Seasonal variation in peritoneal dialysis-associated peritonitis: a multi-centre registry study

Clinical characteristics and antibiotic treatment of peritoneal dialysis-associated peritonitis caused by Pseudomonas species: a review of 15 years' experience from southern China

Pseudomonas can lead to peritoneal dialysis-associated peritonitis, which is characterized by a poor prognosis, such as a substantial failure rate and a high death rate. This study aimed to provide an overview of Pseudomonas peritonitis's clinical features, the regimens of antibiotic, antibiotic resistance, and outcomes in peritoneal dialysis (PD) patients. This study observed patients with Pseudomonas peritonitis in two large PD centers in South China from January 2008 to December 2022. The demographics, symptomatology, antibiotics regimens, resistance to common antibiotics, and clinical outcomes of all included patients were reviewed. A total of 3,459 PD patients were included, among them 57 cases of peritonitis caused by Pseudomonas, including 48 cases (84.2%) of Pseudomonas aeruginosa. The incidence rate of Pseudomonas peritonitis was 0.0041 episode per patient-year. Of them, 28.1% (16 cases) of the patients were accompanied by exit site infection (ESI), and all had abdominal pain and turbid ascites at the time of onset. The most commonly used antibiotic combination was ceftazidime combined with amikacin. Approximately 89% of Pseudomonas species were sensitive to ceftazidime, and 88% were sensitive to amikacin. The overall primary response rate was 28.1% (16 patients), and the complete cure rate was 40.4% (23 patients). There was no significant difference in the complete cure rate of peritonitis using three and other antibiotic treatment regimens (44.8% vs 46.4%; P = 0.9). The successful treatment group had higher baseline albumin level (35.9 ± 6.2; P = 0.008) and residual urine volume (650.7 ± 375.5; P = 0.04). Although the incidence of peritonitis caused by Pseudomonas was low, the symptoms were serious, and prognosis was very poor. Pseudomonas was still highly susceptible to first-line antibiotics currently in use against Gram-negative bacteria. Patients with successful treatment had higher albumin levels and higher urine output.

IMPORTANCE

Although the incidence of peritoneal dialysis-associated peritonitis caused by Pseudomonas is very low, it seriously affects the technique survival of peritoneal dialysis patients. However, there are few studies and reports on Pseudomonas peritonitis in the Chinese mainland area. Therefore, the purpose of this study is to describe the clinical characteristics, the regimens of antibiotic, drug resistance, and outcome of peritoneal dialysis patients in southern China in the past 15 years and summarize the clinical experience in the treatment of Pseudomonas peritonitis.

Peritoneal Dialysis-Related Infections

Peritoneal dialysis (PD) represents an important treatment choice for patients with kidney failure. It allows them to dialyze outside the hospital setting, facilitating enhanced opportunities to participate in life-related activities, flexibility in schedules, time and cost savings from reduced travel to dialysis centers, and improved quality of life. Despite its numerous advantages, PD utilization has been static or diminishing in parts of the world. PD-related infection, such as peritonitis, exit-site infection, or tunnel infection, is a major concern for patients, caregivers, and health professionals-which may result in hesitation to consider this as treatment or to cease therapy when these complications take place. In this review, the definition, epidemiology, risk factors, prevention, and treatment of PD-related infection on the basis of the contemporary evidence will be described.

A Retrospective Descriptive Study of Staphylococcus Species Isolated from Canine Specimens Submitted to a Diagnostic Laboratory in South Africa, 2012-2017

There is a scarcity of published studies on the occurrence of Staphylococcus spp. Among dogs in South Africa. The objective of the study was to characterise the Staphylococcus spp. Isolated from dog samples submitted to a veterinary diagnostic laboratory in South Africa in terms of time, place, and person. This study utilised a dataset of 1627 positive Staphylococcus isolates obtained from a veterinary diagnostic laboratory in South Africa from 2012 to 2017. Out of the 1627 confirmed isolates, 10 different species of Staphylococcus were identified. Among these, 92.0% were classified as coagulase-positive staphylococci (CoPS), 6.0% were coagulase-negative staphylococci (CoNS), and 3.0% were coagulase-variable. Male dogs contributed just over half (53.2%) of the Staphylococcus isolates, while female dogs contributed the remaining 46.8%. The largest proportion of isolates (23.2%) were obtained from dogs aged ≥ 9 years, with the highest number of isolates originating from KwaZulu-Natal Province (45.0%) and the least from Northern Cape Province (0.1%). Out of the total samples included in the records, the majority (46.0%) were skin specimens. The number of Staphylococcus isolates recorded showed limited variation between the seasons (24.3% in autumn, 26.3% in winter, 26.0% in spring, and 24.0% in summer). This study highlighted the diversity of Staphylococcus spp. isolated from dogs, and the burden of staphylococcal carriage among dogs in South Africa. Further research is required to examine the factors that contribute to the observed discrepancies in the proportions of Staphylococcus spp. between the provinces.

