Wastewater-Based Epidemiology of SARS-CoV-2 RNA in Bethlehem, PA and Lehigh University

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

The presentation is generally well done, but the introduction includes some unnecessary information. While many aspects are well established—such as the presence of SARS-CoV in various body fluids and its association with wastewater surveillance (WWS)—the authors could have gone directly into discussing WWS, its importance, and why they conducted the study at their specific site. However, it's ultimately their paper and their choice of presentation style.

 

 

The discussion section could be improved by addressing why different assays targeting different genes resulted in varying detection frequencies, with a comparison to earlier studies. They report data from municipal wastewater and a university area, but it would be beneficial to compare these sites and discuss the advantages and disadvantages of monitoring large versus small catchment areas.

 

 

Line 1: Title: there is no consensus on the wording but still for consistency throughout the manuscript would be great to have wastewater surveillance

Line 10: Regarding healthcare access and status of health (i.e. symptomatic and asymptomatic)

Line 21: what is the correlation coefficient without normalization then?

Line 32: what was you time of this data (date, month, and year)

Lines 34-37: I think so huge data about unemployment may be not needed, you said already the outbreak hit the economy, which might be enough.

Line 69: please regarding WBE  lets be consistent with WWS as done in the opening sentences in abstract.

Line 76: you may support your claim with references: eg. https://doi.org/10.1016/j.watres.2021.117438, https://doi.org/10.1016/j.envpol.2023.122471.

Line 78-79: you claimed throughout the world recommended representing all major continents with both original and systematic review papers, you can go to your reference lists and you could cite papers from there or if you like you can get other references here e.g. https://doi.org/10.1016/j.envpol.2023.122471, https://doi.org/10.3390/w15061018 , https://doi.org/10.1016/j.scitotenv.2024.171877, https://doi.org/10.1016/j.scitotenv.2020.138764, https://doi.org/10.1016/j.scitotenv.2020.140405, https://doi.org/10.1016/j.watres.2020.116296, https://doi.org/10.1016/j.watres.2022.118220

Lines 90-95- could be more information about your campus, was there an outbreak, does it have student housing, or what are the sources of SARS-CoV to your WW samples

Table 2: why black for gene name and targeted gene of PMMoV, if not available you could write “–“

Figures 5-9: if you normalize with PMMoV concentration might be no unit in y axis. Were all these SARS-CoV reported were used for N1 assay. What about figures of N2 and E assays you mentioned earlier-

Discussion is lacking about vaccination during the sampling period and possible variation on the shedding rate of virus from infected people. you can see following literature how shedding rate, and variation on sewage network could affect surveillance data. https://doi.org/10.1016/j.scitotenv.2024.173862

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors report in this manuscript a case study of wastewater-based epidemiology of SARS-CoV-2. The manuscript is well written and can be published with minor revisions.

 

1) In the materials and method section, use mm (instead of inch) as a unit when the authors wrote in the manuscript “a maximum of 1.33 inches of precipitation in the 24 h prior to wastewater sampling”. In addition, in table 1, use m3/d instead of MGD for the flow rate. Use mg/L as a nit for concentration.

 

2) The authors show the general water quality in Figure 4, although they do not show the origin (or measurement methods) of the data in the manuscript. Please mention the origin of the data in the materials and method section. In addition, explain what is cBOD and measurement method for that.

 

3) In figure 5 - 9, “GC/L / deviation” induces misunderstandings, because the readers cannot understand GC means gene copies and the readers cannot understand “/ deviation” means “divided by the deviation factor as defined by equation 2”. Consider revisions for the legends in these figures.

 

4) Lines 610-620, do not forget to use superscripts for 103, 104 and so on. The same problem can also be found elsewhere.

 

5) In the last part of “4. Discussion”, the authors mentioned “The use of PMMoV as an internal reference virus was found to be an effective normalization biomarker to account for changes among the sewershed population throughout the wastewater sampling period.”, although no data are shown in the main manuscript for this statement. No figures and tables were provided as to the correlation of concentrations between PMMoV and SARS-CoV-2. Add some explanations in the main text or move some contents as to the correlation from the discussion section to the introduction section.

 

6) In figure 2 and figure 3, it is preferable to show the plots below detection limits. For example, the results below detection limits can be shown with plots at the lowest positions (The replacement of “1.E+0” with “Below detection limits” is needed for y-ax in this case).

 

Comments on the Quality of English Language

The reviewer does not find fatal problems in the language.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf