Timing of Acquisition of Methicillin-Resistant Staphylococcus aureus Nasal Carriage: Can we Limit Repeat Screening?

INTRODUCTION: Broad-spectrum empiric antibiotics are routinely administered to hospitalized patients with potential infections. These antibiotics provide protection; however, they come with their own negative effects. The utility of Methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nasal screening to steward anti-MRSA empiric antibiotics in hospitalized patients is established. With this current study, we look to determine the optimal frequency of MRSA nasal testing to help limit unnecessary testing consistent with the efforts of Choosing Wisely. We hypothesize that MRSA PCR nasal swab conversion will be low within the first 2 wk after index swab collection. METHODS: We performed a single-center retrospective chart review of all adult patient encounters from October 2019-July 2021 with MRSA PCR nasal testing. We excluded duplicate patient encounters. Further exclusion criteria included patients with a single MRSA PCR swab and those who tested positive for MRSA colonization on their index swab. We evaluated how many conversions from negative to positive there were, and the timing of those relative to those that did not develop colonization while in the hospital. RESULTS: 263 patients had multiple MRSA nares screening. 215 patients had 2 swab collections, 35 patients had 3 swab collections, 9 patients had 4 swab collections, and 4 patients had 5 swab collections. 14 converted from negative to positive. The time of conversions ranged from within 0-36 d, with an overall cumulative conversion of 5%. The rate of cumulative conversion from one week was 1.9%, for 2 wk it was 3.4%. CONCLUSIONS: Findings suggest that MRSA PCR nasal swab conversion is unlikely to occur within 2 wk. Therefore, to optimize resources, further investigation should be conducted to target guidelines as well as systems to limit repeat swab testing. We will investigate the utility of this after implementation.

Evaluating Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Nasal Screening as a Tool for Antimicrobial Stewardship.

INTRODUCTION: Initiation of broad-spectrum empiric antibiotics is common when infection is suspected in hospitalized adults. The benefits of early utilization of effective antibiotics are well documented. However, the negative effects of inappropriate antibiotic use have led to antimicrobial stewardship mandates. Recent data demonstrate the utility of methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nasal screening to steward anti-MRSA empiric antibiotics in pneumonia. We hypothesize that MRSA PCR nasal swabs would also be effective to rule out other MRSA infection to effectively limit unnecessary antibiotics for any infectious source. METHODS: We performed a single-center retrospective chart review of all adult patient encounters from October 2019-July 2021 with MRSA PCR nasal testing. We then reviewed all charts to evaluate for the presence of infections based on source cultures results, as the gold standard. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated from 2 × 2 contingency tables. RESULTS: Among all patients with MRSA nasal screening, 1189 patients had any infection. Prevalence of MRSA nasal carriage among patients screened was 12%. Prevalence of MRSA infection among all infections was 7.5%. MRSA nasal swabs demonstrated a negative predictive value of 100% for MRSA urinary tract infection, 97.9% for MRSA bacteremia, 97.8% for MRSA pneumonia, 92.1% for MRSA wound infection, and 96.6% for other MRSA infections. Overall, MRSA PCR nasal swabs had a sensitivity of 68.5%, specificity of 90.1%, positive predictive value of 23.7%, and negative predictive value of 98.5% for any infections. CONCLUSIONS: MRSA PCR nasal swabs have a high negative predictive value for all infections. Our data support the use of MRSA PCR nasal swabs to rule out MRSA infection and thereby allow early de-escalation of MRSA coverage in hospitalized patients requiring empiric antibiotics. Implementation of MRSA screening could decrease antibiotic-associated morbidity, resistance, and costs. More studies should be conducted to validate these results and support these findings.

Drug and Alcohol Use in Trauma Patients Before and During the COVID-19 Pandemic.

INTRODUCTION: Since the implementation of national stay-at-home orders during the COVID-19 pandemic, there has been rising concerns regarding prolonged social isolation that many individuals face. Given the link between increased stress and alcohol and drug use, our study investigated admission trends and patterns of alcohol and drug use in trauma patients. METHODS: This was a single center, retrospective cohort study comparing trauma patients admitted before the pandemic and during the first wave. We compared patient demographics, injury characteristics, and outcomes of substance screen negative, positive, and unscreened patients admitted. Patients screened positive if they had a positive urine drug screen (UDS) and/or a blood alcohol concentration (BAC) ≥10 mg/dL. RESULTS: There were 3906 trauma admissions in the year prior to and 3469 patients in the first year of the pandemic. No significant demographic differences were presented across time periods. Rates of UDS and BAC screening remained consistent. Equivalent rates of alcohol and drug positivity occurred (34% versus 33%, 17% versus 18%, P = 0.49). The total prevalence of alcohol use disorders (4% versus 5%, P < 0.001) and psychiatric disorders (6% versus 7%, P = 0.02) increased during the pandemic. CONCLUSIONS: The prevalence of diagnosed alcohol use and psychiatric disorders in trauma patients increased during the COVID-19 pandemic while rates of acute alcohol and drug screen positivity remained the same. These observations suggest a possible link between pandemic stressors and exacerbation of alcohol use and psychiatric conditions in trauma patients. During a changing pandemic landscape, it remains pertinent to increased screening for these conditions regardless of substance screen positivity upon admission.

Levofloxacin-Induced Hepatotoxicity in Patients With Legionnaires' Disease: Implications and Management.

Legionnaires' disease (LD), caused by the Legionella bacterium, primarily manifests as pneumonia and could result in a spectrum of clinical severity. As treatment necessitates the use of antibiotics, levofloxacin, a fluoroquinolone, is a commonly preferred option due to its broad-spectrum activity. However, the potential side effects of levofloxacin, including rare instances of hepatotoxicity, introduce a therapeutic challenge. This case report explores the association between levofloxacin and hepatotoxicity and its implications for treating LD.