Known Risk Factors For Infection Research Articles

Gut community structure as a risk factor for infection in Klebsiella pneumoniae-colonized patients.

The primary risk factor for infection with members of the Klebsiella pneumoniae species complex is prior gut colonization, and infection is often caused by the colonizing strain. Despite the importance of the gut as a reservoir for infectious K. pneumoniae, little is known about the association between the gut microbiome and infection. To explore this relationship, we undertook a case-control study comparing the gut community structure of K. pneumoniae-colonized intensive care and hematology/oncology patients. Cases were K. pneumoniae-colonized patients infected by their colonizing strain (N = 83). Controls were K. pneumoniae-colonized patients who remained asymptomatic (N = 149). First, we characterized the gut community structure of K. pneumoniae-colonized patients agnostic to case status. Next, we determined that gut community data is useful for classifying cases and controls using machine learning models and that the gut community structure differed between cases and controls. K. pneumoniae relative abundance, a known risk factor for infection, had the greatest feature importance, but other gut microbes were also informative. Finally, we show that integration of gut community structure with bacterial genotype data enhanced the ability of machine learning models to discriminate cases and controls. Interestingly, inclusion of patient clinical variables failed to improve the ability of machine learning models to discriminate cases and controls. This study demonstrates that including gut community data with K. pneumoniae-derived biomarkers improves our ability to classify infection in K. pneumoniae-colonized patients.IMPORTANCEColonization is generally the first step in pathogenesis for bacteria with pathogenic potential. This step provides a unique window for intervention since a given potential pathogen has yet to cause damage to its host. Moreover, intervention during the colonization stage may help alleviate the burden of therapy failure as antimicrobial resistance rises. Yet, to understand the therapeutic potential of interventions that target colonization, we must first understand the biology of colonization and if biomarkers at the colonization stage can be used to stratify infection risk. The bacterial genus Klebsiella includes many species with varying degrees of pathogenic potential. Members of the K. pneumoniae species complex have the highest pathogenic potential. Patients colonized in their gut by these bacteria are at higher risk of subsequent infection with their colonizing strain. However, we do not understand if other members of the gut microbiota can be used as a biomarker to predict infection risk. In this study, we show that the gut microbiota differs between colonized patients who develop an infection versus those who do not. Additionally, we show that integrating gut microbiota data with bacterial factors improves the ability to classify infections. Surprisingly, patient clinical factors were not useful for classifying infections alone or when added to microbiota-based models. This indicates that the bacterial genotype and the microbial community in which it exists may determine the progression to infection. As we continue to explore colonization as an intervention point to prevent infections in individuals colonized by potential pathogens, we must develop effective means for predicting and stratifying infection risk.

Long-Term Proton Pump Inhibitor Therapy Increases the Risk of Infection in Patients with Incident Hemodialysis

Background: Infection is one of the most common causes of death in patients with chronic kidney disease (CKD). Proton pump inhibitors (PPIs) are not only widely used in patients with CKD but also represent a known risk factor for infection in the general population. Here, we investigated associations between PPIs and infection events in patients with incident hemodialysis. Methods: We analyzed data from 485 consecutive patients with CKD who started hemodialysis at our hospital between January 2013 and December 2019. We analyzed associations between infection events and long-term (≥6 months) PPI use before and after propensity score-matched analysis. Results: Of the 485 patients, PPIs were administered to 177 patients (36.5%). During 24 months of follow-up, infection events occurred in 53 patients (29.9%) with PPIs and 40 patients (13.0%) without PPIs (p < 0.001). Patients with PPIs had a significantly higher cumulative incidence rate of infection events than those without PPIs (hazard ratio [HR] 2.13, 95% confidence interval [CI]: 1.36–3.32; p < 0.001). Even after propensity score-matched analysis (132 patients matched in each), the rate of infection events was higher for patients with PPIs (28.8% vs. 12.1%, HR 2.88, 95% CI: 1.61–5.16; p < 0.001). Similar results were obtained for severe infection events in both unmatched (14.1% vs. 4.5%, HR 2.97, 95% CI: 1.47–6.00; p = 0.002) and propensity score-matched analyses (14.4% vs. 3.8%, HR 4.54, 95% CI: 1.85–11.13; p < 0.001). Conclusions: In patients with incident hemodialysis, long-term PPI use increases the risk of infection. Clinicians should be wary of unnecessarily prolonging PPI therapy.

