Transmission Dynamics and Effectiveness of Control Measures during COVID-19 Surge, Taiwan, April-August 2021

Evaluating the Effect of Public Health and Social Measures Under Rapid Changes in Population-level Immunity Against SARS-CoV-2: A Mathematical Modeling Study

BACKGROUND

Public health and social measures are crucial for controlling the spread of pathogens. However, well-tailored assessments of their impact remain elusive, particularly considering time-varying immunity established from prior exposures and its waning.

METHODS

We developed a mathematical model to estimate the time-varying basic reproduction number, accounting for the dynamics of underlying immunity. Applying this framework, we retrospectively assessed the impact of public health and social measures implemented from November 2021 to April 2022 on SARS-CoV-2 transmission in Korea and discussed potential biases from ignoring underlying immunity.

RESULTS

Our proposed model estimated a notable attenuation in the impact of public health on social measures on SARS-CoV-2 transmission in Korea with the emergence of the Omicron variants while remaining effective throughout the Delta and Omicron periods. These changes during the Omicron period became evident only upon adjusting for underlying immunity and were correlated with observed human mobility patterns in Korea.

CONCLUSIONS

Our findings support the importance of incorporating underlying immunity in evaluating public health and social measures, particularly in the presence of substantial changes over a short period, such as widespread infections or vaccination. This model would stand as a tool for informing public health planning, capable of mitigating the overall disease burden in future epidemics.

Transfusion safety concerns during the COVID-19 pandemic in Taiwan: Altered by evolving control strategies

BACKGROUND

In 2022, the SARS-CoV-2 Omicron surge affected 8.8 million people in Taiwan. This study delves into how the transition from containment to mitigation strategies in COVID-19 control has altered concerns regarding transfusion safety.

METHODS

Blood donations during 2020-2022 in Taiwan were included. Donation details and post-donation information (PDI) were retrieved to assess donation fluctuations and incidences of various PDI. The main effects of PDI reporting were assessed using chi-square test and logistic regression. Additionally, from April to August 2022, we collected disease information from COVID-19 donors, and tested their repository specimens for SARS-CoV-2 RNA and antibodies.

RESULTS

Before 2022, when containment measures were in place, only 8 blood donors with COVID-19 reported PDI. However, by mid-2021, there was a significant decrease in blood donations. In 2022, with mitigation strategies implemented, a total of 3483 donations reported COVID-19 PDI. The incidence of all cause PDI increased from 10.5 per 10,000 donations in 2020-2021 to 29.9 per 10,000 in 2022, with nearly 70% of PDI being related to COVID-19. Female donors reported more PDI events. Additionally, the incidence significantly decreased with age. A total of 1148 repository specimens from COVID-19 donor were tested, revealing no detection of SARS-CoV-2 RNA. The seroprevalence rates of anti-nucleocapsid(N) and anti-spike(S) antibodies were 0.61% and 98.4%, respectively.

CONCLUSION

Transfusion safety concerns in Taiwan progressed alongside the evolution of control strategies, with a one-year delay following the pandemic started. The absence of RNAemia among COVID-19 donors indicates that precautionary measures were commensurate with the risk.

Impact of the Coronavirus Disease 2019 Pandemic on the Management and Outcomes of ST-Segment Elevation Myocardial Infarction Patients: A Retrospective Cohort Study

Background and Objectives: The coronavirus disease 2019 pandemic presented unprecedented challenges in balancing infection control measures with the timely management of ST-segment elevation myocardial infarction (STEMI), a time-sensitive condition. This study investigates the pandemic's effects on STEMI management times and outcomes at a high-volume medical center in Taiwan. Materials and Methods: A retrospective analysis of 1309 STEMI patients was conducted at Chang Gung Memorial Hospital between 2017 and 2022. Patients were divided into pre-pandemic and pandemic groups. Measurement outcomes include in-hospital mortality rate, management times (e.g., door-to-balloon time), the rates of intra-aortic balloon pump (IABP) and/or veno-arterial extracorporeal membrane oxygenation (VA-ECMO) usage, mechanical ventilation, inotropic support, and the length of intensive care unit (ICU) and hospital stay. Kaplan-Meier survival analysis and statistical comparisons were performed to assess temporal trends and prognostic outcomes. Results: No significant difference in in-hospital mortality was observed between pre-pandemic (5.85%) and pandemic (7.03%) groups (p = 0.45). The pandemic group experienced longer management times, including door-to-cath arrival (p = 0.0335) and door-to-balloon time (p = 0.014), although all times remained below the 90 min threshold. Quality improvements during the first outbreak allowed the institution to handle higher case volumes during subsequent waves without further delays. Ninety-day survival analysis showed no significant disparity between groups (p = 0.3655). Conclusions: Pandemic-related delays in STEMI management were effectively mitigated through workflow optimization, preventing significant increases in mortality rates. This study highlights the adaptability of healthcare systems in responding to crises while maintaining quality care for time-sensitive emergencies. Future multicenter studies could provide broader insights into global STEMI management strategies under pandemic conditions.

