Late Reinfection Research Articles

Periprosthetic Joint Infections of the Knee-Comparison of Different Treatment Algorithms.

Background: Periprosthetic joint infection (PJI) following total knee arthroplasty is a serious complication lacking evidence-based diagnostic and treatment protocols, particularly in ruling out persisting infection before reimplantation. Methods: This retrospective analysis assessed the mid-term outcomes of 66 patients undergoing septic two-stage knee revision surgeries from 2007 to 2013, diagnosed as per the Musculoskeletal Infection Society criteria. After implant removal and antibiotic treatment, reimplantation decisions were based on either joint aspiration, blood counts, and clinical examination (group A) or an open biopsy (group B). Both groups underwent meticulous debridement and spacer exchange during the interim period. Results: Late re-infection occurred in 12.1% of all patients. In group A, 13.8% experienced late re-infection, with 14.3% in subgroup A1 and 13.3% in subgroup A2. In group B, 10% had a late re-infection. No significant difference in re-infection or complication rates was found between the groups. Conclusions: The study did not demonstrate the superiority of group B's approach of open biopsy over group A's joint aspiration, clinical examination, and blood counts in preventing re-infection or reducing complications.

Long-term follow-up of infective endocarditis: Rates of reinfection, mortality, and predictors of outcome

Objective: Infective endocarditis (IE) is a severe condition characterized by high mortality rates. We aimed to assess reinfection and mortality rates in IE patients at a tertiary referral center during long-term follow-up. Patients and Methods: We retrospectively analyzed 204 patients meeting modified Duke criteria for definite IE between 2009 and 2019. Early reinfection was defined as occurrence within 6 months, and late reinfection was defined as occurrence 6 months after the initial diagnosis. Results: Mean follow-up duration was 40.3 ± 26.4 months. Valve surgery was performed in 125 patients (69.8%), while 54 (30.2%) received medical therapy alone. Early reinfection was seen in 9 patients (5.1%), and late reinfection in 12 patients (6.7%). Staphylococci (41.9%), Streptococci (26.3%), and Enterococci (15.6%) were common pathogens. Peripheral limb emboli predicted reinfection (HR 4.118, 95% CI 1.471-11.528, p=0.007). Survival rates at 1, 2, and 5 years were 70.2%, 65.7%, and 57.3%, respectively. Age (HR 1.030, 95% CI 1.011 – 1.049, p=0.002), peripheral limb emboli (HR 2.994, 95% CI 1.509-5.940, p=0.002), and septic shock (HR 2.357, 95% CI 1.097-5.065, p=0.028) predicted mortality. Conclusion: Infective endocarditis mortality rates remain high regardless of reinfection. Peripheral limb emboli independently determine reinfection and mortality. Careful management of this group may reduce morbidity and mortality.

Long-term durability of sustained virologic response for hepatitis C virus infection in solid organ transplant recipients receiving direct-acting antivirals

Data are limited regarding the long-term durability of sustained virologic response (SVR) in solid organ transplant recipients who achieve SVR12 with direct-acting antivirals (DAAs) for hepatitis C virus (HCV). We reported the virologic outcomes in 42 recipients who received DAAs for acute or chronic HCV infection after heart, liver, and kidney transplantation. After achieving SVR12, all recipients received HCV RNA surveys at SVR24, and biannually until the last visit. If HCV viremia was detected during the follow-up period, direct sequencing and phylogenetic analysis were performed to confirm late relapse or reinfection. Sixteen (38.1%), 11 (26.2%), and 15 (35.7%) patients underwent heart, liver and, kidney transplantation. Thirty-eight (90.5%) received sofosbuvir (SOF)-based DAAs. No recipients had late relapse or reinfection after a median (range) of post-SVR12 follow-up 4.0 (1.0-6.0) years. We demonstrate that the durability of SVR in solid organ transplant recipients is excellent once SVR12 is achieved with DAAs.

