The Association between Hydro-Meteorological Events and Leptospirosis Hospitalizations in Santa Catarina, Brazil
Round 1
Reviewer 1 Report
Very well written and with a solid research design. The results are clear and an interesting addition to the literature.
I would, however, include an additional paragraph, ideally in the introduction, where information in relation to literature that addressed the determinants of leptospirosis, especially in the case study area, should be discussed. Without it, the discussion that follows does not seem to be based on solid evidence of 'what is expected' in similar and comparable cases.
Otherwise a very good pice of research.
Author Response
Reviewer 1:
Very well written and with a solid research design. The results are clear and an interesting addition to the literature.
I would, however, include an additional paragraph, ideally in the introduction, where information in relation to literature that addressed the determinants of leptospirosis, especially in the case study area, should be discussed. Without it, the discussion that follows does not seem to be based on solid evidence of 'what is expected' in similar and comparable cases.
Otherwise a very good piece of research.
ANSWER: We would like to thank the reviewer for his/her positive feedback on our research paper. We believe that the comments contributed to the overall improvement of the paper’s quality.
A paragraph was introduced in the introduction to add in-depth information in relation to literature that addresses the determinants of leptospirosis.
Author Response File: 
Author Response.docx
Reviewer 2 Report
I have several comments, some are minor and others are major:
In the title, instead of "Br" I feel the need to use "Brazil."
On page 1, line number 39: the statement that the floods being the main cause of death among the environmental disasters may not be correct.
Leptospirosis is an occupational diseases. Authors need to explain how the disease is associated with four types of flooding considered in this study.
On page 3, line number 108: What is the difference between floods and flooding?
Provide description of the study area, particularly about the amount of annual and monthly rainfall. It seems that flash floods occur to many times in a year in the study area. It must have relationships between amount of rainfall, topographic conditions, and distance to the sea. Also, provide the demographic characteristics of the study area..
Figure 2: Hospitalization rates are not readable. Also, there is a need to define the term.
Author Response
Reviewer 2:
ANSWER: We would like to thank the reviewer for his/her comments and suggestions which we believe have contributed for the improvement of the paper.
1. In the title, instead of "Br" I feel the need to use "Brazil."
ANSWER: Changed accordingly.
2. On page 1, line number 39: the statement that the floods being the main cause of death among the environmental disasters may not be correct.
ANSWER: We agree with the reviewer. This was changed in the text.
3. Leptospirosis is an occupational diseases. Authors need to explain how the disease is associated with four types of flooding considered in this study.
ANSWER: Information on how Leptospirosis is associated to the occurrence of flooding was added in the introduction. This comment was also made by reviewer 1.
4. On page 3, line number 108: What is the difference between floods and flooding?
ANSWER: We agree with the reviewer that this sentence is not clear. A sentence was added to clarify each term:
“The HE were divided into four classes of occurrence: 1] flash floods, 2] floods, 3] flooding and 4] cumulative HE (summed occurrence of any type of flash floods, floods and flooding), which were attributed to each different macro-region. The SDC/SC identifies as floods the overflow of the waters of a watercourse (e.g. river flood; maritime flood; dam breakage’s flood). Flash floods are floods which are highly concentrated and energetic floods which produce surface runoff that results from intense or extreme rainfall events. Finally, flooding results on the momentary accumulation of water in certain locations by deficiency in the drainage system, covering a small part of the plain.”
5. Provide description of the study area, particularly about the amount of annual and monthly rainfall. It seems that flash floods occur to many times in a year in the study area. It must have relationships between amount of rainfall, topographic conditions, and distance to the sea. Also, provide the demographic characteristics of the study area.
ANSWER: We partially agree with the reviewer and some more information on precipitation records on SC was added, with an additional paragraph and figure on precipitation being added (new Figure 2).
