Successful Treatment of Prolonged Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Patients With Immunodeficiency With Extended Nirmatrelvir/Ritonavir: Case Series.

Immunocompromised patients with B-cell deficiencies are at risk for prolonged symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We describe 4 patients treated for B-cell malignancies with B-cell-depleting therapies who developed persistent SARS-CoV-2 infection and had resolution of symptoms following an extended course of nirmatrelvir/ritonavir.

Monoclonal Antibodies for Early Treatment of COVID-19 in a World of Evolving SARS-CoV-2 Mutations and Variants.

Monoclonal antibodies targeting the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 spike protein are important outpatient treatment options in coronavirus disease 2019 to mitigate progression of disease and prevent hospitalization. The impact of different RBD mutations on the efficacy of the available monoclonal antibodies and processes for incorporating this impact into treatment algorithms are ill defined. Herein, we synthesize the data surrounding the impact of key RBD mutations on the efficacy of US Food and Drug Administration Emergency Use Authorized monoclonal antibodies and describe our approach at Michigan Medicine at monitoring mutation frequency in circulating virus and developing an algorithm that incorporates these data into outpatient treatment pathways.

Risk Factors for Klebsiella Infections among Hospitalized Patients with Preexisting Colonization.

Klebsiella commonly colonizes the intestinal tract of hospitalized patients and is a leading cause of health care-associated infections. Colonization is associated with subsequent infection, but the factors determining this progression are unclear. A cohort study was performed, in which intensive care and hematology/oncology patients with Klebsiella colonization based on rectal swab culture were enrolled and monitored for infection for 90 days after a positive swab. Electronic medical records were analyzed for patient factors associated with subsequent infection, and variables of potential significance in a bivariable analysis were used to build a final multivariable model. Concordance between colonizing and infecting isolates was assessed by wzi capsular gene sequencing. Among 2,087 hospitalizations from 1,978 colonized patients, 90 cases of infection (4.3%) were identified. The mean time to infection was 20.6 ± 24.69 (range, 0 to 91; median, 11.5) days. Of 86 typed cases, 68 unique wzi types were identified, and 69 cases (80.2%) were colonized with an isolate of the same type prior to infection. Based on multivariable modeling, overall comorbidities, depression, and low albumin levels at the time of rectal swab collection were independently associated with subsequent Klebsiella infection (i.e., cases). Despite the high diversity of colonizing strains of Klebsiella, there is high concordance with subsequent infecting isolates, and progression to infection is relatively quick. Readily accessible data from the medical record could be used by clinicians to identify colonized patients at an increased risk of subsequent Klebsiella infection. IMPORTANCE Klebsiella is a leading cause of health care-associated infections. Patients who are intestinally colonized with Klebsiella are at a significantly increased risk of subsequent infection, but only a subset of colonized patients progress to disease. Colonization offers a potential window of opportunity to intervene and prevent these infections, if the patients at greatest risk could be identified. To identify patient factors associated with infection in colonized patients, we studied 1,978 colonized patients. We found that patients with a higher burden of underlying disease in general, depression in particular, and low albumin levels in a blood test were more likely to develop infection. However, these variables did not completely predict infection, suggesting that other host and microbial factors may also be important. The clinical variables associated with infection are readily available in the medical record and could serve as the foundation for developing an integrated risk assessment of Klebsiella infection in hospitalized patients.

Prolonged Severe Acute Respiratory Syndrome Coronavirus 2 Replication in an Immunocompromised Patient.

We describe a case of chronic coronavirus disease 2019 (COVID-19) in a patient with lymphoma and associated B-cell immunodeficiency. Viral cultures and sequence analysis demonstrate ongoing replication of infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for at least 119 days. The patient had 3 admissions related to COVID-19 over a 4-month period and was treated twice with remdesivir and convalescent plasma with resolution of symptoms. The patient's lack of seroconversion and prolonged course illustrate the importance of humoral immunity in resolving SARS-CoV-2 infection. This case highlights challenges in managing immunocompromised hosts, who may act as persistent shedders and sources of transmission.

Tocilizumab for Treatment of Mechanically Ventilated Patients With COVID-19.