Extra-Anatomic Bypass and Excision is Superior to Graft Salvage Attempts with Antibiotic Beads to Treat Vascular Graft Infections in the Groin

This study aimed to determine if conventional extra-anatomic bypass and graft removal versus aggressive attempts at graft preservation have better survival and limb salvage in patients with localized groin wound infections of vascular grafts. We conducted a retrospective review of 53 consecutive patients with vascular graft infections presenting in the groin. Treatment groups consisted of group 1 (extra-anatomic bypass and graft excision, n=22) and group 2 (initial graft preservation attempts with utilization of antibiotic beads, n=31). In group 2, patients underwent serial debridement and placement of antibiotic beads until culture-negative wounds were achieved. Significantly more patients underwent muscle flap coverage in group 2 (27/31) compared with group 1 (7/22; P<0.001). Data collected included demographics, comorbidities, intraoperative details, and outcomes, including patency, limb salvage, mortality, and number of procedures. Continuous variables were examined with Student's t-test, and dichotomous variables were examined with chi-squared test. Linear and logistic regressions were used to analyze factors associated with outcomes, in addition to Kaplan-Meier analysis with log rankfor actuarial analysis. Both groups were similar with respect to demographics. The overall Kaplan-Meier 1- and 3-year survival rates were 66.2% and 34.1%, with no statistically significant difference between groups. The Kaplan-Meier 1- and 3-year limb salvage rates were 68.8% and 36.6% for group 1 vs. 58.5% and 38.7% for group 2 (P=not significant [NS]). The 1- and 3-year primary patency rates were 71% and 71% in traditional group 1 vs. 72% and 56% in group 2 (P=NS). One-year and 3-year secondary patency rates in traditional group 1 were 83% and 71% vs. 85% and 61% in group 2 (P=NS). Patients in group 1 underwent fewer total procedures when compared with group 2 (2.3±0.2 vs. 5.1±0.7, P=0.03). The late reinfection rate was significantly less in group 1 (4.5%) compared with group 2 (26%; P=0.04). Freedom from reinfection at 1 and 3 years were 94% and 94% in traditional group 1 vs. 74% and 62% in group 2 (P=0.03). Multivariable analysis showed a higher incidence of amputation in patients who suffered reinfection (n=13, P=0.049). There was a higher mortality in patients with septic shock (n=10, P=0.007) and reinfection (n=13, P=0.036). Reinfection was associated with the highest mortality (P=0.03). Conventional graft excision with extra-anatomic bypass resulted in similar mortality when compared with aggressive attempts at graft preservation and trended toward improved limb salvage and patency. However, attempts at graft preservation with antibiotic beads resulted in a significantly higher reinfection rate and greater number of procedures, and therefore, this approach should be used very selectively.

Long-Term Outcome of Mechanical and Biological Prostheses in Patients with Left-Side Infective Endocarditis: A Systematic Review and Meta-Analysis.

Background. Long-term outcomes of patients with infective endocarditis (IE) who received either a mechanical (MP) or biological prosthesis (BP) are conflicting. A meta-analysis of observational studies comparing the long-term outcomes of left-side IE with the use of MP versus BP was performed. Methods. Electronic databases from January 2000 to June 2021 were screened. Studies reporting long-term mortality were analyzed. The primary endpoint was long-term overall mortality. Secondary endpoints were in-hospital/.30-day mortality and freedom from both prosthesis reinfection and reintervention. The pooled hazard ratio (HR) with 95% confidence interval (CI) was calculated for survival according to the random effect model. Results. Thirteen retrospective observational studies reporting on 8645 patients (MP: 4688; BP: 4137) were included for comparison. Twelve studies reported data of long-term survival for a total of 8285 patients (MP: 4517; BP: 3768). The pooled analysis revealed that the use of MP was statistically associated with longer benefits compared to BP (HR 0.74; 95% CI 0.63–0.86; p < 0.0001). The median follow-up time ranged from 1 to 15.3 years. The pooled analysis of five studies reporting data on prosthesis reinfection in 4491 patients (MP: 2433; BP: 2058) did not reveal significant differences (HR 0.60; 95% CI 0.30–1.21; p = 0.15). Five studies reported data on prosthesis reintervention in 4401 patients (MP: 2307; BP: 2094). The meta-analysis revealed a significant difference in favor of MP (HR 0.40; 95% CI 0.29–0.55; p < 0.0001). Meta-regression reported no effect of male gender (p = 0.09) and age (p = 0.77) on long-term survival. Conclusions. In a meta-analysis of retrospective observational studies comparing the long-term outcome of patients who underwent surgery for left-sided IE, the use of MP compared to BP is associated with a significant longer-term survival and with a reduced incidence of late reoperation. The incidence of late reinfection is comparable between the two prostheses.

