Risk Factors for Staphylococcus aureus Nasal Colonization in Joint Arthroplasty Patients

[Intraosseous vancomycin in total knee arthroplasty]

INTRODUCTION

intravenous antibiotic prophylaxis has significantly reduced the incidence of periprosthetic joint infection (PJI) in knee surgeries. However, for patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) or those at risk of colonization, prophylaxis should include vancomycin. Intraosseous (IO) administration of vancomycin could enhance its effectiveness in total knee arthroplasty (TKA).

MATERIAL AND METHODS

a retrospective review was conducted, including 143 patients at risk of PJI scheduled for TKA who received IO vancomycin along with intravenous (IV) cefazolin, referred to as group I (GI), between May 2021 and December 2022. The occurrence of complications in the first three postoperative months was evaluated. Results were compared with 140 patients without risk factors who received standard IV prophylaxis, designated as group II (GII).

RESULTS

in GI, 500 mg of IO vancomycin was administered, injected into the proximal tibia, in addition to standard IV prophylaxis. In GII, patients received only IV cefazolin. The incidence of complications was 1.64% in GI and 1.4% in GII. The PJI rate at 90 postoperative days was 0.69% in GI and 0.71% in GII.

CONCLUSIONS

IO vancomycin administration, along with standard IV prophylaxis, provides a safe and effective alternative for patients at risk of MRSA colonization. This approach minimizes complications associated with IV vancomycin use and addresses logistical challenges of timely administration.

Increased prevalence of Staphylococcus aureus nasal carriage in rheumatoid arthritis patients with moderate/high disease activity

BACKGROUND

Staphylococcus aureus (S. aureus) nasal carriage is a well-known risk factor for surgical site infection (SSI) after total joint arthroplasty. This study aimed to compare the prevalence of S. aureus nasal carriage between patients with osteoarthritis (OA), a degenerative joint disease, and those with rheumatoid arthritis (RA), a chronic autoimmune inflammatory disease, who underwent total joint arthroplasty, and to investigate the influence of RA disease activity on nasal carriage rate.

METHODS

This retrospective study targeted 508 OA and 107 RA patients who underwent S. aureus nasal screening prior to primary total knee and/or hip arthroplasty. RA patients were divided into two groups based on disease activity: the remission/low disease activity (REM/LDA) group and the moderate/high disease activity (MDA/HDA) group. Factors associated with S. aureus nasal carriage were assessed with multivariate logistic regression models.

RESULTS

Of all 615 patients, 155 (25%) carried S. aureus in their nares. Compared to OA patients, RA patients had a significantly higher rate of S. aureus nasal carriage (24% vs. 33%, p = 0.049). Compared to the REM/LDA group (n = 39), the MDA/HDA group (n = 58) had a significantly higher rate of S. aureus nasal carriage (21% vs. 41%, p = 0.032). Multivariate analysis revealed that the MDA/HDA group, but not the REM/LDA group, had a significantly higher odds of S. aureus nasal carriage compared to the OA group (odds ratio: 2.76, 95% confidence interval: 1.07-7.12).

CONCLUSION

Preoperative nasal screening for S. aureus is beneficial, especially in RA patients with moderate/high disease activity.

[Translated article] Results of a preoperative screening and decolonization programme for Staphylococcus aureus in primary hip and knee arthroplasty

INTRODUCTION

Detection and decolonization of Staphylococcus aureus prior to surgery is postulated as an option to reduce the risk of infection in arthroplasties. The aim of this study was to evaluate the effectiveness of a screening programme for S. aureus in total knee arthroplasty (TKA) and total hip arthroplasty (THA), the incidence of infection with respect to a historical cohort, and its economic viability.

MATERIAL AND METHODS

Pre-post intervention study in patients undergoing primary knee and hip prostheses in 2021, a protocol was carried out to detect nasal colonization by S. aureus and eradication if appropriate, with intranasal mupirocin, post-treatment culture with results three weeks between post-treatment culture and surgery. Efficacy measures are evaluated, costs are analyzed and the incidence of infection is compared with respect to a historical series of patients operated on between January and December 2019, performing a descriptive and comparative statistical analysis.

