Emerging multidrug resistance of methicillin-resistant Staphylococcus aureus in hand infections

Diagnosis and Management of Hand Infections

Hand and upper-extremity infections span a broad spectrum of presentations for the hand surgeon, primary care provider, and emergency medicine practitioner. As many hand infections arise from penetrating trauma, knowledge of the offending pathogen, location, and mode of spread allows the clinician to determine the appropriate intervention. Along with a thorough history and physical examination, patient factors such as age, occupation, medical comorbidities, and surgical history should be noted. Timely diagnosis and appropriate management allow for optimal recovery and outcomes. In this article, we describe the ongoing debate regarding the timing and influence of preoperative antibiotics on culture yield, timing of debridement for open fractures as it relates to infection risk, and strategies for obtaining adequate cultures to guide antibiotic therapy for complex infections such as periprosthetic joint and hardware infections. Given the changing epidemiological landscape and increased rates of antibiotic resistance, it is critical to promote antibiotic stewardship. We provide updated treatment recommendations and antibiotic profiles for the treatment of common hand infections. Finally, we discuss newer technologies such as next-generation sequencing and development of promising diagnostic and treatment strategies that will enhance the hand surgeon's ability to treat complex hand infections.

Bacterial and viral infections of the nail unit: Tips for diagnosis and management

The nail unit is the most commonly affected area in hand infections, which can be primary infection or superinfection complicating other nail or skin disorders. Trauma, mechanical or chemical, is usually the trigger enabling infiltration of infectious organisms. Artificial nails and nail polish are also a possible cause of bacterial infection, harboring microorganisms. In severe acute bacterial infection, surgical intervention is often needed to prevent morbidity and disability. Abscess should always be drained, but viral infection such as herpetic whitlow, may mimic an abscess and, in contrast, requires non-operative treatment; to prevent sequelae. A more conservative approach is also generally advisable in less severe bacterial infection, other viral infections and in subacute or chronic nail infection. The present review deals with acute, subacute and chronic bacterial and viral infections of the nail unit, with a focus on diagnostic and treatment options. LEVEL OF EVIDENCE: III, systematic review of level III studies.

Acute-Phase Reactants in Operatively Treated Upper Extremity Infections: A Retrospective Review

Background: There are limited data on the use of acute-phase markers in the diagnosis of upper extremity infections. The goal of this study was to determine the percentage of patients with elevated white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) in the setting of an upper extremity infection requiring operative debridement. Methods: In a retrospective review over 12 years, 61 patients who met the inclusion criteria were identified. Results: C-reactive protein was the most sensitive test in the detection of culture-positive infection compared with ESR and WBC (P < .001, P < .0001, respectively). Ninety percent of patients (55 of 61) presented with an abnormal CRP value. The WBC count and ESR were abnormal in 54% and 67% of our cohort, respectively. Conclusions: C-reactive protein is the most sensitive laboratory test when evaluating upper extremity infections that necessitate debridement. The WBC count and ESR should be interpreted with caution and can be normal even in the presence of an infection.

Optimizing Treatment of Hand Infections: Is MRSA Coverage Always Necessary?

Multiple publications have highlighted the prevalence of methicillin resistant Staphylococcus aureus (MRSA) as a cause of hand infections. We hypothesized that these publications have shifted the empiric treatment of hand infections. The aim of this study was to identify the current standard of care, the most common causative bacteria, and factors leading to extended length of stay for hand infection patients at a suburban hospital to improve treatment and establish an optimized care protocol.

Methods

Retrospective cohort analysis was conducted to identify all patients admitted for hand infections over an 8-year period. A comprehensive chart review of each patient's hospital course was completed.

Results

A total of 70 patients were included. Maximum white blood cell count ≥ 12 was associated with a significantly longer hospital length of stay (9.1 days versus 5.4 days) compared to WBC values < 12 (P < 0.05). Also, 11 out of 23 (47.8%) underwent two or more incision and drainages (I&D's), compared with patients with maximum WBC < 12. Vancomycin use as an empiric antibiotic was widespread (68 patients, 97.1%), despite only 14 (20%) having MRSA positive cultures. Univariate analysis identified a significant increased likelihood for increased length of stay (P < 0.05) and rise in creatinine (P < 0.05) in patients with an initial vancomycin trough level > 20.

