TNF and Fever: Pyrexia could arise as a result of the pyrogenic effects of some inflammatory acute phase reactants such as TNF-alpha (endogenous pyrogens) or as a result of the effect of exogenous pyrogens associated the infecting micro-organisms.40 In addition to pyrexia, enteropathogenic organisms such as E Coli, Salmonella and Shigella species could cause severe diarrhea and vomiting.41 Pyrexia is invariably associated with increased rate of perspiration and water loss via the skin, while diarrhea and vomiting would result in gastro-intestinal water loss.