RESULTS

The groups were statistically comparable. Culture was performed in 89%, with 19 (13%) positive patients. Treatment was confirmed in 18, control culture in 14, all decolonized; none suffered infection. One culture-negative patient suffered from Staphylococcus epidermidis infection. In historical cohort: three suffered deep infection by S. epidermidis, Enterobacter cloacae, Staphylococcus aureus. The cost of the programme is €1661.85.

CONCLUSION

The screening programme detected 89% of the patients. The prevalence of infection in the intervention group was lower than in the cohort, with S. epidermidis being the main micro-organism, different from S. aureus described in the literature and in the cohort. We believe that this programme is economically viable, as its costs are low and affordable.

Alhoot M, Abdul Karim S. Multidrug-Resistant Staphylococcus aureus as Coloniser in Healthy Individuals

Staphylococcus aureus is a common human pathogen that can cause mild superficial infections to deep-seated abscesses and sepsis. One of the characteristics of S. aureus is the ability to colonise healthy individuals while leaving them asymptomatic. These carriers’ risk harbouring an antibiotic-resistant strain that may be harmful to the individual and the community. S. aureus carriage in healthcare personnel is being studied extensively in many parts of the world. However, the relationship between colonisation and disease among those with no previous exposure to healthcare remains untouched. Colonisation of the nasal cavity and its surrounding by pathogenic organisms such as S. aureus leads to the increased risk of infection. Hospital-acquired infections associated with S. aureus infections are common and studies related to these types of infections among various study groups are largely documented. However, over the last decade, an increase in community-associated methicillin-resistant S. aureus has been noted, increasing the need to identify the prevalence of the organism among healthy individuals and assessing the antibiotic resistance patterns. Systemic surveillance of the community for colonisation of S. aureus and identifying the antibiotic-resistant pattern is critical to determine the appropriate empiric antibiotic treatment.

Preoperative and perioperative risk factors, and risk score development for prosthetic joint infection due to Staphylococcus aureus: a multinational matched case-control study

OBJECTIVES

We aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI) and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions.

METHODS

We performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; predictive scores also were developed and validated in an external cohort.

RESULTS

In total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): body mass index >30 kg/m2 (3.0; 1.9 to 4.8), resident in a long-term care facility (2.8; 1.05 to 7.5), fracture as reason for arthroplasty (2.7; 1.4 to 5.03), skin disorders (2.5; 0.9 to 7.04), previous surgery in the index joint (2.4; 1.3 to 4.4), male sex (1.9; 1.2 to 2.9) and American Society of Anesthesiologists index score 3 to 4 (1.8; 1.2 to 2.9). The area under the receiver operating characteristic curve was 0.73 (95% CI 0.68 to 0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1 to 16.2), wound drainage for >72 hours after arthroplasty (4.5; 1.9 to 19.4) and use of metal bearing material versus ceramic (1.9; 1.1 to 3.3). The area under the receiver operating characteristic curve was 0.78 (95% CI 0.72 to 0.83). The predictive scores developed were validated in the external cohort.

DISCUSSION

Predictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.

Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay

BACKGROUND

Staphylococcus aureus is a common organism implicated in prosthetic joint infection after THA and TKA, prompting preoperative culturing and decolonization to reduce infection rates. It is unknown whether colonization is associated with other noninfectious outcomes of THA or TKA.

QUESTIONS/PURPOSES

(1) What is the association between preoperative S. aureus colonization (methicillin-sensitive S. aureus [MSSA] and methicillin-resistant S. aureus [MRSA]) and the noninfectious outcomes (discharge destination, length of stay, Hip/Knee Disability and Osteoarthritis Outcome Score [HOOS/KOOS] pain score, HOOS/KOOS physical function score, 90-day readmission, and 1-year reoperation) of THA and TKA? (2) What factors are associated with colonization with S. aureus ?

