Early Reinfection Research Articles

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.

Rerouting bei Infektionen des vaskulären Zugangs unter Verwendung eines biosynthetischen Gefäßtransplantats (Omniflow® II)

Abstract Background Surgical treatment of infected arteriovenous grafts (AVG) while preserving the hemodialysis access remains a challenge. Partial graft excision (PGE) directly followed by interposition grafting (IG) is an established method but is associated with a high rate of local reinfection. This retrospective study investigated the technique of rerouting using a biosynthetic vascular graft (Omniflow® II). Methods This was a retrospective analysis of all patients at a tertiary referral center undergoing surgical treatment for AVG infections using PGE and IG with the rerouting technique using Omniflow® II between January 2009 and December 2018. Follow-up data were collected until May 2021. Results Fifteen patients (53% male, median age 62 years [range 49-81]) were identified for further analysis, thereof twelve received an Omniflow® II vascular graft. Eleven patients had positive local microbial cultures, with Staphylococcus aureus being the most frequently identified pathogen (9 cases). Mortality and reoperation rates within 30 days were both 0%. Median follow-up was 32 months (range 2–101 months) with a median follow-up index of 0.92 (range 0.18–1). During follow-up a surgical intervention for reinfection was necessary in 3 patients with Omniflow® II at a median of 304 days (range 298–485 days). Conclusion Partial graft excision and direct interposition grafting using a biosynthetic Omniflow® II vascular graft is a valid treatment option in selected patients with AVG infections when total graft excision can be avoided. Using a careful rerouting technique, while preserving clinically noninfected graft sections the risk of early reinfection can be minimized and the dialysis access maintained.

Short Course of Oral Antibiotic Treatment After Two-Stage Exchange Arthroplasty Appears to Decrease Early Reinfection

BackgroundRecent evidence has suggested a benefit to extended postoperative prophylactic oral antibiotics after two-stage exchange arthroplasty for treatment of periprosthetic joint infections. We sought to determine reinfection rates with and without a short course of oral antibiotics after two-stage exchange procedures. MethodsA retrospective review identified patients undergoing two-stage exchange arthroplasty for periprosthetic joint infection of the hip or knee. Patients were excluded if they failed a prior two-stage exchange, had positive cultures at reimplantation, prolonged intravenous antibiotics postoperatively, and/or life-long suppression. This resulted in 444 reimplantations (210 hips and 234 knees). Patients were divided into three cohorts based on the duration of oral antibiotics after reimplantation: no antibiotics (102), ≤2 weeks (266), or >2 weeks (76). The primary endpoint was reinfection within 1 year of reimplantation. ResultsWithin 1 year of reimplantation, there were 34 reinfections. In the no-antibiotic, ≤ 2-week, and >2-week cohorts the reinfection rates were 14.1, 7.0, and 6.4%, respectively. Multivariate Cox regression showed a reduced reinfection rate in the ≤2-week cohort relative to no antibiotics (hazard ratio [HR]: 0.38, P = .01). While the smaller cohort with >2 weeks of antibiotics did not significantly reduce the reinfection rate (HR: 0.41, P = .12), when combined with the ≤2-week cohort, use of oral antibiotics had an overall reduction of the reinfection rate (HR: 0.39, P = .01). ConclusionsThese data support the hypothesis that a short course of oral antibiotics after reimplantation decreases the 1-year reinfection rate. Future randomized studies should seek to examine the efficacy of different durations of oral antibiotics to reduce reinfection. Level of EvidencePrognostic Level IV.

HCV reinfection after HCV therapy among HIV/HCV-coinfected individuals in Europe.

