How can tuna/bonito be tested for histamine? I think I suffered scombroid food poisoning, together with some other people. I actually got the worst of it. The others experienced pain in the mouth. I had facial flushing and tachycardia as well.

This is not the first time this happens as we've experienced pain from both tuna and bonito. Both cooked and raw (tartar).

According to the Wikipedia, this can be due to inappropriate handling of the fish. I bought this last bonito from a fish shop five minutes walking away. I guess it's hardly likely that the error was on me, but I won't rule it out neither. My handling of the bonito was to cut it up, put it into a vacuum bag and freeze. The batch that made us ill was vacuum and unfrozen. I've got more tuna from the same batch in the freezer, so I'll have to throw that out. That's one shop where I'm not buying anymore.

Is there a way of testing for histamine to prevent future problems?
If you say that your handling of the fish was a 5 minute walk and to cut it up and freeze it, it is more than likely that the contamination occurred during the supply chain. Once the enzyme histidine decarboxylase has been formed, it can continue to produce histamine in the fish even if the bacteria are not active.

There are test kits available for checking histamine levels but they are intended for commercial use. http://www.noackgroup.com/Live/ProductCatalog_en.YoCms?GROUP=%24D_FAA_07_01#_1NEO9505 is one of the places that has them.