Reviewer's report 
 Epidemic infectious gastrointestinal illness aboard U.S. Navy ships deployed to the Middle Title: 
East during peacetime operations - 2000-2001. 
 1  15 November 2005 Version: Date: 
 Ben Lopman Reviewer: 
Reviewer's report: 
General 
This draft is a substantial improvement from the previous version I reviewed a few months earlier. 
However, I still have a few reservations that I think the author's may want to address. 
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Major Compulsory Revisions (that the author must respond to before a decision on publication can be reached) 
Abstract - The authors should be careful about referring to this paper as a cohort study. It certainly is 
not a traditional cohort, and if refereed to as a cohort, this should be fully explained as in the text. 
Introduction - As above 
Results - What is the sensitivity of the results (oubbreak incidence) to the threshold level? What is 1 
or 3 standard deviations were used rather than the 95% CI? 
What was the rate ratio comparing outbreak rates in the large:small ships? 
State which statistical test was using in the Poisson models: Likelihood ratio or Wald? 
End of para 2: Jan and May had the most number of outbreaks. What about outbreak rates? 
Discussion - Para 1. I dont think that the evidence is sufficient that the observed decrease in 
recorded outbreaks was due to a public health reponse. Outbreak control remains crude and of 
unproven effectivness. 
If I understand correctly, the methods used in this study meant that the duration of an outbreak 
would be at least 3 weeks - outbreak week(s) + run in week + run out week. The authors need to 
make this limitaion more clear and perhaps exclude the duration of outbreak from the main results 
(in the abstract) It is not enough to say that viral outbreaks are typically of longer duration - this just re-iterates the biases in most surveillance that smaller outbreaks are not captured and therefore 
gives us a skewed understanding of outbreak dynamics. My personal experience in a healthcare 
setting was that when a sensitive outbreak definition was used, many more small outbreaks of viral cause were detected. 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests' 
Reviewer's report 
 Epidemic infectious gastrointestinal illness aboard U.S. Navy ships deployed to the Middle Title: 
East during peacetime operations - 2000-2001. 
 1  15 November 2005 Version: Date: 
 Ben Lopman Reviewer: 
Reviewer's report: 
General 
This draft is a substantial improvement from the previous version I reviewed a few months earlier. 
However, I still have a few reservations that I think the author's may want to address. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can be reached) 
Abstract - The authors should be careful about referring to this paper as a cohort study. It certainly is 
not a traditional cohort, and if refereed to as a cohort, this should be fully explained as in the text. 
Introduction - As above 
Results - What is the sensitivity of the results (oubbreak incidence) to the threshold level? What is 1 
or 3 standard deviations were used rather than the 95% CI? 
What was the rate ratio comparing outbreak rates in the large:small ships? 
State which statistical test was using in the Poisson models: Likelihood ratio or Wald? 
End of para 2: Jan and May had the most number of outbreaks. What about outbreak rates? 
Discussion - Para 1. I dont think that the evidence is sufficient that the observed decrease in 
recorded outbreaks was due to a public health reponse. Outbreak control remains crude and of 
unproven effectivness. 
If I understand correctly, the methods used in this study meant that the duration of an outbreak 
would be at least 3 weeks - outbreak week(s) + run in week + run out week. The authors need to 
make this limitaion more clear and perhaps exclude the duration of outbreak from the main results 
(in the abstract) It is not enough to say that viral outbreaks are typically of longer duration - this just re-iterates the biases in most surveillance that smaller outbreaks are not captured and therefore 
gives us a skewed understanding of outbreak dynamics. My personal experience in a healthcare 
setting was that when a sensitive outbreak definition was used, many more small outbreaks of viral cause were detected. 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests' 
Please review this paper.
user
Reviewer's report 
 Epidemic infectious gastrointestinal illness aboard U.S. Navy ships deployed to the Middle Title: 
East during peacetime operations - 2000-2001. 
 1  15 November 2005 Version: Date: 
 Ben Lopman Reviewer: 
Reviewer's report: 
General 
This draft is a substantial improvement from the previous version I reviewed a few months earlier. 
However, I still have a few reservations that I think the author's may want to address. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can be reached) 
Abstract - The authors should be careful about referring to this paper as a cohort study. It certainly is 
not a traditional cohort, and if refereed to as a cohort, this should be fully explained as in the text. 
Introduction - As above 
Results - What is the sensitivity of the results (oubbreak incidence) to the threshold level? What is 1 
or 3 standard deviations were used rather than the 95% CI? 
What was the rate ratio comparing outbreak rates in the large:small ships? 
State which statistical test was using in the Poisson models: Likelihood ratio or Wald? 
End of para 2: Jan and May had the most number of outbreaks. What about outbreak rates? 
Discussion - Para 1. I dont think that the evidence is sufficient that the observed decrease in 
recorded outbreaks was due to a public health reponse. Outbreak control remains crude and of 
unproven effectivness. 
If I understand correctly, the methods used in this study meant that the duration of an outbreak 
would be at least 3 weeks - outbreak week(s) + run in week + run out week. The authors need to 
make this limitaion more clear and perhaps exclude the duration of outbreak from the main results 
(in the abstract) It is not enough to say that viral outbreaks are typically of longer duration - this just re-iterates the biases in most surveillance that smaller outbreaks are not captured and therefore 
gives us a skewed understanding of outbreak dynamics. My personal experience in a healthcare 
setting was that when a sensitive outbreak definition was used, many more small outbreaks of viral cause were detected. 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) 
------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
I declare that I have no competing interests' 
assistant