COVID-19 Public Health Intervention Reduced Other Respiratory Infections

Wearing a mask and quarantining when sick was able to alleviate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The indirect benefit of these efforts appears to be a reduction in influenza cases and other respiratory infections. A new study led by Lisa G. Winston at the University of California, San Francisco confirmed that COVID-19 public health interventions helped reduce the number of aerial viruses.

Findings suggest that COVID public health guidance, such as masking, is a non-pharmaceutical way to reduce future respiratory illness. Researchers say these interventions were still useful, even when people began to gather more outside.

“Our findings add evidence of effective disease mitigation strategies, but intermittent months of public interaction and movement in the Bay Area, including periods when companies are partially allowed. It is also worth noting that the detection rate of respiratory virus remained low during the period of resumption, the time of public protest, and the period of increased outdoor recreational activity in the summer. It suggests a central role in masking and reducing the collection of closed spaces to impede the transmission of the virus. “

The study “Significant and persistent reduction of non-SARS-CoV-2 respiratory virus infection during COVID-19 public health intervention” medRxiv* Servers and articles have been peer reviewed.

How they did it

In the San Francisco Bay Area, the Shelter-in-Place Order came into effect on March 16, 2020, and the Maskman Date took place on April 17, 2020. Researchers have collected information on aerial viruses in the surrounding area from January 2019 to December 2020. Compare the prevalence of respiratory viruses one year before and during a pandemic.

They examined 17 viral pathogens and 4 bacterial organisms using a respiratory pathogen panel assay (used to detect infectious respiratory viruses) from the Zuckerberg San Francisco General Hospital laboratory information system. .. Researchers analyzed the monthly trend of positive results for respiratory pathogens other than SARS-CoV-2.

Percentage of monthly positive respiratory pathogen tests in 2019 compared to 2020. The percentage of positive tests in 2019 and 2020 is shown monthly. Diagnosis of respiratory viral illness decreased significantly from March to April 2020, and from April to December 2020, the percentage of positive tests was consistent compared to the corresponding month in 2019. It became low. NS, not significant. *, P <0.05; **, P <0.01; ***, P <0.001; ****, p <0.0001. a Shelter-in-Place came into effect on March 16, 2020. b The Masking Ordinance came into effect on April 17, 2020.

Reduction of non-COVID respiratory infections

Researchers evaluated 1,484 tests in 2019 and 2,037 tests in 2020. The test was positive in the range of 13.6% to 39.1% for respiratory infections from January 2019 to March 2020.

April-December 2020 represents the period of the COVID-19 pandemic. For non-SARS-CoV-2 infections, respiratory infections decreased with a positive rate of 0 to 11.1%.

“The percentage of positive tests in January, February and March 2019 was not significantly different from the same month in 2020, but during the COVID-19 restriction period, from April to December 2020. The monthly percentage of positive tests is 2019, “the researchers write.

Human rhinovirus / enterovirus was detected most frequently of all respiratory viruses. Approximately 89.6% of positive respiratory infection test results were due to the human rhinovirus / enterovirus during the pandemic, which was 55% in 2019.

San Francisco data do not show cases of influenza during the 2020-2021 influenza season.

Research limits

Certain study restrictions may have affected the results. The study design included examining two years of data from a single medical system. This may not be translated into other regions with different levels of respiratory infections. There may also be other confusions that can affect results, such as adherence to human demographics and masking. Also, changing indoor policy restrictions in response to increasing cases and increased vaccinations can cause significant fluctuations in monthly respiratory infections.

People may have experienced respiratory infections like the flu, but they were too scared to seek medical care during a pandemic. “Nevertheless, focusing on inpatients who have been tested for respiratory infections rather than a large outpatient population can result from a work-up of mild, undifferentiated illnesses. You can reduce the variation in inspection methods. “

It is not yet definitive which policy or combination of policies was most effective in reducing the number of respiratory infections. Researchers conclude that finding the answer to this question may help shape public health strategies to reduce the transmission of respiratory droplets at home, in the public, or even at work.

*Important Notices

medRxiv Publish preliminary scientific reports that should not be considered definitive as they are not peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.