less acutely toxic, but potentially carcinogenic, dianthraquinones such as
luteoskyrin.
8.4.4 Mycotoxins ofFusarium
Some species ofFusariumcause economically devastating diseases of
crop plants such as wilts, blights, root rots and cankers, and may also be
involved in the post-harvest spoilage of crops in storage. The genus is
also associated with the production of a large number of chemically
diverse mycotoxins both in the field and in storage.
8.4.4.1 Alimentary Toxic Aleukia. Outbreaks of this dreadful disease,
which is also known as septic angina and acute myelotoxicosis, occurred
during famine conditions in a large area of Russia. A particularly severe
outbreak occurred during the period 1942–47 but there had been reports
of the disease in Russia since the 19th century.
Studies in Russia itself demonstrated that the disease was associated
with the consumption of cereals moulded byFusarium sporotrichioides
andF. poaebut the nature of the toxin remained unknown. Studies of
dermonecrosis in cattle in the United States showed it to be caused by a
Fusariummetabolite called T-2 toxin (Figure 8.15) which is one of the
most acutely toxic of a family of compounds called trichothecenes.
There is good evidence that T-2 toxin was a major agent in the
development of alimentary toxic aleukia in humans, the first symptoms
of which are associated with damage of the mucosal membranes of
mouth, throat and stomach followed by inflammation of the intestinal
mucosa. Bleeding, vomiting and diarrhoea, which are all associated with
damage of mucosal membrane systems, were common but recovery at
this stage was possible if the patient was given a healthy, uncontami-
nated, vitamin-rich diet. Continued exposure to the toxin, however, led
to damage of the bone marrow and the haematopoietic system followed
by anaemia and a decrease in erythrocyte and platelet counts. The
occurrence of necrotic tissue and skin haemorrhages were further char-
acteristics of the disease.
As well as giving rise to this sequence of acute symptoms, the
trichothecenes are known to be immunosuppressive and this undoubt-
edly contributed to victims’ sensitivity to relatively trivial infectious
agents. Indeed, many people died of bacterial and viral infections before
succumbing from the direct effects of the toxin itself. Unlike aflatoxin,
the acute toxicity of T-2 toxin is remarkably uniform over a wide range
of animal species (Table 8.4) and it is reasonable to assume that the
human LD 50 will be in the same range. Although improved harvesting
and storage has eliminated alimentary toxic aleukia from Russia this
292 Non-bacterial Agents of Foodborne Illness