Although direct-acting antivirals (DAAs) can clear HCV in nearly all HIV/HCV-coinfected individuals, high rates of reinfection may hamper efforts to eliminate HCV in this population. We investigated reinfection after sustained virological response (SVR) in HIV/HCV-coinfected individuals in Europe. Factors associated with odds of reinfection by 2years after SVR in EuroSIDA participants with one or more HCV-RNA test and 2years follow-up were assessed using logistic regression. Overall, 1022 individuals were included. The median age was 50 (interquartile range: 43-54years), and most were male (78%), injection drug users (52%), and received interferon (IFN)-free DAAs (62%). By 24months, 75 [7.3%, 95% confidence interval (CI): 5.7-8.9%] individuals were reinfected. Among individuals treated prior to 2014, 16.1% were reinfected compared with 4.2% and 8.3%, respectively, among those treated during or after 2014 with IFN-free and IFN-based therapy. After adjustment, individuals who had started treatment during or after 2014 with IFN-free or IFN-based therapy had significantly lower odds of reinfection (adjusted odds ratio = 0.21, 95% CI: 0.11-0.38; 0.43, 95% CI: 0.22-0.83) compared with those who had received therapy before 2014. There were no significant differences in odds of reinfection according to age, gender, European region, HIV transmission risk group or liver fibrosis. Among HIV/HCV-coinfected individuals in Europe, 7.3% were reinfected with HCV within 24months of achieving SVR, with evidence suggesting that this is decreasing over time and with use of newer HCV regimens. Harm reduction to reduce reinfection and surveillance to detect early reinfection with an offer of treatment are essential to eliminate HCV.

Duration of Viral Nucleic Acid Shedding and Early Reinfection With Severe Respiratory Syndrome Coronavirus 2 in Healthcare Workers and First Responders.

We estimated the distributions of duration of SARS-CoV-2 nucleic acid shedding and time to reinfection among 137 persons with at least two positive nucleic acid amplification test (NAAT) results from March to September 2020. We analyzed gaps of varying length between subsequent positive and negative NAAT results and estimated a mean duration of nucleic acid shedding of 30.1 (95% CI 26.3, 34.5) days. The mean time to reinfection was 89.1 (95% CI 75.3, 103.5) days. Together, these indicate that a 90-day period between positive NAAT results can reliably define reinfection in immunocompetent persons although reinfection can occur at shorter intervals.

Resistance Evaluation of Dominant Varieties against Southern Rice Black-Streaked Dwarf Virus in Southern China.

Southern rice black-streaked dwarf virus (SRBSDV), a Fijivirus in the Reoviridae family, is transmitted by the white-backed planthopper (Sogatella furcifera, WBPH), a long-distance migratory insect, and presents a serious threat to rice production in Asia. It was first discovered in China’s Guangdong Province in 2001 and has been endemic in the south of China and north of Vietnam for two decades, with serious outbreaks in 2009, 2010, and 2017. In this study, we evaluated the resistance of 10 dominant rice varieties from southern China, where the virus overwinters and accumulates as a source of early spring reinfection, against this virus by artificial inoculation. The results showed that in all tested varieties there was no immune resistance, but there were differences in the infection rate, with incidence rates from 21% to 90.7%, and in symptom severity, with plant weight loss from 66.71% to 91.20% and height loss from 34.1% to 65.06%. Additionally, and valuably, the virus titer and the insect vector virus acquisition potency from diseased plants were significantly different among the varieties: an over sixfold difference was determined between resistant and susceptible varieties, and there was a positive correlation between virus accumulation and insect vector virus acquisition. The results can provide a basis for the selection of rice varieties in southern China to reduce the damage of SRBSDV in this area and to minimize the reinfection source and epidemics of the virus in other rice-growing areas.

Platelet-Rich Fibrin in Combination with Local Antibiotics Optimizes Wound Healing After Deep Sternal Wound Problems and Prevents Reinfection

Objective: Disturbed wound healing is a significant problem in patients after cardiac surgery. Problems with deep sternal wound healing are rare, but can be quite difficult to treat. Furthermore, the therapy is highly expensive and consumes many of the patient’s personal resources. Another major obstacle in this patient group is reinfection after secondary wound closure. We examined how to prevent early reinfection through the use of growth factors in combination with local antibiotics. Methods: Our study included 232 patients with a deep sternal wound healing problem. After initial vacuum therapy, we planned secondary wound closure. During wound closure, we used only platelet-rich fibrin in a PRF group (109 patients). In another group (123 patients), we covered the wounds intraoperatively with a combination of PRF and local antibiotics (PRF CoDelivery). All patients were observed for 30 days for signs of early surgical site infection. Results: After 30 days, 22 patients (20.2%) in the PRF group showed a persistent problem with wound healing with or without reinfection. In contrast, only 12 patients (9.8%) in the PRF CoDelivery group had this problem (p=0.023 PRF vs. PRF CoDelivery). Conclusion: The combination of growth factors and antibiotics was associated with a significantly reduced incidence of early reinfection and thus can be expected to have a positive impact on wound healing in complicated scenarios. Furthermore, the combination of PRF and local antibiotics was easy to use. Further studies are needed to verify these initial findings.