SARS-CoV-2 reinfection across a spectrum of immunological states.

PurposeSeveral cases of symptomatic reinfection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) after full recovery from a prior episode have been reported. As reinfection has become an increasingly common phenomenon, an improved understanding of the risk factors for reinfection and the character and duration of the serological responses to infection and vaccination is critical for managing the coronavirus disease 2019 (COVID‐19) pandemic.MethodsWe described four cases of SARS‐CoV‐2 reinfection in individuals representing a spectrum of healthy and immunocompromised states, including (1) a healthy 41‐year‐old pediatrician, (2) an immunocompromised 31‐year‐old with granulomatosis with polyangiitis, (3) a healthy 26‐year‐old pregnant woman, and (4) a 50‐year‐old with hypertension and hyperlipidemia. We performed confirmatory quantitative reverse transcription‐polymerase chain reaction and qualitative immunoglobulin M and quantitative IgG testing on all available patient samples to confirm the presence of infection and serological response to infection.ResultsOur analysis showed that patients 1 and 2, a healthy and an immunocompromised patient, both failed to mount a robust serologic response to the initial infection. In contrast, patients 3 and 4, with minimal comorbid disease, both mounted a strong serological response to their initial infection, but were still susceptible to reinfection.ConclusionRepeat episodes of COVID‐19 are capable of occurring in patients regardless of the presence of known risk factors for infection or level of serological response to infection, although this did not trigger critical illness in any instance.

Prevalence and Risk of Infection in Patients with Diabetes following Primary Total Knee Arthroplasty: A Global Systematic Review and Meta-Analysis of 120,754 Knees.

Diabetes mellitus (DM) is a known risk factor for infection following total joint arthroplasty. This study looked at the prevalence and risk of infection in diabetic and non-diabetic patients who had primary total knee arthroplasty (TKA). PubMed, Scopus, Google Scholar, Web of Science, and Science Direct electronic databases were searched for studies published up to 21 April 2022. To compare the risk of infection between diabetic and non-diabetic subjects, a pooled prevalence, and a risk ratio (RR) with 95% confidence intervals (CIs) were used. This research has been registered with PROSPERO (CRD42021244391). There were 119,244 participants from 18 studies, with a total of 120,754 knees (25,798 diabetic and 94,956 non-diabetic). We discovered that the risks of infection in diabetic patients were 1.84 times significantly higher than in non-diabetic patients. Infection was more common in diabetic patients (1.9%) than in non-diabetic patients (1.2%). In a subgroup analysis, the risks of developing deep surgical site infection (SSI) were 1.96 times higher in diabetic patients, but no significant difference when compared in superficial SSI. Prevalence of deep SSI was higher in diabetic (1.5%) than in non-diabetic (0.7%), but the prevalence of superficial SSI was lower in diabetic (1.4%) than in non-diabetic (2.1%). Consistent with previous research, we found diabetes is a risk factor for infection following primary TKA. However, the risk is much lower than previously published data, indicating that other factors play a larger role in infection.

Is pin-plate overlap in tibial plateau fractures associated with increased infection rates?