Seasonal variations of enteric peritonitis in Belgium and France : RDPLF data

Summary Little information is available on the seasonal ecology of germs responsible for peritoneal dialysis peritonitis. We performed a retrospective study based on RDPLF data covering the last 20 years and 20411 episodes of peritonitis. We show that the percentage of enteric peritonitis is highest in summer, lowest in winter and identical in spring and autumn. This higher proportion of organisms of enteric origin in summer has itself tended to increase in recent years. We postulate that a food contamination by enteric germs associated with an increased bacterial translocation at the level of the digestive tract itself favoured by constipation, as well as changes of the food nature could be responsible for this phenomenon. These seasonal variations may suggest that probabilistic initial antibiotic therapy should be adapted in cases of suspected peritonitis before the results of bacteriological analysis.  

Predictors and outcomes of peritoneal dialysis-related infections due to filamentous molds (MycoPDICS)

Introduction

We sought to evaluate the predictors and outcomes of mold peritonitis in patients with peritoneal dialysis (PD).

Methods

This cohort study included PD patients from the MycoPDICS database who had fungal peritonitis between July 2015-June 2020. Patient outcomes were analyzed by Kaplan Meier curves and the Log-rank test. Multivariable Cox proportional hazards model regression was used to estimating associations between fungal types and patients’ outcomes.

Results

The study included 304 fungal peritonitis episodes (yeasts n = 129, hyaline molds n = 122, non-hyaline molds n = 44, and mixed fungi n = 9) in 303 patients. Fungal infections were common during the wet season (p <0.001). Mold peritonitis was significantly more frequent in patients with higher hemoglobin levels, presentations with catheter problems, and positive galactomannan (a fungal cell wall component) tests. Patient survival rates were lowest for non-hyaline mold peritonitis. A higher hazard of death was significantly associated with leaving the catheter in-situ (adjusted hazard ratio [HR] = 6.15, 95%confidence interval [CI]: 2.86–13.23) or delaying catheter removal after the diagnosis of fungal peritonitis (HR = 1.56, 95%CI: 1.00–2.44), as well as not receiving antifungal treatment (HR = 2.23, 95%CI: 1.25–4.01) or receiving it for less than 2 weeks (HR = 2.13, 95%CI: 1.33–3.43). Each additional day of antifungal therapy beyond the minimum 14-day duration was associated with a 2% lower risk of death (HR = 0.98, 95%CI: 0.95–0.999).

Conclusion

Non-hyaline-mold peritonitis had worse survival. Longer duration and higher daily dosage of antifungal treatment were associated with better survival. Deviations from the 2016 ISPD Peritonitis Guideline recommendations concerning treatment duration and catheter removal timing were independently associated with higher mortality.

Gram-negative central line-associated bloodstream infection incidence peak during the summer: a national seasonality cohort study

Central line-associated bloodstream infections (CLABSI) cause increased morbidity, mortality, and hospital costs that are partially preventable. The phenomenon of seasonality among CLABSI rates has not been fully elucidated, but has implications for accurate surveillance and infection prevention trials. Longitudinal dynamic cohort of hospitals participating in hospital-wide and intensive care unit bloodstream infection surveillance for at least one full year over 2000 to 2014. Mixed-effects negative binomial regression analysis calculated the peak-to-low ratio between months as an adjusted CLABSI incidence rate ratio (IRR) with 95% confidence intervals (CI). Multivariate regression models examined the associations between CLABSI pathogens and ambient temperature and relative humidity. The study population included 104 hospital sites comprising 11,239 CLABSI. Regression analysis identified a hospital-wide increase in total CLABSI during July-August, with a higher gram-negative peak-to-low incidence rate ratio (IRR 2.52 [95% CI 1.92-3.30], p < 0.001) compared to gram-positive bacteria (IRR 1.29 [95% CI 1.11-1.48], p < 0.001). Subgroup analysis replicated this trend for CLABSI diagnosed in the intensive care unit. Only gram-negative CLABSI rates were associated with increased temperature (IRR + 30.3% per 5 °C increase [95% CI 17.3-43.6], p < 0.001) and humidity (IRR + 22.9% per 10% increase [95% CI 7.7-38.3), p < 0.001). The incidence and proportion of gram-negative CLABSI approximately doubled during the summer periods. Ambient temperature and humidity were associated with increases of hospital-acquired gram-negative infections. CLABSI surveillance, preventive intervention trials and epidemiological studies should consider seasonal variation and climatological factors when preparing study designs or interpreting their results.