Conclusions

This analysis of hand infection treatment in a suburban hospital demonstrates the incidence of MRSA hand infections may not be universally high across institutions. Each hospital should review its own data to optimize hand infection treatment and its associated costs.

Twenty-Year Trends in Upper-Extremity Infections at a Single Urban Institution

Purpose

Methods

Results

Conclusions

Type of study/level of evidence

Diagnosis and Management of Common Hand Infections

While many hand infections are superficial, diligent evaluation, diagnosis, and treatment of these infections are central for preventing disability and morbidity. Maintaining a wide differential diagnosis is important as some hand infections may mimic others. In geographic areas with more than a 10% to 15% prevalence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) hand infections, empiric antibiotics should adequately cover MRSA. Once culture results are available, antibiotic regimens should be narrowed to reduce the development of resistant pathogens.

Bacterial and Viral Infections of the Nail Unit

Bacterial and viral infections of the nail unit are very common as primary infections, especially bacterial paronychia and warts, but they can also be superinfections complicating other nail disorders. In many nail unit infections, the clinical presentation is nonspecific: in these cases, diagnostic tests are mandatory before treatment, to avoid spread of the infection and drug resistance. The most common forms of bacterial and viral infections that may affect the nail unit are herein described in detail, with diagnostic and treatment options provided.

Increasing Multidrug Antibiotic Resistance in MRSA Infections of the Hand: A 10-Year Analysis of Risk Factors

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is the most common pathogen isolated from hand abscesses. The purpose of this study was to understand trends and changes in longitudinal antibiotic resistance profiles and risk factors for these infections to better guide empiric treatment of hand infections. Methods: We performed a retrospective review of culture-positive hand infections over a 10-year period at an urban academic institution from 2005 to 2014. A subset of MRSA hand infections from 2013 to 2014 was then subanalyzed for risk factors for antibiotic resistance for antibiotics with increasing antibiotic resistance during this period. Results: MRSA grew in 46% of hand infections, with a decreasing incidence over the 10-year study period. However, in the same time period clindamycin and levofloxacin resistance increased from 7% to 31% and 12% to 56%, respectively. Risk factors for clindamycin resistance included nosocomial infections and a history of intravenous drug use and hepatitis C. Risk factors for levofloxacin resistance included a history of diabetes and a fever upon initial presentation. Conclusions: The incidence of multidrug resistance remains high, with growing resistance to clindamycin and levofloxacin. There remains a trend for increased clindamycin resistance for patients with history of intravenous drug use and nosocomial infections. Our findings indicate that clindamycin and levofloxacin should be avoided for empiric treatment for hand infections in patients with these risk factors.

Antibiotic Management and Antibiotic Resistance in Hand Infections

The rates of methicillin-resistant infections in the hand and upper extremity approach 50% in many facilities. In addition, multidrug resistance is beginning to include clindamycin. This article discusses the history, prevalence, and treatment of both community-acquired and health care-associated methicillin-resistant Staphylococcus aureus in regard to hand infections.

Characterizing Hand Infections in an Underserved Population: The Role of Diabetic Status in Antibiotic Choice and Infection Location