IntroductionDespite advances in the treatment of high energy proximal tibia fractures, including the utilization of staged management with external fixation, the infection rate remains high. Overlap between external fixator pin sites and definitive internal fixation has been proposed as a risk factor for infection. MethodsThis retrospective study reviews 244 patients with staged knee-spanning external fixation followed by delayed definitive internal fixation at two separate level one trauma centers. Presence of pin-plate overlap as well as several other known risk factors for infection were recorded and measured to include open fractures, compartment syndrome, operative time and number of incisions. Development of deep infection was the primary outcome. Both univariate and multivariate statistics were applied to determine differences in rates of infection. Results65 (26.6%) patients had presence of pin-plate overlap while 179 (73.4%) patients had no overlap. There were no differences between overlapping and non-overlapping groups with respect to other infectious risk factors. Deep infection occurred in 34 (13.9%) total patients, 18 (27.7%) were in patients with pin-plate overlap and 16 (8.9%) in those without overlap. (P = 0.003; RR 3.01, 95% CI 1.51–4.76). DiscussionThis large, multicenter study demonstrated a statistically significant association between pin-plate overlap and the development of deep infection in tibial plateau fractures. On multivariate analysis, pin-plate overlap was identified as an independent risk factor for infection. When treating these complex injuries, surgeons should consider the definitive fixation construct when placing external fixation pins.

Prior Nonshoulder Periprosthetic Joint Infection Increases the Risk of Surgical Site Infection, Sepsis, and All-Cause Revision After Primary Total Shoulder Arthroplasty.

Periprosthetic joint infection (PJI) after total joint arthroplasty is a known risk factor for infection in subsequent joint arthroplasty. The purpose of this study was to determine whether prior nonshoulder PJI contributes to the increased risk of infectious complications, greater healthcare utilization, and increased revision surgery after primary total shoulder arthroplasty (TSA). Patients who underwent primary TSA for osteoarthritis with prior nonshoulder PJI were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases codes. These patients were propensity matched based on age, sex, Charlson Comorbidity Index, smoking status, and obesity (body mass index >30 kg/m2) to a control cohort of patients who underwent primary TSA for osteoarthritis without any prior PJI. Primary outcomes include 1- and 2-year revision rates. Secondary outcomes include healthcare-specific outcomes of readmission, emergency department visits, length of stay, and mortality. Bivariate analysis was conducted using chi-square tests to compare all outcomes and complications between both cohorts. Compared with patients without prior PJI, those with prior PJI had a significantly higher risk of 90-day surgical site infection (7.61% versus 0.56%) and sepsis (1.79% versus 0.56%) after TSA (P < 0.05 for both). Patients with prior PJI also had a higher risk of 90-day readmission compared with those without prior PJI (3.36% versus 1.23%, P = 0.008). In terms of surgical complications, patients with prior PJI had significantly higher risk of 2-year revision surgery compared with patients without prior PJI (3.36% versus 1.57%, P = 0.034). Prior nonshoulder PJI of any joint increases rates of 90-day surgical site infection, sepsis, and hospital readmission, as well as 2-year all-cause revision after TSA. These results are important for risk-stratifying patients undergoing TSA with prior history of PJI. III.

The effect of pay-for-performance program on infection events and mortality rate in diabetic patients: a nationwide population-based cohort study

BackgroundDiabetes mellitus is a known risk factor for infection. Pay for Performance (P4P) program is designed to enhance the comprehensive patient care. The aim of this study is to evaluate the effect of the P4P program on infection incidence in type 2 diabetic patients.MethodsThis is a retrospective longitudinal cohort study using data from the National Health Insurance Research Database in Taiwan. Diabetic patients between 1 January 2002 and 31 December 2013 were included. Primary outcomes analyzed were patient emergency room (ER) infection events and deaths.ResultsAfter propensity score matching, there were 337,184 patients in both the P4P and non-P4P cohort. The results showed that patients’ completing one-year P4P program was associated with a decreased risk of any ER infection event (27.2% vs. 29%; subdistribution hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.86–0.88). While the number needed to treat was 58 for the non-P4P group, it dropped to 28 in the P4P group. The risk of infection-related death was significantly lower in the P4P group than in the non-P4P group (4.1% vs. 7.6%; HR 0.46, 95% CI 0.45–0.47). The effect of P4P on ER infection incidence and infection-related death was more apparent in the subgroups of patients who were female, had diabetes duration ≥5 years, chronic kidney disease, higher Charlson’s Comorbidity Index scores and infection-related hospitalization in the previous 3 years.ConclusionsThe P4P program might reduce risk of ER infection events and infection-related deaths in type 2 diabetic patients.