Late reinfection with a different severe acute respiratory syndrome coronavirus-2 clade in a patient with refractory arterial hypertension: a case report

BackgroundDifferentiating between persistent infection with intermittent viral shedding and reinfection with severe acute respiratory syndrome coronavirus 2 remains challenging. Although a small number of cases with genomic evidence of second infection have been reported, limited information exists on frequency and determinants of reinfection, time between infections, and duration of immunity after the primary infection.Case presentationWe report a reinfection with severe acute respiratory syndrome coronavirus 2 in a 52-year-old caucasian male whose primary infection was diagnosed in May 2020, during the first wave of the pandemic in Spain, and the second occurred 8 months later, in January 2021. We present a complete dataset including results from real-time polymerase chain reaction, serology, and genome sequencing confirming reinfection with a different clade. Noteworthy was that the patient was immunocompetent but had multiple cardiometabolic comorbidities, including refractory arterial hypertension, that might increase the individual risk in coronavirus disease 2019.ConclusionsThis case of reinfection with severe acute respiratory syndrome coronavirus 2 occurring several months after the primary infection reports the longest time interval between reinfection and initial infection described to date. It raises concerns on the duration of protective immunity, suggesting that it may begin to wane in patients who acquired the initial infection during the first wave of the pandemic. The potential contributing role of arterial hypertension and cardiometabolic comorbidities as risk factors for reinfection deserves investigation.

Contemporary Outcomes After Partial Resection of Infected Aortic Grafts

Aortic graft infection remains a considerable clinical challenge, and it is unclear which variables are associated with adverse outcomes among patients undergoing partial resection. A retrospective, multi-institutional study of patients who underwent partial resection of infected aortic grafts from 2002 to 2014 was performed using a standard database. Baseline demographics, comorbidities, operative, and postoperative variables were recorded. The primary outcome was mortality. Descriptive statistics, Kaplan-Meier (KM) survival analysis, and Cox regression analysis were performed. One hundred fourteen patients at 22 medical centers in 6 countries underwent partial resection of an infected aortic graft. Seventy percent were men with median age 70 years. Ninety-seven percent had a history of open aortic bypass graft: 88 (77%) patients had infected aortobifemoral bypass, 18 (16%) had infected aortobiiliac bypass, and 1 (0.8%) had an infected thoracic graft. Infection was diagnosed at a median 4.3 years post-implant. All patients underwent partial resection followed by either extra-anatomic (47%) or in situ (53%) vascular reconstruction. Median follow-up period was 17 months (IQR 1, 50 months). Thirty-day mortality was 17.5%. The KM-estimated median survival from time of partial resection was 3.6 years. There was no significant survival difference between those undergoing in situ reconstruction or extra-anatomic bypass (P = 0.6). During follow up, 72% of repairs remained patent and 11% of patients underwent major amputation. On univariate Cox regression analysis, Candida infection was associated with increased risk of mortality (HR 2.4; P = 0.01) as well as aortoenteric fistula (HR 1.9, P = 0.03). Resection of a single graft limb only to resection of abdominal (graft main body) infection was associated with decreased risk of mortality (HR 0.57, P = 0.04), as well as those with American Society of Anesthesiologists classification less than 3 (HR 0.35, P = 0.04). Multivariate analysis did not reveal any factors significantly associated with mortality. Persistent early infection was noted in 26% of patients within 30 days postoperatively, and 39% of patients were found to have any post-repair infection during the follow-up period. Two patients (1.8%) were found to have a late reinfection without early persistent postoperative infection. Patients with any post-repair infection were older (67 vs. 60 years, P = 0.01) and less likely to have patent repairs during follow up (59% vs. 32%, P = 0.01). Patients with aortoenteric fistula had a higher rate of any post-repair infection (63% vs. 29%, P < 0.01) CONCLUSION: This large multi-center study suggests that patients who have undergone partial resection of infected aortic grafts may be at high risk of death or post-repair infection, especially older patients with abdominal infection not isolated to a single graft limb, or with Candida infection or aortoenteric fistula. Late reinfection correlated strongly with early persistent postoperative infection, raising concern for occult retained infected graft material.

Late Relapse and Reinfection in HCV Patients Treated with Direct-Acting Antiviral (DAA) Drugs.

