Background: Severe COVID-19 patients who received ventilator management were not very rare even when the omicron variant became dominant, but the clinical characteristics of these patients are still unclear. Methods: The clinical characteristics of severe COVID-19 patients requiring ventilator management were retrospectively investigated from January 2023 to December 2023. Results: Severe COVID-19 patients who received ventilator management accounted for 11 of 275 (4.2%) patients during the omicron variant period. Their mean age was 70.7 (51-85) years, and males were predominant. Ten of eleven (91.7%) patients were managed in the emergency department and had underlying diseases, including chronic lung/heart/kidney diseases and neurological diseases. However, only 4 of 11 (36.4%) had a clear history of vaccination. The patients showed a positive SARS-CoV-2 antigen titer of 3305.7 (12.9-20912). All 11 patients were treated with remdesivir and dexamethasone, and 5 (45.5%) also received sotrovimab. Pathogenic bacteria were isolated from 7 of 11 (63.6%) patients, and all 11 patients were treated with antibiotics. Only 3 of 11 (27.3%) patients were managed using extracorporeal membrane oxygenation (ECMO), but 9 of 11(81.8%) patients survived. Conclusions: These data suggest that severe COVID-19 patients who required ventilator management were less-vaccinated, elderly patients with underlying disease. These patients were treated successfully using antiviral agents, steroids, neutralizing antibodies, and antibiotics, with a few also treated using ECMO in the omicron era.

Background: The titers of SARS-COV-2 antigens are frequently used as markers of viral activity and threshold for release from quarantine and treatment. COVID-19 patients were treated with several antiviral agents, including remdesivir (RDV) and ensitrelvir (ESV), which is a novel anti-SARS-CoV-2 agent recently suggested to have strong antiviral activity. Cases: We present the cases of two patients whose SARS-CoV-2 antigens were successfully decreased by oral administration of ESV after they could not be decreased by RDV drip infusion. Case 1 was a 74-year-old man who was admitted with SARS-CoV-2 infection and had been infected by the virus a month earlier and relapsed twice. He had been treated with rituximab for diffuse B cell lymphoma and not received vaccination for SARS-CoV-2. RDV was administered intravenously two weeks earlier and again 4 days earlier, but it failed to control the infection, and he was transferred to our hospital (day 1). Intravenous RDV was restarted on day 1, but viral antigens remained high until day 5. The RDV was then switched to oral ESV, and viral antigen titers were successfully decreased on days 8, 10, and 12. Case 2 was an 81-year-old man who was admitted with SARS-CoV-2 infection on day 0. He had heart failure and diabetes mellitus, and had not received vaccination for SARS-CoV-2. Intravenous RDV was started on day 1, but viral antigens were still high until day 8. He was then switched from RDV to oral ESV, and viral antigen titers were successfully decreased on day 11. Conclusions: These cases suggest that ESV might be more effective than RDV for reducing viral activity, and it is easy to administer orally.

Many attempts have been made to repurpose existing and approved drugs for the treatment of COVID-19 infection. This involves anti-malarial drugs such as hydroxychloroquine and chloroquine, which have been shown to be less successful than initially believed, with a substantial risk of often fatal complications and interactions. This also involves Remdesivir, which has been shown to decrease recovery time significantly in hospitalized patients. However, for patients who are not yet hospitalized, there is no currently accepted treatment. Treating patients before they need to be admitted or even prophylactically could greatly decrease the load on hospitals, protect healthcare workers and reduce the spread of COVID-19. An in-vitro study indicated that Ivermectin was dynamic against COVID-19-infected cell. Ivermectin has antimicrobial, antiviral, and anticancer, immunomodulatory properties. This drug could reduce the viral load in COVID-9 infected patients, with potential effect on disease progression and spread. Therefore, Ivermectin may be a therapeutic choice for treatment of COVID-19, however, there is still a lack of evidence-based studies to support ivermectin treatment of patients with COVID-19.

Introduction: Concurrent infections or co-infections in patients diagnosed with Coronavirus Disease-19 (COVID-19) are not uncommon and predict a pejorative prognosis. A co-infection accounts for 1 out of every 5 cases of COVID-19 and increases the likelihood of adverse health outcomes such as mechanical ventilations, ICU admissions, and death. Specifically, Legionella spp. co-infection presents additional challenges in COVID-19 patients because of its rarity, similar clinical presentation to SARS-CoV-2, and poorer outcomes without prompt treatment. Cases Presentation: Case 1. A 62-year-old female presented with a 3-day history of subjective fever and worsening shortness of breath. Room air saturation (saO2) was 70% and improved to 100% on noninvasive positive- pressure ventilation (NIPPV). Lung auscultation revealed rales BL. Chest X –Ray (CXR) showed patchy airspace opacities bilaterally (BL), SARS-CoV-2 PCR and urine legionella antigen tests were positive. The diagnosis of hypoxic respiratory failure secondary to COVID-19 and Legionella pneumonia was made. Patient was admitted to intensive care unit (ICU) and managed with decadron, remdesivir, one unit of convalescent plasma for COVID-19 and Azithromycin for Legionella. Patient subsequently developed acute respiratory distress syndrome (ARDS). ARDS protocol was initiated. 13 days after, the patient was compassionately extubated. Case 2. A 41-year-old male presented with 5-day history of fever, worsening shortness of breath, cough and diarrhea. Patient admitted history of ethanol abuse. SaO2 was 88% and improved on oxygen canula. Lung auscultation revealed rhonchi BL. CXR showed extensive left lung consolidation. Urine test for legionella antigen was positive. COVID-19 PCR was negative, but SARS-CoV-2 IgG was reactive. The diagnosis of Legionnaire disease was made. Despite initial treatment with Azithromycin, patient's hypoxia continued to worsen requiring NIPPV, and subsequently mechanical ventilation in the ICU. The adjunction of empiric treatment for COVID-19 with convalescent plasma, remdesivir and steroids improved both clinicals and laboratory findings. Discussion: The cases illustrated the practical challenges of managing COVID-19 and legionella co- infection. Legionella spp and SARS-CoV-2 overlapping incubation periods and similar clinical presentations and complications. In the absence of diagnosis and treatment, legionella pneumonia has an intrinsic mortality rate of up to 80%. As some COVID-19 mitigation strategies, such as the closure of businesses, have enhanced the conditions for Legionella spp proliferation, the incidence of Co-infection with COVID-19 may increase. We recommend clinicians to have high-indexed suspicion of COVID-19 and Legionella co-infection in order to obtain complete work up at patient’s initial presentation.