Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

Multicenter Evaluation of the DiaSorin Molecular Simplexa Congenital CMV Direct PCR Test on Neonatal Saliva and Urine Specimens.

Cytomegalovirus (CMV) is the most common virus associated with congenital infection worldwide and is a major cause of sensorineural hearing loss (SNHL) and developmental delay. Up to 90% of infants with congenital CMV (cCMV) infection are asymptomatic at birth, making the diagnosis challenging. Postnatal diagnosis involves testing newborn saliva and/or urine collected before 21 days of life to confirm cCMV infection. This multicenter study evaluated the performance of the Simplexa Congenital CMV Direct real-time PCR assay for the qualitative detection of CMV in newborn saliva (n = 2,023) and urine (n = 1,797) specimens. Compared to two PCR/bidirectional sequencing assays, the Simplexa Congenital CMV Direct assay demonstrated positive percent agreement (PPA) and negative percent agreement (NPA) of 98.6% and 99.9%, respectively, for saliva samples and a PPA of 97.8% and an NPA of 99.9% for urine specimens. Overall concordance was κ = 0.98 or near perfect compared to the composite reference methods with both sample types. By 95% probit analysis, the limit of detection (LoD) using the AD-169 reference strain was 350 ± 12 copies/mL in urine. The LoDs of saliva swabs in either 1 mL or 3 mL of transport medium were 274 ± 12 copies/mL and 300 ± 14 copies/mL, respectively. The Simplexa Congenital CMV Direct assay can be applied to both saliva and urine specimens collected from newborns less than 21 days of age to rapidly and reliably identify CMV infection.

Multi-center clinical evaluation of the Panther Fusion SARS-CoV-2/Flu A/B/RSV assay in nasopharyngeal swab specimens from symptomatic individuals.

The symptomology is overlapping for respiratory infections due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), influenza A/B viruses, and respiratory syncytial virus (RSV). Accurate detection is essential for proper medical management decisions. This study evaluated the clinical performance of the Panther Fusion SARS-CoV-2/Flu A/B/RSV assay in nasopharyngeal swab (NPS) specimens from individuals of all ages with signs and symptoms of respiratory infection consistent with COVID-19, influenza, or RSV. Retrospective known-positive and prospectively obtained residual NPS specimens were collected during two respiratory seasons in the USA. Clinical performance was established by comparing Panther Fusion SARS-CoV-2/Flu assay results to a three-molecular assay composite comparator interpretation for SARS-CoV-2 and to the FDA-cleared Panther Fusion Flu A/B/RSV assay results for all non-SARS-CoV-2 targets. A total of 1,900 prospective and 95 retrospective NPS specimens were included in the analyses. The overall prevalence in prospectively obtained specimens was 20.7% for SARS-CoV-2, 6.7% for influenza A, and 0.7% for RSV; all influenza B-positive specimens were retrospective specimens. The positive percent agreement of the Panther Fusion assay was 96.9% (378/390) for SARS-CoV-2, 98.0% (121/123) for influenza A virus, 95.2% (20/21) for influenza B virus, and 96.6% (57/59) for RSV. The negative percent agreement was ≥98.5% for all target viruses. Specimens with discordant Panther Fusion SARS/Flu/RSV assay results all had cycle threshold values of ≥32.4 (by comparator or by Panther Fusion SARS/Flu/RSV assay). Only five co-infections were detected in the study specimens. The Panther Fusion SARS-CoV-2/Flu/RSV assay provides highly sensitive and specific detection of SARS-CoV-2, influenza A virus, influenza B virus, and RSV in NPS specimens.

Screening pediatric surgical patients during the COVID-19 pandemic.

ABSTRACT: SARS-CoV-2 has profoundly affected the way healthcare is delivered and has created significant strain on medical facilities globally. As a result, hospitals have had to continuously adapt in order to provide optimal patient care while minimizing the risk of SARS-CoV-2 transmission, particularly in the surgical setting. Texas Children's Hospital developed a set of protocols for surgical screening and clearance of patients in the context of the COVID-19 pandemic. These screening protocols were designed to mitigate the risk of exposing patients and healthcare providers to SARS-CoV-2 and have evolved significantly as a result of the emerging changes in medicine, technology, and governmental regulations. In this article, we share the reasoning behind the development, implementation, and successive modification of our institutional screening protocols.

The Emergence of Zoonotic Onchocerca lupi Infection in the United States--A Case-Series.

This case-series describes the 6 human infections with Onchocerca lupi, a parasite known to infect cats and dogs, that have been identified in the United States since 2013. Unlike cases reported outside the country, the American patients have not had subconjunctival nodules but have manifested more invasive disease (eg, spinal, orbital, and subdermal nodules). Diagnosis remains challenging in the absence of a serologic test. Treatment should be guided by what is done for Onchocerca volvulus as there are no data for O. lupi. Available evidence suggests that there may be transmission in southwestern United States, but the risk of transmission to humans is not known. Research is needed to better define the burden of disease in the United States and develop appropriately-targeted prevention strategies.