Genomic Surveillance of SARS-CoV-2 in Taiwan: A Perspective on Evolutionary Data Interpretation and Sequencing Issues

This review presents a comprehensive perspective on the genomic surveillance of SARS-CoV-2 in Taiwan, with a focus on next-generation sequencing and phylogenetic interpretation. This article aimed to explore how Taiwan has utilized genomic sequencing technologies and surveillance to monitor and mitigate the spread of COVID-19. We examined databases and sources of genomic sequences and highlighted the role of data science methodologies in the explanation and analyses of evolutionary data. This review addressed the challenges and limitations inherent in genomic surveillance, such as concerns regarding data quality and the necessity for interdisciplinary expertise for accurate data interpretation. Special attention was given to the unique challenges faced by Taiwan, including its high population density and major transit destination for international travelers. We underscored the far-reaching implications of genomic surveillance data for public health policy, particularly in influencing decisions regarding travel restrictions, vaccine administration, and public health decision-making. Studies were examined to demonstrate the effectiveness of using genomic data to implement public health measures. Future research should prioritize the integration of methodologies and technologies in evolutionary data science, particularly focusing on phylodynamic analytics. This integration is crucial to enhance the precision and applicability of genomic data. Overall, we have provided an overview of the significance of genomic surveillance in tracking SARS-CoV-2 variants globally and the pivotal role of data science methodologies in interpreting these data for effective public health interventions.

The Perspectives of Community Pharmacists Toward the Name-Based Rationing System During the COVID-19 Pandemic in Taiwan: Cross-Sectional Survey Study

BACKGROUND

In Taiwan's public health system, community-based pharmacists are key first-line health care providers due to their high accessibility. During the COVID-19 pandemic, the pharmacists played a central role in the distribution of these supplies through the Name-Based Rationing System (NBRS), during an acute shortage of masks and testing kits, that helped reduce the spread of the disease. The NBRS, an innovative government-guided strategy developed after the COVID-19 outbreak, provided equitable and convenient access to masks and COVID-19 test kits.

OBJECTIVE

This study aimed to investigate (1) Taiwanese pharmacists' knowledge, attitude, and practices (KAPs) of COVID-19, with the intention to assess their preparedness for public health emergencies and their capabilities to implement COVID-19-related policies effectively; (2) their perspectives toward the NBRS; and (3) the association between individual's KAP and corresponding perspectives toward the NBRS.

METHODS

A cross-sectional, web-based survey was conducted in 2 major cities in Taiwan, from June 18 to September 11, 2022, during the peak of the COVID-19 pandemic. To gauge community pharmacists' KAP, a 66-question instrument was developed using guidelines from the Taiwanese Centers for Disease Control, the International Pharmaceutical Federation, and the Taiwanese Pharmacist Association. The instrument's internal consistency reliability was ascertained using Cronbach α (0.819), and its content validity was verified by field experts.

RESULTS

Overall, 343 Taiwanese community pharmacists were recruited in the study. Among them, 88% (303/343) scored high on knowledge domain questions related to SARS-CoV-2; 58% (201/343) and 39% (136/343) held positive and neutral attitudes toward COVID-19-related policies, respectively; and 77% (266/343) practiced infectious disease prevention measures in compliance with official guidelines. The results demonstrated a high level of competency in pharmacists in a public health crisis. It revealed that factors including age, pharmacy characteristics, and the number of customers were associated with their perceptions and willingness to continuously participate in the NBRS. Overall, the community pharmacists showed greater support for the COVID-19-testing NBRS compared with the mask NBRS, because of the more favorable influence on the revenue and workforce of the pharmacies and the well-being of the pharmacists. Responses also highlighted concerns about rapid government policy changes and supply dynamics, underscoring the importance of effective communication and considering supply availability in facilitating a successful NBRS.

CONCLUSIONS

The strong KAP of the community pharmacists justified the government leveraging their expertise in Taiwan's COVID-19 response. While community pharmacies have proven to be essential distribution centers through the NBRS, improving community connections, communication with the government, and supply management are recommended to strengthen the system. These potential approaches aim to ensure successful NBRS implementation and better preparedness for future public health emergencies. Overall, pharmacists have demonstrated their integral role in achieving equitable outcomes and their dedication to public health efforts during crises.

Population Behavior Changes Underlying Phasic Shifts of SARS-CoV-2 Exposure Settings Across 3 Omicron Epidemic Waves in Hong Kong: Prospective Cohort Study

BACKGROUND

Exposure risk was shown to have affected individual susceptibility and the epidemic spread of COVID-19. The dynamics of risk by and across exposure settings alongside the variations following the implementation of social distancing interventions are understudied.

