Bone and Joint Infections in Children and Adolescents in Luanda, Angola

Round 1

Reviewer 1 Report

The study represents an assessment of the disease and therapy situation in a country that has a lower medical standard than usual in Europe and the USA. The author presents this fact and openly limits the informative value of the study.

The following points of criticism and suggestion are to be understood in this context.

S1. Line 38 Please explain which parameters made a patient a suspected case

S2 line 43 which diagnostic procedure was used here?

S2 line 46 how was the end of the illness defined?

S2 line 48 According to which criteria was malnutrition recorded?

S2 line 50 Concerning the statement of the general condition: is that a rough estimate?

S2 line 58 how was traction exercised? Table 1 differentiates between traction and surgical measures. Please explain the difference

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for the opportunity to read this article, the topic is very
important and indicates the need for screening diagnostics in children.
A short blood test can speed up diagnosis and reduce treatment costs.

However, for the article to be published, even as a short report, it
requires some corrections.

Introduction

There is no precise definition of how large a group of children is
associated with SCD, which is the primary differential screening
diagnosis. What are the risk factors for SCD and the most common
complications?

Without the purpose of work

Materials and methods

No information available on the number of children whose data has been
assessed

No information about the reason for the child's hospitalization (main
disease entity)

The authors of the study compared children from a huge, very diverse age
range. Children 0-15 years old differ significantly from each other -
both in terms of bone structure and mental development.

The chapter lacks information about the study group - the
characteristics of the study group, partial information appears in the
chapter results - average age, (line 43-48)….

The authors in the chapter write about the comparison of children with
and without SCD, but they nowhere indicate what values ​​will be compared

Results

Results mixed with the description of the test material, unclear. In the
previous chapter, the authors indicate that they compared two groups of
children - they do not, however, present the results of statistical
significance, but only rather vague numerical and percentage results.

The chapter requires significant corrections

Discussion

In short, it says nothing at all.

No conclusions

WORK NEEDS SIGNIFICANT CHANGES

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

First of all, I would like to congratulate the authors for this study, but I would like to suggest some changes.

In the Introduction section, the authors could better explain the definition and diagnosis of sickle cell disease, including the usual clinical, laboratory and radiographic findings and the prevalence according to age, sex and race.

Regarding the materials and methods, the authors must include which statistical analyzes were used for this study and which findings were compared in each analysis. It is also important to include in this section the details of each group (“n” and all the findings used for comparison).

Next, I suggest that the authors reorganize the results section, separating the results of each group and each analysis. I also suggest redoing table 1.

In the discussion, the authors explained the study's limitations well, but hoped to find a better discussion regarding the results found between the groups (SCD vs. non-SCD), exploring the differences.

This is an interesting article, but it needs to be improved before publishing, I suggest  also including more recent articles in the references.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

In the abstract, the authors stated they compared the prognosis of osteomyelitis in children with and without sickle-cell disease. The authors also clearly stated the limitations of their study, which are understandable.

However, what is lacking in my point of view is a clear structure of the report. If the aim was to compare the prognosis of osteomyelitis in children with and without sickle-cell disease then the results and discussion, do not reflect this aim. However, it is also unclear what the aim of the study was to begin with, as in the abstract it seems the prognosis of osteomyelitis was the aim, however, in the introduction it is stated that so far, few studies have looked into efficacy and safety of antibiotic treatment in SCD patients. Neither of which is looked at in more detail during results and discussion.  

I am further lacking a clear presentation, discussion and most importantly conclusion of their findings. It seems that the main finding was that patients suffering from SCD required blood transfusions more often, but also probably presented with lower hemoglobin levels to begin with. If and how that is associated with osteomyelitis or the use of antibiotics rather than the sickle cell anemia remains unclear.

The authors also state that they have started doing PCR analysis and bacteriology samples, adding those could greatly increase the value and output of this study.

Author Response

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Round 2

Reviewer 2 Report

The authors considered only some of my suggestions in relation to the original version of the presented case report.

 Unfortunately, the age range of the described children is still very wide and extremely diverse in terms of physiological developmental features

I am asking for justification of such a large age range of the examined children, whether children over 10 years of age should be rejected (before the onset of puberty).

Is the age difference not statistically significant when comparing ?

How is the age distribution in each group?

Why is the standard deviation for age higher than the age itself ? (Table 1), Similarly, in the case of History in days in both groups, the average number of days is smaller than SD ?

In the description of the group, the authors indicate the group of children 1 month -13 years (line 52), and at the beginning of the chapter (line44), the age is defined as 0-15 years

The work requires corrections in the Materials section

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Once again I would like to congrats the authors for this study, but still need to be improved before publish.

