Assessing the influence of the COVID-19 pandemic on the incidence, clinical presentation, and clindamycin resistance rates of Streptococcus pyogenes infections

Objectives

Streptococcus pyogenes (group A Streptococcus [GAS]) is a prevalent cause of community-acquired bacterial infections, with invasive GAS (iGAS) infections presenting severe morbimortality. Clindamycin is generally used based on its antitoxin effect. This study investigates changes in iGAS incidence, clinical presentation, outcomes, and clindamycin resistance in an adult cohort.

Methods

This is a retrospective analysis of S. pyogenes episodes from a tertiary adult hospital in Barcelona (Spain) between 2015 and 2023. The pre-pandemic period includes data from 2015-2019. The pandemic period, from 2020-2021, and post-pandemic period comprised 2022 to the first semester of 2023.

Results

The global incidence of GAS infections in the pre-pandemic and post-pandemic periods were 2.62 and 2.92 cases per 10.000 hospital admissions, whereas for iGAS cases, they were 1.85 and 2.34. However, a transient decrease was observed during the pandemic period: 1.07 and 0.78 per 10.000 hospital admissions. There was a significant decrease in GAS and iGAS infections during the pandemic period compared with the pre-pandemic incidence (P <0.001 for GAS infections and P = 0.001 for iGAS cases) and the post-pandemic incidence (P = 0.032 for GAS infections and P = 0.037 for iGAS cases). The most common source of infection was skin and soft tissue infections with 264 (54%) cases. Skin and soft tissue infections and cases of necrotizing fasciitis increased during the pandemic. Clindamycin resistance occurred in 13.5% of isolations during the pre-pandemic and 17.5% in post-pandemic period (P = 0.05).

Conclusions

Our study revealed a temporary reduction in iGAS infections, followed by resurgence in the post-pandemic period. The observed rise in clindamycin resistance emphasizes the importance of monitoring local resistance patterns for tailored treatment.

Diagnosis of Bone Marrow Necrosis following Severe Vaso-Occlusive Crisis in Patient with Compound Heterozygous Sickle Cell Disease

Introduction

Bone marrow necrosis is a rare entity that can develop in context of a sickle cell disease vaso-occlusive crisis. Its physiopathology is related to an endothelial dysfunction taking place in bone marrow microvasculature.

Case Presentation

A 30-year-old patient with history of compound heterozygous sickle cell disease was admitted following SARS-CoV-2 infection with fever and diarrhea. After initial favorable evolution, he developed a severe vaso-occlusive crisis with intense hemolysis and multi-organ ischemic complications. Patient then developed high fever and hypoxemia. With the suspicion of acute thoracic syndrome, a red blood cell exchange was performed. Respiratory symptoms ceased but patient persisted febrile with very high levels of acute phase reactants, persistent pancytopenia, and leucoerythroblastic reaction. An infectious cause was ruled out. Afterward, bone marrow aspiration and bone marrow biopsy showed a picture of bone marrow necrosis, which is an extremely rare complication of vaso-occlusive crisis but, paradoxically, more frequent in milder heterozygote cases of sickle cell disease. Ultimately, large deposits of complement membrane attack complex (particles C5b-9) were demonstrated after incubation of laboratory endothelial cells with activated plasma from the patient.

Discussion

The clinical presentation and findings are consistent with a case of bone marrow necrosis. In this setting, the demonstration of complement as a potential cause of the endothelial dysfunction mimics the pattern of atypical hemolytic uremic syndrome and other microangiopathic anemias. This dysregulation may be a potential therapeutic target for new complement activation blockers.

Mortality risk model validation in a prospective cohort of patients from the sixth wave of the COVID-19 pandemic in a hospital emergency department

OBJECTIVES

To validate risk factors for mortality in patients treated for COVID-19 in a hospital emergency department during the sixth wave of the pandemic.

MATERIAL AND METHODS

Prospective observational noninterventional study. We included patients over the age of 18 years with a confirmed diagnosis of COVID-19 between December 1, 2021, and February 28, 2022. For each patient we calculated a risk score based on age 50 years or older (2 points) plus 1 point each for the presence of the following predictors: Barthel index less than 90 points, altered level of consciousness, ratio of arterial oxygen saturation to fraction of inspired oxygen less than 400, abnormal breath sounds, platelet concentration less than 100 × 109/L, C-reactive protein level of 5 mg/dL or more, and glomerular filtration rate less than 45 mL/min. The model was assessed with the area under the receiver operating characteristic curve (AUC).