OBJECTIVE

This study aims to examine the population's trajectory of exposure risk in different settings and its association with SARS-CoV-2 infection across 3 consecutive Omicron epidemic waves in Hong Kong.

METHODS

From March to June 2022, invitation letters were posted to 41,132 randomly selected residential addresses for the recruitment of households into a prospective population cohort. Through web-based monthly surveys coupled with email reminders, a representative from each enrolled household self-reported incidents of SARS-CoV-2 infections, COVID-19 vaccination uptake, their activity pattern in the workplace, and daily and social settings in the preceding month. As a proxy of their exposure risk, the reported activity trend in each setting was differentiated into trajectories based on latent class growth analyses. The associations of different trajectories of SARS-CoV-2 infection overall and by Omicron wave (wave 1: February-April; wave 2: May-September; wave 3: October-December) in 2022 were evaluated by using Cox proportional hazards models and Kaplan-Meier analysis.

RESULTS

In total, 33,501 monthly responses in the observation period of February-December 2022 were collected from 5321 individuals, with 41.7% (2221/5321) being male and a median age of 46 (IQR 34-57) years. Against an expanding COVID-19 vaccination coverage from 81.9% to 95.9% for 2 doses and 20% to 77.7% for 3 doses, the cumulative incidence of SARS-CoV-2 infection escalated from <0.2% to 25.3%, 32.4%, and 43.8% by the end of waves 1, 2, and 3, respectively. Throughout February-December 2022, 52.2% (647/1240) of participants had worked regularly on-site, 28.7% (356/1240) worked remotely, and 19.1% (237/1240) showed an assorted pattern. For daily and social settings, 4 and 5 trajectories were identified, respectively, with 11.5% (142/1240) and 14.6% (181/1240) of the participants gauged to have a high exposure risk. Compared to remote working, working regularly on-site (adjusted hazard ratio [aHR] 1.47, 95% CI 1.19-1.80) and living in a larger household (aHR 1.12, 95% CI 1.06-1.18) were associated with a higher risk of SARS-CoV-2 infection in wave 1. Those from the highest daily exposure risk trajectory (aHR 1.46, 95% CI 1.07-2.00) and the second highest social exposure risk trajectory (aHR 1.52, 95% CI 1.18-1.97) were also at an increased risk of infection in waves 2 and 3, respectively, relative to the lowest risk trajectory.

CONCLUSIONS

In an infection-naive population, SARS-CoV-2 transmission was predominantly initiated at the workplace, accelerated in the household, and perpetuated in the daily and social environments, as stringent restrictions were scaled down. These patterns highlight the phasic shift of exposure settings, which is important for informing the effective calibration of targeted social distancing measures as an alternative to lockdown.

Environment contamination and intra-hospital spread of COVID-19 in a tertiary care Hospital in Taiwan

BACKGROUND

The role of environmental contamination in COVID-19 transmission within hospitals is still of interest due to the significant impact of outbreaks globally. However, there is a scarcity of data regarding the utilization of environmental sampling for informing infection control measures during SARS-CoV-2 outbreaks.

METHODS

This retrospective study analyzed incident event investigations conducted at a single center from May 1, 2021, to August 31, 2021. Investigations were initiated following the identification of a COVID-19 confirmed case (referred to as the index case) who had stayed in a hospital area outside the dedicated COVID-19 ward/bed and without specific COVID-19 precautions. Measures to prevent intra-hospital spread included contact tracing, adjusted testing policies, isolation of confirmed cases, quarantine of close contacts, environmental disinfection, and PCR testing of environmental samples.

RESULTS

Among the 18 incident events investigated, the index case was a healthcare personnel in 8 events, a patient in 8 events, and a caregiver in 2 events. The median number of confirmed COVID-19 cases within 14 days was 13 (IQR, 7-31) for events with SARS-CoV-2 RNA detected on environmental surfaces, compared to only one (IQR, 1-1.5) for events without surface contamination (P = 0.04). Environmental contamination was independently associated with a higher number of COVID-19 cases (P < 0.001).

CONCLUSION

This study highlights environmental contamination as an indicator of the severity of incident events and provides a framework for incident event management, including a protocol for environmental sampling. Implementing these measures can help prevent the spread of COVID-19 within healthcare facilities.

COVID-19 public health surveillance and response in Taiwan: From containment to mitigation

Taiwan learned from its 2003 SARS experience and established multiple surveillance systems to be able to detect and respond to COVID-19. With the find, test, trace, isolate, and support (FTTIS) strategy, Taiwan was successful in containing SARS-CoV-2 from spreading for two years. During the surge of the Omicron variant in the community, COVID-19 control strategy shifted from containment to mitigation in April 2022, to reduce morbidity and mortality. Lessons learned from COVID-19 response re-emphasizes the importance of having sensitive public health surveillance and linking surveillance with public health actions.

