the risk of SFTS is high in geographic areas where farmland area begins to diminish and at mid-level altitudes. Our findings can help to improve the efficiency of ecological and animal surveillance in high-risk areas. Using finer geographic resolution, such surveillance can help raise awareness among local residents in areas with a high risk of SFTS.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4111-3) contains supplementary material, which is available to authorized users.