PONE-D-21-10066

Seasonal influenza during the COVID-19 pandemic in Bangladesh

PLOS ONE

Dear Dr. Akhtar,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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ACADEMIC EDITOR: Please see comments made by reviewers and provide point by point response in your revised manuscript

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We look forward to receiving your revised manuscript.

Kind regards,

Muhammad Adrish, MD, MBA, FCCP, FCCM

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: I Don't Know

Reviewer #3: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is a well written and timely report detailing reduced hospitalizations due to seasonal influenza during the COVID-19 pandemic in Bangladesh. The results are consistent with reports from other countries, and represent a valuable addition to this expanding literature. I have only one minor comment and suggestion for improvement. Since this study relied on data from a hospital based influenza surveillance system, it necessarily does not capture non-hospitalized influenza infections. Therefore, the epidemiologic picture of seasonal influenza presented is limited, and could be affected by unmeasured confounding variables, such as reduced diagnosis or hospitalization rates for severe influenza disease due to redirected public health resources. While this limitation does not invalidate this report, it should be discussed as a limitation in the Discussion section of the manuscript.

Reviewer #2: The study was considered not so satisfied in results which might be further explored and explained.

And when it comes to the question whether a statistical model could be applied to actual disease outbreak alarming, more data would be needed to do modeling.

Reviewer #3: The authors studied the changes in influenza epidemic patterns in Bangladesh during COVID-19 pandemic using hospital-based influenza surveillance data of Bangladesh from 2016-2020 and reported that 2020 influenza season was delayed and less intense than the previous years. I have some questions about data analysis.

How is the average curve calculated? Was a function in the R mem package used to align the curves of seasons 2016-2019 to generate the average curve? Why were the average seasonal thresholds of 2016-2019 used to identify the beginning, ending and intensity of 2020 influenza season instead of letting the data from 2020 determine the thresholds.

Please give the MEM results (refer to tables in references 14, 15) for each season separately.

Why is the last black point (2020 around weeks 40-45, y-axis is round 0.18) in Figure 2 black (epidemic) instead of blue (post-epidemic) since it is already lower than the post-threshold. Also shouldn’t the start of the epidemic be the first week where the rate is higher than pre-threshold? The black points or blue point (Figure 3) seem to start before the rate reaches pre-epidemic threshold.

Last sentence on pages 10-11: “MEM software defines the beginning and end of the epidemic periods as the times at which the rate of positive cases is higher than optimized seasonal data, ..” shouldn’t “optimizes seasonal data” be “pre-epidemic threshold”?

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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Seasonal influenza during the COVID-19 pandemic in Bangladesh

PONE-D-21-10066R1

Dear Dr. Akhtar,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Muhammad Adrish, MD, MBA, FCCP, FCCM

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

All comments have been addressed.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: (No Response)

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: (No Response)

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: (No Response)

Reviewer #3: No

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: (No Response)

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #3: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No