The risk of hepatitis C virus (HCV) recurrence after direct-acting antiviral (DAA) treatment is <0.5%. However, the distinction between HCV RNA late relapse and reinfection still represents a challenge in virological diagnostics. The aim of this study was to employ next-generation sequencing (NGS) to investigate HCV RNA recurrence in patients achieving a sustained virologic response (SVR) at least six months post-treatment. NGS was performed on plasma samples from six HCV-positive patients (Pt1–6) treated with DAA. NGS of HCV NS5B was analyzed before treatment (T0), after HCV RNA rebound (T1), and, for Pt3, after a second rebound (T2). Reinfection was confirmed for Pt5, and for the first rebound observed in Pt3. Conversely, viral relapse was observed when comparing T0 and T1 for Pt6 and T1 and T2 for Pt3. Z-scores were calculated and used to predict whether HCV-positive patient samples at different time points belonged to the same quasispecies population. A low Z-score of <2.58 confirmed that viral quasispecies detected at T0 and T1 were closely related for both Pt1 and Pt2, while the Z-score for Pt4 was suggestive of possible reinfection. NGS data analyses indicate that the Z-score may be a useful parameter for distinguishing late relapse from reinfection.

The risk of hepatitis C virus recurrence in hepatitis C virus-infected patients treated with direct-acting antivirals after achieving a sustained virological response: A comprehensive analysis.

The risk for hepatitis C virus (HCV) recurrence persists after HCV eradication with direct-acting antivirals (DAAs), particularly in patients with ongoing high-risk behaviours. Our aim was to assess the risk of HCV recurrence (late relapse and/or reinfection) post-sustained virological response (SVR). We searched the literature for studies reporting HCV recurrence rates post-SVR in PubMed, Web of Science and the Cochrane Library. Identified publications were divided into groups based on patient risk for HCV reinfection: low-risk HCV mono-infection, high-risk HCV mono-infection and a human immunodeficiency virus (HIV)/HCV coinfection. The HCV recurrence rate for each study was calculated by using events divided by the person-years of follow-up (PYFU). HCV recurrence was defined as confirmed, detectable HCV RNA post-SVR. In the 16 studies of low-risk patients, the pooled recurrence rate was 0.89/1000 PYFU (95% confidence interval [CI], 0.16-2.03). For the 19 studies of high-risk patients, the pooled recurrence rate was 29.37/1000 PYFU (95% CI, 15.54-46.91). For the eight studies of HIV/HCV-coinfected patients, the pooled recurrence rate was 23.25/1000 PYFU (95% CI, 4.24-53.39). The higher pooled estimates of recurrence in the high-risk and HIV/HCV-coinfected populations were predominantly driven by an increase in reinfection rather than late relapse. The HCV recurrence risk after achieving SVR with all-oral DAAs therapy is low, and the risk of HCV recurrence in high-risk and HIV/HCV-coinfected populations was driven by an increase in reinfection rather than late relapse.

Long-term follow-up of patients with infective endocarditis in a tertiary referral center

BackgroundInfective endocarditis (IE) remains a severe disease with high mortality. Most studies report on short-term outcome while real world long-term outcome data are scarce. This study reports reinfection rates and mortality data during long-term follow-up. MethodsA total of 270 patients meeting the modified Duke criteria for definite IE admitted to a tertiary care center between July 2000 and June 2007 were analyzed retrospectively. Early reinfection was defined as a new IE episode within 6 months; late reinfection as a new IE episode beyond 6 months follow-up. ResultsMedian follow-up was 8.5 years. Early reinfection occurred in 10 patients (3.7%), late reinfection in 18 patients (6.7%). Staphylococci (39.7%) were the most frequent causative microorganisms, followed by Streptococci (30.0%) and Enterococci (17.8%). Independent predictors of any reinfection were heart failure (HR 3.02, 95% CI 1.42–6.41), peripheral embolization (HR 4.00, 95% CI 1.58–10.17) and implanted pacemakers (HR 3.43, 95% CI 1.25–9.36).Survival rates were 71.1%, 55.2% and 43.3% at respectively 1-, 5- and 10-years follow-up. Independent predictors for mortality were age (HR 1.03, 95% CI 1.01–1.04), diabetes mellitus (HR 2.24, 95% CI 1.46–3.45), hemodialysis (HR 2.70, 95% CI 1.37–5.29), heart failure (HR 1.64, 95% CI 1.19–2.26), stroke (HR 1.73, 95% CI 1.18–2.52), antimicrobial treatment despite surgical indication (HR 5.53, 95% CI 3.59–8.49) and non-Streptococci causative microorganisms (HR 1.84, 95% CI 1.28–2.64). ConclusionsContemporary mortality rates of infective endocarditis remain high, irrespective of reinfection. Heart failure, peripheral embolization and presence of a pacemaker were predictors of reinfection.

