BackgroundUnderstanding COVID-19 outcomes remains a challenge. While numerous biomarkers have been proposed for severity at admission, limited exploration exists for markers during the infection course, especially for the requirement of oxygen therapy. This study investigates the potential of eosinophil count normalization as a predictor for oxygen weaning during the initial wave of the pandemic.MethodsA retrospective study was conducted between March and April 2020 (first wave) among adults admitted directly to a medicine ward. Biological abnormalities, including lymphocyte count, eosinophil count, and C-reactive protein (CRP), were gathered daily during the first week of admission according to oxygen level. In case of worsening, oxygen level was censored at 15 L/min. The primary aim was to assess whether eosinophil count normalization predicts a subsequent decrease in oxygen requirements.ResultsOverall, 132 patients were admitted, with a mean age of 59.0 ± 16.3 years. Of the patients, 72% required oxygen, and 20.5% were admitted to the intensive care unit after a median delay of 48 hours. The median CRP at admission was 79 (26–130) mg/L, whereas the eosinophil count was 10 (0–60)/mm3. Eosinophil count normalization (≥100/mm3) by day 2 correlated significantly with decreased oxygen needs (<2 L) with hazard ratio (HR) = 3.7 [1.1–12.9] (p = 0.04). Likewise, CRP < 80 mg/L was associated with reduced oxygen requirements (p < 0.001). Predictors, including underlying chronic respiratory disease, exhibited a trend toward a negative association (p = 0.06).ConclusionThe study highlights the relationship between eosinophil count and CRP, with implications for predicting oxygen weaning during COVID-19. Further research is warranted to explore the relevance of these biomarkers in other respiratory infections.

BACKGROUND:While sensitive molecular diagnostic tests enable accurate and rapid diagnosis of many respiratory viruses, their impact on antibiotic management remains uncertain. Our study aimed to evaluate the impact of respiratory syndromic molecular testing panel in real-life clinical practice. METHOD:Retrospective descriptive study involving consecutive hospitalized patients in an infectious disease department who had been prescribed a respiratory syndromic molecular testing panel on nasopharyngeal swab samples (FilmArray Respiratory Panel 2 plus) during hospitalization from October 1st, 2021, to February 28th, 2023. RESULTS:All in all, 94 out of 210 screened patients were included in the study. Syndromic molecular testing results influenced antibiotic treatment in seven cases: discontinuation in four cases (three virus identifications), changes in two (Mycoplasma pneumoniae positive cases), and initiation in two (negative viral PCRs and one positive bacterial culture). CONCLUSION:In our study, respiratory syndromic molecular testing had low impact on antibiotic modification.

We present the case of an 81-year-old man, who was immunocompetent, who was admitted to the hospital with symptoms of fever and dyspnea suspected to be caused by COVID-19. Further examination revealed a triple coinfection, as determined by multiplex polymerase chain reaction testing, caused by the respiratory syncytial virus, human coronavirus OC43, and rhinovirus. Upon auscultation, diffuse wheezing without crackles was detected. After ruling out the possibility of acute heart failure with pulmonary edema, the patient was treated with nebulization of terbutaline for a period of 72 hours. This case serves to demonstrate the potential dangers of lifting barrier measures, such as mandatory face masks in high-risk areas, during the fall-winter season. In addition, it highlights the challenges that may arise in the post-COVID-19 era because reliance on flu vaccinations alone may not be sufficient.

Abstract Background The initial need for oxygen during Covid-19 has been correlated with the severity of lung involvement observed on CT-scan caused by the cytokine storm. A recent study showed that the normalization of eosinophil count (≥100/mm3) after 48 hours of appropriate regimen was related to a favorable outcome in sepsis. Our work intends to assess the kinetics of eosinophil count over time based on oxygen levels during the acute phase of this viral infection. Methods Retrospective study, conducted between March-April 2020 (first wave), among adults admitted directly to a medicine ward. Biological abnormalities, including lymphocyte count, eosinophil count, and CRP were gathered daily during the first week of admission (day 0) according to oxygen level. In case of worsening requiring ICU, oxygen level was censored at 15 L/min. Aim of the study was to investigate whether normalization of eosinophil count could predict a decrease in oxygen requirements, and potentially patient’s outcome. Values were presented as median with 95% CI and statistical analysis utilized the Chi-2 square test. Results 132 patients were admitted, mean age 59.0±16.3 years. Mean onset of symptoms was 7±4 days. Majority of patients had cardiovascular disease (43.1%), underlying respiratory disease (16.7%), diabetes (18.9%), immunosuppression (8.3%) and obesity (10.6%). At admission, median (IQR) CRP=79(26-130) mg/L, lymphocyte count=1005(730-1380)/mm3 and eosinophil count=10(0-60)/mm3. 72% of patients required oxygen supply. Lung CT-scan (n=103) revealed: 53.5% had moderate (25-50%) to severe ( >50%) involvement. Twenty-seven patients (20.5%) required ICU due to condition worsening. Eosinophil count increased continuously until normalization from day0 to day3, while the oxygen level started to decrease on day 3 without any rebound observed thereafter (Figure 1). Similarly, CRP decreased to 43 mg/L on day2, but ultimately increased again. Patients requiring < 2L/min of oxygen were significantly associated with an eosinophil count≥100/mm3 on day 2 OR=0.2 [0.07-0.56] (p=0.002). Conclusion Normalization of eosinophil count over time seems predictive of a decrease of oxygen requirement during Covid-19. Those data should be confirmed on other type of respiratory tract infections. Disclosures All Authors: No reported disclosures