Does Urbanization Increase the Risk of Emerging Infectious Diseases in China? A Spatial Econometric Analysis

Round 1

Reviewer 1 Report

This study explored the relationship between urbanization and emerging infectious diseases (EID) in China, and found that the incidences of EIDs was associated with the degree of urbanization in cities. After a careful reading about this manuscript, I find several important issues related to the main idea of this study.

First, how did the authors ascertain urbanization could be the potential determinant of the increase of EID incidences? Is there any prior knowledge to support this pre-assumption? The association between urbanization and EID incidences cannot be identical to the corresponding causation. The authors need to clearly state it in Introduction section.

This study constructed an evaluation system of urbanization comprehensive index (UCI), which was applied as a control variable to explain EID incidences. However, the authors also selected income, education level, and other control variables. These variables look like part of the urbanization. I have no idea why the authors excluded them in the construction of UCI. In addition, why did the authors consider the incidence of tuberculosis as a control variable to explain the hepatitis, syphilis and gonorrhea incidences? It does not make any sense.

This paper includes a lot of meaningless content but lacks some necessary parts. For instance, there is no need to explicitly state the details of entropy method in Methodology section, whereas the necessary Discussion section was ignored in this paper. The authors used a large number of words to explain the association between urbanization and EID based on previous literature in Introduction section. This statement was too long and and the logic was not clear enough. Also, Figure 1 was not a necessary part in this paper.

Similar issue appeared in Methodology section as well. The authors should simplify the narrative of the methods and should not introduce too much about the commonly used methods. Table 2 can be removed since the authors did not interpret it at all in the main text.

There is no need to use three spatial weight matrix for the experiment. Just select one and implement the corresponding calculation.

Section 4.1 was badly stated. The authors did not interpret the result and thus Table 3 can be removed.

In section 4.2,  the ordinate titles of the subfigures can be changed to Global Moran's I.  The information summary of the results was not accurate and sufficient. The authors need to better interpret the similarities and differences of the autocorrelation of the three types of weights under different indicators.

The authors did not implement the thematic mapping canonically in Figures 4-7. The nine-dashed line was not complete. The scale unit is recommended to be changed to km. It is better to use two decimal places in the Legend of maps. The coefficients of various control variables in different regions can be expressed spatially, and the predicted incidences can be compared with the true ones to clarify the logic.

The entire Result section included a large number of Tables and was not friendly for the readers. The authors had not organized this section very well. In fact, the experimental results were not satisfactory. The fitting results were not significant, and the adjusted R2 of the model was too small.

The authors must reconduct the experiment and rewrite the Methodology, Result, Discussion sections before the paper is considered to be accepted for publication.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Does urbanization increase the risk of emerging infectious diseases in China? A spatial econometric analysis

Thanks for opportunity to review this paper. This is a very informative and insightful paper, which highlights keys area of public health, economic and population impacts of urbanization by identifying the gaps and indicative relationships for planning. The introduction and background is well research and conforms with available and known knowledge. Though it modelled within China it is generally applicable globally.

The in-depth analysis of social environmental, individual physical impacts and social services impacts of urbanization is well investigated and the analysis derived plausible. However, from reading the paper the correlation drawn between urbanization and contact between humans and wide life that is a potential source of zoonotic diseases is not clear to me.

Regarding the methodology and models applied, I’m limited in my understanding of the methods applied for the spatial autocorrection test, the econometric model and other metrices applied among others applied in the paper. It however appears very comprehensive leading to useful conclusions and recommendations.

This is a very academic paper for the research world though the discussions, analysis and conclusion made provide valuable data for public health practitioners, economists and social planners.  

The current significant impact of COVID-19 pandemic due to urbanization resulting from travel and migration is indicated in the paper, however the focus on hepatitis, tuberculosis and sexually transmitted diseases totally removes the spotlight from COVID-19. More data on COVID-19 and its relationship to urbanization would add more value and utility to this paper considering the current trajectory of the pandemic and its control and implications to global economy.

In the light of all the comments made, this is a great and informative paper, well-written in language and comprehension, of a greatly timely and relevant subject matter. The methodology looks detailed, and so are the discussions. The conclusions and recommendations are also well-grounded in the data provided.

I recommend this paper for publication without any need for modifications.

Author Response

Dear Reviewer,

Thank you very much for your affirmation and recognition of our study. Your recognition is the greatest encouragement to us.

Reviewer 3 Report

• I think it is strongly needed extensive manuscript revision.
• Authors need to meticulously review and refine inconsistent fonts or formula expressions. In equations (3)-(5), the meaning of the subscript it is not specified. I don't know whether Equation (8) is a general mathematical expression. In Equations (9) and (10), it seems appropriate to replace year i with year t. It is confusing because region i and year i are represented by the same subscript i.
• In Figure 1, it is not specified the definition of urbanization. As the author has mentioned in this manuscript, there are various kinds of urbanization. And it is not specified what kind of infectious diseases are indicated by the triangle. From Figure 1, the increase in infectious diseases due to urbanization is not clearly visible at all. 
• Figure 2 is written too carelessly. No meaningful information at all.
• The authors noted three influencing factors: Social environment effects, physical environment effects and social services effects. There doesn't seem to be any mention of how the introduced urbanization factors match each of the above three influence factors.
• In Table 3, can the minimum incidence of syphilis be negative? It is necessary to check the reliability of the data.
• The y-axis label in Figure 3 is not a matrix. It should be Morans‘s I.
• What scatter plot is described in lines 364-369? No related figures or data are specified at all.
• What does "+-" in Figure 4-7 mean? And there is no need to separately display the South China Sea as an inset box. There is absolutely no point in checking the color code in that area.
• In Table 5, the incidence of hepatitis was analyzed using two models, SLM and SEM. However, in Table 6, it is not known which model was used to analyze syphilis and gonorrhea incidence. It seems that only one model was analyzed. Furthermore, no SDM analysis results exist throughout the paper. But why did the authors introduce the SDM model in Equation 5?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have not addressed my concerns about the manuscript. It remains many issues required to be addressed. For instance, the sections of this revised manuscript are too trivial and confusing. Is it necessary to arrange the "Literature review" section separately?  The authors need to reduce the number of sections and avoid to use the headings of level 3 (e.g., 3.1.1). Moreover, The thematic mapping in Figures 2-5 is still not implemented properly. The nine-dashed line is still not complete. And the authors should state the units of UCI and incidences in maps or legends.

I feel quite confused about the revision. Are Table 2 and Figure 1 necessary to be presented? And the authors said they had selected one spatial weight matrix for the entire experiment.  Why did the other two appear in section 4.3? My previous comment suggested that the coefficients of various control variables in different regions can be expressed spatially and the predicted incidences can be compared with the true ones to clarify the logic. It is not difficult to be implemented and can be helpful for possibly new findings such as the regional variation of the incidence regressions. I have no idea why the authors chose to ignore it.

I still think the authors have not organized the entire Result section properly. Also, the added Discussion section is perfunctory.

The authors did not revise the paper carefully. For example,  the tuberculosis incidence  was removed from the control variables, but the main text has not been revised (e.g., lines 384-385, For control variables, the coefficients of tuberculosis incidence are significantly positive……).

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

It is judged that the author has raised the paper to a state where it can be published by faithfully responding to the comments of reviewers.

Author Response

Dear Professor, 

Thank you for your recognition of this article, and thanks again for your kind suggestions and comments.