METHODS

Between July 2015 and March 2019, 8078 patients underwent primary THA in a single healthcare system, and 17% (1382) were excluded because they were not tested preoperatively for S. aureus nasal colonization, leaving 6696 patients in the THA cohort. Between June 2015 and March 2019, 9434 patients underwent primary TKA, and 12% (1123) were excluded because they were not tested for S. aureus colonization preoperatively, leaving 8311 patients in the TKA cohort. The goal of the institution's standardized care pathways is to test all THA and TKA patients preoperatively for S. aureus nasal colonization; the reason the excluded patients were not tested could not be determined. Per institutional protocols, all patients were given chlorhexidine gluconate skin wipes to use on the day before and the day of surgery, and patients with positive S. aureus cultures were instructed to use mupirocin nasal ointment twice daily for 3 to 5 days preoperatively. Adherence to these interventions was not tracked, and patients were not rescreened to test for S. aureus control. The minimum follow-up time for each outcome and the percentage of the cohort lost for each was: for discharge destination, until discharge (0 patients lost); for length of stay, until discharge (0.06% [4 of 6696] lost in the THA group and 0.01% [1 of 8311] lost in the TKA group); for HOOS/KOOS pain score, 1 year (26% [1734 of 6696] lost in the THA group and 24% [2000 of 8311] lost in the TKA group); for HOOS/KOOS physical function, 1 year (33% [2193 of 6696] lost in the THA group and 28% [2334 of 8311] lost in the TKA group); for 90-day readmission, 90 days (0.06% [4 of 6696] lost in the THA group and 0.01% [1 of 8311] lost in the TKA group); and for 1-year reoperation, 1 year (30% [1984 of 6696] lost in the THA group and 30% [2475 of 8311] lost in the TKA group). Logistic regression models were constructed to test for associations between MSSA or MRSA and nonhome discharge, length of stay greater than 1 day, improvement in the HOOS/KOOS pain subscale (≥ the minimum clinically important difference), HOOS/KOOS physical function short form (≥ minimum clinically important difference), 90-day readmission, and 1-year reoperation. We adjusted for patient-related and hospital-related factors, such as patient age and hospital site. Variable significance was assessed using the likelihood ratio test with a significance level of p < 0.05. To assess factors associated with S. aureus colonization, we constructed a logistic regression model with the same risk factors.

RESULTS

Among the THA cohort, after controlling for potentially confounding variables such as patient age, smoking status, and BMI, S. aureus colonization was associated with length of stay greater than 1 day (MSSA: odds ratio 1.32 [95% CI 1.08 to 1.60]; MRSA: OR 1.88 [95% CI 1.24 to 2.85]; variable p < 0.001 by likelihood ratio test) but not the other outcomes of THA. Male sex (OR 1.26 [95% CI 1.09 to 1.45]; p = 0.001) and BMI (OR 1.02 for a one-unit increase over median BMI [95% CI 1.01 to 1.03]; p = 0.003) were patient-related factors associated with S. aureus colonization, whereas factors associated with a lower odds were older age (OR 0.99 [95% CI 0.98 to 0.99]; p < 0.001) and Black race compared with White race (OR 0.64 [95% CI 0.50 to 0.82]; p < 0.001). Among the TKA cohort, S. aureus colonization was associated with 90-day readmission (MSSA: OR 1.00 [95% CI 0.99 to 1.01]; MRSA: OR 1.01 [95% CI 1.00 to 1.01]; variable p = 0.007 by likelihood ratio test). Male sex (OR 1.19 [95% CI 1.05 to 1.34]; p = 0.006) was associated with S. aureus colonization, whereas factors associated with a lower odds of colonization were older age (OR 0.99 [95% CI 0.98 to 0.99]; p < 0.001), Veterans RAND-12 mental component score (OR 0.99 [95% CI 0.99 to 1.00]; p = 0.027), Black race compared with White race (OR 0.70 [95% CI 0.57 to 0.85]; p < 0.001), and being a former smoker (OR 0.86 [95% CI 0.75 to 0.97]; p = 0.016) or current smoker (OR 0.70 [95% CI 0.55 to 0.90]; p = 0.005) compared with those who never smoked.

CONCLUSION

After controlling for the variables we explored, S. aureus colonization was associated with increased length of stay after THA and 90-day readmission after TKA, despite preoperative decolonization. Given that there is little causal biological link between colonization and these outcomes, the association is likely confounded but may be a proxy for undetermined social or biological factors, which may alert the surgeon to pay increased attention to outcomes in patients who test positive. Further study of the association of S. aureus colonization and increased length of stay after THA and readmission after TKA may be warranted to determine what the confounding variables are, which may be best accomplished using large cohorts or registry data.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Risk factors for preoperative nasal carriage of methicillin-resistant bacteria in total hip and knee arthroplasty patients

BACKGROUND

The present study aimed to identify risk factors for preoperative nasal carriage of resistant bacteria - MRSA methicillin-resistant Staphylococcus (S.) aureus, MRSE (methicillin-resistant Staphylococcus epidermidis), and MRCNS (methicillin-resistant coagulase negative staphylococci) in total hip and knee arthroplasty (THA and TKA) patients.

METHODS

Nasal cultures were obtained from 538 patients before THA (262 primary and 26 revision) and TKA (241 primary and 9 revision). These were classified either as methicillin-resistant bacteria (group MR) or methicillin-susceptible bacteria (including culture-negative) (group MS). Patient characteristics were compared between these groups using logistic regression models.

RESULTS

The resistant bacteria were preoperatively present in 33.1% (178 patients) among all patients. MRSE, MRCNS, and MRSA were detected in 27.5% (148 patients), 3.7% (20 patients), and 1.9% (10 patients). In the unadjusted comparisons of the patient characteristics between the groups MR and MS, a significant difference was found in the percentages of diabetic patients (15.2% vs. 9.2%, P = 0.04); the association remained after the multivariable adjustment for possible risk factors (P < 0.001). In addition, the diabetic patients in the group MR showed a higher percentage of receiving insulin injection than those in the group MS (25.9% vs. 6.1%, P = 0.063), and their mean levels of HbA1c were significantly higher in the group MR than the MS (6.8% vs. 6.4%, P = 0.03).

CONCLUSIONS

We identified diabetes as a risk factor for the preoperative nasal carriage of resistant bacteria. Our results suggest that, in order to prevent a surgical site infection (SSI), extra care should be taken in performing joint arthroplasties for diabetic patients, especially using insulin and with high HbA1c levels (≥6.6%) prior to the surgical procedures.

Predictors of Staphylococcus Aureus Nasal Colonization in Joint Arthroplasty Patients

Early identification and treatment of Staphylococcus aureus (S. aureus) nasal colonization can reduce the risk of prosthetic joint infection. The purpose of this study was to evaluate patient-specific predictors for S. aureus nasal colonization in total joint arthroplasty patients to aid in preoperative screening protocols. A total of 2,147 arthroplasty patients who were preoperatively screened for S. aureus nasal colonization were retrospectively reviewed. Factors analyzed consisted of procedure type, primary diagnosis, gender, ethnicity, body mass index, the presence of chronic obstructive pulmonary disease, obstructive sleep apnea, hypertension, diabetes mellitus, use of immunosuppression medication, smoking history, and chronic kidney disease. Univariate and multivariate analyses were performed with significance p < 0.05 and 95% confidence intervals. Overall, 3.7% (79) of our cohort tested positive for methicillin-resistant Staphylococcus aureus (MRSA), and 23.2% (493) tested positive for methicillin-sensitive Staphylococcus aureus (MSSA). Independent predictors for MRSA colonization were of Hispanic ethnicity (p = 0.001, odds ratio [OR] 13.98, confidence interval [CI] 2.97-65.76), immunosuppression medication use (p = 0.006, OR 2.82, CI 1.35-5.87), and revision total hip arthroplasty (THA) procedure (p < 0.001, OR 7.51, CI 2.58-21.89). Independent predictors for MSSA colonization were body mass index (BMI) >35 (p = 0.002, OR 1.57, CI 1.19-2.1). Variables were found to be protective against MSSA colonization including female gender (p = 0.012, OR 0.76, CI 0.61-0.94), age 60 to 69 (p = 0.025, OR 0.75, CI 0.58-0.96), and age 70 to 79 (p = 0.002, OR 0.63, CI 0.47-0.84). Age, Hispanic ethnicity, gender, revision THA, use of immunosuppression medication, and elevated BMI were independent risk factors for S. aureus nasal colonization.

