Alhumaid, Saad

Background: Acute Respiratory Distress Syndrome (ARDS) is caused by non-cardiogenic pulmonary edema and occurs in critically ill patients. It is one of the fatal complications observed among severe COVID-19 cases managed in intensive care units (ICU). Supportive lung-protective ventilation and prone positioning remain the mainstay interventions. Purpose: We describe the severity of ARDS, clinical outcomes, and management of ICU patients with laboratory-confirmed COVID-19 infection in multiple Saudi hospitals. Methods: A multicenter retrospective cohort study was conducted of critically ill patients who were admitted to the ICU with COVID-19 and developed ARDS. Results: During our study, 1154 patients experienced ARDS: 591 (51.2%) with severe, 415 (36.0%) with moderate, and 148 (12.8%) with mild ARDS. The mean sequential organ failure assessment (SOFA) score was significantly higher in severe ARDS with COVID-19 (6 ± 5, p = 0.006). Kaplan–Meier survival analysis showed COVID-19 patients with mild ARDS had a significantly higher survival rate compared to COVID-19 patients who experienced severe ARDS (p = 0.023). Conclusion: ARDS is a challenging condition complicating COVID-19 infection. It carries significant morbidity and results in elevated mortality. ARDS requires protective mechanical ventilation and other critical care supportive measures. The severity of ARDS is associated significantly with the rate of death among the patients.

Measles is an RNA virus infectious disease mainly seen in children. Despite the availability of an effective vaccine against measles, it remains a health issue in children. Although it is a self-limiting disease, it becomes severe in undernourished and immune-compromised individuals. Measles infection is associated with secondary infections by opportunistic bacteria due to the immunosuppressive effects of the measles virus. Recent reports highlight that measles infection erases the already existing immune memory of various pathogens. This review covers the incidence, pathogenesis, measles variants, clinical presentations, secondary infections, elimination of measles virus on a global scale, and especially the immune responses related to measles infection.

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.