Influence of seasonal variability on orthopedic surgical outcomes in pediatric patients: a review of surgical site infections

Surgical site infections (SSIs) are challenging, with highly variable reported rates for children undergoing orthopedic surgery. It has been shown in adults that there is seasonal variability in SSI rates, with peak incidences in the summer months. We reviewed 8766 pediatric orthopedic procedures completed at a quaternary children's hospital over a 43-month period. Data collected included: age, sex, BMI, season of procedure, cultures, and other variables related to risks and treatment of SSIs. Of 4875 male and 3891 female pediatric patients undergoing orthopedic procedures, 47 patients (0.54%) with an average age of 11.3 years (range: 2.0-18.6) developed an SSI. Average time between surgery and diagnosis was 27.7 ± 19.8 days. Sixty percent of SSI patients had a BMI in the 85th percentile or above, and 49% of SSI patients had a BMI above the 95th percentile. Thirty-eight patients had positive cultures, with most common infections being due to methicillin-sensitive Staphylococcus aureus in 11 (29%) cases, polymicrobial in 9 (24%), pseudomonas in 5 (13%), and coagulase-negative Staphylococcus in 5 (13%). SSI rate in winter (0.18%) was significantly lower than in autumn (0.77%, P = 0.006) and summer (0.69%, P = 0.02). The difference did not reach statistical significance from the infection rate in spring (0.53%, P = 0.06). Twenty-nine (62%) SSI cases were considered elective in nature, and the other 18 (38%) cases were for acute traumatic injuries. There is a significantly higher SSI rate in summer and autumn than winter for pediatric patients undergoing orthopedic surgeries. Most patients with SSIs were overweight or obese.

Seasonal and Temperature-associated Effect on Infection in Implant-based Breast Reconstruction

BACKGROUND AND OBJECTIVES

Despite advances in medicine, infection at the surgical site is an impregnation problem that most surgeons confront. Although studies on the seasonality of infection have been conducted in various areas, no study has confirmed the relationship between seasonal temperature and infection after breast reconstruction.

METHODS

From 2008 to 2018, a retrospective study was conducted on patients who underwent implant-based breast reconstruction. Patient demographics, intraoperative data, postoperative data, and temperature information were collected. Temperature differences between cases with and without infection were examined. The differences in the incidence and risk of infection by season were estimated according to the hot season (July to August) and the nonhot season (September to June).

RESULTS

Of the 460 cases enrolled, 42 cases developed an infection. Among them, 15 (35.71%) cases developed infection during the hot season (P = 0.003). According to the logistic regression model, the risk of infection was 2.639 times higher in the hot season than in the nonhot season (95% confidence interval, 1.282-5.434; P = 0.008). When the temperature was higher than 25°C, the risk of infection increased by 45.2% for every 1°C increase, which was statistically significant (odds ratio, 1.452; 95% confidence interval, 1.198-1.76; P < 0.001).

CONCLUSION

In conclusion, the hot season or average temperatures higher than 25°C increase the risk of infection in patients undergoing implant-based breast reconstruction. It is essential to focus on skin hygiene during the healing of the incision site.

The effect of radiological imaging on treatment delay and hospitalisation in patients with peritoneal dialysis-related peritonitis: A secondary analysis of the PROMPT study

BACKGROUND

In peritoneal dialysis-related peritonitis (peritonitis), delayed antibiotic therapy is associated with adverse outcomes. Identifying barriers to timely treatment may improve outcomes.

AIM

To determine the impact of radiological investigations on treatment delay and predictors of hospitalisation and length of stay (LOS).

METHODS

Retrospective review of patients with presumed peritonitis in Western Australia.

RESULTS

In 153 episodes of peritonitis, 79 (51.6%) resulted in admission with a median LOS of 3 days (Q1, Q3: 1, 6). In a multivariable model, significant predictors of admission were abnormal exit-site (odds ration (OR) 5.7; 95% confidence interval (CI): 1.4, 23.6; p = 0.02), failure to detect a cloudy bag (OR 11.9; 95%CI: 3.2, 44.7; p < 0.001), female sex (OR 3.3; 95% CI: 1.4, 9.7; p = 0.027), radiological imaging within 24 h (OR 8.8; 95% CI: 2.2, 34.8; p = 0.002) and contact with ambulant care facility (OR 0.32, 95% CI: 0.11, 0.98; p = 0.04). Imaging within 24 h of presentation occurred in 41 (27%) episodes of peritonitis, mostly plain X-rays (91%), of which 83% were clinically irrelevant. Imaging performed within 24 h of presentation increased the median time to antibiotic treatment (2.9 h (Q1, Q3: 1.6, 6.4) vs 2.0 h (Q1, Q3: 1, 3.8; p = 0.046)). Imaging performed prior to administering antibiotics significantly increased the median time to treatment (4.7 h (Q1, Q3: 2.9, 25) vs 1.5 h (Q1, Q3: 0.75, 2.5; p < 0.001)) in those where imaging followed antibiotic treatment.

CONCLUSIONS

Half of all presentations with peritonitis result in hospital admission. Radiological imaging was associated with an increased risk of hospitalisation, potentially contributes to treatment delay, and was mostly clinically unnecessary. When required, imaging should follow antibiotic therapy.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

The influence of seasonal factors on the incidence of peritoneal dialysis-associated peritonitis

OBJECTIVES

To investigate the effects of climatic variables on peritoneal dialysis-associated peritonitis (PDAP) among patients receiving PD, such as seasonal variations in temperature and humidity.

METHODS

A retrospective analysis was performed on PD patients, from 1 January 2011, to 31 December 2019. We evaluated the influence of seasonal factors on peritonitis rates and outcomes.

