Purpose To evaluate the evolution of chemosensation via extended psychophysical testing in patients who suffered from sudden chemosensory loss due to coronavirus disease 2019 (COVID-19). Additionally, this study sought to determine whether odor threshold testing provided additional information on olfactory loss due to COVID-19 compared to the more common odor identification testing. Methods Prospective cohort study of patients with sudden chemosensory loss since February 2020 and confirmed COVID-19 infection via RT-PCR or serology testing. Olfactory function was tested extensively using the “Sniffin Sticks” test battery. In addition, we screened gustatory perception and nasal cooling sensations using psychophysical tests. Results Seventy-two patients completed the study. After a mean of 37 days, 37% of patients showed olfactory dysfunction, 7% were dysgeusic, and 48% showed signs of low sensitivity for cooling sensation. A longer duration of anosmia before smell improvement was correlated with lower olfactory function at 5 weeks. Odor threshold detection was more affected by COVID-19 compared to odor identification. Conclusion Five weeks after developing sudden chemosensory loss due to COVID-19, a high proportion of patients were dysosmic and showed signs of low nasal cooling sensitivity, whereas most of them had normal taste function. SARS-CoV-2 affected mainly odor thresholds, possibly suggesting that the major cause of loss of smell lies at the level of the olfactory neuroepithelium, rather than in the central nervous system.

Objectives.To compare the type of pathogens isolated from patients with early-onset intensive care unit (ICU)-acquired pneumonia with those isolated from patients with late-onset ICU-acquired pneumonia and to study risk factors for the isolation of pathogens that are potentially resistant to multiple drugs.Design.Prospective cohort study.Setting.Patients admitted to the ICU of a 677-bed, university-affiliated teaching hospital in Belgium during 1997-2002.Methods.ICU-acquired pneumonia was defined as a case of pneumonia that occurred 2 days or more after admission to the ICU in combination with a positive results of radiologic analysis, clinical signs and symptoms, and a positive culture result. All cases of pneumonia were categorized as either early onset (within 7 days after admission) and late onset (7 days or more after admission), with or without previous antibiotic treatment, and the corresponding pathogens were analyzed. Risk factors for the isolation of pathogens potentially resistant to multiple drugs (ie, Pseudomonas aeruginosa, Serratia marcescens, Enterobacter species, Morganella morganii, methicillin-resistant Stapylococcus aureus, Citrobacter species, Acinetobacter species, Burkholderia species, extended-spectrum β-lactamase–producing pathogens, and Stenotrophomonas maltophilia) were analyzed using logistic regression analysis.Results.A total of 4,200 patients stayed at the ICU for 2 or more days, 298 of whom developed ICU-acquired pneumonia, for an overall incidence of 13 cases (95% confidence interval [CI], 11-14 cases) per 1,000 ICU-days. Pathogens potentially resistant to multiple drugs were isolated from 52% of patients with early-onset pneumonia. Risk factors for the isolation of these pathogens were greater age and previous receipt of antibiotic prophylaxis (adjusted odds ratio [aOR], 4.6 [95% CI, 1.6-13.0]) or antibiotic therapy (aOR, 8.2 [95% CI, 2.8-23.8]). The length of ICU admission and hospital stay were weaker risk factors for the isolation of these pathogens.Conclusions.Pathogens potentially resistant to multiple drugs were isolated in 52% of cases of early-onset ICU-acquired pneumonia. Previous antibiotic use (both prophylactic and therapeutic) is the main risk factor for the isolation of these pathogens.