Group A Streptococcus Meningitis Following Arnold-Chiari Correction Surgery: A Case Report

Group A Streptococcus (GAS) can cause invasive disease but rarely causes meningitis. Here we report a three-year-old girl with a GAS meningitis after Arnold-Chiari type I corrective surgery. Six days after surgery she presented fever, headache, vomiting and surgical wound inflammatory signs. A cerebrospinal fluid (CSF) collection with a fistulous path to skin was identified and GAS was found in blood and CSF cultures. Despite targeted antibiotherapy, due to lack of improvement and difficult management of the CSF fistula, she needed to be submitted to several surgical corrections and increased antibiotherapy spectrum. Despite the low risk in acquiring bacterial meningitis after neurosurgery, these procedures may be a direct route for infection. Surgery complications like a fistula are a known risk factor for infection and although uncommon, GAS meningitis may be difficult to manage and can cause serious morbidity.

Comparison of infection in cemented, cementless and hybrid primary total knee arthroplasty: a network meta-analysis and systematic review of randomized clinical trials.

Prosthetic joint infection (PJI) is a serious complication of joint replacement surgeries. Surgeons often take extra measures to reduce the risk of PJI. Whilst many studies have compared between cemented, cementless and hybrid fixation (femoral cementless, tibial cemented), most focus on survivorship, clinical and function outcome scores as primary endpoints. This meta-analysis aims to study the association between fixation methods and risk of PJI in primary total knee arthroplasty (TKA). A systematic review and network meta-analysis of randomized controlled trials (RCT) were performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing prevalence of PJI in each fixation type were extracted and analysed. Twelve RCT comprising a total of 1573 knees were included. Six RCT compared between cemented (n = 486 knees) and cementless (n = 440 knees) fixation, while six RCT compared between hybrid (n = 324 knees) and cementless (n = 323 knees) fixation. Network meta-analysis did not reveal any fixation type that significantly increased the infection rate in TKA. Rate of all infection was lowest in cemented TKA as compared to cementless (odds ratio (OR) 0.90, 95% confidence interval (CI) 0.35-2.28) and hybrid (OR 0.63, 95%CI 0.13-2.99) TKA. Rate of PJI requiring revision surgery was lowest in cementless TKA as compared to cemented (OR 0.89, 95%CI 0.30-2.41) and hybrid (OR 0.57, 95%CI 0.09-2.71) TKA. Rate of PJI not requiring revision surgery was lowest in cemented TKA as compared to hybrid (OR 0.56, 95%CI 0.06-6.10) and cementless (OR 0.55, 95% 0.14-5.63). Unlike total hip arthroplasties, fixation method is not a predisposing risk factor for infections in TKA. However, this meta-analysis may not have sufficient statistical power to show a significant difference between fixation types. It is recommended that prophylactic precautions against other known risk factors for infection should still be clinically practiced. Level I, meta-analysis of randomized controlled trials.

Stage 1 acute kidney injury is independently associated with infection following cardiac surgery

ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality. MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS). ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45). ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity.

Nationwide multicenter follow-up cohort study of hip arthroplasties performed for osteonecrosis of the femoral head.

