Novel intervention based on an individualized bundle of care to decrease infection in kidney transplant recipients.

BACKGROUND: Infection remains a relevant complication after kidney transplantation (KT). A well-established strategy in modern medicine is the application of bundles of evidence-based practice in clinical settings. The objective of this study is to explore the application of a personalized bundle of measures aimed to reduce the incidence of infection in the first 12 months after KT. METHODS: A single-center prospective cohort of 148 patients undergoing KT between February 2018 and September 2019 that received an individualized infection prevention strategy was compared to a preintervention cohort (n = 159). The bundle comprised a review of the patient's immunization history, infection risk by country of origin, screening for latent tuberculosis infection (LTBI), antimicrobial prophylaxis, and immunological assessment. Individualized recommendations were accordingly provided at a scheduled visit at day +30 after transplantation. RESULTS: The intervention cohort showed a higher compliance rate with the recommended vaccine schedule, screening for geographically restricted infections and LTBI, and intravenous immunoglobulin and vitamin D supplementation (p values <.001). The 1-year incidence rate of infection was lower in the intervention cohort (42.6% vs. 57.9%; p value = .037), as was the rate of infection-related hospitalization (17.6% vs. 32.1%; p value = .003) and the incidence of severe bacterial infection. There were no differences in graft rejection or mortality rates between groups. CONCLUSIONS: A multifaceted intervention, including a bundle of evidence-based practices, enhanced compliance with recommended preventive measures and was correlated with a reduction in the 12-month incidence of infection after KT.

Management of cytomegalovirus in adult solid organ transplant patients: GESITRA-IC-SEIMC, CIBERINFEC, and SET recommendations update.

Cytomegalovirus (CMV) infection remains a significant challenge in solid organ transplantation (SOT). The last international consensus guidelines on the management of CMV in SOT were published in 2018, highlighting the need for revision to incorporate recent advances, notably in cell-mediated immunity monitoring, which could alter the current standard of care. A working group including members from the Group for the Study of Infection in Transplantation and the Immunocompromised Host (GESITRA-IC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Transplantation (SET), developed consensus-based recommendations for managing CMV infection in SOT recipients. Recommendations were classified based on evidence strength and quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The final recommendations were endorsed through a consensus meeting and approved by the expert panel.

Human microRNA sequencing and cytomegalovirus infection risk after kidney transplantation.

Cytomegalovirus (CMV)-seropositive kidney transplant recipients (KTRs) with detectable CMV-specific cell-mediated immunity according to the QuantiFERON-CMV assay (QTF-CMV) are expected to have adequate immune protection. Nevertheless, a proportion of patients still develop CMV infection. Human microRNAs (hsa-miRNAs) are promising biomarkers owing to their high stability and easy detection. We performed whole blood miRNA sequencing in samples coincident with the first reactive QTF-CMV after transplantation or cessation of antiviral prophylaxis to investigate hsa-miRNAs differentially expressed according to the occurrence of CMV infection. One-year incidence of CMV viremia was 55.0% (median interval from miRNA sequencing sampling of 29 days). After qPCR validation, we found that hsa-miR-125a-5p was downregulated in KTRs developing CMV viremia within the next 90 days (ΔCt: 7.9 ± 0.9 versus 7.3 ± 1.0; P = .011). This difference was more evident among KTRs preemptively managed (8.2 ± 0.9 versus 6.9 ± 0.8; P < .001), with an area under the receiver operating characteristic curve of 0.865. Functional enrichment analysis identified hsa-miR-125a-5p targets involved in cell cycle regulation and apoptosis, including the BAK1 gene, which was significantly downregulated in KTRs developing CMV viremia. In conclusion, hsa-miR-125a-5p may serve as biomarker to identify CMV-seropositive KTRs at risk of CMV reactivation despite detectable CMV-CMI.

Natural history and prognostic factors of candidemia in kidney transplant recipients: A retrospective, multinational study.