The emergence and successful elimination of SARS-CoV-2 dominant strains with increasing epidemic potential in Taiwan's 2021 outbreak

Taiwan's experience with severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003 guided its development of strategies to defend against SARS-CoV-2 in 2020, which enabled the successful control of Coronavirus disease 2019 (COVID-19) cases from 2020 through March 2021. However, in late-April 2021, the imported Alpha variant began to cause COVID-19 outbreaks at an exceptional rate in Taiwan. In this study, we aimed to determine what epidemiological conditions enabled the SARS-CoV-2 Alpha variant strains to become dominant and decline later during a surge in the outbreak. In conjunction with contact-tracing investigations, we used our bioinformatics software, CoVConvert and IniCoV, to analyze whole-genome sequences of 101 Taiwan Alpha strains. Univariate and multivariable regression analyses revealed the epidemiological factors associated with viral dominance. Univariate analysis showed the dominant Alpha strains were preferentially selected in the surge's epicenter (p = 0.0024) through intensive human-to-human contact and maintained their dominance for 1.5 months until the Zero-COVID Policy was implemented. Multivariable regression found that the epidemic periods (p = 0.007) and epicenter (p = 0.001) were two significant factors associated with the dominant virus strains spread in the community. These dominant virus strains emerged at the outbreak's epicenter with frequent human-to-human contact and low vaccination coverage. The Level 3 Restrictions and Zero-COVID policy successfully controlled the outbreak in the community without city lockdowns. Our integrated method can identify the epidemiological conditions for emerging dominant virus with increasing epidemiological potential and support decision makers in rapidly containing outbreaks using public health measures that target fast-spreading virus strains.

Epidemiological characteristics of the three waves of COVID-19 epidemic in Taiwan during April 2022 to March 2023

BACKGROUND

Taiwan experienced a relatively low incidence of COVID-19 before 2022. However, from April 2022 to March 2023, the country was struck by a nationwide outbreak that occurred in three waves. Despite the considerable magnitude of the epidemic, the epidemiological characteristics of this outbreak have yet to be clearly understood.

METHODS

This was a nationwide, population-based, retrospective cohort study. We recruited patients who had been confirmed as domestically-acquired COVID-19 patients from April 17, 2022, to March 19, 2023. The three epidemic waves were analyzed in terms of numbers of cases, cumulative incidence, numbers of COVID-19-related deaths, mortality, gender, age, residence, SARS-CoV-2 variant sub-lineages, and reinfection status.

RESULTS

The numbers of COVID-19 patients (cumulative incidence per million population) were 4,819,625 (207,165.3) in the first wave, 3,587,558 (154,206.5) in the second wave, and 1,746,698 (75,079.5) in the third wave, showing a progressive decline. The numbers of COVID-19-related deaths and mortalities also decreased throughout the three waves. The coverage of vaccination was observed to increase over time.

CONCLUSION

During the three waves of COVID-19 epidemic, the numbers of cases and deaths gradually declined, while the vaccine coverage increased. It may be appropriate to consider easing restrictions and returning to normality. However, continued monitoring of the epidemiological situation and tracking the emergence of new variants are crucial to prevent the possibility of another epidemic.

Analysis of effectiveness and outcome of traumatic brain injury treatment in ED during COVID-19 pandemic: A multicenter in Taiwan

The coronavirus disease 2019 has become a threat to global healthcare because of its rapid spread and evolution. In severe cases, the initial management of the disease is mainly supportive therapy and mechanical ventilation. Therefore, we investigated whether a modified emergency department workflow affects the efficacy will influence the efficacy and patient outcomes of traumatic brain injury (TBI) in Taiwan. This retrospective observational study used the Chang Gung Research Database in Taiwan from 7 hospitals in the Chang Gung Memorial Hospital System. Clinical index parameters and treatment efficiencies were analyzed between the locally transmitted period (January 20, 2020-June 7, 2020, period 2) and the community spread period (May 19, 2021-July 27, 2021, period 4) with the same interval of the pre-pandemic in 2019 as a reference period. During the locally transmitted period, only the time interval for patients who had to wait for a brain CT examination was, on average, 7.7 minutes shorter, which reached statistical significance. In addition, the number of TBI patients under 18 years of age decreased significantly during the community spread period. The "Door to the operating room (OR)," with polymerase chain reaction (PCR) testing, was on average 109.7 minutes slower than without the PCR testing in the reference period 2019. TBI treatment efficiency was delayed because of the PCR test. However, the surgical volume and functional outcome during these 2 periods were statistically insignificant compared to the pre-pandemic period because the spread of the virus was well controlled and hospital capacity was increased.