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.

Definitions for coronavirus disease 2019 reinfection, relapse and PCR re-positivity

Definitions for coronavirus disease 2019 reinfection, relapse and PCR re-positivity

Evaluation of BioPlex 2200 Syphilis Total With Automated Rapid Plasma Reagin: Experience From a Tertiary Medical Center.

Treponema-specific assays are widely adopted in the first step of the reverse algorithm of serologic syphilis screening. The new BioPlex 2200 Syphilis Total and rapid plasma reagin (RPR) test is designed to perform the first 2 steps of the algorithm simultaneously. However, limited data regarding the BioPlex Syphilis Total and RPR in clinical practice exist. A total of 293 random samples at a tertiary medical center were tested by BioPlex Syphilis Total and RPR, BioPlex Syphilis IgG, Architect Syphilis TP, and BD Macro-Vue RPR card. Treponema pallidum particle agglutination (TP-PA) assay and clinical chart review were used to resolve discrepancies. Comparisons were performed among treponemal-specific assays and between 2 RPR tests. Good overall agreements (>91%) were achieved between BioPlex Syphilis Total, BioPlex Syphilis IgG, and Architect Syphilis TP. Overall agreement between BioPlex RPR and BD RPR was 86.8% with positive percent agreement of 66.7% and negative percent agreement of 96.3%. There were 37 discordant samples including 30 with BD RPR+/BioPlex RPR- and 7 with BD RPR-/BioPlex RPR+. Negative BioPlex RPR results were observed in samples with reactive BD RPR: 10 (91%) of 11 for BD RPR 1:1, 13 (65%) of 20 for BD RPR 1:2, 6 (35%) of 17 for BD RPR 1:4, and 1 (7%) of 14 for BD RPR 1:8. The discordant samples were predominantly from patients with high-risk of syphilis reinfection and included 9 patients with an early reinfection. Our results demonstrated that BioPlex Syphilis Total and Architect Syphilis TP performed similarly. The BioPlex RPR missed a small number of early syphilis reinfections, and its implementation should depend on the patient population that the laboratory serves.

High rates of early HCV reinfection after DAA treatment in people with recent drug use attended at mobile harm reduction units

Background and AimsThe World Health Organization recently called for the elimination of hepatitis C virus (HCV) and has identified people who inject drugs (PWID) as a key target population. Clinical trials analyzing currently available all-oral regimens have demonstrated a high degree of efficacy in this population, with a relatively low reinfection rate. There is an urgent need to confirm these data in a harm reduction and active consumption setting. The primary aim of this study was to evaluate the HCV reinfection rate in people with recent drug use followed at low-threshold mobile harm reduction units. MethodWe included people with recent drug use (smoked or injected heroin/cocaine in the previous 6 months) who received HCV treatment and were attended at two low-threshold mobile harm reduction units over 19 months. Sustained virologic response was assessed 12 weeks after therapy (SVR12). The incidence density of HCV reinfection was defined as the number of reinfections per 100-person years (PY) using person-time of observation and was stratified by drug consumption at initiation of HCV treatment. Cox proportional hazard regression analysis was used to assess factors associated with reinfection. ResultsDuring the study period, 160 people who used drugs in the past 6 months completed HCV therapy. 122 (73.9%) and 88 (53.3%) reported injecting drug use in the 6 months and 30 days prior to HCV treatment, respectively. The overall SVR12 was 68% in the ITT analysis (reinfection = failure) and 90.7% in the modified intent-to-treat analysis (considering reinfections as response and removing people who were missing SVR data). The cohort at-risk for reinfection (n = 121) included 47 (39.2%) people who initiated HCV treatment with recently reported abstinence. Reinfection was identified in 10 persons (8.3%), and the median time to reinfection was 7.2 (IQR 4.2–18) months. Total follow-up time at-risk was 101.1-PY (median 0.6 years, IQR 0.3–1.3). The overall incidence of reinfection was 9.8 per 100-PY (95% CI 4.7,18.2). The incidence of reinfection was higher amongst those who had injected drugs in the previous 6 months (16.7 [95%CI 8.0; 30.7] per 100-PY) and in the previous 30 days (18.9 [95% CI 8.1; 37.2] per 100-PY). In the adjusted analysis, only injecting drugs use in the month prior to initiation of HCV therapy was associated with reinfection (aHR 8.7, 95%CI 1.0; 73.6; p 0.04). ConclusionHigh efficacy of HCV treatment, was found in people with recent drug use attended and followed at low-threshold mobile harm reduction units. The high rate of early HCV reinfections in this setting should promote surveillance for reinfection at 7-month intervals after ending the treatment or earlier.