BACKGROUND: The natural history of candidemia in kidney transplant recipients (KTR) remains poorly understood. This study aimed to evaluate mortality, prognostic factors and overall graft loss after candidemia in KTRs. METHODS: This is a retrospective multicentre study enrolling all KTRs ≥15 years old with candidemia diagnosed at hospitals in Brazil, Spain and Italy from 2010 to 2020. Primary endpoints were mortality rates at 14 and 30 days. Secondary endpoints were prognostic factors of 14-day mortality and overall graft loss. RESULTS: We enrolled 93 KTRs of which 75 were from Brazil. The mean time interval from transplantation to the onset of candidemia was 45.2 ± 61.5 months. 42% of all patients were on haemodialysis, 31.3% had an episode of sepsis and 39% underwent surgery within 30 days before fungemia. European patients were more likely to receive echinocandin (32 vs. 72%, p < .001). 22.7% of Brazilian patients did not receive any antifungal before death. All-cause mortality at 14 days was higher in Brazil (41.3 vs. 11.1%, p = .016). Candida colonisation (OR 6.91 [95% CI: 1.08-44.3], p = .042) and hypotension (OR 4.87 [95% CI: 1.62-14.66], p = .005) were associated with 14-day mortality. Echinocandin treatment had a protective effect (OR 0.19 [95% CI: 0.05-0.73], p = .015). Graft loss at 90 days occurred in 48% of patients (70.7 in Brazil vs. 22.2% in Europe, p < .01). CONCLUSIONS: Candidemia in KTR is usually documented late after engraftment in patients requiring HD, surgical procedures and dysbiosis secondary to antibiotic use. Mortality was higher in Brazil. Echinocandin therapy was associated with improved survival.

Predictive value of fecal calprotectin and lactoferrin levels for negative outcomes in Clostridioides difficile infection.

PURPOSE: We investigated the role of fecal calprotectin (FC) and lactoferrin (FL) as predictive biomarkers in Clostridioides difficile infection (CDI). METHODS: We assembled a prospective cohort including all patients with a laboratory-confirmed CDI diagnosis between January and December 2017. FL and FC levels were measured at diagnosis by commercial ELISA and EIA kits. We investigated the diagnostic accuracy of FC and FL to predict CDI recurrence and severity (study outcomes) and explored optimal cut-off values in addition to those proposed by the manufacturers (200 µg/g and 7.2 µg/mL, respectively). RESULTS: We included 170 CDI cases (152 first episodes and 18 recurrences). The rates of recurrence (first episodes only) and severity (entire cohort) were 9.2% (14/152) and 46.5% (79/170). Both FL and FC levels were significantly higher in patients who developed study outcomes. Optimal cut-off values for FC and FL to predict CDI recurrence were 1052 µg/g and 6.0 µg/mL. The optimal cut-off value for FC yielded higher specificity (60.9%) and positive predictive value (PPV) (16.9%) than that proposed by the manufacturer. Regarding CDI severity, the optimal cut-off value for FC (439 µg/g) also provided higher specificity (43.9%) and PPV (54.1%) than that of the manufacturer, whereas the optimal cut-off value for FL (4.6 µg/mL) resulted in an improvement of PPV (57.5%). CONCLUSION: By modifying the thresholds for assay positivity, the measurement of FC and FL at diagnosis is useful to predict recurrence and severity in CDI. Adding these biomarkers to current clinical scores may help to individualize CDI management.

Production of OXA-48 carbapenemase acts as an independent risk factor for poor outcome in Klebsiella pneumoniae infection.

PURPOSE: To know whether the production of OXA-48 carbapenemase exerts an independent impact on the outcome of Klebsiella pneumoniae infection, once adjusted by clinical syndrome and baseline risk factors. METHODS: We performed a case-cohort study including 117 infectious episodes due to OXA-48-producing K. pneumoniae (OXA-48-Kp) and 117 episodes due to non-OXA-48-producing strains (non-OXA-48-Kp). Both groups were matched (1:1 ratio) by clinical syndrome (source of infection, preceding invasive procedures and indwelling devices, and associated bacteremia) and hospitalization ward at infection onset. Multivariate Cox regression was used to investigate the association between OXA-48-Kp infection and clinical cure by day 14 (primary outcome) and 30-day all-cause mortality (secondary outcome). RESULTS: Both study groups were well balanced regarding underlying conditions and comorbidity burden. Sepsis or septic shock were more frequent in OXA-48-Kp cases than non-OXA-48-Kp controls (41 [35.0%] vs. 17 [14.5%]; P-value < 0.0001). Clinical cure by day 14 was less commonly achieved in OXA-48-Kp cases (49 [41.9%] vs. 95 [81.2%]; P-value < 0.001), whereas 30-day all-cause mortality was higher (33 [28.2%] vs. 18 [15.4%]; P-value = 0.018). Multivariate analysis confirmed that OXA-48-Kp infection was independently associated with the lack of 14-day clinical cure (adjusted hazard ratio [aHR]: 0.45; 95% confidential interval [95%CI]: 0.29-0.70; P-value < 0.0001). A non-significant association was observed for 30-day all-cause mortality (aHR: 1.65; 95%CI: 0.92-2.94; P-value = 0.093). CONCLUSION: Our matched analysis suggests that the production of OXA-48 carbapenemase acts as an independent risk factor for poor outcome in K. pneumoniae infection as compared to episodes due to non-carbapenemase-producing strains.