“The eastern part of SC state has three large topographic units: the Coastal Plains, the Coastal Sierras and the Western Plateau, with very different altitudes and topographic characteristics, namely 1) 77% of its territory is above 300m of altitude; 2) 56.22% of the area is covered by plateaus between 300m and 900m; and 3) 20.45% are mountains higher than 900m. To the west we have the region known as Plateau Catarinense, where altitudes vary between 700 and 1800m. The Coastal Plains are in direct contact with the Atlantic Ocean, the Sierras are arranged obliquely to the shoreline and the Plateau constitutes the most continental and extensive unit of the territory of Santa Catarina [34]”
Figure 2: Accumulated monthly precipitation in the State of Santa Catarina between the years 2005 to 2014.
Some considerations on general characteristics of SC were already included in the text, namely:
“This study was conducted for the State of Santa Catarina [SC] which is located in the southern region of Brazil [Figure 1, top left panel]. Santa Catarina has an area of 95736.165 km², with an estimated population of 6 767 148 inhabitants [32] and with a Human Development Index-HDI of 0.84, being considered as the best ranked State in Brazil, with 27 cities among the 100 with higher quality of life in the country.
The study area is located at an intersection of many routes, that connects the different parts of the country and Latin America, strengthening its positioning as a socioeconomic development pole, supported by the agriculture and industry sectors. SC state has its largest population contingent located in the coastal region [54.5%] where the higher urbanization rates are present and, consequently, a greater coverage of water supply. Potable water reaches 85.6% in the state, but basic sanitation does not exceed 15.5% of wastewater and sewage treated in the state [33], which has one of the lowest rates of sewage treatment in Brazil. Santa Catarina’s coastal region is located in an area of low elevation, while the inland is dominated by plateau areas with altitudes reaching 1755 meters. Moreover, the coastal area is dominated by the estuaries of SC’s main rivers [Figure 1, low panel].”
Author Response File: Author Response.docx
Reviewer 3 Report
1 Revise abstract minor spelling
2 Introduction: This section should be more concise and relevant.
3 Figure is unclear.
4 discussion contains figures
5 Section Discussion: This section is poorly written. More efforts should be put on the explanation for why the results occurred, instead of just comparing with others' results.
Author Response
Reviewer 3:
1 Revise abstract minor spelling
ANSWER: The abstract was reviewed.
2 Introduction: This section should be more concise and relevant.
ANSWER: The introduction was changed to accommodate all the three reviewers’ comments, namely, to describe the determinants of leptospirosis, especially in the case study area. Some redundant sentences were deleted to make the introduction clearer and more to the point.
3 Figure is unclear.
ANSWER: We assume that the reviewer refers to the old figure 2, which was changed.
4 discussion contains figures
ANSWER: We thank the reviewer for pointing that out. The figure and corresponding text were changed to the results section.
5 Section Discussion: This section is poorly written. More efforts should be put on the explanation for why the results occurred, instead of just comparing with others' results.
ANSWER: We agree with the reviewer. The most important facts which we think contributed to the occurrence of the association between hospitalization by Leptospirosis and the occurrence of floods/flooding/flash floods were highlighted, namely:
· The highest mean precipitation indexes for SC were observed in January predominantly which favored occurrence of extreme events related to a large volume of precipitation in a short time
· The maximum rates of hospitalization for Leptospirosis were identified in the months and/or subsequent month in which there were the highest number of current HE events, which is related Leptospirosis incubation period, which varies from 2 to 30 days, with an average of 7–10 days.
· The coastal macro-regions of health present the highest rates of hospitalization, which might be associated with the fact that there are more people living there and that the coastal areas have been affected by a higher number of hydrological events (than inland areas) because of its geographical constrains. The coastal areas are dominated by the estuaries of SC’s main rivers and located in an area of low elevation, while the inland is dominated by plateau areas. Thus, when coastal areas are prone to suffer more hydrological event than inland areas.
Nevertheless, we would like to emphasize that the focus of this article was not set on explaining why correlations happen in the way they happen. Although we argue some hypothesis on the discussion, to correctly respond to that question a very different approach should have been adopted
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I revised version of the manuscript is much improved than the earlier version. I am in favor of its acceptance.
