Serotype transmission dynamics and reduced incidence of invasive pneumococcal disease caused by different serotypes after implementation of non-pharmaceutical interventions during COVID-19 pandemic

Abstract

To block the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) a number of non-pharmaceutical interventions (NPIs) are being implemented. Taiwan successfully controlled coronavirus disease of 2019 (COVID-19) mainly by NPIs that were centered on facial masking, enhanced hand hygiene, social distancing, international travel controls, effective quarantine and contact-tracing policy [1, 2]. After the first case of COVID-19 was detected on January 21 2020, a rise in local demand for surgical masks and N95 respirators was observed and at least 50% of people spontaneously wore a facial mask in public places since early February 2020 [3, 4]. Among the total 799 COVID-19 cases reported in 2020, annual incidence rate of COVID-19 in Taiwan was remarkably low (0.238/100,000; n=56) for locally acquired (local) cases and high (3.153/100,000; n=743) for internationally acquired (imported) cases (Taiwan CDC, https://data.cdc.gov.tw/en/dataset). It is perceived that NPIs that are currently being implemented to reduce the COVID-19 should also prevent both acquisition and transmission of other viral and bacterial respiratory tract infections [5‒9]. In this observational study we examined the monthly incidence rates of invasive pneumococcal disease (IPD) and serotype distribution in age groups at high risk and from high pneumococcal transmission settings between January 2020 and February 2021. The differential serotype transmission dynamics revealed by various level of reduction in IPD caused by different serotypes was discussed.