Post-transplant dynamics and clinical significance of CMV-specific neutralizing antibodies in kidney transplant recipients treated with T-cell-depleting agents.

We measured cytomegalovirus (CMV)-specific antibodies that neutralize epithelial cell infection (CMV-AbNEIs) in 101 CMV-seropositive kidney transplant recipients (KTRs) at baseline and post-transplant months 3 and 6. All the patients received antithymocyte globulin and 3-month valganciclovir prophylaxis. There were no significant differences in pre-transplant AbNEIs titers between KTRs that developed or did not develop any-level CMV infection or the composite of high-level infection and/or disease. One-year CMV infection-free survival was comparable between KTRs with or without pre-transplant CMV-AbNEIs. No differences were observed by months 3 and 6 either. We observed no protective role for CMV-AbNEIs among CMV-seropositive KTRs undergoing T-cell-depleting induction.

Nirmatrelvir/ritonavir for the treatment of immunocompromised adult patients with early-stage symptomatic COVID-19: A real-life experience.

Regardless of vaccination status, progression to severe coronavirus disease 2019 (COVID-19) is still a relevant cause of morbidity among immunocompromised patients. Despite the proven efficacy of nirmatrelvir/ritonavir (NMV/r), concerns remain regarding the potential for drug-to-drug interactions (DDIs) and the safety in this at-risk population. We aimed to evaluate the clinical outcomes of immunocompromised patients treated with NMV/r, as well as the occurrence of DDIs and treatment-emergent adverse events (TEAEs). This retrospective observational study included all the patients with some form of immunosuppression and laboratory-confirmed COVID-19 that received NMV/r at our center from April to August 2022. The main outcome was worsening of the clinical status (increase of ≥1 point from baseline in a validated clinical progression scale) by Days +7 and +28 after the initiation of therapy. Safety outcomes included the rates of any TEAE and potentially severe DDIs. We included 110 patients. Main causes of immunosuppression were hematological malignancy (58.2%) (mainly multiple myeloma [22.7%] and non-Hodgkin lymphoma [13.6%]), active chemotherapy (30.0%) and hematopoietic stem cell transplantation (14.5%). Clinical worsening by Days +7 and +28 was observed in four (3.6%) and five patients (4.5%), respectively. Only one patient had a positive SARS-CoV-2 polymerase chain reaction test at Day +28. At least one potentially severe DDI was observed in 56.4% of the patients. The rate of attributable TEAEs was 10.9%, although only two patients (1.8%) required premature discontinuation of NMV/r. Early initiation of NMV/r therapy should be considered in immunocompromised patients with COVID-19, with particular attention to interacting medications.

Previous use of statins does not improve the outcome of bloodstream infection after kidney transplantation.

Previous studies have suggested that exposure to statins confers a protective effect in bloodstream infection (BSI) due to the anti-inflammatory and immunomodulatory properties attributed to these lipid-lowering drugs. Scarce evidence is available for the solid organ transplant population. Therefore, we compared the time to clinical cure (primary outcome) and the time to fever resolution, new requirement of intensive care unit admission or renal replacement therapy, and 30-day all-cause mortality (secondary outcomes) between kidney transplant (KT) recipients with post-transplant BSI that were receiving or not statin therapy for at least the previous 30 days. We included 80 KT recipients that developed 109 BSI episodes (43 [39.4%] and 66 [60.6%] episodes within the statin and non-statin groups, respectively). The median interval since the initial prescription to BSI was 512 days (interquartile range [IQR]: 172-1388). Most episodes were of urinary source and due to Enterobacterales. There were no differences in the median time to clinical cure in the statin and non-statin groups (3.4 [IQR: 3-6.8] versus 4 [IQR: 2-6] days; p-value = .112). The lack of effect was confirmed by multiple linear regression analysis adjusted for confounding factors (standardized ß coefficient = 0.040; p-value = .709). No significant differences were observed for any of the secondary outcomes either. Vital signs and laboratory values at BSI onset and after 72-96 h were similar in both groups. In conclusion, previous statin therapy had no apparent protective effect on the outcome of post-transplant BSI among KT recipients.

