Sepsis, which kills an estimated 6 million people worldwide each year, has been revealed to be more of a concern in Australian hospitals than previously thought.

A study released on Monday by the University of Sydney and the George Institute for Global Health, showed that the incidence and mortality rates of sepsis in Australian intensive care units (ICU) are significantly underestimated.

Sepsis occurs when the body responds to the infection by shutting down, damaging the patient's own tissues, with currently no definitive tissue or blood tests to detect it.

"The gold standard for diagnosis is clinical identification of organ dysfunction caused by infection," the authors led by Professor Simon Finfer from the George Institute said.

"At the population level, this would require either prospective cohort studies or retrospective medical record reviews on a scale impractical for routine disease surveillance."

Researchers conducted a study with thorough and ongoing sepsis examinations of patients at a Sydney ICU and compared their results to the preexisting sepsis rate estimate data, as provided by the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation (ANZICS-CORE).

According to their paper published in the Medical Journal of Australia, the research revealed that "the estimated incidence of sepsis among adult ICU patients was significantly higher when based upon prospective clinical diagnosis than when applying the ANZICS-CORE database criteria".

Finfer and his colleagues called for a reassessment of sepsis rate data to help reduce the impact of what they call "a major public health challenge and a threat to patient safety".