Laboratory Diagnosis of Mycobacterium tuberculosis Infection and Disease in Children.

Diagnosis of tuberculosis in children is challenging; even with advanced technologies, the diagnosis is often difficult to confirm microbiologically in part due to the paucibacillary nature of the disease. Clinical diagnosis lacks standardization, and traditional and molecular microbiologic methods lack sensitivity, particularly in children. Immunodiagnostic tests may improve sensitivity, but these tests cannot distinguish tuberculosis disease from latent infection and some lack specificity. While molecular tools like Xpert MTB/RIF have advanced our ability to detect Mycobacterium tuberculosis and to determine antimicrobial resistance, decades old technologies remain the standard in most locales. Today, the battle against this ancient disease still poses one of the primary diagnostic challenges in pediatric laboratory medicine.

Can newly developed, rapid immunochromatographic antigen detection tests be reliably used for the laboratory diagnosis of influenza virus infections?

Five years ago, the Point-Counterpoint series was launched. The initial article asked about the role of rapid immunochromatographic antigen testing in the diagnosis of influenza A virus 2009 H1N1 infection (D. F. Welch and C. C. Ginocchio, J Clin Microbiol 48:22-25, 2010, http://dx.doi.org/10.1128/JCM.02268-09). Since that article, not only have major changes been made in immunochromatographic antigen detection (IAD) testing for the influenza viruses, but there has also been rapid development of commercially available nucleic acid amplification tests (NAATs) for influenza virus detection. Further, a novel variant of influenza A, H7N9, has emerged in Asia, and H5N1 is also reemergent. In that initial article, the editor of this series, Peter Gilligan, identified two issues that required further consideration. One was how well IAD tests worked in clinical settings, especially in times of antigen drift and shift. The other was the role of future iterations of influenza NAATs and whether this testing would be available in a community hospital setting. James Dunn, who is Director of Medical Microbiology and Virology at Texas Children's Hospital, has extensive experience using IAD tests for diagnosing influenza. He will discuss the application and value of these tests in influenza diagnosis. Christine Ginocchio, who recently retired as the Senior Medical Director, Division of Infectious Disease Diagnostics, North Shore-LIJ Health System, and now is Vice President for Global Microbiology Affairs at bioMérieux, Durham, NC, wrote the initial counterpoint in this series, where she advocated the use of NAATs for influenza diagnosis. She will update us on the commercially available NAAT systems and explain what their role should be in the diagnosis of influenza infection.

Comparison of Bruker Biotyper® and Vitek® MS matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry platforms for the identification of filamentous fungi.

Aims: To evaluate the performance of two matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry platforms to identify molds isolated from clinical specimens. Methods: Fifty mold isolates were analyzed on Bruker Biotyper® and Vitek® MS platforms. Two Bruker Biotyper extraction protocols were assessed alongside the US FDA-approved extraction protocol for Vitek MS. Results: The Bruker Biotyper modified NIH-developed extraction protocol correctly identified more isolates than Bruker's protocol (56 vs 33%). For species in the manufacturers' databases, Vitek MS correctly identified 85% of isolates, with 8% misidentifications. The Bruker Biotyper identified 64%, with no misidentifications. For isolates not in the databases, the Bruker Biotyper did not misidentify any, and Vitek MS misidentified 36%. Conclusion: Both the Vitek MS and Bruker Biotyper accurately identified the fungal isolates, however Vitek MS was more likely to misidentify isolates than the Bruker Biotyper.

There are two different mass spectrometry systems that can be used in the hospital laboratory to find out what kind of mold is growing from a patient sample: the Vitek^® MS and Bruker Biotyper^® systems. This study compared how well they work for mold identification and also looked at two different ways to prepare the mold for testing. The Vitek MS system identified more molds, but also made more mistakes when identifying them. The Bruker Biotyper identified fewer molds but did not make any mistakes on the identification. The Vitek MS system sometimes gets the type of mold wrong, so more tests may be needed to be sure of the result. The Bruker Biotyper is more accurate because it got all of the molds correct, but it could not identify as many.

Invasive Community-Onset Gram-Positive Infections From July 2018 Through December 2022 at 2 Children's Hospitals.

