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

• Published in: International journal of infectious diseases 2021-10, Vol.111, p.196-203
• Main Authors: Dirkx, Kirsten K.T., Mulder, Bert, Post, Annelies S., Rutten, Martijn H., Swanink, Caroline M.A., Wertheim, Heiman F.L., Cremers, Amelieke J.H.
• Format: Article
• Language: English
• Subjects: COVID-19; IPD; Pandemic; S. pneumoniae; Surveillance
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2021.08.060

•During the COVID-19 pandemic less invasive pneumococcal disease (IPD) was reported.•This drop was caused by multiple factors, going beyond transmission.•Selective identification of IPD will alter insight into serotype dynamics.•Alternative monitoring strategies could improve the scope of IPD surveillance. Objectives: Streptococcus pneumoniae is the leading bacterial pathogen causing respiratory infections. Since the COVID-19 pandemic emerged, less invasive pneumococcal disease (IPD) was identified by surveillance systems worldwide. Measures to prevent transmission of SARS-CoV-2 also reduce transmission of pneumococci, but this would gradually lead to lower disease rates. Design: Here, we explore additional factors contributing to the instant drop in pneumococcal disease cases captured in surveillance. Results: 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. Conclusions: Depending on the setting, we discuss alternative monitoring strategies that could improve understanding of pneumococcal disease dynamics.