RESULTS

Over the 9-year study period, 667 peritonitis episodes occurred, in 401 PD patients. Diarrhea-associated peritonitis occurred more frequently in summer compared with other seasons. Eating raw and cold food was identified as the primary cause of peritonitis in the summer. More peritonitis episodes occurred during summer. The peritonitis rate associated with gram-negative bacteria (p = 0.050) during summer was higher than those in all other seasons. The gram-negative bacterial peritonitis rate was positively correlated with monthly mean temperature (r = 0.504, p < 0.01) and humidity (r = 0.561, p < 0.01). A similar trend was observed for Enterobacterial peritonitis (temperature: r = 0.518, p < 0.01; humidity: r = 0.456, p = 0.001). Logistic regression analysis showed that summer was a risk factor for peritonitis (p = 0.041). Peritonitis prognosis during summer was significantly worse than those for all other seasons (p = 0.037).

CONCLUSIONS

Seasonal variations exist in the incidence of dialysis-associated peritonitis, with peak incidents caused by gram-negative bacteria in the summer. High average temperature and humidity are associated with significant increases in the gram-negative bacteria and Enterobacterial peritonitis rates. Peritonitis prognosis during summer is worse.

Seasonality of peritoneal dialysis-related peritonitis in Japan: a single-center, 10-year study

BACKGROUND

Peritonitis is one of the major complications of peritoneal dialysis (PD). Although several reports have indicated seasonality of peritonitis, the observation periods were short, and there were no reports from Japan. Therefore, the purpose of this study was to investigate the long-term seasonality of peritonitis in a single institution in Japan.

METHODS

Of 126 patients who started PD in our hospital between January 1, 2009, and December 31, 2018, 25 patients (15 men, 10 patients with diabetes) developed peritonitis with a total of 42 episodes. The median age at onset was 63 years, and the median duration from the start of PD to the onset of peritonitis was 22 months.

RESULTS

The 10-year incidence of peritonitis was 0.12 episodes per patient-year. Compared with the reference season of winter (December-February), the incidence rate ratios (95% confidence interval) for spring (March-May), summer (June-August), and autumn (September-November) were 1.75 (0.65-4.75), 1.56 (0.57-4.31), and 2.42 (0.94-6.23), respectively. In addition, no seasonality of Gram-positive and Gram-negative organisms was observed.

CONCLUSION

No seasonality was evident in the incidence of PD-related peritonitis in our hospital over a 10-year period. These findings suggest that the development of peritonitis in Japanese PD patients is not affected by seasonality.

Associations between season and surgical site infections in orthopaedic foot and ankle surgery

BACKGROUND

Surgical site infections (SSI) in orthopaedic surgery are common nosocomial complications that contribute significantly to patient morbidity and increased healthcare costs. While past studies support an increase in the incidence of SSI during the summer months in orthopaedic spine surgery and joint arthroplasty, there has not been any study examining the association between season and SSI in the setting of orthopaedic foot and ankle surgery.

METHODS

A retrospective analysis of data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2011-2015 was conducted. 17,939 patients who received at least one of 218 CPT codes specific to orthopaedic foot and ankle surgery were identfied from the NSQIP database. Descriptive statistics of patient demographics, comorbidities, and complications were stratified by quarter of admission.

RESULTS

Of the 17,939 patients, there were 4995 in the 1st quarter (27.8%), 4078 in the 2nd quarter (22.7%), 4333 in the 3rd quarter (24.2%), and 4533 in the 4th quarter (25.3%). The overall rate of surgical complications was 2.3%. The highest incidence of surgical complications was during the summer at 2.7% and the lowest was during the fall at 2.1% (p=0.338). The summer months also demonstrated the highest incidence of medical complications at 5.9% (p=0.524). There were significantly more women undergoing surgery in the winter and summer months (p=0.028).

CONCLUSION

The surgical site infection rate in the setting of orthopaedic foot and ankle surgery was higher, although not significantly, in the summer months.

LEVEL OF EVIDENCE

Level III retrospective.

Outpatient Antibiotic Prescription Trends in the United States: A National Cohort Study

OBJECTIVETo characterize trends in outpatient antibiotic prescriptions in the United StatesDESIGNRetrospective ecological and temporal trend study evaluating outpatient antibiotic prescriptions from 2013 to 2015SETTINGNational administrative claims data from a pharmacy benefits manager PARTICIPANTS. Prescription pharmacy beneficiaries from Express Scripts Holding CompanyMEASUREMENTSAnnual and seasonal percent change in antibiotic prescriptionsRESULTSApproximately 98 million outpatient antibiotic prescriptions were filled by 39 million insurance beneficiaries during the 3-year study period. The most commonly prescribed antibiotics were azithromycin, amoxicillin, amoxicillin/clavulanate, ciprofloxacin, and cephalexin. No significant changes in individual or overall annual antibiotic prescribing rates were found during the study period. Significant seasonal variation was observed, with antibiotics being 42% more likely to be prescribed during February than September (peak-to-trough ratio [PTTR], 1.42; 95% confidence interval [CI], 1.39-1.61). Similar seasonal trends were found for azithromycin (PTTR, 2.46; 95% CI, 2.44-3.47), amoxicillin (PTTR, 1.52; 95% CI, 1.42-1.89), and amoxicillin/clavulanate (PTTR, 1.78; 95% CI, 1.68-2.29).CONCLUSIONSThis study demonstrates that annual national outpatient antibiotic prescribing practices remained unchanged during our study period. Furthermore, seasonal peaks in antibiotics generally used to treat viral upper respiratory tract infections remained unchanged during cold and influenza season. These results suggest that inappropriate prescribing of antibiotics remains widespread, despite the concurrent release of several guideline-based best practices intended to reduce inappropriate antibiotic consumption; however, further research linking national outpatient antibiotic prescriptions to associated medical conditions is needed to confirm these findings.Infect Control Hosp Epidemiol 2018;39:584-589.

