The impact of the SARS-CoV-2 pandemic on the development of respiratory infections caused by Aspergillus spp., Mucor spp., and Pneumocystis jirovecii within the National Health System of Spain

Fungal diseases cause over 1.5 million deaths annually, with Mucor spp. being major threats. The COVID-19 pandemic led to the widespread use of facemasks, which reduced the transmission of SARS-CoV-2 and other respiratory infections, including fungal diseases. This study examines the impact of COVID-19 pandemic and the use of face masks on the incidence of fungal respiratory infections in Spain. A retrospective longitudinal study was conducted on patients hospitalized with respiratory fungal infections in Spanish NHS hospitals from 2017 to 2022. The data were divided into two periods: pre-COVID-19 (2017-2019) and post-COVID-19 (2020-2022). Patients diagnosed with aspergillosis, mucormycosis, or pneumocystosis were included. The incidence rate was calculated per 100,000 population. Statistical analyses included Chi-square tests, odds ratios (OR), and ANOVA, with significance set at p < 0.05. Between 2017 and 2022, 17,374 patients were hospitalized for Aspergillus infections, 6,598 for Pneumocystis, and 474 for Mucor. Aspergillus incidence rose from 5.34 to 6.94 per 100,000, with a peak of 8.18 in the third year of the pandemic. Pneumocystis and mucormycosis also showed increased incidences. Case fatality rates (CFR) increased for all infections during the pandemic. Aspergillosis had the highest CFR (29.9%), with SARS-CoV-2 coinfection affecting 32% of cases. Coinfection significantly increased hospital stays and ICU admissions, especially for aspergillosis CONCLUSIONS: The COVID-19 pandemic significantly increased the incidence and severity of respiratory fungal infections in Spain, particularly aspergillosis. Pneumocystosis and mucormycosis also showed moderate increases. Case fatality rates increased in all three infections. SARS-CoV-2 coinfection had the greatest clinical impact on aspergillosis, with increased ICU admissions longer hospital stays, and increased mortality. Similar trends of increased severity and fatal outcomes were observed in pneumocystosis and mycosis when co-infected with SARS-CoV-2.