An evaluation of risk factors for Staphylococcus aureus colonization in a pre-surgical population

Staphylococcus aureus (SA) colonization has significant implications in healthcare-associated infections. Here we describe a prospective study conducted in pre-surgical outpatients, done with the aim of identifying demographic and clinical risk factors for SA colonization. We found younger age to be a potential predictor of SA colonization.

Molecular characteristics and risk factor analysis of Staphylococcus aureus colonization put insight into CC1 colonization in three nursing homes in Shanghai

Research indicates that Staphylococcus aureus colonization in the elderly with predisposing risks is associated with subsequent infection. However, the molecular epidemiology and risk factors for S. aureus colonization among residents and staff in nursing homes (NHs) in China remain unclear. A multicenter study was conducted in three NHs in Shanghai between September 2019 and October 2019. We explored the prevalence, molecular epidemiology, and risk factors for S. aureus colonization. All S. aureus isolates were characterized based on antimicrobial resistance, virulence genes, multilocus sequence typing (MLST), staphylococcus protein A (spa) typing, and staphylococcal cassette chromosome mec (SCCmec) typing. NH records were examined for potential risk factors for S. aureus colonization. S. aureus and methicillin-resistant S. aureus (MRSA) isolates were detected in 109 (100 residents and 9 staff, 19.8%, 109/551) and 28 (24 residents and 4 staff, 5.1%, 28/551) subjects among 496 residents and 55 staff screened, respectively. Compared to methicillin-susceptible S. aureus isolates, all 30 MRSA isolates had higher resistance rates to most antibiotics except minocycline, rifampicin, linezolid, vancomycin, and teicoplanin. Sequence type (ST) 1 (21.3%) was the most common sequence type, and t127 (20.5%) was the most common spa type among 122 S. aureus isolates. SCCmec type I (70%) was the dominant clone among all MRSA isolates. CC1 (26/122, 21.3%) was the predominant complex clone (CC), followed by CC398 (25/122, 20.5%), CC5 (20/122, 16.4%) and CC188 (18/122, 14.8%). Female sex (OR, 1.70; 95% CI, 1.04-2.79; P = 0.036) and invasive devices (OR, 2.19; 95% CI, 1.26-3.81; P = 0.006) were independently associated with S. aureus colonization.

What is the most cost-effective strategy for nasal screening and Staphylococcus aureus decolonization in patients undergoing total hip arthroplasty?

Background

To reduce periprosthetic joint infection after total hip arthroplasty (THA), several nasal screening and decolonization strategies for methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) have been performed. These include universal decolonization (UD; i.e., no screening and decolonization for all patients), universal screening and target decolonization (US; i.e., screening for all patients and decolonization for bacterial positive patients), and target screening and decolonization (TS; i.e., screening and decolonization for high-risk populations only). Although TS is the most cost-effective strategy, useful risk factors must be identified. The purpose of this study was to evaluate the presence of predictive factors that enable the TS strategy to be successfully implemented and to compare the costs of each strategy.