MUL+DO: a multicomponent index for the quick diagnosis of peritonitis in peritoneal dialysis patients

Peritoneal infection is a common problem that has a negative impact on the survival of patients and the technique. The early administration of peritoneal infection treatment reduces complications. The goal of this study is to propose a multicomponent index (MUL+DO) for the quick and efficient diagnosis of peritoneal infection. We selected a training cohort of peritoneal effluent samples which were analysed by Multistix ® 10 SG Siemens test strips for leukocyte detection. Then, each sample was examined according to the gold standard: number of leukocytes, polymorphonuclear percentage and microbiological culture. We constructed the MUL+DO index by adding one point to the MULTISTIX [0-1-2-3] modified chromatic scale if the patient reported pain. The MUL+DO index ranged from 0 to 4. A model validation cohort was then created. MUL+DO was applied to each sample and leukocytes and polymorphonuclear percentage were also assessed. The training cohort ultimately included 134 samples, 34 of which with infection (25.4% [17.6-33.1]). Samples with a MUL+DO value greater than 1 presented a sensitivity and specificity of 100%. The validation cohort included 100 samples with 16 infections (16% [8.3-23.7]). Assuming a sample with a MUL+DO value greater than 1 to be positive, we obtained a sensitivity of 100% and a specificity of 95.2%. The MUL+DO index applied to the training cohort showed a perfect separation of the positive and negative populations. All positive patients presented a score ≥2. In the validation cohort, the MUL+DO reported a sensitivity of 100% and a specificity of 95.2%.

Seasonal Variation in the Peritoneal Dialysis-Related Infections: A Single Center Experience in the Mediterranean

Seasonal variation in the incidence of peritoneal dialysis-related infections (PDRI) has been sparingly investigated, especially in the Mediterranean. Our aim was to explore this association in Malta. All PDRI occurring between Jan-2008 and Dec-2012 were retrospectively studied.A total of 137 patients were followed-up for a median time of 32.5 months (range: 2-81). During this time, 19% never had PDRI, 11.7% transferred permanently to hemodialysis and 6.6% received a kidney transplant. A total of 279 PDRI were identified, equating to 145 catheter-related infections (CRI) and 144 peritonitis episodes (including 10 catheter related peritonitis). A spring peak in the overall gram positive PDRI (0.61 vs. 0.34/patient-year-at-risk, P=0.05), together with a peak in gram negative peritonitis in the warm period (0.13 vs. 0.07/patient-year at risk, P=0.04) was identified. The incidence rate ratios (Confidence Interval) involving the overall gram positive PDRI, gram positive peritonitis, coagulase-negative Streptococci (CoNS) and Streptococci were 1.82 (1.18-2.82, P=0.007), 2.20 (1.16-4.16, P=0.02), 2.65 (1.17-6.02, P=0.02] and 3.18 (1.03-9.98, P=0.04) in spring when compared to winter. No significant difference in the overall PDRI, peritonitis or CRI rates between seasons or warm/cold period was identified.To our knowledge, this is the first study which examines the effect of seasons on the incidence of PDRI in the Mediterranean basin. Findings suggest that spring confers a higher risk for gram positive PDRIs, gram positive peritonitis, CoNS and Streptococcus, whilst the warm period was associated with a peak in the gram negative peritonitis.

Dialysate White Blood Cell Change after Initial Antibiotic Treatment Represented the Patterns of Response in Peritoneal Dialysis-Related Peritonitis

Background. Patients with peritoneal dialysis-related peritonitis usually have different responses to initial antibiotic treatment. This study aimed to explore the patterns of response by using the changes of dialysate white blood cell count on the first five days of the initial antibiotic treatment. Materials and Methods. A retrospective cohort study was conducted. All peritoneal dialysis-related peritonitis episodes from January 2014 to December 2015 were reviewed. We categorized the patterns of antibiotic response into 3 groups: early response, delayed response, and failure group. The changes of dialysate white blood cell count for each pattern were determined by multilevel regression analysis. Results. There were 644 episodes in 455 patients: 378 (58.7%) of early response, 122 (18.9%) of delayed response, and 144 (22.3%) of failure episodes. The patterns of early, delayed, and failure groups were represented by the average rate reduction per day of dialysate WBC of 68.4%, 34.0%, and 14.2%, respectively (p value < 0.001 for all comparisons). Conclusion. Three patterns, which were categorized by types of responses, have variable rates of WBC declining. Clinicians should focus on the delayed response and failure patterns in order to make a decision whether to continue medical therapies or to aggressively remove the peritoneal catheter.