To identify modifiable factors related to post-operative dislocation and reoperation in patients with osteonecrosis of the femoral head (ONFH) in a large cohort. We studied 4995 hip arthroplasties: total hip arthroplasty (THA) was performed in 79% of patients; bipolar hemiarthroplasty (BP), 17%; total resurfacing arthroplasty (tRS), 3%; and hemi-resurfacing arthroplasty (hRS), 1%. A new type of BP (accounting for 49% of BPs) comprised a femoral component with a polished or smooth, small-diameter (approximately 10mm) neck with a round or oval axial cut surface and no sharp corners. The infection rate was relatively low (0.56%) even though 58% of cases of ONFH were associated with systemic steroid use, a known risk factor for infection. Post-operative dislocation occurred in 4.3% of cases, with re-operation needed in 3.9%. The dislocation rate was related to surgery type: 5.2% in THA, 0.9% in BP, and 0% in tRS and hRS. Among total arthroplasties with six month or longer follow-up (3670 THAs and 159 tRSs), the risk factors for post-operative dislocation were younger (≤ 40years) or older (≥ 62years) age, higher body weight, posterolateral approach, and smaller prosthetic head diameter. Regarding the need for re-operation, higher body weight and surgery type were identified as risk factors. The relatively high dislocation rate of 5.2% in THA is a cause for concern. The identified risk factors for dislocation should be considered when selecting THA for treatment. Prosthesis survivorship in hRSs was inferior to that in BPs or THAs. Body weight also affected the survivorship of hip arthroplasties.

Mechanism of Injury May Influence Infection Risk from Early Blood Transfusion.

Blood transfusion is a known risk factor for infection in trauma patients. Differences based on mechanism of injury have not been well described. We hypothesize that infection risk in trauma patients with early blood transfusion is different based on blunt or penetrating mechanism of injury. Adults admitted to the trauma intensive care unit from January 2010 through January 2015 were reviewed retrospectively. Those receiving transfusion after 24 h were excluded. Infections were defined as positive bronchoalveolar lavage, blood, urine, wound, or abdominal cultures. Logistic regression identified independent predictors of infection. Significance was considered at p ≤ 0.05. With blunt trauma (n = 625), the transfusion rate was 36% (n = 223), with 30% (n = 186) infections. Those with an infection were more severely injured, had a higher operation rate, lower Glasgow Coma Score (GCS), longer hospital stay, and higher transfusion rate (all p < 0.001). With penetrating trauma (n = 292), the transfusion rate was 54% (n = 159), with 26% (n = 77) infections. Those with an infection were older, more severely injured, had a higher operation rate, lower GCS, longer length of stay, and higher transfusion rate (all p < 0.01). Controlling for age, injury severity score (ISS), revised trauma score (RTS), GCS, and hospital stay, transfusion was an independent predictor of infection in patients with blunt (odds ratio: 2.1, 95% confidence intervals: 1.272-3.393, p = 0.003) but not penetrating trauma. Early blood transfusion increases infection risk in blunt but not penetrating trauma.

Factors associated with inconsistent condom use with clients among female sex workers in Podgorica, Montenegro

Female sex workers (FSWs) are a group at increased risk for human immunodeficiency virus (HIV) infection, and inconsistent condom use with clients is a known risk factor for infection in this group. The aim of the study was to determine factors associated with inconsistent condom use with clients among female sex workers in Podgorica, Montenegro. We conducted an HIV bio-behavioral cross-sectional study in a sample of female sex workers recruited by snowball sampling. A total of 142 FSWs were recruited. Eighty-one (57.0%) of them used condoms consistently with clients. HIV prevalence was 0.0%. In the multivariate analysis inconsistent condom use with clients in the previous month was associated with clients’ negative personal attitude [age-adjusted odds ratio (AOR) = 22.7, 95% confidence interval (CI) = 2.3–228.0] or client’s indifference (AOR = 13.0, 95% CI = 1.4–118.9) towards using condom during sex with sexual workers, decision making by clients or by mutual agreement with client about using a condom (AOR = 10.2, 95% CI = 3.7–28.0), and early age of first sex (AOR = 5.4, 95% CI = 1.6–18.5). Our results suggest not only the need for further promotion of condom use, information and education for FSW but also the need to strengthen negotiation skills of FSWs with clients on regular use of condoms, as well as the need to extend prevention programs to clients of FSWs.

