Gastrointestinal Viruses Surge Back in California After COVID-19 Lockdowns, Study Finds
California experienced a significant decline in gastrointestinal viruses during the COVID-19 pandemic, only to witness a resurgence in late 2022, according to a recent study published in the Journal of Clinical Microbiology.
After stay-at-home orders were implemented in response to the pandemic, viruses such as norovirus, rotavirus, and adenovirus virtually vanished from Californian communities for nearly two years. However, researchers observed that these viruses returned to pre-pandemic levels, with adenovirus strains even surpassing previous infection rates.
Niaz Banaei, M.D., professor of Pathology and Medicine (Infectious Diseases) at Stanford University and Medical Director of Clinical Microbiology Laboratory, Stanford Health Care, noted that adenovirus F40/41, the strains primarily associated with gastroenteritis, experienced a two-fold increase in levels compared to before the pandemic.
The study suggests that the resurgence of these viruses can be attributed to the weakened collective community immunity resulting from reduced virus exposure during the pandemic. Similar trends have been witnessed with other infections, such as respiratory syncytial virus, in 2022.
To assess changes in the prevalence of gastrointestinal pathogens, researchers compared detection rates before, during, and after California’s COVID-19 shelter-in-place orders. They utilized a polymerase chain reaction (PCR) panel test called the BioFire FilmArray GI panel, which detects 22 of the most common diarrhea-causing pathogens. Approximately 18,000 tests conducted between January 2018 and December 2022 were analyzed.
The research aimed to investigate the transmission dynamics of gastroenteritis-causing pathogens during the pandemic lockdown, given the noticeable changes in positive rates for certain pathogens. Understanding the reasons behind the disappearance and resurgence of specific viruses during lockdown could potentially aid in interrupting their spread, particularly in lower- and middle-income countries where gastroenteritis contributes to significant illness and death, particularly among children.
Philip L. Bulterys, Nicole Y. Leung, Atif Saleem, Indre Budvytiene, Benjamin A. Pinsky, and Niaz Banaei conducted the research. Banaei expressed that the study opens up avenues for further exploration into the biology of gastrointestinal pathogens. Key questions that arise include why certain pathogens disappeared while others were unaffected during the lockdown, and why some are now resurging to unprecedented levels. By gaining a deeper understanding, researchers may be able to develop strategies to prevent the spread of these pathogens, prepare for future pandemics, and mitigate the impact of gastroenteritis in vulnerable populations.
Reference:
“Postpandemic Effects of COVID-19 Shelter-in-Place Orders on the Gastrointestinal Pathogen Landscape” by Philip L. Bulterys, Nicole Y. Leung, Atif Saleem, Indre Budvytiene, Benjamin A. Pinsky, and Niaz Banaei, Journal of Clinical Microbiology, 19 July 2023, DOI: 10.1128/jcm.00385-23