The Relationship Between Presentation and the Time of Initial Administration of Antibiotics With Outcomes of Peritonitis in Peritoneal Dialysis Patients: The PROMPT Study

Introduction

The impact of time to treatment on clinical outcome is an established precept in infectious disease but is not established in peritoneal dialysis–related peritonitis (PDRP).

Methods

In a prospective multicenter study of PDRP, symptom-to-contact time (SC), contact-to-treatment time (CT), defined as the time from health care presentation to initial antibiotic, and symptom-to-treatment time (ST) were determined.

Results

One hundred sixteen patients had 159 episodes of PDRP. Median SC for all episodes was 5.0 hours (first to third quartile [Q1–Q3]: 1.3–13.9); CT, 2.3 hours (Q1–Q3: 1.2–4.0); and ST, 9.0 hours (Q1–Q3: 4.7–25.3). Thirty-eight (23.9%) patient episodes (28 catheter removals and 10 deaths) met the primary composite outcome of PD failure at 30 days (PD-fail). The risk of PD-fail increased by 5.5% for each hour of delay of administration of antibiotics (odds ratio [OR] for CT: 1.055; 95% confidence interval [CI]: 1.005–1.109; P = 0.032). Neither SC (OR: 1.00; 95% CI: 0.99–1.01; P = 0.74) nor ST (OR: 1.00; 95% CI: 0.99–1.01; P = 0.48) was associated with PD-fail. In a multivariable analysis, only CT for presentation to a hospital-based facility compared with a community facility (OR: 1.068; 95% CI: 1.013–1.126; P = 0.015) and female sex (OR: 2.4; 95% CI: 1.1–5.4; P = 0.027) were independently associated with PD-fail. Each hour of delay in administering antibacterial therapy from the time of presentation to a hospital facility increased the risk of PD failure or death by 6.8%.

Discussion

Strategies targeted to expedited antibiotic treatment should be implemented to improve outcomes from PDRP.

Center-Specific Factors Associated with Peritonitis Risk-A Multi-Center Registry Analysis

♦

BACKGROUND

Previous studies have reported significant variation in peritonitis rates across dialysis centers. Limited evidence is available to explain this variability. The aim of this study was to assess center-level predictors of peritonitis and their relationship with peritonitis rate variations. ♦

METHODS

All incident peritoneal dialysis (PD) patients treated in Australia between October 2003 and December 2013 were included. Data were accessed through the Australia and New Zealand Dialysis and Transplant Registry. The primary outcome was peritonitis rate, evaluated in a mixed effects negative binomial regression model. Peritonitis-free survival was assessed as a secondary outcome in a Cox proportional hazards model. ♦

RESULTS

Overall, 8,711 incident PD patients from 51 dialysis centers were included in the study. Center-level predictors of lower peritonitis rates included smaller center size, high proportion of PD, low peritoneal equilibration test use at PD start, and low proportion of hospitalization for peritonitis. In contrast, a low proportion of automated PD exposure, high icodextrin exposure and low or high use of antifungal prophylaxis at the time of peritonitis were associated with a higher peritonitis rate. Similar results were obtained for peritonitis-free survival. Overall, accounting for center-level characteristics appreciably decreased peritonitis variability among dialysis centers (p = 0.02). ♦

CONCLUSION

This study identified specific center-level characteristics associated with the variation in peritonitis risk. Whether these factors are directly related to peritonitis risk or surrogate markers for other center characteristics is uncertain and should be validated in further studies.

Stability of Tigecycline in Different Types of Peritoneal Dialysis Solutions

♦

INTRODUCTION

Intraperitoneal tigecycline is a potential option for the treatment of peritoneal dialysis (PD)-associated peritonitis caused by microorganisms resistant to commonly used antibiotics. However, the stability of tigecycline must be assessed in the PD solution before evaluating its safety and therapeutic efficacy in PD-associated peritonitis. The objective of this study was to investigate the stability of tigecycline in 3 types of PD solutions at different temperatures for various time points. ♦

METHODS

A total of 27 PD bags (9 PD bags for each type of PD solution; 1.5% glucose, 7.5% icodextrin, and 1.5% glucose pH neutral) containing 2 μg/mL of tigecycline were prepared and stored at either 4, 25, or 37°C. An aliquot was withdrawn immediately before (0 hour) and after pre-defined time points. Each sample was analyzed in duplicate for the concentration of tigecycline using a stability-indicating high-performance liquid chromatography (HPLC) technique. Samples were also assessed for pH, color changes, and evidence of precipitation immediately after preparation and on each day of analysis. ♦

RESULTS

Tigecycline in all 3 types of PD solutions retained more than 90% of its initial concentration for at least 216, 72, and 8 hours at 4, 25, and 37°C, respectively. There was no evidence of precipitation at any time under the tested storage conditions. The pH and color of tigecycline admixed PD solutions stored at 4, 25, and 37°C remained essentially unchanged for 336, 96, and 48 hours respectively. ♦

CONCLUSION

The results obtained from the study provide a platform for future clinical studies aiming to determine the safety and therapeutic efficacy of intraperitoneally administered tigecycline for the treatment of PD-associated peritonitis.

