Five consecutive epidemiological waves of COVID-19: a population-based cross-sectional study on characteristics, policies, and health outcome

Abstract

Background This study was conducted with the intension of providing a more detailed view about the dynamics of COVID-19 pandemic. To this aim, characteristics, implemented public health measures, and health outcome of COVID-19 patients during five consecutive waves of the disease were assessed. Methods This study was a population-based cross-sectional analysis of data on adult patients who were diagnosed with COVID-19 during five waves of the disease in Iran. Chi-squared test, One-way ANOVA, and Logistic Regression analysis were applied. A detailed literature review on implemented public health policies was performed by studying published documents and official websites responsible for conveying information about COVID-19. Results Data on 328,410 adult patients was analyzed. Main findings indicated that the probability of dying with COVID-19 has increased as the pandemic wore on, showing its highest odd during the third wave (odds ratio: 1.34, CI: 1.283–1.395) and has gradually decreased during the next two waves. The same pattern was observed in the proportion of patients requiring ICU admission (P < 0.001). First wave presented mainly with respiratory symptoms, gastrointestinal complaints were added during the second wave, neurological manifestations with peripheral involvement replaced the gastrointestinal complaints during the third wave, and central nervous system manifestations were added during the fourth and fifth waves. A significant difference in mean age of patients was revealed between the five waves (P < 0.001). Moreover, results showed a significant difference between men and women infected with COVID-19, with men having higher rates of the disease at the beginning. However, as the pandemic progressed the proportion of women gradually increased, and ultimately more women were diagnosed with COVID-19 during the fifth wave. Our observations pointed to the probability that complete lockdowns were the key measures that helped to mitigate the virus spread during the first twenty months of the pandemic in the country. Conclusion A changing pattern in demographic characteristics, clinical manifestations, and severity of the disease has been revealed as the pandemic unfolded. Reviewing COVID-19-related public health interventions highlighted the importance of immunization and early implementation of restrictive measures as effective strategies for reducing the acute burden of the disease.

Assessing the impact of the Gamma variant on COVID-19 Patient admissions in a Southern Brazilian tertiary hospital - A comparison of dual pandemic phases

“…These factors remained independent risk factors after the multivariate analysis, as shown in previous studies. [2,17,19,21,22]…”

Extraversion in COVID-19 Coping

“…As a result of a new virus first reported by the World Health Organization (WHO) in December 2019, and declared a pandemic 11 March 2020 [6], various waves have been reported of COVID-19. In Iran, for example, five waves of the COVID-19 pandemic were identified between March 2020 and December 2021 [7], when COVID-19 became endemic throughout the world [8]. These five waves noted in Iran are in contrast to, for example, nine waves specified in the UK [9], and seven waves identified in Canada [10], among differences in waves reported around the world.…”

Relevance of comorbidities for main outcomes during different periods of the COVID‐19 pandemic

“…Given the changing nature of the infection-due to the different variants of COVID-19 and the corresponding waves of the disease experienced, knowledge of the similarities and differences between the characteristics of the infection and outcomes between waves remains relatively scarce. 7,13,14 Several articles have already reported on the role of different comorbidities with regard to different relevant outcomes among COVID-19 patients. However, this has usually been done in relatively small sample sizes, among hospitalized patients or without exploring differences between the different periods in the pandemic.…”