Long-Term Results of Patch Repair in Destructive Valve Endocarditis.

Treatment of destructive endocarditis with abscess formation is a surgical challenge and associated with significant morbidity and mortality. A root replacement is often performed in case of an annular abscess. This retrospective study was designed to assess the long-term outcome of extensive debridement and patch reconstruction as an alternative approach. Between November 2007 and November 2016, a selected group of 79 patients (29.6% of all surgical endocarditis cases) with native valve endocarditis (NVE, 53.2%) or prosthetic valve endocarditis (PVE, 46.8%) valve endocarditis underwent surgical therapy with extensive annular debridement and patch reconstruction. Their postoperative course, freedom from recurrent endocarditis, and survival at 1, 5, and 7 years were evaluated. About two-thirds of patients were in a stable condition, one-third of patients were in a critical state. The median logistic EuroSCORE I was 17%. Infected tissue was removed, and defect closure was performed, either with autologous pericardium for small defects, or with bovine pericardium for larger defects. Overall, in-hospital mortality was 11.3% (NVE: 9.7%, PVE: 13.2%; p = 0.412). In single valve endocarditis survival at 1, 5, and 7 years was 81, 72, 72%, respectively for NVE, and 80, 57, 57%, respectively for PVE (p = 0.589), whereas in multiple valve endocarditis survival at 1, 5, and 7 years was 82, 82, 82% for NVE, and 61, 61, and 31%, respectively for PVE (p = 0.132). Confirmed late reinfection was very low. Surgical treatment of destructive endocarditis with abscess formation using patch repair techniques offers acceptable early and long-term results. The relapse rate was low. PVE and involvement of multiple valves were associated with worse outcomes.

Recurrence Rate of Hepatitis C Virus After Achieving a Sustained Virologic Response in Kurdistan Region, Iraq

Background: Hepatitis C virus (HCV) is a public health issue. Successful treatment of HCV infection results in sustained virologic response (SVR) in the majority of subjects. Subsequent recurrence of HCV, either from late relapse or reinfection, may occur. The aim of this study was to assess the recurrence rate of HCV in Iraqi patients. Methods: In this study, 113 patients who completed anti-HCV therapy successfully were recruited. While 23 patients received a classical regimen of peg-interferon plus ribavirin, 90 patients received direct-acting antiviral therapy. Those patients were followed up for three years. HCV recurrence rate was calculated using events/ person years of follow-up (PYFU). Results: Among the recruited patients, HCV RT-PCR was positive in 1 (0.88%) patient giving a recurrence rate of 2.95 per 1000 PYFU. When the data were stratified according to the treatment regimen, the recurrence rate was 14.49 per 1000 PYFU in patients who received the classical regimen of interferon and ribavirin. Conclusions: The overall recurrence rate was low in Iraq. No recurrence was recorded in patients received direct-acting antiviral therapy. Further studies are needed with a larger sample size and longer follow-up to determine the relapse rate in Iraq.

Therapeutic penetrating keratoplasty for microbial keratitis in Taiwan from 2001 to 2014

