Hi Margareth, sorry for the late reply. CC'ing DSpace Technical Support list as discussed, so others can offer their ideas / learn from this.
There are a few ways the bitstream count can get up, from my experience...
There are some basic reasons like
* The bitstream URL has been indexed directly in a search engine like Google, and people are visiting the PDF (for example) straight from there
* The item has multiple bitstreams, and a visitor could be downloading each of them from the item page without refreshing the item page and generating a new 'hit'
* The item has one bitstream, but a visitor is downloading it multiple times from the item page -- sometimes people will do this accidentally, or a proxy server will cause a re-download, or a spider will get stuck and start downloading things too many times, or a visitor is viewing the PDF in the browser, and hits 'refresh', etc...
And then there's one other possible tip that I discovered while i was investigating a similar issue -- if you have Apache or nginx (or similar) webserver in front of your DSpace instance, and a visitor's browser or PDF viewer "streams" the PDF instead of doing a straight download (this is particularly true of browsers with PDF viewer plugins that will display the retrieved document inline) then it can end up looking like lots and lots of GET requests (with 206 responses instead of 200). I don't *think* this results in additional DSpace statistics 'hits', but it certainly can show up in some basic HTTP log statistics when looking at downloads, so I thought it was worth mentioning just in case.
Hope this helps! Anyone else had similar situations where they could track down the explanation?
Cheers
Kim