Comba, Işın Y.

Elizabethkingia species are Gram-negative bacilli that were most recently linked to a cluster of infections in the Midwestern United States from 2016 to 2017. Inappropriate empirical and directed antibiotic selection for this organism is common among providers and is an independent risk factor for mortality.

Abstract We provide an elaborate review of cases published between January 2005 and April 2021 on hemophagocytic lymphohistiocytosis (HLH) in HIV patients. Seventy articles describing 81 adult patients (age ≥19 years) were included. The median age was 40 years, and 78% were males. Only 65% were known to have HIV before presentation. CD4 count was ≥200 cells/mm3 in 23%, and HIV viral load was <200 copies/mL in 41%. The lack of meticulous reporting of ≥5 of 8 criteria for HLH diagnosis was evident in a third of cases. At least 1 infectious agent—other than HIV—was believed to trigger HLH in 78% of patients. The most common were Epstein-Barr virus (26%), human herpesvirus 8 (21%), and Histoplasma capsulatum (17%). Sixty percent survived. Among those, 93% received treatment for identified secondary trigger(s), while 51% received HLH-directed therapy. There was significant heterogeneity in the treatment regimens used for HLH.

Abstract Background Elizabethkingia spp. are non-enteric, gram-negative bacilli that are ubiquitous in environment. It has recently been identified as a causative pathogen in hospital outbreaks of life-threatening bloodstream infections in the Midwestern United States. Methods Retrospective electronic medical record review was performed for patients with Elizabethkingia spp. isolated from any site between November 2011 and September 2020 at our tertiary academic medical center. Antimicrobial susceptibilities are performed using Wadsworth agar dilution method. Results Fifteen cases with Elizabethkingia spp. were included. Ten patients (66.7%) were male and fourteen (93.3%) were Caucasian. The median age was 58 years (IQR 42-67). Four patients had diabetes mellitus, with two of these having end-organ damage (nephropathy, neuropathy, or retinopathy). Five patients had a tracheostomy, two patients had a history of lung transplantation, and four patients had active malignancy at the time of diagnosis (table 1). The most common clinical syndrome was respiratory infection (n=6), followed by catheter-related bloodstream infection (CRBSI) (n=4). Three patients were considered to be asymptomatically colonized. Five patients (33.3%) died, one of which was attributable to Elizabethkingia infection. A total of 55 isolates from all sites were available from the fifteen patients. The most common site of isolation was respiratory tract (23/55, 41.8%). In total, 33 of 55 isolates had polymicrobial growth, with the highest rate occurring in respiratory tract specimens (Table 2). A total of 23 clinical isolates were included in tabulation of antimicrobial susceptibility profiles; except for aztreonam (n=13). 95.7% of Elizabethkingia isolates were susceptible to trimethoprim-sulfamethoxazole, followed by levofloxacin and piperacillin-tazobactam (87% and 73.9%, respectively). All isolates were uniformly resistant to amikacin, aztreonam, and tobramycin (Table 3). Conclusion Elizabethkingia spp. can result in respiratory, bloodstream, and sinus infections especially in patients with active malignancy and tracheostomy. Amongst tested antimicrobials, trimethoprim-sulfamethoxazole showed the most favorable susceptibility profile (Figure 1). Figure 1. AN, amikacin; ATM, aztreonam; CAZ, ceftazidime; CIP, ciprofloxacin; FEP, cefepime; GM, gentamicin; LVX, levofloxacin; MEM, meropenem; NN, tobramycin; SXT, sulfamethoxazole/trimethoprim; TZP, piperacillin/tazobactam. Disclosures All Authors: No reported disclosures