To study the surgical outcome of therapeutic penetrating keratoplasty (TPK) for medically uncontrolled microbial keratitis at a tertiary hospital in Taiwan over a 14-year period. This is a retrospective case series study. Patients who underwent TPK at National Taiwan University Hospital in 2001-2014 were included. Patients were divided into 3 diagnostic groups: bacterial keratitis, fungal keratitis, and acanthamoeba keratitis. Each of the following criteria was evaluated: graft clarity at 1 month and 1 year postoperatively, cure of the disease, and anatomical success rate. A total of 107 TPKs were included. TPK eradicated the infection in 57/62 (91.9%) of bacterial keratitis, 33/41 (80.5%) of fungal keratitis, and 9/10 (90.0%) of acanthamoeba keratitis. 22/57 grafts (38.6%) of bacterial keratitis, 22/38 grafts (57.9%) of fungal keratitis, and 5/10 grafts (50.0%) of acanthamoeba keratitis remained clear at 1 year postoperatively. The 1-year graft survival rate did not significantly differ among these 3 groups. The leading causes of graft failure were late endothelial decompensation and graft reinfection. A higher percentage of graft clarity was achieved in grafts <8.5 mm in diameter than in larger grafts (55.4% vs. 31.4%, P = 0.027). Of the 14 patients with endophthalmitis at the time of TPK, the infection was successfully treated in 13 patients except 1 patient required evisceration. TPK is valuable in the management of medically uncontrolled microbial keratitis, although the 1-year graft survival rate is unsatisfactory. TPK combined with intravitreal antibiotics and vitrectomy is also a beneficial treatment strategy for patients with endophthalmitis secondary to microbial keratitis.

Biosynthetic vascular graft: a valuable alternative to traditional replacement materials for treatment of prosthetic aortic graft infection?

To report the experience of a tertiary vascular surgery center using Omniflow II® biosynthetic vascular grafts for treatment of prosthetic aortic graft infection. Retrospective analysis of all patients with prosthetic graft infections who underwent in situ aortic reconstruction using Omniflow II® grafts or other conduits between March 2015 and May 2017. Early and late mortality, perioperative complications, and reinfection rate were analyzed. Sixteen patients (14 males, median age 68.5, range 57-89) with prosthetic aortic graft infection were treated at our center. Eight patients received an Omniflow II® biosynthetic graft, two patients silver-triclosan coated grafts, three patients bovine pericardial tube grafts, and three patients composite bovine pericardial tube grafts with Omniflow II® graft extensions. Perioperative complications occurred in seven patients (43.8%). Early mortality rate was 18.7% (n = 3). In addition, four patients died during follow-up after a median of 11 months (range 0-34 months). We did not observe any reinfections. Bypass grafts were patent in all patients. No major limb amputations were performed during follow-up. Treatment of prosthetic aortic graft infection with Omniflow II® vascular grafts is feasible. Graft material seems to have an excellent resistance to infection and might be a valuable alternative to traditional replacement materials. Especially long-term durability has to be continuously monitored and documented.

Revascularization with Obturator or Hemi-neoaortoiliac System for Partial Aortic Graft Infections

Infections of isolated limbs of prosthetic grafts are challenging. Management can be morbid, involving partial or complete removal of all prosthetic material followed by aortic reconstruction. More limited resections of only infected material and reconstruction of the affected iliac limb has been reported as a viable surgical option. We review 2 academic institution's experiences treating limited aortic graft infections by obturator canal bypass (OCB) or hemi-neoaortoiliac system (H-NAIS). A retrospective review of OCB at one institution between 1995 and 2013 and H-NAIS at the other institution between 2003 and 2014 was conducted. Demographics, comorbidities, and postoperative and medium-term events were recorded. Outcomes were patency, limb salvage, graft preservation without reinfection, and survival. OCB was performed in 18 limbs and H-NAIS in 34 limbs. The OCB group had a higher prevalence of cancer (40% vs. 10%; P=0.04). The most common treatment indication was infection of an aortobifemoral bypass limb in both groups. No differences were seen in overall graft infection, with one patient suffering a late graft reinfection (6% of OCB versus 0% in H-NAIS; P=0.35). There were no perioperative deaths in either group. Regarding major adverse limb events, there were no amputations performed in the perioperative period in either group. The most frequent organism cultured in both OCB and H-NAIS was Staphylococcus aureus. Surgery duration was similar between the groups (OCB 379±115minutes vs. H-NAIS 370±137minutes; P=0.8) as was the length of stay (OCB 10.5±5.3days vs. H-NAIS 12.4±10.6days; P=0.4). At 36months, there was no difference in primary patency (OCB 45% vs. H-NAIS 63%; P=0.7), primary-assisted patency (OCB 51% vs. H-NAIS 61%; P=0.5), or secondary patency (OCB 68% vs. H-NAIS 63%; P=0.6) between the groups. Endovascular and open reinterventions occurred more frequently in OCB than in H-NAIS (61.1% vs. 23.5%; P=0.007). There were no differences in overall survival (OCB 83% vs. H-NAIS 81%; P=0.6), and no significant difference in amputation rate was seen during the follow-up period (OCB 17% vs. H-NAIS 6%; P=0.35). OCB and H-NAIS are effective strategies for treatment of limited aortic graft infections with reasonable patency, survival, and limb salvage at medium-term follow-up. Prudent patient selection and institutional experience with aortic graft infection treatment leads to good outcomes with lifelong follow-up recommended. Further study of the optimal treatment strategy for this complex group of patients is needed.

