Systemic inflammatory response syndrome (SIRS) may have an infectious or non-infectious etiology. If infection is suspected or proven, patients with SIRS are said to have sepsis. Microbial invasion of the blood stream is not essential since local inflammation can also elicit distant organ dysfunction and hypotension. 70% of the cases of sepsis are due to gram positive or gram negative bacteria while remaining are due to fungi and a mixture of other micro-organisms. Approximately two-thirds of the cases occur in patients with significant underlying illness. Rising incidents of severe sepsis is due to ageing population, chronic diseases and high frequency of sepsis development in AIDS.