Comprehensive analysis of current epidemiology, clinical features and prognostic factors of puerperal endometritis: A retrospective cohort analysis.

Background: Puerperal endometritis has not been recently investigated. We aimed to describe the current dimension of the endometritis in the context of other causes of puerperal fever and investigate the microbiology and need for curettage in these patients. Methods: A retrospective cohort study was conducted based on a prospectively maintained database of patients with puerperal fever, (2014-2020) in which cases fulfilling criteria for endometritis were selected for further analysis. Description of clinical and microbiological features was performed and determination of the factors related with puerperal curettage requirement were studied using univariate and multivariate analysis through binary logistic regression. Results: From 428 patients with puerperal fever, endometritis was the main cause of puerperal fever (233 patients, 52.7 %). Curettage was required in 96 of them (41.2 %). Culture of endometrial samples were performed in 62 (64.5 %), of which 32 (51.6 %) yielded bacterial growth. Escherichia coli was the most common microorganism in curettage cultures (46.9 %). Multivariate analysis identified the following predictive factors for curettage: the presence of pattern compatible with retained products of conception (RPOC) in transvaginal ultrasonography (odds ratio [OR]: 17.6 [95 % confidence interval [CI]: 8.4-36.6]; P-value < 0.0001), fever during the first 14 days after delivery (OR:5.1; [95 % CI: 1.57-16.5]; P-value 0.007), abdominal pain (OR: 2.9; [95 % CI: 1.36-6.1]; P-value 0.012) and malodorous lochia (OR:3.5; [95 % CI: 1.25-9.9]; P-value 0.017). Scheduled cesarean delivery was protective (OR: 0.11 [95 % CI 0.01-1.2]; P-value 0.08). Conclusions: Endometritis is still the main cause of puerperal fever. Women requiring curettage typically presented with abdominal pain and foul-smelling lochia, an ultrasound image compatible with RPOC and fever in the first 14 days postpartum. Curettage culture is useful for the microbiological affiliation mostly yielding gram-negative enteric flora.

Comparison of intracellular cytokine staining versus an ELISA-based assay to assess CMV-specific cell-mediated immunity in high-risk kidney transplant recipients.

The best method for monitoring cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) among high-risk kidney transplant (KT) recipients remains uncertain. We assessed CMV-CMI by intracellular cytokine staining (ICS) by flow cytometry and a commercial interferon (IFN)-γ release assay (QuantiFERON®-CMV [QTF-CMV]) at posttransplant months 3, 4, and 5 in 53 CMV-seropositive KT recipients that had received induction therapy with antithymocyte globulin (ATG) and a 3-month course of valganciclovir prophylaxis. The discriminative capacity (areas under receiver operating characteristics curve [auROCs]) and diagnostic accuracy to predict immune protection against CMV infection from the discontinuation of prophylaxis to month 12 were compared between both methods. There was significant although moderate correlations between CMV-specific IFN-γ-producing CD8+ T-cell counts enumerated by ICS and IFN-γ levels by QTF-CMV at months 3 (rho: 0.493; p = 0.005) and 4 (rho: 0.440; p = 0.077). The auROCs for CMV-specific CD4+ and CD8+ T-cells by ICS were nonsignificantly higher than that of QTF-CMV (0.696 and 0.733 vs. 0.678; p = 0.900 and 0.692, respectively). The optimal cut-off of ≥0.395 CMV-specific CD8+ T-cells yielded a sensitivity of 86.4%, specificity of 54.6%, positive predictive value of 79.2% and negative predictive value of 66.7% to predict protection. The corresponding estimates for QTF-CMV (IFN-γ levels ≥0.2 IU/mL) were 78.9%, 37.5%, 75.0%, and 42.9%, respectively. The enumeration of CMV-specific IFN-γ-producing CD8+ T-cells at the time of cessation of prophylaxis performed slightly better than the QTF-CMV assay to predict immune protection in seropositive KT recipients previously treated with ATG.

Lung abscess and empyema in a heart transplant recipient from Thailand.

The case discussed involves a 69-year-old Thai woman who underwent orthotopic heart transplantation 9 months before this event. She presented with fever without localizing signs or symptoms. However, her chest images revealed mass-like consolidation in the left upper lobe. Blood culture and lung tissue identified Rhodococcus equi. She was successfully treated with a combination of antimicrobial therapy, optimization of immunosuppressants, and surgical resection.