Late Reinfection May Recur More Than 5 Years After Reimplantation of THA and TKA: Analysis of Pathogen Factors.

Two-stage reimplantation has consistently yielded high rates of success for patients with chronic prosthetic joint infection, although results more than 5 years after reimplantation are not commonly reported. Numerous factors may contribute to the risk of reinfection, although these factors-as well as the at-risk period after reimplantation-are not well characterized. (1) What is the risk of reinfection after reimplantation for prosthetic joint infection at a minimum of 5 years? (2) Is the bacteriology of the index infection associated with late reinfection? (3) Is the presence of bacteria at the time of reimplantation associated with late reinfection? Between 1995 and 2010, we performed 97 two-stage revisions in 93 patients for prosthetic joint infection of the hip or knee, and all are included in this retrospective study. During that time, the indications for this procedure generally were (1) infections occurring more than 3 months after the index arthroplasty; and (2) more acute infections associated with prosthetic loosening or resistant organisms. One patient (1%) was lost to followup; all others have a minimum of 5 years of followup (mean, 11 years; range, 5-20 years) and all living patients have been seen within the last 2 years. Patients were considered free from infection if they did not have pain at rest or constitutional symptoms such as fever, chills, or malaise. The patients' bacteriology and resistance patterns of these organisms were observed with respect to recurrence of infection. Odds ratios and Fisher's exact test were performed to analyze the data. The incidence of reinfection was determined using cumulative incidence methods that considered death as a competing event. Reinfection occurred in 12 of the 97 joints resulting in implant revision. The estimated 10-year cumulative incidence of infection was 14% (95% confidence interval [CI], 7%-23%) and incidence of infection from the same organism was 5% (95% CI, 1%-11%). Five occurred early or within 2 years and three were resistant pathogens (methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, or vancomycin-resistant Enterococcus). Seven late hematogenous infections occurred and all were > 4 years after reimplantation and involved nonresistant organisms. Three of the five (60%) early infections were caused by resistant bacteria, whereas all seven late infections were caused by different organisms or a combination of different organisms than were isolated in the original infection. The early reinfections were more often caused by resistant organisms, whereas late infections involved different organisms than were isolated in the original infection and none involved resistant organisms. With the numbers available, we found no difference between patients in whom bacteria were detected at the time of reimplantation and those in whom cultures were negative in terms of the risk of reinfection 5 years after reimplantation (18.6% [18 of 97] versus 81.4% [79 of 97], odds ratio 1.56 [95% CI, 0.38-6.44]; p = 0.54); however, with only 93 patients, we may have been underpowered to make this analysis. In our study, resistant organisms were more often associated with early reinfection, whereas late failures were more commonly associated with new pathogens. We believe the most important finding in our study is that substantial risk of late infection remains even among patients who seemed free from infection 2 years after reimplantation for prosthetic joint infections of the hip or knee. This highlights the importance of educating our patients about the ongoing risk of prosthetic joint infection. Level III, therapeutic study.

CORR Insights®: Late Reinfection May Recur More Than 5 Years After Reimplantation of THA and TKA: Analysis of Pathogen Factors.

CORR Insights®: Late Reinfection May Recur More Than 5 Years After Reimplantation of THA and TKA: Analysis of Pathogen Factors.

Risk of Late Relapse or Reinfection With Hepatitis C Virus After Achieving a Sustained Virological Response: A Systematic Review and Meta-analysis.