Introduction Patients with diabetes mellitus (DM) in underserved communities are at greater risk for hand infections. We aimed to describe the features of hand infections presenting to an urban hospital via laboratories, microbiology, and antibiotic choice with respect to diabetic status. Materials and Methods Patients presenting with any hand infection were reviewed and stratified by DM status and infection location. Labs, culture results, antibiotic regimens, and significant predictors of laboratories or infection location were analyzed. Results Fifty-three patients were included: DM ( n = 24), no-DM ( n = 24), and unknown status ( n = 5). Culture rates were comparable between all groups. Mean erythrocyte sedimentation rate (ESR) was significantly higher in DM (76.19 vs. 51.33); mean white blood cell count (WBC) and C-reactive protein (CRP) were comparable. Diabetics had higher odds of increased ESR (odds ratio [OR] = 1.03). Diabetics received vancomycin/piperacillin/tazobactam (VAN/PTZ) significantly more often (52% vs. 8%). Providers treated DM with VAN/PTZ or any VAN-containing regimen more often than with any other regimen. Proximal infections had significantly higher mean CRP (136.9 vs. 50.5) and WBC (5.19 vs. 3.9) and higher CRP (OR = 1.02). Conclusion This study highlights the need for systematic criteria to better risk- stratify patients for appropriate antibiotic treatment. It may not be appropriate to treat both groups differently, as overly aggressive antibiotic selection may contribute to drug-resistance development.

Surgical Upper Extremity Infections in Immunosuppressed Patients: A Comparative Analysis With Diagnosis and Treatment Recommendations for Hand Surgeons

Background: Immunosuppression is encountered in patients with oncologic, transplant, and autoimmune disorders. The purpose of this study is to provide guidance for physicians treating surgical hand and upper extremity (UE) infections in immunosuppressed (IS) patients. Methods: We retrospectively reviewed our database of patients presenting with UE infections over 3 years. IS patients were matched randomly to non-IS patients. Patient background, infection presentation, surgical evaluation, and microbiology variables were recorded. Infection variables included mechanism, location, and type. Outcomes included inpatient length of stay (LOS) and need for repeat drainage. Results: We identified 35 IS and 35 non-IS out of 409 UE infection patients. Patients most commonly had a hematologic malignancy (34%) as their IS class, and the most frequent immunosuppressive medication was glucocorticoids (57%). IS patients were more likely to be older and less likely to have a history of drug abuse or hepatitis C virus infections. IS infections were more likely to have idiopathic mechanisms, more likely to involve deeper anatomy such as joints, bone, tendon sheath, or muscle/fascia, and less likely to present with leukocytosis. IS cultures more commonly exhibited atypical Mycoplasma or fungus. There was no difference between IS and non-IS patients regarding LOS or recurrent drainage. Conclusions: Mechanism and white blood cell count are less reliable markers of infection severity in IS patients. Physicians treating infections in IS patients should maintain a higher suspicion for deeper involved anatomy and atypical microbiology. Nonetheless, with careful inpatient management and closer surveillance, outcomes in IS patients can approach that of non-IS patients.

Development and Validation of a Prognostic, Risk-Adjusted Scoring System for Operative Upper-Extremity Infections

PURPOSE

Acute infections of the distal upper extremity (UE) can require one and possibly multiple debridements. We aimed to develop and validate a prognostic scoring system based on patient, infection, and microbiology risk factors to help with operative planning and patient counseling.

METHODS

We studied all acute surgical UE infections distal to the elbow joint over a 5-year period. A split-sample design was created with 1:1 randomization into development and validation samples. The primary outcome was infection persistence, defined as the need for additional operative drainage according to usual indications. Multivariable logistic regression identified risk factors for persistent infections in the development sample, which was translated to a simple clinical scoring system derived from regression coefficients. The model was then tested separately against the validation sample.

RESULTS

A total of 602 patients were included; 31% of all infections exhibited persistence. Independent risk factors from the development sample included diabetes (3 points), smoking (2 points), leukocytosis at presentation (2 points), animal bite mechanism (3 points), osteomyelitis (4 points), tenosynovitis (7 points), pyarthrosis (3 points), necrotizing fasciitis (11 points), and methicillin-resistant Staphylococcus aureus (3 points). These were all confirmed in the validation sample. Infections were categorized into 3 groups based on risk for persistent infection: low (less than 8 points), medium (8-11 points), and high (12 points or more). In the validation sample, the probability of persistent infection for these 3 groups was 23%, 57%, and 79%, respectively. The c statistic for the model in the validation sample was 0.79.

