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retention of erythrocyte integrity. Emboli of necrotic hepatocytes and cell debris evident in hepatic vessels (Figure 5) Figure 4: Liver histopathology revealing pan-necrosis with fragmentation of hepatocellular cords due to cell dissociation and only sinusoidal lining still intact. Figure 5: Liver histopathology with emboli of necrotic hepatocytes in vessels (arrows). Water samples collected were initially examined directly under the microscope revealing large conglomerates of round to oval shaped, variably sized algae resembling cyanobacteria (Figure 6). Figure 6: Direct microscopic examination of water revealed sheets of round to oval cyanobacterial bodies. This water sample was the submitted for algal analysis. Algae were identified as exclusively Microcystis aeruginosa and an extremely high algal count of > 1 000 000 cells/ml was documented. Microcystis aeruginosa is a common unicellular, planktonic freshwater cyanobacterium which are regularly found at the surface of water bodies in spring and summer. The existence of intracellular structures, the gas vesicles, provides cells with buoyancy. These hollow, gas-filled structures can keep Microcystis cells close to the surface of water body, where there is optimal light and oxygen for growth. Cyanobacteria may adopt different strategies to reduce the possibility of being consumed by their upper trophic level of food web, such as morphology and intracellular toxins. Cyanobacteria are capable of producing 3 different structural groups namely cyclic peptides (microcystins, nodularins) which target hepatic function; alkaloids (anatoxins, saxitoxins) that target the nervous system and lipopolysaccharides which are potential irritants. This toxin production creates health risks for populations (animal and human) living and harvesting in contaminated areas where these cyanobacteria bloom. Blooms occur when nutrient levels spike in aquatic environments or nutrient levels are selective toward microcystin producing cyanobacteria. The microcystins are produced by the genera Microcystis, Anabaena and Oscillatoria and are protein phosphatase inhibitors and potent hepatotoxins. Toxicity of microcystis in mammals is characterized by fulminant intrahepatic hemorrhage followed by hypovolaemic shock, secondary to massive hepatocellular necrosis and collapse of hepatic parenchyma and death. Under these circumstances Microcystis aeruginosa (most commonly) or Anabaena and Oscillatoria (less frequently) are among the most ecologically damaging species due to their toxicity to aquatic and terrestrial organisms. The nature of this pathology in conjunction with the clinical history and photographic evidence, algal identification and Microcystis aeruginosa counts would strongly support a diagnosis of microcystis poisoning. 2016 SEPTEMBER 23