Purpose Eosinopenia has been described in COVID-19. With this study, we aim to study the peripheral blood eosinophil counts in COVID-19 patients and to investigate whether there is an association... Show morePurpose Eosinopenia has been described in COVID-19. With this study, we aim to study the peripheral blood eosinophil counts in COVID-19 patients and to investigate whether there is an association between the peripheral blood eosinophil counts and disease severity of COVID-19. Methods We revised the electronical medical records of confirmed COVID-19 patients with polymerase chain reaction (PCR) assays in the Groene Hart Ziekenhuis, Gouda, The Netherlands. We divided patients in mild, moderate and severe groups based on clinical severity of COVID-19. Clinical severity was based on the therapy needed and the outcome of patients. We compared clinical characteristics, laboratory results and outcome between the three groups. Results Of the 230 patients included in this study, the mild, moderate and severe groups consisted of 16.5%, 45.7% and 37.8% of the included patients, respectively. The mean age was 68 years (IQR 57-78). 63% of patients were male. A significant decrease in the peripheral eosinophil counts was found corresponding to the increase of COVID-19 severity. In the mild, moderate and severe groups, the percentage of patients with eosinopenia was 73.7%, 86.7% and 94.3%, respectively (p value 0.002). Conclusion Eosinopenia is significantly more frequent present in patients with a severe COVID-19. Show less
Influenza viruses have caused significant pandemics and epidemics throughout history and continue to be a health problem in humans. New molecular diagnostic assays can be used in the clinical... Show moreInfluenza viruses have caused significant pandemics and epidemics throughout history and continue to be a health problem in humans. New molecular diagnostic assays can be used in the clinical setting to explore relevant clinical manifestations, virus characteristics, and virus epidemiology. This thesis focuses on a variety of subjects related to the molecular diagnosis and clinical consequences of seasonal and pandemic influenza virus infections. Our findings demonstrate that molecular assays are highly sensitive and afford practical detection of resistance mutations, virulence markers and virus expression. We show that computational phylogenetics can provide accurate confirmation of an institutional influenza outbreak. Clinical observational studies reveal that immunocompromised patients can display remarkable prolonged influenza virus excretion with common antiviral resistance development, and that resistant viruses can be transmissible and pathogenic. We demonstrate that host immune responses correlate with virus-associated symptoms and sustained viral clearance. The results described in this thesis confirm that molecular diagnostic assays should be widely implemented in the clinical setting to improve influenza virus laboratory diagnostics. The inherent viral genetic variability and antigenic plasticity is a continuous incentive for new clinical and molecular research to keep up with relevant mutations and to improve our medical understanding of influenza virus infections. Show less