Treatment for hepatitis C virus (HCV) can lead to sustained virological response (SVR) in over 90% of people. Subsequent recurrence of HCV, either from late relapse or reinfection, reverses the beneficial effects of SVR. A search identified studies analysing HCV recurrence post-SVR. The recurrence rate for each study was calculated using events/person years of follow-up (PYFU). Results were pooled using a random-effects model and used to calculate 5-year recurrence risk. Three patient groups were analysed: (1) Mono-HCV infected "low-risk" patients; (2) Mono-HCV infected "high-risk" patients (injecting drug users or prisoners); (3) human immunodeficiency virus (HIV)/HCV coinfected patients. Recurrence was defined as confirmed HCV RNA detectability post-SVR. In the 43 studies of HCV mono-infected "low-risk" patients (n = 7969) the pooled recurrence rate was 1.85/1000 PYFU (95% confidence interval [CI], .71-3.35; I(2) = 73%) leading to a summary 5-year recurrence risk of 0.95% (95% CI, .35%-1.69%). For the 14 studies of HCV monoinfected "high-risk" patients (n = 771) the pooled recurrence rate was 22.32/1000 PYFU (95% CI, 13.07-33.46; I(2) = 27%) leading to a summary 5-year risk of 10.67% (95% CI, 6.38%-15.66%). For the 4 studies of HIV/HCV coinfected patients the pooled recurrence rate was 32.02/1000 PYFU (95% CI, .00-123.49; I(2) = 96%) leading to a summary 5-year risk of 15.02% (95% CI, .00%-48.26%). The higher pooled estimates of recurrence in the high-risk and coinfected cohorts were driven by an increase in reinfection rather than late relapse. SVR appears durable in the majority of patients at 5 years post-treatment. The large difference in 5 year event rate by risk group is driven mainly by an increased reinfection risk.

Use and durability of femoral vein for autologous reconstruction with infection of the aortoiliofemoral axis

To analyze early and late mortality, venous morbidity, reinfection, and freedom from reintervention after using the femoral vein (FV) for vascular reconstruction with infection of the aortoiliofemoral axis. By reviewing our database, 86 patients could be identified with implantation of FV grafts in infected fields between November 1995 and July 2012. The patient records were retrospectively analyzed and follow-up information obtained from patients or their general physician. Seventy-one patients presented with prosthetic graft infection and 15 with an infected aneurysm. For data analysis, patients were divided into an aortoiliac (n = 67) and a femoral group (n = 19). Study end points assessed were early and late mortality, incidence of deep vein thrombosis of the FV donor limb, graft patency, limb salvage, reinfection, and freedom from reintervention. Sixty-seven aortoiliac reconstructions were performed using 84 FV grafts with an operative mortality of 9%. After a mean follow-up of 45 months, survival, patency, limb salvage, and freedom from reintervention were 45%, 97%, 94%, and 91%, respectively, at 5 years. Twenty FV grafts were employed for 19 femoral reconstructions with an operative mortality of 10.5%. Here, mean follow-up was 35 months and survival, patency, limb salvage, and freedom from reintervention were 29%, 87%, 93%, and 81%, respectively, at 5 years. Specimen culture confirmed Staphylococcus (epidermidis and aureus) as the predominant microorganism. Venous morbidity after FV harvest showed an incidence of deep venous thrombosis of 13.7% for popliteal and 10.6% for tibial level at a follow-up of 24 months with only mild clinical symptoms (21% limb swelling). Vascular reconstruction using autologous FV in arterial and graft infection of the aortoiliofemoral axis provides durable long-term results with acceptable mortality and morbidity.

Evaluation of peritoneal reinfection after fecal peritonitis

To investigate the role of a previous abdominal infection on peritonitis. Twenty-seven adult female Wistar rats were submitted to fecal peritonitis by an intraperitoneal injection of a solution of rat feces. The animals were divided into three groups (n = 9 each): Group 1 - control - intraperitoneal injection of an amount of fecal solution known to be lethal (10 ml/kg), Group 2 - reinfection - intraperitoneal injection of an amount of fecal solution known not to be lethal (2 ml/kg) followed by an injection of fecal solution (10 ml/kg) 30 days later, Group 3 - late reinfection - intraperitoneal injection of 2 ml/kg feces followed by an injection of 10 ml/kg four months later. All animals in Group 1 died within seven days after injection of the fecal solution. In contrast, in the pre-infected Group 2 only one animal died 24 hours after injection of the fecal solution (10 ml/kg). In Group 3, eight of the nine animals in each subgroup died over a period of seven days. The difference in survival time between groups 1, 2 and 3 was for p = 0.0042 (logrank test). Milder peritoneal sepsis due to fecal infection raises the organic resistance to a new more intense fecal contamination occuring after a short period of time. However, this protection did not persist over a prolonged period of time.