Carmon L, Bachar Y, Babiev AS, Hazn I, Hershkovitz E, Shaki D, Loewenthal N, Haim A, Hazan G. Impact of COVID-19 outbreak on the seasonality and incidence of type 1 diabetes mellitus: A nationwide cohort study. World J Diabetes 2025; 16(8): 108724 [DOI: 10.4239/wjd.v16.i8.108724]
Corresponding Author of This Article
Lior Carmon, MD, Pediatric Endocrinology Unit, Soroka University Medical Center, 151 Rager Street, Beer-Sheva 8457108, Israel. liorca2@clalit.org.il
Research Domain of This Article
Endocrinology & Metabolism
Article-Type of This Article
Retrospective Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Diabetes. Aug 15, 2025; 16(8): 108724 Published online Aug 15, 2025. doi: 10.4239/wjd.v16.i8.108724
Impact of COVID-19 outbreak on the seasonality and incidence of type 1 diabetes mellitus: A nationwide cohort study
Lior Carmon, Yoav Bachar, Amit S Babiev, Itai Hazn, Eli Hershkovitz, David Shaki, Neta Loewenthal, Alon Haim, Guy Hazan
Lior Carmon, Eli Hershkovitz, David Shaki, Neta Loewenthal, Alon Haim, Guy Hazan, Pediatric Endocrinology Unit, Soroka University Medical Center, Beer-Sheva 8457108, Israel
Lior Carmon, Amit S Babiev, Itai Hazn, Eli Hershkovitz, David Shaki, Neta Loewenthal, Alon Haim, Guy Hazan, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8457108, Israel
Yoav Bachar, Amit S Babiev, Itai Hazn, Clinical Research Center, Soroka University Medical Center, Beer-Sheva 8457108, Israel
Author contributions: Carmon L and Hazan G designed the study; Carmon L wrote the original draft of the manuscript; Bachar Y, Babiev AS, Hazn I, and Hazan G performed the research and statistical analysis; Hershkovitz E, Shaki D, Loewenthal N, and Haim A reviewed the manuscript; Hazan G reviewed manuscript and made major contributions to the final version; Haim A and Hazan G edited the manuscript; and all authors approved the final version of the manuscript.
Institutional review board statement: This study was approved by the Medical Ethics Committee of Review Board of Soroka University Medical Center, approval No. 0167-23-SOR.
Informed consent statement: This population-based retrospective study utilized a nationwide computerized database. All data were de-identified before analysis.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: Data Availability Statement: The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Lior Carmon, MD, Pediatric Endocrinology Unit, Soroka University Medical Center, 151 Rager Street, Beer-Sheva 8457108, Israel. liorca2@clalit.org.il
Received: April 24, 2025 Revised: May 25, 2025 Accepted: July 9, 2025 Published online: August 15, 2025 Processing time: 113 Days and 4.3 Hours
Abstract
BACKGROUND
Type 1 diabetes mellitus (T1DM) is an autoimmune disease with a multifactorial pathogenesis. Viral infections have been proposed as contributing triggers, supported by the disease’s seasonal pattern, which typically shows higher incidence in autumn and winter. The coronavirus disease 2019 (COVID-19) pandemic and associated lockdowns created a unique context to examine the incidence and seasonality of T1DM during a period characterized by reduced circulation of common viral infections.
AIM
To investigate the incidence and seasonality of T1DM before and during COVID-19 pandemic in relation to global viral infection rates.
METHODS
This population-based retrospective study utilized a nationwide computerized database. Extracted data included the number of new T1DM cases over the 8 years preceding and during the COVID-19 pandemic, demographic characteristics of affected individuals, and nationwide respiratory virus polymerase chain reaction data from weekly nasal wash sample collections.
RESULTS
A total of 2176 patients were diagnosed with new-onset T1DM during the pre-pandemic period, compared to 348 cases during the pandemic. In the same periods, 33727 respiratory virus-positive polymerase chain reaction results from nasal wash samples were recorded pre-pandemic, compared to 2603 during the pandemic. Additionally, 363399 positive COVID-19 cases were reported during the pandemic period. Seasonality analysis revealed a higher rate of new-onset T1DM cases and a weaker seasonal pattern during the pandemic. Trend analysis showed a consistent increase in T1DM incidence prior to COVID-19, with a more variable trend observed during the pandemic. Correlation analysis between T1DM incidence and respiratory viruses demonstrated a weak correlation between T1DM incidence and a few respiratory viruses.
CONCLUSION
The observed increase in new-onset T1DM cases and the disruption of its typical seasonal pattern during the COVID-19 pandemic suggest a potential association between respiratory virus exposure and the development of T1DM.
Core Tip: This population-based study assessed incidence and seasonality of type 1 diabetes mellitus (T1DM) before and during the coronavirus disease 2019 pandemic. A higher rate of new-onset T1DM and diminished seasonal pattern were observed during the pandemic, coinciding with reduced circulation of common respiratory viruses due to lockdown measures. These findings suggest respiratory viruses, including severe acute respiratory distress syndrome corona virus-2, may serve as environmental triggers for T1DM. Weak positive correlations were identified between T1DM incidence and respiratory viruses (e.g., respiratory syncytial virus, influenza). The results support a potential link between viral exposure and T1DM pathogenesis, highlighting the need for further research into underlying mechanisms and preventive strategies.