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.

A Meta-Analysis of Outcomes of In Situ Reconstruction after Total or Partial Removal of Infected Abdominal Aortic Grafts?

Objective: To determine the most appropriate indication for total resection (TR) or partial resection(PR) of infected aortic grafts.Methods: A meta-analysis was conducted on the rates of early/late mortality, amputations and reinfection. A meta-regression was performed with 8 variables: patient age, male prevalence, presence of prosthetic duodenal fistula (PDF), presence of virulent or nonvirulent organisms, urgency, omentoplasty and follow-up.Results: For TR and PR, the rates of early mortality and reinfection were 16.8% and 10.5%, 11% and 27% respectively.For TR, the rates of early mortality and reinfection for in situ reconstruction with allografts and veins were 23% and 10.7%, 10.5% and 2.8% respectively.For TR, urgency, male gender and omentoplasty all had a negative correlation with early mortality. Omentoplasty had a positive correlation with late mortality. Male gender, PDF and virulent organisms had a negative correlation with reinfection, whereas nonvirulent organisms had a positive correlation. Presence of PDF and follow-up had a negative correlation with amputation, whereas male gender had a positive correlation. For PR, no statistical correlation was analyzable except a negative correlation between PDF and reinfection.Conclusion: For TR, operative mortality increases in males, and in emergencies, so total removal of the infected aortic graft seems not advisable, and alternative interventions should be considered. With regard to the risk of reinfection, TR appears recommendable in the presence of nonvirulent infectious organisms, but there is increased risk in the presence of virulent organisms and PDF, and so other optimal options may be discussed.For PR results were not analyzable except for a negative correlation in the presence of PDF.

Chronic periprosthetic hip infection: micro-organisms responsible for infection and re-infection.

This study aimed to delineate the infecting micro-organisms identified at the first-time revision for infected THA, analyze pre-operative versus intra-operative findings, as well as intra-operative ones against re-infection micro-organisms. Microbiological laboratory findings were studied in 73 patients (mean age, 51.93 ± 10.9years) with chronic periprosthetic hip infection pre-operatively and intra-operatively. Forty-three patients had a two-stage revision THA while 30 patients were treated with a modified resection arthroplasty using the Ilizarov apparatus. Re-infection developed in 29 cases. Its microbial species were identified. Pre-operative findings on micro-organisms coincided 50.7% with the intra-operative ones. Bacterial growth in the intra-operative tests was detected in 72 (98.5%) cases. Gram-positive single genus infection was identified in 35 patients (48%); microbe associations were present in 33 patients (45%). Staphylococcus species prevailed. Gram-negative infection was detected in 5.5% of cases. One case (1.5%) did not have any microbe growth. Re-infection happened in 10 cases (23.2%) in a two-stage revision THA. In the resection arthroplasty group, early re-infection was observed in 63.3% of cases. Among a total of 29 re-infection cases, staphylococcus species were identified in 19 cases, present either in associations or as single germs. Intra-operative microbiological tests at the first-time revision for infected THR detect a reliable spectrum of micro-organisms to assess microbial resistance to antibiotics, develop treatment protocols, and for prognostic purposes. Preventive measures at primary THR and strategies to fight periprosthetic infection and reinfection should be targeted on staphylococci.

Are homografts superior to conventional prosthetic valves in the setting of infective endocarditis involving the aortic valve?