Methods

A total of 1654 patients scheduled for primary or revision THA (1464 female, 190 male; mean age 64 years) were screened prior to surgery for bacterial colonization of the nasal mucosa. Risk factors for positive MRSA and S. aureus (including both MRSA and MSSA) tests were analyzed according to the following parameters: sex, age ≥ 80 years, body mass index ≥ 30 kg/m², antibiotic use within 3 years, corticosteroid use, serum albumin < 3.5 g/dL, glomerular filtration rate < 50 mL/min, presence of brain, thyroid, cardiac, or pulmonary disease, diabetes, asthma, smoking status, and whether revision surgery was performed. The average cost of each strategy was calculated.

Results

In total, 29 patients (1.8 %) tested positive for MRSA and 445 (26.9 %) tested positive for S. aureus. No parameters were identified as independent risk factors for MRSA and only female sex was identified as a risk factor for S. aureus (p = 0.003; odds ratio: 1.790; 95 % confidence interval: 1.210–2.640). The average cost of each strategy was 1928.3 yen for UD, 717.6 yen for US, and 717.6 yen for TS (for eradicating MRSA), and 1928.3 yen for UD, 1201.6 yen for US, and 1160.4 yen for TS (for eradicating S. aureus).

Conclusions

No useful predictive parameters for implementing the TS strategy were identified. Based on cost implications, US is the most cost-effective strategy for THA patients.

Is Preoperative Staphylococcus aureus Screening and Decolonization Effective at Reducing Surgical Site Infection in Patients Undergoing Orthopedic Surgery? A Systematic Review and Meta-Analysis With a Special Focus on Elective Total Joint Arthroplasty

BACKGROUND

Staphylococcus aureus is a major pathogen implicated in orthopedic infections worldwide. Preoperative decolonization has been promoted but different strategies present mixed results. Thus, the goals of this study are to determine (1) whether S aureus screening and/or decolonization is effective at reducing surgical site infection in orthopedic surgery, (2) with a special focus on elective total joint arthroplasty (TJA), and (3) which preoperative S aureus screening/treatment strategy is most cost-effective for TJA.

METHODS

PubMed, Ovid MEDLINE, and Cochrane databases were searched on January 1, 2020, using a systematic strategy. We included papers with data comparing surgical site infection and periprosthetic joint infection rate in orthopedic surgery and/or elective total hip and knee arthroplasty patients before/after S aureus screening and/or decolonization protocol and papers evaluating the cost-effectiveness of different S aureus screening/treatment strategies.

RESULTS

A total of 1260 papers were screened, and 32 papers were ultimately included. Results showed an increased risk of developing any infection (relative risk [RR] = 1.71 ± 0.16) and S aureus infection (RR = 2.79 ± 0.45) after orthopedic surgery without previous nares and whole-body decolonization. Focusing exclusively on elective TJA, there was an increased risk of developing any infection (RR = 1.70 ± 0.17) and S aureus infection (RR = 2.18 ± 0.41) if no decolonization is performed. All strategies appeared to be cost-effective, although universal decolonization without screening seemed to be the most advantageous.

CONCLUSION

Preoperative S aureus screening/decolonization protocol lowered the risk of infection after elective orthopedic and TJA surgeries. However, further studies are needed to determine optimal clinical and cost-effective methodologies.

Decolonization of Staphylococcus aureus

Staphylococcus aureus infections are associated with increased morbidity, mortality, hospital stay, and health care costs. S aureus colonization has been shown to increase risk for invasive and noninvasive infections. Decolonization of S aureus has been evaluated in multiple patient settings as a possible strategy to decrease the risk of S aureus transmission and infection. In this article, we review the recent literature on S aureus decolonization in surgical patients, patients with recurrent skin and soft tissue infections, critically ill patients, hospitalized non-critically ill patients, dialysis patients, and nursing home residents to inform clinical practice.