Helicobacter pylori and public health.

Gastric cancer and peptic ulcer between them cause the death of over a million people each year. A number of articles this year have studied changes in the prevalence of the infection in a variety of countries and ethnic groups. They confirm the known risk factors for infection, principally a low standard of living, poor education, and reduced life span. The prevalence of infection in developed countries is falling, but more slowly now than was the case before, meaning that a substantial number of the population will remain infected in the years to come. Reinfection is more common in less developed countries. The incidence of gastric cancer is highest in populations with a high prevalence of infection. Population test and treat is a cost-effective means of preventing gastric cancer. Peptic ulcer is the commonest cause of death in patients undergoing emergency surgery. The alleged risk that treatment may cause some to develop reflux esophagitis remains controversial.

Acanthamoeba Keratitis Associated With Tap Water Use During Contact Lens Cleaning

Contact lens-associated Acanthamoeba keratitis continues to be a significant cause of visual morbidity in the United States. Although exposure to water sources while wearing lenses has been a known risk factor for infection for decades, this behavior in several contact lens hygiene protocols continues to prevail. In this review, we surveyed the currently available contact lens cleaning solutions for both soft and rigid gas-permeable contact lenses and reviewed the cleaning instructions of the available solutions. Discrepancies between clinician recommendations and written instructions on a solution packages continues to persist, and we advocate a revision in current manufacturer guidelines to include explicit warnings against use of tap or distilled water sources for cleaning contact lenses or their storage cases.

Models of highly pathogenic avian influenza epidemics in commercial poultry flocks in Nigeria and Ghana

State-scale and premises-scale gravity models for the spread of highly pathogenic avian influenza (H5N1) in Nigeria and Ghana were used to provide a basis for risk maps for future epidemics and to compare and rank plausible culling and vaccination strategies for control. Maximum likelihood methods were used to fit the models to the 2006-2007 outbreaks. The sensitivity and specificity of the state-scale model-generated probabilities that any given state would be involved in an epidemic were each 57 %. The premises-based model indicated that reactive, countrywide vaccination strategies, in which the order in which flocks are vaccinated was strictly determined by known risk factors for infection, were more effective in reducing the final size of the epidemic and the epidemic impact than vaccinating flocks at random or ring vaccination. The model suggests that an introduction of highly pathogenic avian influenza (H5N1) into Ghana had a high chance (84 %) of causing a major outbreak. That this did not happen was most probably a result of the very swift Ghanaian response to news of the first introductions.

Apparent declining efficacy in randomized trials

Apparent declining efficacy in randomized trials

An atypical morphologic presentation of coccidioides spp. in fine‐needle aspiration of lung

Infection due to Coccidioides spp., a dimorphic fungal pathogen, usually presents as a chronic pulmonary disease, occasionally with pulmonary nodules. On cytology, large spherules filled with endospores are typically seen. We report an unusual case of coccidioidomycosis in a 39-year-old female from an area nonendemic for Coccidioides and without other known risk factors for infection. Fine-needle aspiration of the patient's cavitary lung lesion revealed Coccidioides spp., which demonstrated atypical delicate septate hyphal forms and chains of conidia, with none of the large spherules typical of Coccidioides spp. Atypical hyphal and other forms of Coccidioides spp. have been reported in several studies, primarily from biopsy or tissue resection specimens. However, this is the first case to our knowledge that the organism has presented solely as conidial and atypical hyphal forms in an aspirated specimen. Pathologists who are unfamiliar with this atypical hyphal formation may misdiagnose the organism as several different fungi, including Aspergillus spp. or Fusarium spp. It is important to differentiate among fungi, as antifungal treatments may vary. Cytologists should be aware of the diverse morphologies demonstrated by Coccidioides spp. and include this organism in their differential diagnosis, even in patients seemingly devoid of pertinent risk factors.