CONCLUSIONS

Persistence of acute surgical distal UE infections is mediated by patient and microbiology factors, as well as infection mechanism and type. Surgeons can use this risk-adjusted prognostic scoring system to anticipate which infections may require additional therapeutic debridement and plan operative schedules and counsel patients accordingly.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

MRSA Incidence and Antibiotic Trends in Urban Hand Infections: A 10-Year Longitudinal Study

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is the most reported pathogen in hand infections at urban medical centers throughout the country. Antibiotic sensitivity trends are not well known. The purposes of this study were to examine and determine the drug resistance trends for MRSA infections of the hand and to provide recommendations for empiric antibiotic treatment based on sensitivity profiles. Methods: A 10-year longitudinal, retrospective chart review was performed on all culture-positive hand infections encountered at a single urban medical center from 2005 to 2014. The proportions of all organisms were calculated for each year and collectively. MRSA infections were additionally subanalyzed for antibiotic sensitivity. Results: A total of 815 culture-positive hand infections were identified. Overall, MRSA grew on culture in 46% of cases. A trend toward decreasing annual MRSA incidence was noted over the 10-year study period. There was a steady increase in polymicrobial infections during the same time. Resistance to clindamycin increased steadily during the 10-year study, starting at 4% in 2008 but growing to 31% by 2014. Similarly, levofloxacin resistance consistently increased throughout the study, reaching its peak at 56% in 2014. Conclusions: The annual incidence of MRSA in hand infections has declined overall but remains the most common pathogen. There has been an alternative increase in the number of polymicrobial infections. MRSA resistance to clindamycin and levofloxacin consistently increased during the study period. Empiric antibiotic therapy for hand infections should not only avoid penicillin and other beta-lactams but should also consider avoiding clindamycin and levofloxacin for empiric treatment.

Evolving Threat of Community Acquired Methicillin Resistant Staphylococcus aureus Upper Extremity Infections in the South Pacific: 2011-2015

Background: Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) rates have been increasing worldwide and contribute to a growing "global health security threat" as reported by the WHO. Our group previously reported an overall rate of 7% in CA-MRSA upper extremity infections between 2004-2009 at the Auckland Regional Hand Unit. This fell below the Center for Disease Control (CDC) recommendation for empiric antimicrobial cover once local rates exceed 10-15%. We examined prevalence and characteristics of CA-MRSA upper extremity infections in our region over a subsequent 5-year period. Methods: One thousand two hundred and fifty-two patients with upper extremity infections requiring operative management between 2011 and 2015 inclusive were included in this study. Associated clinical characteristics were recorded including ethnicity, cultured organisms, antibiotic sensitivities, infection rate, and treatment practice. Results: One hundred and fifty (12%) of patients had culture positive CA-MRSA upper extremity infections. There was an increasing annual trend. Of note, rates of CA-MRSA in the Maori and Pacific Island ethnic subpopulations exceeded 15% in 2014 and 2015. Susceptibilities, associated factors and patient demographics are reported. Conclusions: Our unit enjoys significantly lower rates of CA-MRSA upper extremity infections than has been reported internationally. However, trends are increasing relative to our prior 6-year report, and the threshold for empiric treatment has been met within the Maori and Pacific Island ethnic subpopulations. This evolving threat is also highlighted by increasing cases of multi-drug resistant CA-MRSA. Evolving regional guidelines for empiric coverage of CA-MRSA among high-risk ethnic subpopulations identified by this study are underway.

Infections of the hand: an overview

Infections of the hand are common entities that are frequently encountered by orthopaedic surgeons and primary care physicians.

A high clinical suspicion and a thorough medical history with information about the social and working history of the patients, correct identification of the type and cause of the infection, and prompt initiation of appropriate treatment by the infectious diseases physicians and orthopaedic surgeons are required.

Late diagnosis and inappropriate treatment may be a significant cause of morbidity for the hand and mortality for the patients. This article reviews the clinical spectrum and microbiology of the most common infections of the hand, and discusses the current concepts for their treatment. The aim is to increase the awareness of the treating physicians of the diagnosis and management of infections in the hand.

