The latest GBD incidence,prevalence paper (Lancet 2018:392:1789-1858 - on my RG site) has global absolute incidence (2017) and prevalence (2017) with a category "diarrheal diseases".(Table 1) These are 6.92 billion (incidence) and 93.5 million(prevalence)

By dividing by total world population in the study (say about about 7 billion) one could estimate incidence of about 1 episode per person per year.

I believe more detailed country, disease and population data is available in GBD supplements and appendices available on line. Then you can use incidence rates per population to estimate episodes per person per year in sub groups..

Thank you so much for your quick response...so essentially I need to divide the age specific absolute incidence (number of cases) by age specific population of each country to get the number of episodes per person per year? if so thank you so much Prof. Leigh

Maybe it is not big difference, but I read that WHO recommend using ''prevalence'' rather than incidence in the GBD study. Since diarrhea is accute conditions, it doesn't change estimates.

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