What Are the Risk Factors for Infection in Hemiarthroplasties and Total Hip Arthroplasties?

Late infection is the second most frequent early complication after total hip arthroplasty (THA) and the most frequent after hemiarthroplasty. Known risk factors for infection after THA include posttraumatic osteoarthritis, previous surgery, chronic liver disease, corticoid therapy, and excessive surgical time. However, risk factors for hemiarthroplasty are not clearly established. We therefore determined the preoperative and intraoperative risk factors for late infection (more than 3 months after surgery) in patients with hemiarthroplasties and THAs. We retrospectively compared 47 patients with a hip arthroplasty (23 hemiarthroplasties, 24 total hip arthroplasties) and late infection with 200 randomly-selected patients with primary arthroplasty (100 hemiarthroplasties, 100 total hip arthroplasties) during the same time period of time without any infection during followup. Potential risk factors were identified from medical records. Minimum followup was 12 months (mean, 27 months; range, 12-112 months) for the study group and 18 months (mean, 84 months; range, 18-144 months) for the control group. The following factors were more frequent in late infected hemiarthroplasties: female gender; previous surgery; obesity (body mass index greater than 30 kg/m(2)); glucocorticoid and immunosuppressant treatments; prolonged surgical time; inadequate antibiotic prophylaxis; prolonged wound drainage; hematoma; dislocation; and cutaneous, urinary, and/or abdominal infections. The following were more frequent in infected total hip arthroplasties: posttraumatic osteoarthritis; previous surgery; glucocorticoids; chronic liver disease; alcohol and intravenous drug abuse; prolonged surgical time; prolonged wound drainage; dislocation; subsequent surgery; and cutaneous, urinary, respiratory and abdominal infections. Diabetes did not appear to be a risk factor. Our data suggest there are specific risk factors for infection in hemiarthroplasties. The major risk factors for late infection in hip arthroplasty must be recognized so they can be minimized or controlled if not possible to employ prophylactic measures.

Comparison of QuantiFERON-TB Gold In-Tube Test and Tuberculin Skin Test for Identification of LatentMycobacterium tuberculosisInfection in Healthcare Staff and Association Between Positive Test Results and Known Risk Factors for Infection

We compared a whole-blood interferon-gamma release assay (QuantiFERON-TB Gold In-Tube test, hereafter "QFT-in tube test") with a tuberculin skin test (TST) to determine which test more accurately identified latent Mycobacterium tuberculosis infection in healthcare staff. A total of 481 hospital staff members were recruited from 5 hospitals in Melbourne, Australia. They provided information about demographic variables and tuberculosis (TB) risk factors (ie, birth or travel in a country with a high prevalence of TB, working in an occupation likely to involve contact with M. tuberculosis or individuals with TB, or being a household contact of an individual with a proven case of pulmonary TB). The QFT-in tube test and the TST were administered in accordance with standardized protocols. Concordance between the test results and positive risk factors was analyzed using the kappa statistic, the McNemar test, and logistic regression. A total of 358 participants had both a TST result and a QFT-in tube test result available for comparison. There were fewer positive QFT-in tube test results than positive TST results (6.7% vs. 33.0%; P<.001). Agreement between the tests was poor (71%; kappa=0.16). A positive QFT-in tube test result was associated with birth in a country with a high prevalence of TB, the number of years an individual had lived in a country with a high prevalence of TB (ie, the effect of each additional year, treated as a continuous variable), and high-risk occupational contact. A positive TST result was associated with older age, receipt of bacille Calmette-Guérin (BCG) vaccination, and working in an occupation that involved patient contact. Receipt of BCG vaccination was most strongly associated with discordant results in instances in which the TST result was positive and the QFT-in tube test result was negative. In a population of healthcare staff with a low prevalence of TB and a significant rate of BCG vaccination, a positive QFT-in tube test result was associated with the presence of known risk factors for TB exposure, whereas a positive TST result was more strongly associated with a prior history of BCG vaccination.