Background: Invasive infections caused by Streptococcus pyogenes (invasive group A streptococcus [iGAS]) and Streptococcus pneumoniae (invasive pneumococcal disease [IPD]) decreased substantially at the beginning of the COVID-19 pandemic. Our study sought to evaluate the extent of this decrease and the trends of these infections since reversion of societal adjustments incident to the pandemic. We also wanted to compare the frequency of these infections with invasive community-onset Staphylococcus aureus (I-CO-SA) infections and common respiratory viral infections in this period. Methods: Cases of iGAS, IPD, and I-CO-SA infections were identified prospectively and retrospectively at 2 large US children's hospitals by positive cultures from July 2018 through December 2022. Admission data were used to estimate frequency. For comparison, rates of respiratory syncytial virus (RSV), influenza, and SARS-CoV-2 were estimated by the number of positive viral test results at each institution. Results: I-CO-SA infections showed little variation in the study period. Rates of iGAS infection and IPD decreased by 46% and 44%, respectively, from 2019 to 2020, coinciding with a substantial decrease in RSV and influenza. In 2022, RSV and influenza infection rates increased to prepandemic winter season rates, coinciding with a return to prepandemic rates of IPD (225% increase from 2021 to 2022) and a surge above prepandemic rates of iGAS infections (543% increase from 2021 to 2022). Conclusions: The COVID-19 pandemic had an unexpected influence on IPD and iGAS infections that was temporally related to changes in rates of viral infections.

Molecular diagnosis of subcutaneous Pythium insidiosum infection by use of PCR screening and DNA sequencing.

Pythium insidiosum is an emerging human pathogen classified among brown algae and diatoms that can cause significant morbidity and mortality in otherwise healthy individuals. Here we describe a pediatric patient with pythiosis acquired in the southern United States, diagnosed by molecular screening and DNA sequencing of internal transcribed spacer region 1.

Retrospective analysis of infection and antimicrobial resistance patterns of Mycoplasma genitalium among pregnant women in the southwestern USA.

BACKGROUND: Mycoplasma genitalium is a sexually transmitted infection (STI) pathogen. There have been no published studies concerning symptomatology, prevalence data, antibiotic resistance profiling or reports of co-infection with other STI in pregnant women. OBJECTIVE: To describe these characteristics among pregnant women attending prenatal clinics in a large tertiary care centre. DESIGN: Remnant genital samples collected from pregnant women between August 2018 and November 2019 were tested for M. genitalium and Trichomonas vaginalis by the transcription-mediated amplification technique. Specimens with detectable M. genitalium RNA were sequenced for 23S rRNA mutations associated with azithromycin resistance and parC and gyrA mutations associated with resistance to moxifloxacin. Demographic, obstetric and STI co-infection data were recorded. RESULTS: Of the 719 samples, 41 (5.7 %) were positive for M. genitalium. M. genitalium infection was associated with black race, Hispanic ethnicity and young age (p=0.003, p=0.008 and p=0.004, respectively). M. genitalium infection was also associated with T. vaginalis co-infection and Streptococcus agalactiae (group B Streptococcus) colonisation (p≤0.001 and p=0.002, respectively). Of the 41 positive samples, 26 (63.4%) underwent successful sequencing. Eight (30.8%) had 23S rRNA mutations related to azithromycin resistance. One of 26 (3.8%) positive samples with sequencing results had the gyrA gene mutation and 1 of 18 sequenced samples (5.6%) had the parC gene mutation associated with moxifloxacin resistance. CONCLUSIONS: Prevalence rates of M. genitalium in pregnant women was 5.7%. M. genitalium infection disproportionately affects young black women co-infected with T. vaginalis. Pregnant women remain at risk for persistent infection with M. genitalium due to decreased azithromycin susceptibility.

Molecular Epidemiology of Contemporary Invasive Haemophilus influenzae Isolates in Texas Children.

Although vaccination has reduced the incidence of Haemophilus influenzae type b, nontypeable H. influenzae and other encapsulated types remain a health threat. Little is known regarding the contemporary molecular epidemiology of these organisms. We conducted multilocus sequence typing on invasive H. influenzae during a period of increasing incidence.

Performance of six SARS-CoV-2 RNA detection systems in symptomatic and asymptomatic pediatric and maternal patients.

Aim: This study evaluated the real-world performance of six test systems for detection of SARS-CoV-2 in 138 pediatric and 110 adult maternal patients. Materials & methods: Nasopharyngeal swabs were tested directly using the Aptima™ SARS-CoV-2 (Aptima) and Simplexa™ COVID-19 Direct (Simplexa), and with Altona RealStar® RT-PCR and CDC RT-PCR with nucleic acid extracted on the Roche® MagNA Pure 96 (Altona-MP96) or bioMérieux EMAG® (Altona-EMAG). Results/Conclusion: Overall percent-positive and percent-negative agreements among the six test systems were, respectively: Aptima: 94.8 and 100%; Altona-MP96: 96.5 and 99.3%; CDC-MP96: 100 and 99.3%; Altona-EMAG: 86.1 and 100%; CDC-EMAG: 98.2 and 100%; Simplexa: 87 and 99.2%. The six test systems showed agreement ranging from 92.7 (κ = 0.85) to 98.8% (κ = 0.98).