Cite this article: EFORT Open Rev 2019;4:183-193. DOI: 10.1302/2058-5241.4.180082

Septic Arthritis of the Wrist

Septic arthritis of the wrist is an uncommon condition, but one that can result in substantial morbidity. Timely identification and treatment is critical to patient care. No serum laboratory values have been shown to consistently confirm wrist joint infection. Thus, diagnosis is made based mainly on a thorough patient history, physical examination, and joint aspiration. When infection is suspected, aspiration of the wrist should be performed to confirm the diagnosis. Broad-spectrum antibiotics and joint aspiration or surgery are required to manage the infection and prevent sequelae.

Determination of Antimicrobial Potential of Five Herbs used in Ayurveda Practices against Candida albicans, Candida parapsilosis and Methicillin Resistant Staphylococcus aureus

Background

Medicinal plants are an important source of novel antimicrobial agents. Ayurvedic treatment involves the use of a variety of medicinal plants that merit investigation.

Aims

To investigate the antimicrobial activity of bark of Pongamia pinnata (L.) Pierre, stem of Rubia cordifolia Linn, leaves of Jasminum officinale Linn, stem of Berberis ceylanica C.K. Schneid. and fruit of Garcina zeylanica Roxb.

Subjects and Methods

Aqueous and ethanolic extracts of dried bark of Pongamia pinnata (Magul karanda), dried stem of Rubia cordifolia Linn (Welmadata), tender leaves of Jasminum officinale Linn (Jasmine) and dried stem of Berberis ceylanica (Dāruharidrā) were prepared according to standard protocols and tested for antimicrobial activity against five clinical isolates and one standard strain each of Candida albicans (ATCC 10231), Candida parapsilosis (ATCC 22019) and six Methicillin Resistant Staphylococcus aureus (MRSA) clinical isolates using the well diffusion method. Experiments were done in triplicates using well diffusion method. The plant extracts which gave a zone of inhibition in the well diffusion assay were further tested for Minimum Inhibitory Concentrations (MIC).

Results

Aqueous and ethanolic extracts of Berberis ceylanica and ethanolic extract of Rubia cordifolia had antimicrobial activity against Candida albicans and Candida parapsilosis. Aqueous and ethanolic extracts of Garcinia zeylanica, and the ethanolic extracts of Jasminum officinale, Rubia cordifolia and Pongamia pinnata had antimicrobial activity against MRSA.

Conclusions

Berberis ceylanica and Rubia crodifolia had antimicrobial activity against Candida species while Garcinia zeylanica, Jasminum officinale, Rubia crodifolia and Pongamia pinnata had antimicrobial activity against MRSA.

Adherence of staphylococcus aureus to catheter tubing inhibition by quaternary ammonium compounds

INTRODUCTION

S. aureus is a Gram positive bacterium which is responsible for a wide range of infections. This pathogen has also the ability to adhere to biotic or abiotic surface such as central venous catheter (CVC) and to produce a biofilm. The aim of this study was to evaluate the effect of hexadecyltrimethyl ammonium bromide (HTAB) and Hexadecylbetainate chloride (HBC) on Staphylococcus aureus adherence to the catheter tubing and on bacteria growth.

METHODS

Broth microdilution method was used to determine the Minimal Inhibitory Concentration (MIC). The detection of slime production was done by Congo Red Agar method, and the adherence of bacteria to the catheter tubing was evaluated by the enumeration of bacteria on plate counts.

RESULTS

The results of this study showed that the MICs of HTAB were ranged from 0.125 to 0.5 µg/mL, and those of HBC fluctuated between 2 to 8 µg/mL. HTAB and HBC inhibited bacteria adhesion on the surface of the catheter tubing.

CONCLUSION

This study showed that HTAB and HBC can prevent the adherence of S. aureus strains to the surface of catheter tubing, suggesting that they could be used to prevent the risk of catheter related bloodstream infections.

Surgeon preferences regarding antibiotic prophylaxis for ballistic fractures

BACKGROUND

Scant evidence exists to support antibiotic use for low velocity ballistic fractures (LVBF). We therefore sought to define current practice patterns. We hypothesized that most surgeons prescribe antibiotics for LVBF, prescribing is not driven by institutional protocols, and that decisions are based on protocols utilized for blunt trauma.