Dynamics of Human Anelloviruses in Plasma and Clinical Outcomes Following Kidney Transplantation.

BACKGROUND: Torque teno virus, the major member of the genus Alphatorquevirus , is an emerging biomarker of the net state of immunosuppression after kidney transplantation. Genetic diversity constitutes a main feature of the Anelloviridae family, although its posttransplant dynamics and clinical correlates are largely unknown. METHODS: The relative abundance of Alphatorquevirus , Betatorquevirus , and Gammatorquevirus genera was investigated by high-throughput sequencing in plasma specimens obtained at various points during the first posttransplant year (n = 91 recipients). Total loads of all members of the Anelloviridae family were also quantified by an "in-house" polymerase chain reaction assay targeting conserved DNA sequences (n = 195 recipients). In addition to viral kinetics, clinical study outcomes included serious infection, immunosuppression-related adverse event (opportunistic infection and cancer)' and acute rejection. RESULTS: Alphatorquevirus DNA was detected in all patients at every point, with an increase from pretransplantation to month 1. A variable proportion of recipients had detectable Betatorquevirus and Gammatorquevirus at lower frequencies. At least 1 change in the predominant genus (mainly as early transition to Alphatorquevirus predominance) was shown in 35.6% of evaluable patients. Total anelloviruses DNA levels increased from baseline to month 1, to peak by month 3 and decrease thereafter, and were higher in patients treated with T-cell depleting agents. There was a significant albeit weak-to-moderate correlation between total anelloviruses and TTV DNA levels. No associations were found between the predominant Anelloviridae genus or total anelloviruses DNA levels and clinical outcomes. CONCLUSIONS: Our study provides novel insight into the evolution of the anellome after kidney transplantation.

Impact of polymorphisms in genes orchestrating innate immune responses on replication kinetics of Torque teno virus after kidney transplantation.

Background: Torque teno virus (TTV) DNAemia has been proposed as a surrogate marker of immunosuppression after kidney transplantation (KT), under the assumption that the control of viral replication is mainly exerted by T-cell-mediated immunity. However, Tthe impact on post-transplant TTV kinetics of single genetic polymorphisms (SNPs) in genes orchestrating innate responses remains unknown. We aimed to characterize the potential association between 14 of these SNPs and TTV DNA levels in a single-center cohort of KT recipients. Methods: Plasma TTV DNAemia was quantified by real-time PCR in 221 KT recipients before transplantation (baseline) and regularly through the first 12 post-transplant months. We performed genotyping of the following SNPs: CTLA4 (rs5742909, rs231775), TLR3 (rs3775291), TLR9 (rs5743836, rs352139), CD209 (rs735240, rs4804803), IFNL3 (rs12979860, rs8099917), TNF (rs1800629), IL10 (rs1878672, rs1800872), IL12B (rs3212227) and IL17A (rs2275913). Results: The presence of the minor G allele of CD209 (rs4804803) in the homozygous state was associated with undetectable TTV DNAemia at the pre-transplant assessment (adjusted odds ratio: 36.96; 95% confidence interval: 4.72-289.67; p-value = 0.001). After applying correction for multiple comparisons, no significant differences across SNP genotypes were observed for any of the variables of post-transplant TTV DNAemia analyzed (mean and peak values, areas under the curve during discrete periods, or absolute increments from baseline to day 15 and months 1, 3, 6 and 12 after transplantation). Conclusion: The minor G allele of CD209 (rs4804803) seems to exert a recessive protective effect against TTV infection in non-immunocompromised patients. However, no associations were observed between the SNPs analyzed and post-transplant kinetics of TTV DNAemia. These negative results would suggest that post-transplant TTV replication is mainly influenced by immunosuppressive therapy rather than by underlying genetic predisposition, reinforcing its clinical application as a biomarker of adaptive immunity.

Corrigendum: Brief Research Report: Virus-Specific Humoral Immunity at Admission Predicts the Development of Respiratory Failure in Unvaccinated SARS-CoV-2 Patients.

[This corrects the article DOI: 10.3389/fimmu.2022.878812.].

Influence of single-nucleotide polymorphisms in TLR3 (rs3775291) and TLR9 (rs352139) on the risk of CMV infection in kidney transplant recipients.

