Pneumonia Caused by Severe Acute Respiratory Syndrome Coronavirus 2 and Influenza Virus: A Multicenter Comparative Study

Dynamics of Absences Due to Respiratory Infections, Including COVID-19, Among Medical Staff in a Regional Pediatric Hospital

Background: Respiratory infections pose a significant public health challenge, particularly among healthcare workers (HCWs). The COVID-19 pandemic exacerbated absenteeism due to respiratory illnesses, affecting healthcare workforce stability. Identifying factors influencing absenteeism is crucial for workforce resilience and effective care. Methods: This retrospective longitudinal study analyzed HCW absenteeism due to respiratory diseases from 2017 to 2023 at the "Sf. Maria" Children's Emergency Hospital in Iași, Romania. Data from 3827 HCWs were examined, including demographic and occupational variables (age, gender, job role) and disease types. Statistical analyses (chi-square tests, ANOVA, and regression models) were conducted using SPSS to assess absenteeism trends and associated risk factors. Results: Sick leave peaked in 2020 (8322 days) and remained high in 2021 (8134 days), gradually decreasing in 2022-2023 but not returning to pre-pandemic levels (~5000 days/year). Nurses accounted for most leave days, while male staff and HCWs aged 41-50 were most affected. Seasonal variations showed higher absenteeism in transitional months and lower rates in summer. COVID-19 was the leading cause of absenteeism during the pandemic, with quarantine measures further increasing sick leave duration. Conclusions: Pediatric hospitals must strengthen infection control measures to protect HCWs and sustain care continuity. Preventive actions such as immunization, staff training, and health monitoring are critical in reducing absenteeism, maintaining a resilient workforce, and ensuring quality care during health crises.

Prevalence and clinical impact of mono- and co-infections with endemic coronaviruses 229E, OC43, NL63, and HKU-1 during the COVID-19 pandemic

Introduction

Endemic human coronaviruses (eHCoVs) are found worldwide and usually result in mild to moderate upper respiratory tract infections. They can lead to more severe illnesses such as croup, bronchiolitis, and pneumonia in vulnerable populations. During the coronavirus disease 2019 (COVID-19) pandemic, information on HCoV prevalence and incidence and clinical impact of co-infections of HCoV with SARS-CoV-2 was lacking.

Objectives

Thus, this study aimed to determine the prevalence and clinical significance of infections caused by eHCoVs during the COVID-19 pandemic in Bulgaria.

Methods

From January 2021 to December 2022, nasopharyngeal swabs of patients with acute upper or lower respiratory tract infections were tested for 17 respiratory viruses using multiplex real-time polymerase chain reaction assays. The clinical data and laboratory parameters of patients infected with respiratory viruses were analysed.

Results

Of the 1375 patients screened, 24 (1.7 %) were positive for HCoVs, and 197 (14.3 %) were positive for eight other seasonal respiratory viruses. Five (0.7 %) of 740 patients positive for SARS-CoV-2 were co-infected with eHCoVs. Co-infected patients had a mean C-reactive protein level of 198.5 ± 2.12 mg/mL and a mean oxygen saturation of 82 ± 2.8 mmHg, while those in patients co-infected with SARS-CoV-2 and other respiratory viruses were 61.8 mg/mL and 92.8 ± 4.6 mmHg, respectively (p < 0.05). Pneumonia was diagnosed in 63.3 % of patients with HCoV infection and 6 % of patients positive for other seasonal respiratory viruses (p < 0.05). Patients with SARS-CoV-2 mono-infection stayed in hospital for an average of 5.8 ± 3.7 days, whereas the average hospital stay of patients with eHCoV and SARS-CoV-2 co-infection was 9 ± 1.4 days (p < 0.05).

Conclusion

These findings indicate the low prevalence of eHCoVs and low co-infection rate between eHCoVs and SARS-CoV-2 during the COVID-19 pandemic in Bulgaria. Despite their low incidence, such mixed infections can cause severe signs that require oxygen therapy and longer hospital stays, underlining the need for targeted testing of severe COVID-19 cases to identify potential co-infections.