Detection of Mpox Virus Using Microbial Cell-Free DNA: The Potential of Pathogen-Agnostic Sequencing for Rapid Identification of Emerging Pathogens.

BACKGROUND: The 2022 global outbreak of Monkeypox virus (MPXV) highlighted challenges with polymerase chain reaction detection as divergent strains emerged and atypical presentations limited the applicability of swab sampling. Recommended testing in the United States requires a swab of lesions, which arise late in infection and may be unrecognized. We present MPXV detections using plasma microbial cell-free DNA (mcfDNA) sequencing. METHODS: Fifteen plasma samples from 12 case-patients were characterized through mcfDNA sequencing. Assay performance was confirmed through in silico inclusivity and exclusivity assessments. MPXV isolates were genotyped using mcfDNA, and phylodynamic information was imputed using publicly available sequences. RESULTS: MPXV mcfDNA was detected in 12 case-patients. Mpox was not suspected in 5, with 1 having documented resolution of mpox >6 months previously. Six had moderate to severe mpox, supported by high MPXV mcfDNA concentrations; 4 died. In 7 case-patients, mcfDNA sequencing detected coinfections. Genotyping by mcfDNA sequencing identified 22 MPXV mutations at 10 genomic loci in 9 case-patients. Consistent with variation observed in the 2022 outbreak, 21 of 22 variants were G > A/C > T. Phylogenetic analyses imputed isolates to sublineages arising at different time points and from different geographic locations. CONCLUSIONS: We demonstrate the potential of plasma mcfDNA sequencing to detect, quantify, and, for acute infections with high sequencing coverage, subtype MPXV using a single noninvasive test. Sequencing plasma mcfDNA may augment existing mpox testing in vulnerable patient populations or in patients with atypical symptoms or unrecognized mpox. Strain type information may supplement disease surveillance and facilitate tracking emerging pathogens.

Epidemiologic and Clinical Features of Mpox-Associated Deaths - United States, May 10, 2022-March 7, 2023.

As of March 7, 2023, a total of 30,235 confirmed and probable monkeypox (mpox) cases were reported in the United States,† predominantly among cisgender men§ who reported recent sexual contact with another man (1). Although most mpox cases during the current outbreak have been self-limited, cases of severe illness and death have been reported (2-4). During May 10, 2022-March 7, 2023, 38 deaths among persons with probable or confirmed mpox¶ (1.3 per 1,000 mpox cases) were reported to CDC and classified as mpox-associated (i.e., mpox was listed as a contributing or causal factor). Among the 38 mpox-associated deaths, 94.7% occurred in cisgender men (median age = 34 years); 86.8% occurred in non-Hispanic Black or African American (Black) persons. The median interval from symptom onset to death was 68 days (IQR = 50-86 days). Among 33 decedents with available information, 93.9% were immunocompromised because of HIV. Public health actions to prevent mpox deaths include integrated testing, diagnosis, and early treatment for mpox and HIV, and ensuring equitable access to both mpox and HIV prevention and treatment, such as antiretroviral therapy (ART) (5).

Evaluating the Impact of a Urinalysis to Reflex Culture Process Change in the Emergency Department at a Veterans Affairs Hospital.

Background: Although automated urine cultures (UCs) following urinalysis (UA) are often used in emergency departments (EDs) to identify urinary tract infections (UTIs), results are often reported as no organism growth or the growth of clinically insignificant organisms, leading to the overdetection and overtreatment of asymptomatic bacteriuria (ASB). Methods: A process change was implemented at a US Department of Veterans Affairs medical center ED that automatically cancelled UCs if UAs had < 5 white blood cells per high-power field (WBC/HPF). An option for do not cancel (DNC) UC was available. Data were prospectively collected for 3 months postimplementation and included UA/UC results, presence of UTI symptoms, antibiotics prescribed, and health care utilization. Results: Postintervention, 684 UAs (37.2%) were evaluated from ED visits. Postintervention, of 255 UAs, 95 (37.3%) were negative with UC cancelled, 95 (37.3%) were positive with UC processed, 43 (16.9%) were ordered as DNC, and 22 (8.6%) were ordered without a UC. UC processing despite a negative UA significantly decreased from 100% preintervention to 38.6% postintervention (P < .001). Inappropriate prescribing of antibiotics for ASB was reduced from 10.2% preintervention to 1.9% postintervention (odds ratio = 0.17; P = .01). In patients with negative UA specimens, antibiotic prescribing decreased by 25.3% postintervention. No reports of outpatient, ED, or hospital visits for symptomatic UTI were found within 7 days of the initial UA postintervention. Conclusions: The UA to reflex culture process change resulted in a significant reduction in processing of inappropriate UCs and unnecessary antibiotic use for ASB. There were no missed UTIs or other adverse patient outcomes.

Successful Treatment of Multi-Drug Resistant Pseudomonas aeruginosa Bacteremia with the Recommended Renally Adjusted Ceftolozane/Tazobactam Regimen.

INTRODUCTION: Ceftolozane/tazobactam (C/T) is a novel antibiotic approved for complicated intra-abdominal and urinary tract infections caused by Gram-positive and Gram-negative organisms, including some MDR strains. Little is known about the use of this agent for treatment of bacteremia and even less so about the appropriateness of the renally defined regimens. We describe a case of a 66-year-old man with a history of chronic kidney disease (baseline Cr = 3-4 mg/dl) and recurrent nephrolithiasis with bilateral stents who had positive concurrent urine and blood cultures for MDR Pseudomonas aeruginosa (PSA), susceptible only to amikacin and colistin. Due to the MDR phenotype and his underlying kidney disease, the 375 mg (250 mg/125 mg) dose of C/T was given as monotherapy every 8 h for his bloodstream infection. METHODS: Once steady state was anticipated, blood was obtained at the end of infusion (1 h), and at 3, 5 and 8 h for drug concentration determination using a validated high-performance liquid chromatography method at the Center for Anti-Infective Research and Development, Hartford Hospital, Hartford. RESULTS: The minimum inhibitory concentration (MIC) for the PSA was 2/4 for C/T, indicating susceptibility. Concentration of ceftolozane of 21.87 µg/ml at 8 h indicated that serum concentrations were maintained above the MIC throughout the dosing interval. The patient was given 25 days of C/T and experienced a successful clinical outcome. Blood cultures obtained at 1 and 3 weeks after completion of treatment remained sterile. No adverse events were attributed to C/T. CONCLUSION: In this patient, the renally adjusted dose of C/T was safe and provided sufficiently high drug concentrations that exceeded the MIC of the infecting organism over the course of therapy. More data are required to determine the clinical utility of C/T in the setting of MDR PSA bacteremia.