BACKGROUND: Severe coronavirus disease 2019 (COVID-19) can manifest in rapid decompensation and respiratory failure with elevated inflammatory markers, consistent with cytokine release syndrome for which IL-6 blockade is an approved treatment. METHODS: We assessed effectiveness and safety of IL-6 blockade with tocilizumab in a single-center cohort of patients with COVID-19 requiring mechanical ventilation. The primary endpoint was survival probability postintubation; secondary analyses included an ordinal illness severity scale integrating superinfections. Outcomes in patients who received tocilizumab compared with tocilizumab-untreated controls were evaluated using multivariable Cox regression with propensity score inverse probability of treatment weighting (IPTW). RESULTS: 154 patients were included, of whom 78 received tocilizumab and 76 did not. Median follow-up was 47 days (range, 28-67). Baseline characteristics were similar between groups, although tocilizumab-treated patients were younger (mean: 55 vs 60 years), less likely to have chronic pulmonary disease (10% vs 28%), and had lower D-dimer values at time of intubation (median: 2.4 vs 6.5 mg/dL). In IPTW-adjusted models, tocilizumab was associated with a 45% reduction in hazard of death (HR, .55; 95% CI, .33-.90) and improved status on the ordinal outcome scale [OR per 1-level increase, .58; .36-.94). Although tocilizumab was associated with an increased proportion of patients with superinfections (54% vs 26%; P < .001), there was no difference in 28-day case fatality rate among tocilizumab-treated patients with versus without superinfection (22% vs 15%; P = .42). Staphylococcus aureus accounted for ~50% of bacterial pneumonia. CONCLUSIONS: In this cohort of mechanically ventilated COVID-19 patients, tocilizumab was associated with lower mortality despite higher superinfection occurrence.

Tocilizumab for treatment of mechanically ventilated patients with COVID-19.

BACKGROUND: Severe COVID-19 can manifest in rapid decompensation and respiratory failure with elevated inflammatory markers. This presentation is consistent with cytokine release syndrome in chimeric antigen receptor T cell therapy, for which IL-6 blockade is approved treatment. METHODS: We assessed effectiveness and safety of IL-6 blockade with tocilizumab in a single-center cohort of patients with COVID-19 requiring mechanical ventilation. The primary endpoint was survival probability post-intubation; secondary analyses included an ordinal illness severity scale integrating superinfections. Outcomes in patients who received tocilizumab compared to tocilizumab-untreated controls were evaluated using multivariable Cox regression with propensity score inverse probability weighting (IPTW). FINDINGS: 154 patients were included, of whom 78 received tocilizumab and 76 did not. Median follow-up was 47 days (range 28-67). Baseline characteristics were similar between groups, although tocilizumab-treated patients were younger (mean 55 vs. 60 years), less likely to have chronic pulmonary disease (10% vs. 28%), and had lower D-dimer values at time of intubation (median 2.4 vs. 6.5 mg/dL). In IPTW-adjusted models, tocilizumab was associated with a 45% reduction in hazard of death [hazard ratio 0.55 (95% CI 0.33, 0.90)] and improved status on the ordinal outcome scale [odds ratio per 1-level increase: 0.59 (0.36, 0.95)]. Though tocilizumab was associated with an increased proportion of patients with superinfections (54% vs. 26%; p<0.001), there was no difference in 28-day case fatality rate among tocilizumab-treated patients with versus without superinfection [22% vs. 15%; p=0.42]. INTERPRETATION: In this cohort of mechanically ventilated COVID-19 patients, tocilizumab was associated with a decreased likelihood of death despite higher superinfection occurrence. Randomized controlled trials are urgently needed to confirm these findings.

Longitudinal epidemiology of multidrug-resistant (MDR) Acinetobacter species in a tertiary care hospital.

BACKGROUND: Acinetobacter species are well-known causes of health care-associated infections. The longitudinal epidemiology of this species in the hospital setting is poorly understood. A sudden, persistent increase in multidrug-resistant (MDR) A baumannii infections occurred beginning in June 2006 at Temple University Hospital in Philadelphia. An analysis was done to describe the longitudinal molecular epidemiology of MDR A baumannii in a tertiary care hospital. METHODS: This was an epidemiologic investigation using repetitive extragenic palindromic-PCR (rep-PCR) of patients with a positive culture for MDR A baumannii admitted to the hospital between February 2006 and January 2010. MDR A baumannii were defined as susceptible only to colistin and/or tigecycline. RESULTS: The incidence rate of MDR A baumannii rose from 0.36 cases per 1,000 patient-days (pre-epidemic) to 0.86 cases per 1,000 patient-days, due mainly to an increase in the surgical intensive care unit. Enhanced infection control measures were implemented, but waves of MDR A baumannii continued to be documented through routine surveillance. Of 32 strains collected in 2006-2007, a single predominant clone and 2 minor clones accounted for almost all of the cases of MDR A baumannii studied. Of 24 strains collected in 2008-2009, another clone, different from those studied in the earlier period, predominated, and was accompanied by 3 minor variants. CONCLUSION: Following an outbreak in the surgical intensive care unit, MDR A baumannii persisted in our institution for a 3-year period despite rigorous infection control measures. An unexpected strain replacement occurred during this period, with the original predominant strain disappearing completely and new minor clones displacing the original minor clones.