Myxovirus Resistance Protein A as a Marker of Viral Cause of Illness in Children Hospitalized with an Acute Infection

Application of a Machine Learning-Based Classification Approach for Developing Host Protein Diagnostic Models for Infectious Disease

In recent years, infectious disease diagnosis has increasingly turned to host-centered approaches as a complement to pathogen-directed ones. The former, however, typically requires the interpretation of complex multiple biomarker datasets to arrive at an informative diagnostic outcome. This report describes a machine learning (ML)-based classification workflow that is intended as a template for researchers seeking to apply ML approaches for developing host-based infectious disease biomarker classifiers. As an example, we built a classification model that could accurately distinguish between three disease etiology classes: bacterial, viral, and normal in human sera using host protein biomarkers of known diagnostic utility. After collecting protein data from known disease samples, we trained a series of increasingly complex Auto-ML models until arriving at an optimized classifier that could differentiate viral, bacterial, and non-disease samples. Even when limited to a relatively small training set size, the model had robust diagnostic characteristics and performed well when faced with a blinded sample set. We present here a flexible approach for applying an Auto-ML-based workflow for the identification of host biomarker classifiers with diagnostic utility for infectious disease, and which can readily be adapted for multiple biomarker classes and disease states.

Respiratory tract viral infections associated sepsis in patients with underlying liver disease: Viral sepsis an entity to look forward!

BACKGROUND

Sepsis remains a global health burden associated with significant morbidity and mortality. Bacteria are known to be the predominant pathogens in sepsis; however, viral etiologies in sepsis are still under diagnosed. Respiratory viral pathogens have been previously linked to sepsis, but the knowledge of incidence, disease burden and mortality of viral-induced sepsis remains limited. This study aimed at understanding the role of respiratory viral infections in the causation of sepsis in liver disease patients.

METHODS

In this retrospective study, the clinical records of liver disease patients with influenza-like illness, whose requests for respiratory viral testing were received from January 2019 to December 2022, were reviewed. Respiratory viruses were identified using FilmArray 2.0 respiratory panel (BioFire Diagnostics, Utah, USA).

RESULTS

Of 1391 patients tested, a respiratory viral etiology was detected in 23%. The occurrence of sepsis was seen in 35%. Among these, isolated viral etiology with no other bacterial/fungal coinfection was found in 55% of patients. Rhinovirus/Enterovirus was found as the most common underlying viral etiology (23.4%). The sepsis prevalence was higher among patients with associated comorbidities (45%) and decompensated cirrhosis (84%). On multi-variable analysis, no factor was found independently associated with sepsis-related mortality.

CONCLUSION

This study underlines the importance of isolated viral etiology in causation of sepsis among liver disease patients. Patients with comorbidities, older age and decompensated cirrhosis are at an increased risk of developing sepsis and are associated with poorer outcomes. Accurate and timely identification of the viral etiology in sepsis would prevent the misuse of antibiotics and improve overall patient care.

Detection of group A streptococcus in children with confirmed viral pharyngitis and antiviral host response

Our aim was to study the detection of group A streptococcus (GAS) with different diagnostic methods in paediatric pharyngitis patients with and without a confirmed viral infection. In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis. A confirmed viral infection was defined as a positive virus diagnostic test (nucleic acid amplification test [NAAT] and/or serology) together with an antiviral immune response of the host demonstrated by elevated (≥ 175 µg/L) myxovirus resistance protein A (MxA) blood concentration. Testing for GAS was performed by a throat culture, by 2 rapid antigen detection tests (StrepTop and mariPOC) and by 2 NAATs (Simplexa and Illumigene). Altogether, 83 children were recruited of whom 48 had samples available for GAS testing. Confirmed viral infection was diagnosed in 30/48 (63%) children with febrile pharyngitis. Enteroviruses 11/30 (37%), adenoviruses 9/30 (30%) and rhinoviruses 9/30 (30%) were the most common viruses detected. GAS was detected by throat culture in 5/30 (17%) with and in 6/18 (33%) patients without a confirmed viral infection. Respectively, GAS was detected in 4/30 (13%) and 6/18 (33%) by StrepTop, 13/30 (43%) and 10/18 (56%) by mariPOC, 6/30 (20%) and 9/18 (50%) by Simplexa, and 5/30 (17%) and 6/18 (30%) patients by Illumigene.

CONCLUSION

GAS was frequently detected also in paediatric pharyngitis patients with a confirmed viral infection. The presence of antiviral host response and increased GAS detection by sensitive methods suggest incidental throat carriage of GAS in viral pharyngitis.

WHAT IS KNOWN

•The frequency and significance of GAS-virus co-detection are poorly characterised in children with pharyngitis. •Detection of a virus and the antiviral host response likely indicates symptomatic infection.

WHAT IS NEW

•Group A streptococcus (GAS) was detected in 17-43% of the children with confirmed viral pharyngitis depending on the GAS diagnostic method. •Our results emphasize the risk of detecting and treating incidental pharyngeal carriage of GAS in children with viral pharyngitis.