The drop in reported invasive pneumococcal disease among adults during the first COVID-19 wave in the Netherlands explained

Streptococcus pneumoniae is the main bacterial pathogen causing respiratory infections. Since the COVID-19 pandemic emerged, less pneumococcal disease was identified by surveillance systems around the world. Measures to prevent transmission of SARS-CoV-2 also reduce transmission of pneumococci, but this would gradually lead to lower disease rates. Here, we explore additional factors that have contributed to the instant drop in pneumococcal disease cases captured in surveillance. Our observations on referral practices and other impediments to diagnostic testing indicate that residual IPD has likely occurred but remained undetected by conventional hospital-based surveillance. Depending on setting, we discuss alternative monitoring strategies that could improve sight on pneumococcal disease dynamics.