Risk stratification for cytomegalovirus (CMV) infection after kidney transplantation (KT) remains to be determined. Since endosomal toll-like receptors (TLRs) are involved in viral sensing, we investigated the impact of common single-nucleotide polymorphisms (SNPs) located within TLR3 and TLR9 genes on the occurrence of overall and high-level (≥1,000 IU/ml) CMV infection in a cohort of 197 KT recipients. Homozygous carriers of the minor allele of TLR3 (rs3775291) had higher infection-free survival compared with reference allele carriers (60.0% for TT versus 42.3% for CC/CT genotypes; P-value = 0.050). Decreased infection-free survival was observed with the minor allele of TLR9 (rs352139) (38.2% for TC/CC versus 59.3% for TT genotypes; P-value = 0.004). After multivariable adjustment, the recessive protective effect of the TLR3 (rs3775291) TT genotype was confirmed (adjusted hazard ratio [aHR]: 0.327; 95% CI: 0.167-0.642; P-value = 0.001), as was the dominant risk-conferring effect of TLR9 (rs352139) TC/CC genotypes (aHR: 1.865; 95% CI: 1.170-2.972; P-value = 0.009). Carriers of the TLR9 (rs352139) TC/CC genotypes showed lower CMV-specific interferon-γ-producing CD4+ T-cell counts measured by intracellular cytokine staining compared with the TT genotype (median of 0.2 versus 0.7 cells/µl; P-value = 0.003). In conclusion, TLR3/TLR9 genotyping may inform CMV infection risk after KT.

Genetic polymorphisms in TLR3, IL10 and CD209 influence the risk of BK polyomavirus infection after kidney transplantation.

Genetic determinants of BK polyomavirus infection after kidney transplantation remain poorly investigated. We assessed the potential impact of 13 different single nucleotide polymorphisms within genes mainly involved in innate immune responses on the risk of BKPyV viremia in 204 KT recipients. After a median follow-up of 1121.5 days, the cumulative incidence of any-level BKPyV viremia was 24.5% (50/204). There was a significant association between the minor T allele of TLR3 (rs3775291) SNP and the development of BKPyV viremia (adjusted hazard ratio [aHR]: 2.16; 95% confidence interval [CI]: 1.08-4.30; P value = 0.029), whereas the minor G allele of CD209 (rs4804803) SNP exerted a protective role (aHR: 0.54; 95% CI: 0.29-1.00; P value = 0.050). A higher incidence of BKPyV viremia was also observed for the minor G allele of IL10 (rs1800872) SNP, although the absence of BKPyV events among homozygotes for the reference allele prevented multivariable analysis. The BKPyV viremia-free survival rate decreased with the increasing number of unfavorable genotypes (100% [no unfavorable genotypes], 85.4% [1 genotype], 70.9% [2 genotypes], 52.5% [3 genotypes]; P value = 0.008). In conclusion, SNPs in TLR3, CD209 and IL10 genes play a role in modulating the susceptibility to any-level BKPyV viremia among KT recipients.

Reduction of Instrumentation-Related Spine Surgical Site Infections After Optimization of Surgical Techniques. A Single Center Retrospective Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Although surgical risk factors for developing spine surgical site infections (S-SSI) have been identified, the impact of such knowledge in its prevention has not been demonstrated. METHODS: We evaluated in 500 patients undergoing spine surgery between 2011 and 2019 at Hospital 12 de Octubre the changes in S-SSI rates over time. Surgical variables independently related to S-SSI were analyzed by univariate and multivariate analysis using binary logistic regression models. A case-control sub-analysis (1:4), matched by the surgical variables identified in the overall cohort was also performed. RESULTS: Twenty cases of S-SSI were identified (4%), with a significant decrease in the incidence rate across consecutive time periods (6.6% [2011-2014] vs .86% [2015-2019]; P-value <.0001)). Multivariate analysis identified arthrodesis involving sacral levels (odds ratio [OR]: 2.57; 95% confidence interval [95%CI]: 1.02-6.47; P-value = .044) and instrumentation over 4-8 vertebrae (OR: 2.82; 95%CI: 1.1-7.1; P-value = .027) as independent risk factors for S-SSI. The reduction in the incidence of S-SSI concurred temporally with a reduction in instrumentations involving 4-8 vertebrae (55% vs 21.8%; P-value <.0001) and sacral vertebrae (46.9% vs 24.6%; P-value <.0001) across both periods. The case-control analysis matched by these surgical variables failed to identify other factors independently related to the occurrence of S-SSI. CONCLUSIONS: Spinal fusion of more than 4 levels and the inclusion of sacral levels were independently related to the risk of S-SSI. Optimization of surgical techniques by reducing these two types of instrumentation could significantly reduce S-SSI rates.