BackgroundSurgical dogma suggests that homografts should be used preferentially, compared with conventional xenograft or mechanical prostheses, in the setting of infective endocarditis (IE), because they have greater resistance to infection. However, comparative data that support this notion are limited. MethodsFrom the prospective databases of 2 tertiary academic centers, we identified 304 consecutive adult patients (age ≥17 years) who underwent surgery for active IE involving the aortic valve (AV), in the period 2002 to 2014. Short- and long-term outcomes were evaluated using propensity scores and inverse-probability weighting to adjust for selection bias. ResultsHomografts, and xenograft and mechanical prostheses, were used in 86 (28.3%), 139 (45.7%), and 79 (26.0%) patients, respectively. Homografts were more often used in the setting of prosthetic valve endocarditis (58.1% vs 28.8%, P = .002) and methicillin-resistant Staphylococcus (25.6% vs 12.1%, P = .002), compared with conventional prostheses. Early mortality occurred in 17 (19.8%) in the homograft group, and 20 (9.2%) in the conventional group (P = .019). During follow-up (median: 29.4 months; interquartile-range: 4.7-72.6 months), 60 (19.7%) patients died, and 23 (7.7%) experienced reinfection, with no significant differences in survival (P = .23) or freedom from reinfection rates (P = .65) according to the types of prostheses implanted. After adjustments for baseline characteristics, using propensity-score analyses, use of a homograft did not significantly affect early death (odds ratio 1.61; 95% confidence interval [CI], 0.73-3.40, P = .23), overall death (hazard ratio 1.10; 95% CI, 0.62-1.94, P = .75), or reinfection (hazard ratio 1.04; 95% CI, 0.49-2.18, P = .93). ConclusionsNo significant benefit to use of homografts was demonstrable with regard to resistance to reinfection in the setting of IE. The choice among prosthetic options should be based on technical and patient-specific factors. Lack of availability of homografts should not impede appropriate surgical intervention.

Antibodies to Echinococcus granulosus Egg Antigens in Hydatid Patients: Characterization by Immunoblot and Diagnostic Value

Cystic echinococcosis/hydatidosis, caused by Echinococcus granulosus, is a chronic zoonotic larval cestode infection in humans. Human hydatidosis is a public health parasitic disease that is cosmopolitan in its distribution. Several years may last between contamination with E. granulosus eggs and development of symptomatic cysts. Antigens expressed by embryos at early differentiation steps between the embryo and the young cyst may be interesting as markers of early infection or reinfection. This study investigates antibody response (IgG) to E. granulosus egg antigens by Immunoblot (IB) and ELISA in 20 hydatid patients surgically confirmed. We have also tested sera using protoscoleces and hydatid cyst fluid (HCF) from E. granulosus. The results show that hydatid patients reacted to eggs as well as protoscoleces and HCF. However, eggs share antigens in common with other life-cycle stages, but also support the notion that they may possess some unique stage-specific antigens determinants. The possible functional significance and the potential use of combined assessment of these antigens in IB with Ig G response in ELISA are discussed.

Evaluation of a hepatitis C virus (HCV) antigen assay for routine HCV screening among men who have sex with men infected with HIV

BackgroundFor detection of early HCV infection and reinfection, commercial HCV-RNA tests are available. However, these tests are relatively time-consuming and expensive. A commercially available test that may supplement current screening methods, targets the HCV core protein. MethodsDuring five waves of anonymous surveys at the Amsterdam STI clinic between 2009-2012, all HIV-infected MSM (N=439) were tested for HCV-antibodies (AxSYM HCV 3.0, Abbott), and HCV-RNA (TMA Versant, Siemens). To evaluate the potential value of the ARCHITECT HCV antigen (HCV-Ag) assay (Abbott), all HCV-RNA-positive sera (N=31) were tested with this assay, as well as two HIV-infected HCV-RNA-negative controls. In addition, all included samples were tested for alanine aminotransferase (ALT). ResultsAmong 439HIV-infected MSM, 31 (7.1%) tested positive for HCV-RNA; the HCV-Ag assay showed concordant positive results for 31/31 (100%). A substantial number of MSM, i.e., 5/31 (16.1%), had detectable HCV-RNA but were HCV-seronegative at the time of screening and were presumed to have been recently infected. Concordant HCV-RNA-negative results were obtained in 57/60 control-samples. Specificity was 95.0% (95% CI: 86.1-99.0). The detection limit was between 3.0 and 3.7 Log10 IU/mL, irrespective of HCV genotype/subtype. ALT concentrations were elevated (i.e.,>40 U/L) in 9/31 (29.0%) HCV-RNA positive MSM, including 1/5 (20.0%) MSM with recent HCV-infection. ConclusionsThe HCV-Ag assay proved a valuable screening tool for detection of active HCV infection among HIV-infected MSM with and without anti-HCV. Adding ALT to current screening methods would improve case finding marginally. We therefore recommend implementation of routine HCV-Ag screening for populations at risk for HCV-(re)infection.