RESULTS

Of the 1156 patients included, 790 (68%) had received at least 2 vaccine doses. The probability of 30-day survival was 96%. A risk score was calculated for 609 patients. Four hundred seventeen patients were at low risk of death, 180 were at intermediate risk, and 10 were at high risk. The probability of death within 30 days was 1%, 13%, and 50% for patients in the 3 risk groups, respectively. The sensitivity, specificity, and positive and negative predictive values of a risk score of 3 points or less were 88%, 72%, 19%, 99%, respectively.The AUC for the model was 0.87.

CONCLUSION

The risk model identified low risk of mortality and allowed us to safely discharge patients treated for COVID-19 in our tertiary-care hospital emergency department.

Impact of Early Intrapatient Variability of Tacrolimus Concentrations on the Risk of Graft-Versus-Host Disease after Allogeneic Stem Cell Transplantation Using High-Dose Post-Transplant Cyclophosphamide

Tacrolimus (Tac) is a pivotal immunosuppressant agent used to prevent graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (alloHSCT). Tac is characterized by a narrow therapeutic window and a high inter-patient and intra-patient pharmacokinetic variability (IPV). Although high IPV of Tac concentrations has been associated with adverse post-transplant outcomes following solid organ transplantation, the effects of Tac IPV on alloHSCT recipients have not been determined. Tac IPV was therefore retrospectively evaluated in 128 alloHSCT recipients receiving high-dose post-transplant cyclophosphamide (PTCy) and the effects of Tac IPV on the occurrence of acute GVHD (aGVHD) were analyzed. Tac IPV was calculated from pre-dose concentrations (C0) measured during the first month after Tac initiation. The cumulative rates of grades II-IV and grades III-IV aGVHD at day +100 were 22.7% and 7%, respectively. Higher Tac IPV was associated with a greater risk of developing GVHD, with patients having IPV > 50th percentile having significantly higher rates of grades II-IV (34.9% vs. 10.8%; hazard ratio [HR] 3.858, p < 0.001) and grades III-IV (12.7% vs. 1.5%; HR 9.69, p = 0.033) aGVHD than patients having IPV ≤ 50th percentile. Similarly, patients with IPV > 75th percentile had higher rates of grades II-IV (41.9% vs. 16.5%; HR 3.30, p < 0.001) and grades III-IV (16.1% vs. 4.1%; HR 4.99, p = 0.012) aGVHD than patients with IPV ≤ 75th percentile. Multivariate analyses showed that high Tac IPV (>50th percentile) was an independent risk factor for grades II-IV (HR 2.99, p = 0.018) and grades III-IV (HR 9.12, p = 0.047) aGVHD. Determination of Tac IPV soon after alloHSCT could be useful in identifying patients at greater risk of aGVHD.

Risk score for mortality due to COVID-19: a prospective temporal validation cohort study in the emergency department of a tertiary care hospital

OBJECTIVES

To validate a previously described hospital emergency department risk model to predict mortality in patients with COVID-19.

MATERIAL AND METHODS

Prospective observational noninterventional study. Patients aged over 18 years diagnosed with COVID-19 were included between December 1, 2020, and February 28, 2021. We calculated a risk score for each patient based on age 50 years (2 points) plus 1 point each for the presence of the following predictors: Barthel index 90 points, altered level of consciousness, ratio of arterial oxygen saturation to fraction of inspired oxygen 400, abnormal breath sounds, platelet concentration 100 × 109/L, C reactive protein level 5 mg/dL, and glomerular filtration rate 45 mL/min. The dependent variable was 30-day mortality. We assessed the score's performance with the area under the receiver operating characteristic curve (AUC).

RESULTS

The validation cohort included 1223 patients. After a median follow-up of 80 days, 143 patients had died; 901 patients were classified as having low risk (score, 4 points), 270 as intermediate risk (5-6 points), and 52 as high risk ( 7 points). Thirty-day mortality rates at each risk level were 2.8%, 22.5%, and 65.4%, respectively. The AUC for the score was 0.883; for risk categorization, the AUC was 0.818.

CONCLUSION

The risk score described is useful for stratifying risk for mortality in patients with COVID-19 who come to a tertiary-care hospital emergency department.