The authors still need to improve introduction section and explain better the aim of the study.

The authors still need to clarify and explain better the materials/methods and results, specially regarding the statistical analyzes.

The discussion remains with lack of explainations regarding the findings  and aim of the study.

The paper still have major issues regarding the design of study and results.

The authors need to clarify the aim of the study, which statistical analyzes were used and still need to improve the discussion section.

Regarding the results, in the line 79-80 the authors said: "SCD was screened in 60 %(27/45) of patients and the disease was found in 51%(23/45) of the whole series."

If they screened only 60% of the "n" (27 patients), the second part of this sentence is wrong because the authors included  for this analysis 40% of patients without test for SCD.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

I would like to start out by thanking the authors for dealing with this important subject. 

However, I am still lacking improvements to my original suggestions. 

I can see, the authors have added some points to the introduction, thank you for that and also for adding a clearer stated aim at the end of the introduction, nevertheless I still think the introduction could be improved by a better structure and additional information that better lead to this aim.

I further think, regarding the methods the author should add more detail, especially about their statistics (Which tests were used etc).

Regarding the results, I think the authors should improve this section, by also making it more clear what the actual results were and by better pointing out their findings.

Lastly, the discussion very nicely discusses the limitations of the study, with a lot of them being understandable, what is still missing though is the discussion of the actual results. For example, the authors state “In conclusion, bone and joint infections in Luanda, Angola are severe diseases with high rate of complications and sequelae.” as one of their main findings, but to my understanding from their introduction, this is more part of the reason why they started this study and less a result of their own study. The second conclusion they draw is “Large proportion of patients also suffer from SCD and require blood transfusion during hospitalization.” However, the aim of the study was to “characterize the features of osteomyelitis in a sub-Saharan African 42 setting in Luanda, Angola, with special emphasis on the effect of SCD.” an aim that is completly left out during most parts of the manuscript.  

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

I would like to congratulate the authors for the study, after some revisions and despite some limitations, the authors managed to carry out a great study.

Author Response

We thank the reviewer for his/her valuable work.

Reviewer 4 Report

I am sorry, but as mentioned in the earlier revisions I am still unsure about the aim of the study.

The authors keep adding factors to the introduction (now osteonecrosis and bone infarction) but the aim ist still unclear:

You are dealing with

1. Osteomyelitis in general without involvement of SCD
2. Osteomyelitis as a complication of SCD
3. Vaso-occlusive crisis as a osteoarticular complication of SCD
4. Osteonecrosis/bone infaction as a complication of SCD

Maybe I am completely mistaken but: I understand that the factors mentioned above are not always easily distinguishable and that, especially as patients present themselves very late to a hospital and the diagnosis, especially in the presented setting, and thus finding the best treatment is not too easy. However, treatment should still start in a timely manner. These factors are the reason why your study is important. 

But my question remains: what is your aim of the study? Point out there is a problem? Find the best treatment? Find out the prevalence of each of these factors?

If I am mistaken, please excuse me, but I do find it very hard to find a clear aim and purpose of the study throughout the manuscript. In the introduction you say your aim was to characterize the features of osteomyelitis in a sub-Saharan setting with a special emphasis on SCD.

However, while the results still focus on the characterization of these patients, the discussion is only partially focusing on the results. Nonetheless, a clear-cut conclusion is still lacking as in your conclusion you only state what you basically already talked about in the introduction without including your own results.

Is your conclusion that it is indeed very hard to distinguish the cause for bone and joint infections from each other and thus it is hard to find the correct treatment? If so: what do you propose as a possible solution? The difficulty itself cannot be your conclusion as it is the reason you started the study in the first place.

Or is your aim to not find a treatment strategy but to actually “just” characterize bone and joint infections in the population in order to get an idea about the underlying reasons (so rather a descriptive study), then please state this as your research aim and write your introduction and discussion accordingly. If this is your goal then you need to analyse e.g. whether the symptoms a patients presents him/herself can predict the diagnosis and thus which treatment would be best. Or if you can predict the best possible treatment from the presented symptoms. etc. However, in this case a student’s t test for statistical analysis is not sufficient.

Again, I understand the limitations and problems you are faced with during your study, and I understand its importance. However, the manuscrip can still be improved with the data you have and it should be improved for publication.  

Author Response

Thank you for your comments.

Point-by-point answers have been enclosed

Author Response File: Author Response.pdf

Round 4

Reviewer 4 Report

Thank you for adressing the suggestions and revising the manuscript.