Seasonal Variation of Common Surgical Site Infections: Does Season Matter?

OBJECTIVE

To evaluate seasonal variation in the rate of surgical site infections (SSI) following commonly performed surgical procedures.

DESIGN

Retrospective cohort study.

METHODS

We analyzed 6 years (January 1, 2007, through December 31, 2012) of data from the 15 most commonly performed procedures in 20 hospitals in the Duke Infection Control Outreach Network. We defined summer as July through September. First, we performed 3 separate Poisson regression analyses (unadjusted, multivariable, and polynomial) to estimate prevalence rates and prevalence rate ratios of SSI following procedures performed in summer versus nonsummer months. Then, we stratified our results to obtain estimates based on procedure type and organism type. Finally, we performed a sensitivity analysis to test the robustness of our findings.

RESULTS

We identified 4,543 SSI following 441,428 surgical procedures (overall prevalence rate, 1.03/100 procedures). The rate of SSI was significantly higher during the summer compared with the remainder of the year (1.11/100 procedures vs 1.00/100 procedures; prevalence rate ratio, 1.11 [95% CI, 1.04-1.19]; P=.002). Stratum-specific SSI calculations revealed higher SSI rates during the summer for both spinal (P=.03) and nonspinal (P=.004) procedures and revealed higher rates during the summer for SSI due to either gram-positive cocci (P=.006) or gram-negative bacilli (P=.004). Multivariable regression analysis and sensitivity analyses confirmed our findings.

CONCLUSIONS

The rate of SSI following commonly performed surgical procedures was higher during the summer compared with the remainder of the year. Summer SSI rates remained elevated after stratification by organism and spinal versus nonspinal surgery, and rates did not change after controlling for other known SSI risk factors.

Postoperative infection in spine surgery: does the month matter?

OBJECT

The relationship between time of year and surgical site infection (SSI) following neurosurgical procedures is poorly understood. Authors of previous reports have demonstrated that rates of SSI following neurosurgical procedures performed during the summer months were higher compared with rates during other seasons. It is unclear, however, if this difference was related to climatological changes or inexperienced medical trainees (the July effect). The aim of this study was to evaluate for seasonal variation of SSI following spine surgery in a network of nonteaching community hospitals.

METHODS

The authors analyzed 6 years of prospectively collected surveillance data (January 1, 2007, to December 31, 2012) from all laminectomies and spinal fusions from 20 hospitals in the Duke Infection Control Outreach Network of community hospitals. Surgical site infections were defined using National Healthcare Safety Network criteria and identified using standardized methods across study hospitals. Regression models were then constructed using Poisson distribution to evaluate for seasonal trends by month. Each analysis was first performed for all SSIs and then for SSIs caused by specific organisms or classes of organisms. Categorical analysis was performed using two separate definitions of summer: June through September (definition 1), and July through September (definition 2). The prevalence rate of SSIs during the summer was compared with the prevalence rate during the remainder of the year by calculating prevalence rate ratios and 95% confidence intervals.

RESULTS

The authors identified 642 SSIs following 57,559 neurosurgical procedures (overall prevalence rate = 1.11/100 procedures); 215 occurred following 24,466 laminectomies (prevalence rate = 0.88/100 procedures), and 427 following 33,093 spinal fusions (prevalence rate = 1.29/100 procedures). Common causes of SSI were Staphylococcus aureus (n = 380; 59%), coagulase-negative staphylococci (n = 90; 14%), and Escherichia coli (n = 41; 6.4%). Poisson regression models demonstrated increases in the rates of SSI during each of the summer months for all SSIs and SSIs due to gram-positive cocci, S. aureus, and methicillin-sensitive S. aureus. Categorical analysis confirmed that the rate of SSI during the 4-month summer period was higher than the rate during the remainder of the year, regardless of which definition for summer was used (definition 1, p = 0.008; definition 2, p = 0.003). Similarly, the rates of SSI due to grampositive cocci and S. aureus were higher during the summer months than the remainder of the year regardless of which definition of summer was used. However, the rate of SSI due to gram-negative bacilli was not.

CONCLUSIONS

The rate of SSI following fusion or spinal laminectomy/laminoplasty was higher during the summer in this network of community hospitals. The increase appears to be related to increases in SSIs caused by gram-positive cocci and, more specifically, S. aureus. Given the nonteaching nature of these hospitals, the findings demonstrate that increases in the rate of SSI during the summer are more likely related to ecological and/or environmental factors than the July effect.

Peritoneal dialysis-related peritonitis: towards improving evidence, practices, and outcomes

Peritonitis is a common serious complication of peritoneal dialysis that results in considerable morbidity, mortality, and health care costs. It also significantly limits the use of this important dialysis modality. Despite its importance as a patient safety issue, peritonitis practices and outcomes vary markedly and unacceptably among different centers, regions, and countries. This article reviews peritonitis risk factors, diagnosis, treatment, and prevention, particularly focusing on potential drivers of variable practices and outcomes, controversial or unresolved areas, and promising avenues warranting further research. Potential strategies for augmenting the existing limited evidence base and reducing the gap between evidence-based best practice and actual practice also are discussed.

