PCSY-D-25-00082

Bifurcation, Sensitivity, and Noise: Stochastic Dynamics of Cholera with Vaccination and Sanitation Controls

PLOS Complex Systems

Dear Dr. Welu,

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Kind regards,

Joshua Kiddy K. Asamoah, PhD

Academic Editor

PLOS Complex Systems

Joshua Asamoah

Academic Editor

PLOS Complex Systems

Hocine Cherifi

Editor-in-Chief

PLOS Complex Systems

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Reviewers' Comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does this manuscript meet PLOS Complex Systems’s publication criteria ? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.-->?>

Reviewer #1: Yes

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

Reviewer #1: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)??>

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. 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

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

Reviewer #1: Yes

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Reviewer #1: Re-derive R₀ Cleanly

• Keep (A, I, B) or (A, I, T, B) as infected states.

• Use the same DFE (S₀, V₀) from your DFE theorem.

• Linearize the B equation correctly; write the environmental block as r − η − − ζ ..

• Report R₀ = R_hh + R_env with both parts dimensionally positive and discuss the case r > η + + ζ (environmental invasion).(environmental invasion).

Bifurcation Proofs

• For β ₁: perform center-manifold analysis at R₀ = 1, compute coefficients (a, b), and show subcritical (backward) behavior under explicit parameter conditions.₁: perform center-manifold analysis at R₀ = 1, compute coefficients (a, b), and show subcritical (backward) behavior under explicit parameter conditions.

• For β ₂: carry out an analogous analysis and demonstrate supercritical (forward) bifurcation.₂: carry out an analogous analysis and demonstrate supercritical (forward) bifurcation.

• Add a 2-parameter continuation plot (AUTO or MATCONT) showing stability of branches.

Stochastic Section

• Define noise structure explicitly (is σ eX dWe multiplicative in which states?).ₓX dWₜ multiplicative in which states?).

• Replace 'R₀ˢ' with invasion probability and/or the top Lyapunov exponent of the linearized SDE; present Monte Carlo estimates with confidence intervals.

• For '30% greater dispersion' claims, provide the actual statistic (ΔIQR or coefficient of variation) at day t, with sample size n, seed, and CI.

Sensitivity Analysis

• Specify parameter priors and sampling design (LHS size, distributions, correlations).

• Include barplots with error bars; report both first-order (Sᵢ) and total-order (S_Tᵢ) sensitivity indices.

• If claiming 'log-sensitivity of B to ζ implies 15–20% more effort,' include the elasticity curve and relate elasticity to program coverage targets.implies 15–20% more effort,' include the elasticity curve and relate elasticity to program coverage targets.

Figures & Code

• Include all referenced figures (axes, legends, parameter values) for transparency.

• Archive MATLAB scripts (RK4, Euler-Maruyama, continuation routines) with a README for reproducibility.

Sample Abstract Rewrite

We develop a cholera model (SVAITRS-B) that links vaccination with waning protection, asymptomatic carriage, treatment failure, and an explicit environmental reservoir. Using a next-generation approach at the disease-free equilibrium (DFE) that retains vaccination coupling, we decompose the basic reproduction number R₀ into human-to-human and environmental components. Center-manifold analysis shows a backward bifurcation when varying the person-to-person transmission rate β ₁ under specific parameter constraints, whereas varying the environmental transmission rate ₁ under specific parameter constraints, whereas varying the environmental transmission rate β ₂ yields a forward (transcritical) bifurcation. Stochastic simulations with multiplicative noise highlight greater outbreak variability in the human transmission pathway than in the environmental pathway, while the latter governs long-run persistence. Global and local sensitivity analyses identify ₂ yields a forward (transcritical) bifurcation. Stochastic simulations with multiplicative noise highlight greater outbreak variability in the human transmission pathway than in the environmental pathway, while the latter governs long-run persistence. Global and local sensitivity analyses identify β ₁, ₁, β ₂, ₂, γ e, and ᵢ, and ζ as key levers. We provide code and parameter priors to support reproducibility and policy exploration.as key levers. We provide code and parameter priors to support reproducibility and policy exploration.

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what does this mean? ). If published, this will include your full peer review and any attached files.). If published, this will include your full peer review and any attached files.

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Reviewer #1: No

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Figure resubmission:

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Attachments

Attachment

Submitted filename: Peer_Review_Cholera_Model_PC_SY.docx

Bifurcation, Sensitivity, and Noise: Stochastic Dynamics of Cholera with Vaccination and Sanitation Controls

PCSY-D-25-00082R1

Dear Dr. Welu,

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,

Emma Faid

Staff Admin

PLOS Complex Systems

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

Reviewer #1: All comments have been addressed

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publication criteria ? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.-->?>

Reviewer #1: Yes

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

Reviewer #1: N/A

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4. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)??>

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. 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: Yes

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

PLOS Complex Systems 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

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Reviewer #1: (No Response)

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what does this mean? ). If published, this will include your full peer review and any attached files.). If published, this will include your full peer review and any attached files.

Do you want your identity to be public for this peer review? If you choose “no”, your identity will remain anonymous but your review may still be made public. If you choose “no”, your identity will remain anonymous but your review may still be made public.

For information about this choice, including consent withdrawal, please see our Privacy Policy .-->

Reviewer #1: Yes: Oludoun Yetunde Olajumoke

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