Shedding of measles vaccine RNA in children after receiving measles, mumps and rubella vaccination.

BACKGROUND: Measles, mumps, and rubella(MMR) vaccination is critical to measles outbreak responses. However, vaccine reactions and detection of measles vaccine RNA in recently immunized persons may complicate case classification especially in those presenting with another respiratory viral illness. We aim to characterize cases of measles vaccine shedding in recently vaccinated children presenting with respiratory viral symptoms. METHODS: Children who were tested with a multiplex respiratory panel <30 days after receiving MMR were identified. Remnant nasopharyngeal(NP) samples were tested for measles vaccine by PCR. Medical records were reviewed for demographics, presenting symptoms, and test results. RESULTS: From January 2022 to March 2023, 127 NP from children who received MMR were tested. Ninety-six NP were collected after the first dose, of which 33(34.4 %) were positive for vaccine RNA. The median interval between MMR and detection was 11.0 days. Thirty-one NP were collected after the second MMR and 1(3.2 %) was positive; time between the vaccination and detection was 18.9 days. Median cycle threshold(Ct) value of the measles PCR for vaccine shedding was significantly higher than median Ct in children with wild-type infection. CONCLUSION: Shedding of measles vaccine RNA is not uncommon and vaccine RNA can be detected up to 29 days post MMR; the amount of vaccine RNA shedding is low indicated by high Ct values. Clinicians and public health officials should consider performing measles vaccine testing on those testing positive for measles within one month of MMR vaccination, especially if the Ct value is high and definitive epidemiological links are absent.

Accelerating Initiation of Adequate Antimicrobial Therapy Using Real-Time Decision Support and Microarray Testing.

INTRODUCTION: Bloodstream infections (BSI) represent a common cause of sepsis and mortality in children. Early and adequate empirical antimicrobial therapy is a critical component of successful treatment of BSI. Rapid PCR-based diagnostic technologies, such as nucleic acid microarrays, can decrease the time needed to identify pathogens and antimicrobial resistance and have the potential to ensure patients are started on adequate antibiotics as early as possible. However, without appropriate processes to support timely and targeted interpretation of these results, these advantages may not be realized in practice. METHODS: Our Antimicrobial Stewardship Program (ASP) implemented a quality improvement initiative using the Institute for Healthcare Improvement's Model for Improvement to decrease the time between a nucleic acid microarray result for Gram-positive bacteremia and the time a patient was placed on adequate antimicrobial therapy. The primary effective intervention was a near real-time notification system to the managing physicians of inadequate antimicrobial therapy via a call from the ASP team. RESULTS: Following the intervention, the average time to adequate antimicrobial therapy in patients with Gram-positive BSI and inadequate coverage decreased from 38 hours with the nucleic acid microarray result alone to 4.7 hours when results were combined with an ASP clinical decision support intervention, an 87% reduction. CONCLUSIONS: The positive effects of rapid-detection technologies to improve patient care are enhanced when combined with clinical decision support tools that can target inadequate antimicrobial treatments in near real time.

Reliability of the Verigene system for the identification for Gram-positive Bacteria and detection of antimicrobial resistance markers from children with bacteremia.

BACKGROUND: Targeted antimicrobial therapy can reduce morbidity in patients with sepsis. Molecular methodologies used in the clinical laboratory can provide information about infectious agents faster than traditional culture methods. Using molecular information to make clinical decisions more quickly has been shown to improve patient outcomes, and reduce length of stay and healthcare cost in adults. Its effect on pediatric care is less well described. METHODS: Blood cultures growing Gram-positive cocci or Gram-positive bacilli on Gram stain were evaluated by molecular and traditional methodologies. Results from the molecular platform, Luminex Verigene® Blood Culture - Gram-positive Panel (BC-GP) were compared to results from standard culture and susceptibility testing (Vitek™ MS, Vitek™, E-test®). Overall statistical agreement is evaluated. RESULTS: 1231 positive pediatric blood cultures grew single isolates detectable by the BC-GP panel. 899 were correctly identified to species, 282 to genus, 50 isolates were not detected. All organisms detected by BC-GP that grew in single isolate cultures were identified as the same organism by Vitek™ MS with the exception of 7 organisms.112 cultures were found to have polymicrobial growth of Gram-positive organisms. Excellent overall agreement was noted for antimicrobial resistance markers with only 5 samples displaying discordant results. DISCUSSION: In general, clinicians can use the identification and antimicrobial resistance marker data gained from Luminex Verigene® BC-GP with confidence to alter empiric coverage. Rare instances of disagreement with traditional culture data led to maintaining the empiric clinical approach and did not result in patient harm.

Risk Factors for Staphylococcus aureus Acquisition in the Neonatal Intensive Care Unit: A Matched Case-Case-Control Study.

OBJECTIVE To determine risk factors independent of length of stay (LOS) for Staphylococcus aureus acquisition in infants admitted to the neonatal intensive care unit (NICU). DESIGN Retrospective matched case-case-control study. SETTING Quaternary-care referral NICU at a large academic children's hospital. METHODS Infants admitted between January 2014 and March 2016 at a level IV NICU who acquired methicillin resistant (MRSA) or susceptible (MSSA) S. aureus were matched with controls by duration of exposure to determine risk factors for acquisition. A secondary post hoc analysis was performed on the entire cohort of at-risk infants for risk factors identified in the primary analysis to further quantify risk. RESULTS In total, 1,751 infants were admitted during the study period with 199 infants identified as having S. aureus prevalent on admission. There were 246 incident S. aureus acquisitions in the remaining at-risk infant cohort. On matched analysis, infants housed in a single-bed unit were associated with a significantly decreased risk of both MRSA (P=.03) and MSSA (P=.01) acquisition compared with infants housed in multibed pods. Across the entire cohort, pooled S. aureus acquisition was significantly lower in infants housed in single-bed units (hazard ratio,=0.46; confidence interval, 0.34-0.62). CONCLUSIONS NICU bed design is significantly associated with S. aureus acquisition in hospitalized infants independent of LOS. Infect Control Hosp Epidemiol 2018;39:46-52.