Methicillin-resistant Staphylococcus aureus colonization in patients undergoing primary total hip arthroplasty

Introduction. Nasal and skin colonization by methicillin-resistant Staphylococcus aureus (MRSA) are linked to a higher incidence of infection after total joint replacement. The prevalence of colonization is poorly defined in Latin American countries.Aim. The aim of the present study was to determine the prevalence of MRSA colonization in the nostrils and groin using real-time polymerase chain reaction (RT-PCR) in patients undergoing total hip arthroplasty (THA).Methodology. In this cross-sectional study, 146 patients undergoing THA between December 2015 and March 2017 in a tertiary-care university-affiliated hospital in Chile were screened for MRSA colonization before the procedure using RT-PCR independently in the nostrils and groin. Risk factors for colonization were documented.Results. Seven of the 146 (5 %) patients undergoing THA were carriers of MRSA in the nostrils and/or the groin. Recent antibiotic use was identified as a risk factor for colonization, OR=4.86 [95 % confidence interval (CI): 1.56-13.96]. Patients reporting at least one of the seven surveyed risk factors had an OR of 2.39 (95 % CI: 0.37-25.77) for colonization. MRSA colonization frequency was twofold higher in the groin as opposed to the nostrils (P=0.014).Conclusion. Five percent of the patients undergoing THA were identified as carriers of MRSA. Recent antibiotic use is a relevant risk factor for MRSA colonization in patients undergoing primary total hip arthroplasty.

Prevalence of Staphylococcus aureus colonization in patients for total joint arthroplasty in South Africa

BACKGROUND

Periprosthetic joint infections (PJIs) are a major source of morbidity and mortality for patients undergoing total joint arthroplasty (TJA). Staphylococcus aureus (S. aureus) colonization is an independent, modifiable risk factor for periprosthetic joint infections. Post-operative infections are reported to be ten times greater in S. aureus carriers than in non-carriers in developed countries though recorded data is lacking for the developing world. This study aims to determine the prevalence of S. aureus colonization in patients awaiting TJA in South Africa.

METHODS

We prospectively assessed 119 patients awaiting total knee arthroplasty and total hip arthroplasty between May and October 2016. We screened three separate anatomical sites on each patient for S. aureus. Patients with positive cultures were treated with intranasal mupirocin ointment and chlorhexidine body wash. Univariate and comparative statistical analyses to determine risk factors for colonization was conducted using t tests, Fisher's exact tests, and chi-square analyses.

RESULTS

The overall prevalence of methicillin-sensitive S. aureus colonization was 31.9% (n = 38). There were no patients colonized with methicillin-resistant S. aureus. Nasal swabs returned a yield of 81.6% (n = 31), with groin swabs and axillary swabs at 39.5% (n = 15) and 28.9% (n = 11), respectively. Eradication was successful in 94.74% (n = 36) after 5 days treatment. All patients (100%) were decolonized after counseling and repeat eradication treatment. The overall complication rate was 7.6% (n = 9). The 30-day readmission rate in the S. aureus-colonized group was 7.9% (n = 3) as opposed to 7.4% (n = 6) in the non-colonized cohort. There were no 60- and 90-day readmissions and no cases were revised at a mean follow-up of 2.26 years.

CONCLUSIONS

The rate of S. aureus colonization in patients undergoing elective TJA in a developing country was 31.9% and is equivalent to reported rates in developed countries. Eradication treatment with combined intranasal mupirocin ointment and chlorhexidine body wash is a successful treatment modality. A larger cohort of patients is recommended to determine risk factors and post-operative septic sequelae in this population group.

[Treatment of rheumatic disease with renal insufficiency]

BACKGROUND

Reduced renal function is not rare in patients with inflammatory rheumatic diseases and is associated with an increased risk of treatment-induced and perioperative adverse events.

METHOD

A literature search was carried out for the medical treatment and perioperative management of rheumatic disease in the presence of renal insufficiency.