NK1.1+ CD8+ T cells escape TGF-β control and contribute to early microbial pathogen response.

Following microbial pathogen invasion, one of the main challenges for the host is to rapidly control pathogen spreading to avoid vital tissue damage. Here we report that an effector CD8(+) T-cell population that expresses the marker NK1.1 undergoes delayed contraction and sustains early anti-microbial protection. NK1.1(+) CD8(+) T cells are derived from CD8(+) T cells during priming, and their differentiation is inhibited by transforming growth factor-β signalling. After their own contraction phase, they form a distinct pool of KLRG1 CD127 double-positive memory T cells and rapidly produce both interferon-γ and granzyme B, providing significant pathogen protection in an antigen-independent manner within only a few hours. Thus, by prolonging the CD8(+) T-cell response at the effector stage and by expressing exacerbated innate-like features at the memory stage, NK1.1(+) cells represent a distinct subset of CD8(+) T cell that contributes to the early control of microbial pathogen re-infections.

Post-liver transplant hepatitis C virus recurrence: an unresolved thorny problem.

Hepatitis C virus (HCV)-related cirrhosis represents the leading cause of liver transplantation in developed, Western and Eastern countries. Unfortunately, liver transplantation does not cure recipient HCV infection: reinfection universally occurs and disease progression is faster after liver transplant. In this review we focus on what happens throughout the peri-transplant phase and in the first 6-12 mo after transplantation: during this crucial period a completely new balance between HCV, liver graft, the recipient's immune response and anti-rejection therapy is achieved that will deeply affect subsequent outcomes. Nearly all patients show an early graft reinfection, with HCV viremia reaching and exceeding pre-transplant levels; in this setting, histological assessment is essential to differentiate recurrent hepatitis C from acute or chronic rejection; however, differentiating the two patterns remains difficult. The host immune response (mainly cellular mediated) appears to be crucial both in the control of HCV infection and in the genesis of rejection, and it is also strongly influenced by immunosuppressive treatment. At present no clear immunosuppressive strategy could be strongly recommended in HCV-positive recipients to prevent HCV recurrence, even immunotherapy appears to be ineffective. Nonetheless it seems reasonable that episodes of rejection and over-immunosuppression are more likely to enhance the risk of HCV recurrence through immunological mechanisms. Both complete prevention of rejection and optimization of immunosuppression should represent the main goals towards reducing the rate of graft HCV reinfection. In conclusion, post-transplant HCV recurrence remains an unresolved, thorny problem because many factors remain obscure and need to be better determined.

In situ revascularisation for femoropopliteal graft infection: ten years of experience with silver grafts

The purpose of this study was to analyze clinical outcome of patients for femoropopliteal graft infection who were treated by in situ reconstruction with a silver-coated prosthesis. From December 2001 to December 2011, 27 patients were treated for femoropopliteal graft infection. Twenty patients (74%) were male and seven (26%) were female. Mean age was 65 years. The primary endpoint was recurrence of infection. Secondary endpoints were early and late mortality and morbidity, primary graft patency, major amputation rates and patient survival. Early reinfection occurred in 11% and late in 8% of patients. Perioperative mortality was 7% and late was 4%. Above-knee amputation was performed in 4% of patients during early postoperative course and in 12% of patients during follow-up. Early and late graft patency was 96% and 72%, respectively. Results of in situ implantation of silver-coated grafts for femoropopliteal prosthesis infection are according to our opinion acceptable, but the risk of reinfection remains.