Comparison of Mid-Turbinate and Nasopharyngeal Specimens for Molecular Detection of SARS-CoV-2 Among Symptomatic Outpatients at a Pediatric Drive-Through Testing Site.

BACKGROUND: Nasopharyngeal (NP) specimen testing by reverse transcriptase polymerase chain reaction (RT-PCR) is the standard of care for detecting SARS-CoV-2. Data comparing the sensitivity and specificity of the NP specimen to the less invasive, mid-turbinate (MT) nasal specimen in children are limited. METHODS: Paired clinical NP and research MT specimens were collected from children <18 years with respiratory symptoms and tested by molecular assays to detect SARS-CoV-2 RNA. Sensitivity, specificity, and agreement (Cohen's kappa [κ]) were calculated for research MT specimens compared to the clinical NP specimens. RESULTS: Out of 907 children, 569 (62.7%) had parental consent and child assent when appropriate to participate and provided paired MT and NP specimens a median of 4 days after symptom onset (range 1-14 days). 16.5% (n = 94) of MT specimens were positive for SARS-CoV-2 compared with 20.0% (n = 114) of NP specimens. The sensitivity of research MT compared to clinical NP specimens was 82.5% (95% CI: 74.2%, 88.9%), specificity was 100.0% (95% CI: 99.2%, 100.0%), and overall agreement was 96.1% (κ = 0.87). The sensitivity of MT specimens decreased with time from 100% (95% CI: 59.0%, 100.0%) on day 1 of illness to 82.1% (95% CI: 73.8%, 88.7%) within 14 days of illness onset; sensitivity was generally >90% when specimens were collected within the first week of illness. CONCLUSION: MT specimens, particularly those collected within the first week of illness, have moderately reduced sensitivity and equivalent specificity to less-tolerated NP specimens in pediatric outpatients. MT specimen use in children may represent a viable alternative to NP specimen collection.

Comparison of traditional phenotypic identification methods with partial 5' 16S rRNA gene sequencing for species-level identification of nonfermenting Gram-negative bacilli.

Correct identification of nonfermenting Gram-negative bacilli (NFB) is crucial for patient management. We compared phenotypic identifications of 96 clinical NFB isolates with identifications obtained by 5' 16S rRNA gene sequencing. Sequencing identified 88 isolates (91.7%) with >99% similarity to a sequence from the assigned species; 61.5% of sequencing results were concordant with phenotypic results, indicating the usability of sequencing to identify NFB.

Update in Pediatric Diagnostic Microbiology.

Infants and young children are uniquely susceptible to primary viral and bacterial infections, predisposing them to responses of greater frequency and severity than in adults. Etiologies and manifestations of infections in pediatric patients are often different than those in adults. It can be challenging for clinical laboratories to implement appropriate microbiologic methods for rapid and accurate diagnoses in this population. Laboratorians should be cognizant of the distinctive features of children to provide comprehensive pediatric clinical microbiology services. This article discusses laboratory aspects of several clinically significant pediatric pathogens that cause severe harm to patients and impact public health responses.

Complications of Otitis Media and Sinusitis Caused by Streptococcus anginosus Group Organisms in Children.

BACKGROUND: The Streptococcus anginosus group (SAG, S. anginosus, S. intermedius and S. constellatus) are often associated with severe disease and abscess formation. In our institution, we observed an apparent increase in frequency of intraorbital and intracranial infections resulting from SAG at Texas Children's Hospital. We undertook a retrospective review to describe the frequency and clinical features of these infections. METHODS: We reviewed the database of the microbiology laboratory at Texas Children's Hospital from 2011 to 2018 for SAG-positive cultures. Cases included were those associated with (1) either otitis media or sinusitis and (2) Pott's puffy tumor, orbital abscesses, mastoiditis, epidural abscesses, subdural empyema, brain parenchymal abscesses or dural enhancement by imaging. The number of overall diagnoses were determined using diagnostic codes and used to estimate the proportion of disease caused by SAG. RESULTS: Ninety-five cases were identified meeting inclusion criteria. The median age of patients was 11.4 years, and 75.8% were previously healthy. S. intermedius was most commonly isolated (80%) followed by S. constellatus (12.6%) and S. anginosus (7.4%); 50.5% of cases were polymicrobial. Among polymicrobial cases, Staphylococcus aureus was most frequently isolated. All patients underwent surgical intervention. 8.4% of patients experienced persistent neurologic deficits. We observed a significant increase in disease incidence during the study period; in addition, the overall proportion of all intracranial infections caused by SAG increased. CONCLUSIONS: Complications of otitis media and sinusitis caused by SAG are associated with substantial morbidity. These infections are becoming increasingly common at our center although the precise reason for this temporal trend is unclear.