RESULTS

Patients with rheumatic disease and renal insufficiency have a higher risk of cardiovascular disease, bone loss and immunodeficiency than those without kidney disease. The perioperative rate of cardiovascular and infectious complications and the risk of acute kidney failure are elevated in these patients. The pharmacokinetics of many drugs used in rheumatology is influenced by the kidney function. Especially methotrexate is contraindicated in patients with an estimated glomerular filtration rate (eGFR) <45 ml/min. Nonsteroidal anti-inflammatory drugs (NSAIDS) and cyclooxygenase (COX)-2 inhibitors should not be used with renal insufficiency or only for a short term with the lowest effective dose. The treatment of osteoporosis with antiresorptive drugs may lead to adynamic bone disease in advanced kidney disease, and, therefore, the use of these drugs is controversial.

CONCLUSION

Medication should be modified in patients with rheumatic disease and kidney involvement according the grade of renal insufficiency. There is also a need for special perioperative management in these patients, with interdisciplinary cooperation of rheumatologists, nephrologists and orthopedic doctors.

Health Disparities in Staphylococcus aureus Transmission and Carriage in a Border Region of the United States Based on Cultural Differences in Social Relationships: Protocol for a Survey Study

Background

Health care–associated Staphylococcus aureus infections are declining but remain common. Conversely, rates of community-associated infections have not decreased because of the inadequacy of public health mechanisms to control transmission in a community setting. Our long-term goal is to use risk-based information from empirical socio-cultural-biological evidence of carriage and transmission to inform intervention strategies that reduce S aureus transmission in the community. Broad differences in social interactions because of cultural affiliation, travel, and residency patterns may impact S aureus carriage and transmission, either as risk or as protective factors.

Objective

This study aims to (1) characterize S aureus carriage rates and compare circulating pathogen genotypes with those associated with disease isolated from local clinical specimens across resident groups and across Hispanic and non-Hispanic white ethnic groups and (2) evaluate social network relationships and social determinants of health-based risk factors for their impact on carriage and transmission of S aureus.

Methods

We combine sociocultural survey approaches to population health sampling with S aureus carriage and pathogen genomic analysis to infer transmission patterns. Whole genome sequences of S aureus from community and clinical sampling will be phylogenetically compared to determine if strains that cause disease (clinical samples) are representative of community genotypes. Phylogenetic comparisons of strains collected from participants within social groups can indicate possible transmission within the group. We can therefore combine transmission data with social determinants of health variables (socioeconomic status, health history, etc) and social network variables (both egocentric and relational) to determine the extent to which social relationships are associated with S aureus transmission.

Results

We conducted a first year pilot test and feasibility test of survey and biological data collection and analytic procedures based on the original funded design for this project (#NIH U54MD012388). That design resulted in survey data collection from 336 groups and 1337 individuals. The protocol, described below, is a revision based on data assessment, new findings for statistical power analyses, and refined data monitoring procedures.

Conclusions

This study is designed to evaluate ethnic-specific prevalence of S aureus carriage in a US border community. The study will also examine the extent to which kin and nonkin social relationships are concordant with carriage prevalence in social groups. Genetic analysis of S aureus strains will further distinguish putative transmission pathways across social relationship contexts and inform our understanding of the correspondence of S aureus reservoirs across clinical and community settings. Basic community-engaged nonprobabilistic sampling procedures provide a rigorous framework for completion of this 5-year study of the social and cultural parameters of S aureus carriage and transmission.

Septic patients in the intensive care unit present different nasal microbiotas

AIM

The primary objective of this study was to evaluate correlations among mortality, intensive care unit (ICU) length of stay and airway microbiotas in septic patients.

MATERIALS & METHODS

A deep-sequencing analysis of the 16S rRNA gene V4 region was performed.

RESULTS

The nasal microbiota in septic patients was dominated by three nasal bacterial types (Corynebacterium, Staphylococcus and Acinetobacter). The Acinetobacter type was associated with the lowest diversity and longest length of stay (median: 9 days), and the Corynebacterium type was associated with the shortest length of stay. We found that the Acinetobacter type in the >9-day group was associated with the highest mortality (33%).

CONCLUSION

Septic patients have three nasal microbiota types, and the nasal microbiota is related to the length of stay and mortality.