MATERIALS AND METHODS

A web-based questionnaire was emailed to the membership of the Orthopaedic Trauma Association (OTA). The questionnaire included demographic information and questions about LVBF treatment practices. Two hundred and twenty surgeons responded. One hundred and fifty-four (70 %) respondents worked at a Level-1 trauma center, 176 (80 %) had received fellowship education in orthopaedic trauma and 104 (47 %) treated at least 10 ballistic fractures annually. Responses were analyzed with SAS 9.3 for Windows (SAS Institute Inc, Cary, NC).

RESULTS

One hundred eighty-six respondents (86 %) routinely provide antibiotics for LVBF. Those who did not were more apt to do so for intra-articular fractures (8/16, 50 %) and pelvic fractures with visceral injury (10/16, 63 %). Most surgeons (167, 76 %) do not believe the Gustilo-Anderson classification applies to ballistic fractures, and (20/29, 70 %) do not base their antibiotic choice on the classification system. Few institutions (58, 26 %) have protocols guiding antibiotic use for LVBF.

CONCLUSIONS

Routine antibiotic use for LVBF is common; however, practice is not dictated by institutional protocol. Although antibiotic use generally follows current blunt trauma guidelines, surgeons do not base their treatment decisions the Gustilo-Anderson classification. Given the high rate of antibiotic use for LVBF, further study should focus on providing evidence-based treatment guidelines.

The Effects of Early Antibiotic Administration on Bacterial Culture Growth From Hand Abscesses

BACKGROUND

Traditional management of hand abscesses consists of withholding antibiotics prior to drainage to optimize bacterial culture growth and outcome. The purpose of this study was to determine the effect of preoperative empiric antibiotics on the rate of culture growth and rate of adverse events in patients with acute hand abscesses.

METHODS

We performed a retrospective review of prospectively collected data on 88 consecutive hand abscesses that received empiric antibiotics prior to incision and drainage from 2012 to 2013 at an urban academic institution. We analyzed patient demographics, bacteriology, culture growth results, time to surgery, and frequency of adverse events.

RESULTS

The overall rate of positive culture growth was 90% (n = 79) despite running the antibiotics for a mean of 31 hours prior to debridement. Furthermore, 96% of the isolates were given a susceptible antibiotic during that time. The mean number of debridements was 1.5 per patient, but 4 re-operations were necessary for wound complications. No patients required an amputation or were upgraded to intensive care.

CONCLUSIONS

Preoperative empiric antibiotic administration does not appear to greatly reduce bacterial culture growth from hand abscesses. The adverse events are relatively few for simple abscesses treated with pre-surgical antibiotics and decompression within 24 hours.

Risk factors associated with clindamycin-resistant, methicillin-resistant Staphylococcus aureus in hand abscesses

PURPOSE

To identify risk factors for clindamycin resistance in acute hand abscesses caused by methicillin-resistant Staphylococcus aureus (MRSA).

METHODS

We performed a retrospective review of 247 consecutive culture-positive hand abscesses from 2010 to 2012 at an urban hospital. Historical and laboratory data from patients with abscesses that grew MRSA with and without clindamycin resistance were compared in a multivariate analysis.

RESULTS

Methicillin-resistant Staphylococcus aureus grew on culture from 103 abscesses; 16% of those isolates were resistant to clindamycin. Multivariate analysis showed that younger age, intravenous drug use, and nosocomial acquired MRSA were significant risk factors for concurrent clindamycin resistance. Patients with a history of intravenous drug use and nosocomial acquired MRSA were, respectively, 11 and 5 times more likely to have concurrent clindamycin resistance. History of MRSA infection and human immunodeficiency virus were not identified as risk factors.

CONCLUSIONS

Patients with a history of intravenous drug use or recent contact with health care facilities appear to be a potential reservoir for emerging multidrug-resistant MRSA. Selection of clindamycin as an empiric antibiotic should be especially avoided for these groups.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.