Concurrent infections are a common complication of viral respiratory infections. They pose diagnostic challenges due to an overlap of similar symptoms, resistance to treatment and extending length of hospital stay. In this review we will extensively discuss the most common concurrent infections in patients with coronavirus disease 2019 (COVID-19). A thorough literature search was conducted in online databases such as PubMed, Google Scholar and included systematic reviews, meta-analyses, prospective and retrospective cohort studies in this review. Bacterial co-infections are the most common concurrent infections in patients with COVID-19 succeeded by viral and fungal co-infections. The prevalence of co-infections in COVID-19 patients is higher in intensive care units (ICU). Gram negative bacteria such as Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, whereas gram positive bacteria such as Staphylococcus aureus are common pathogens for bacterial co-infections. The findings for the most common viral co-infection are inconsistent however, larger number of studies report respiratory viral co-infections such as influenza and respiratory syncytial virus. Fungal co-infections in COVID-19 patients are most commonly caused by the Candida spp. and occur predominantly in patients admitted in the ICU and are associated with high mortality and morbidity in COVID-19 patients. Continuous research on concurrent infections occurring in COVID-19 is essential. Larger prospective studies based on stratified groups of age, gender, and both ICU and non-ICU settings should be conducted. Studies on microbial susceptibility can lend more weight to empirical antibiotic and antifungal therapy. Early diagnosis of concurrent infections in COVID-19 is imperative to prevent poor patient outcomes.

As a result of the frequent endurance sports that are being practiced nowadays, many techniques have been introduced to this field with favorable outcomes regarding to the management approaches of the different injuries. However, no previous investigations have adequately discussed the pathophysiology of iliotibial band friction syndrome (ITBS) based on recent evidence from the current studies in the literature. In the present investigation, we have discussed the pathophysiology and related classification of iliotibial band friction injuries based on the current studies in the literature. The current evidence about the pathophysiology of the condition is still controversial, although epidemiological investigations indicate that ITBS is becoming a more prevalent condition among runners and other endurance athletes. Furthermore, many factors can attribute to the development of the condition and have been reported to take essential roles in the pathophysiology of the disease. Some of these factors include gender, iliotibial band tightness, rearfoot eversion and weak hip abductors. Further investigations are still needed to completely understand the pathophysiology of the disease to help clinicians aim to achieve better interventions to enhance the outcome of practicing endurance and excessive exercises.