Seasonal variation in health care-associated bloodstream infection: increase in the incidence of gram-negative bacteremia in nonhospitalized patients during summer

OBJECTIVE

Recent research has suggested that episodes of gram-negative (GN) bloodstream infection (BSI) are more common in the population during summer months. Our objective was to determine if the same phenomenon could be observed in patients with health care-associated (HCA) BSI, and if so, whether a summer peak was less apparent in patients accommodated in a climate-controlled hospital environment.

METHODS

Data from episodes of HCA BSI spanning an 11-year period were analyzed. To test for seasonal variation in HCA BSI among hospitalized and nonhospitalized patients, and between GN and gram-positive organisms, the χ(2) goodness-of-fit test was used.

RESULTS

There were 440 episodes of HCA GN BSI of which 259 (59%) occurred in inpatients and 181 (41%) occurred in noninpatients. A significant increase in the frequency of HCA GN BSI was observed in nonhospitalized patients during the summer months (P = .03) but not in climate-controlled hospitalized patients. The most common source of infection in these patents was an intravascular device (38%).

CONCLUSIONS

We found an increased incidence of GN HCA BSI during summer that was not apparent in our inpatient cohort. The cause is unknown. It might be prudent to advise patients at risk of BSI (eg, those receiving intravascular infusions) to minimize exposure to high environmental temperature and to educate on possible behavioral factors that may increase risk.

Seasonal humidity may influence Pseudomonas aeruginosa hospital-acquired infection rates

OBJECTIVE

The objective of this study was to determine the association of seasonal climatic conditions with the incidence of Pseudomonas aeruginosa infections.

METHODS

A retrospective study was carried out to evaluate all infections caused by P. aeruginosa in a 660-bed tertiary-care hospital in Brazil over a period of 5 years. To assess seasonal patterns, monthly temperature, relative humidity, and precipitation averages were obtained. Correlations of seasonal variations with infection rates (IR) were determined by Pearson correlation coefficient. Linear regression was used to determine trends, and multivariable linear regression was performed using a Poisson distribution.

RESULTS

A total of 844 cases of P. aeruginosa infection were identified for 1 058 501 patient-days during 1826 days (overall IR 7.97/10 000 patient-days). The mean temperature was 18.2±2.8°C, relative humidity was 80.3±3.6%, and precipitation was 104.7±64.38mm. The Pearson correlation was significant between urinary tract infection and temperature (R=0.29; p=0.021) and precipitation (R=0.27; p=0.036). A correlation was also significant between hospital-associated pneumonia and precipitation (R=0.29; p=0.022) and relative humidity (R=0.31; p=0.013). Relative humidity was associated with a higher IR of other infections caused by P. aeruginosa, but it was not possible to build a predictive model when multiple linear regression and Poisson regression were tested.

CONCLUSION

Climatic conditions are another factor that may interfere with the IR of Pseudomonas aeruginosa.

Seasonality of staphylococcal infections

Characterization of seasonal variation of Staphylococcus aureus is important in understanding the epidemiology of, and designing preventive strategies against this highly virulent and ever-evolving pathogen. In this review, we summarize the findings of epidemiological studies that have evaluated seasonality in S. aureus colonization and infection. Although most studies published to date are methodologically weak, some seasonal variation in the occurrence of S. aureus infection appears to exist, particularly an association of warm-weather months with S. aureus skin and soft-tissue infections. We highlight the limitations of the published literature, and provide suggestions for future studies on this topic.

The risk of peritonitis after an exit site infection: a time-matched, case-control study

BACKGROUND

Exit site infections (ESIs) have been previously associated with the development of peritonitis; however, the evidence to support this association is limited. We conducted a time-matched, case-control study to determine the association between ESIs and subsequent peritonitis.

METHODS

The cohort comprised 962 incident adult peritoneal dialysis (PD) patients from January 2000 to December 2009. Patients with an ESI were matched to those with no ESI based on the duration of PD. The subsequent risk of peritonitis was determined using Cox models and conditional logistic regression.

RESULTS

During the study period, there were a total of 1002 ESI and 1228 peritonitis episodes among 962 individuals. The time to subsequent peritonitis was shorter in individuals who had at least one ESI [hazard ratio (HR) 1.59; 95% confidence interval (CI) 1.22-2.07, P<0.001]. The risk of peritonitis post-ESI was increased for all Gram-positive infections [adjusted hazard ratio (aHR) 1.75; 95% CI 1.25-2.43], and for the subtypes of coagulase-negative Staphylococcus (CNS) and S. aureus, but not for Gram-negative or culture-negative infections. These findings were similar when examining the odds of subsequent peritonitis within prespecified time intervals of the ESI through conditional logistic regression.

CONCLUSIONS

The risk of peritonitis after ESI is increased, particularly with S. aureus and CNS, despite appropriate antibiotic treatment of the ESI.