Histamine
Bacteria present on some fish species, such as tuna, sardines, mackerel, swordfish and marlin
can convert the naturally occurring amino acid histidine in the fish into histamine. This may
lead to histamine food poisoning (or Scromboid poisoning).The presence of histamine is
normally an indicator of a failure in the cold chain and that the fish has been subject to
elevated temperatures.
The low prevalence and low levels of histamine detected in this survey tends to indicate good
temperature control of the fish used in the manufacture of sushi. A similar survey conducted
by ACT Health in 1997 found a similar prevalence, with a single sample of tuna from 29 fresh
fish samples containing detectable level of histamine.