Molecular testing is redefining accuracy & time to diagnose Sepsis

Molecular testing is redefining accuracy & time to diagnose Sepsis

Sepsis is a serious medical condition that arises when the body’s own response to infection can lead to tissue damage, organ failure and death particularly if not identified early on and treated promptly.  Sepsis is a race to the death -between the bugs that cause it and the immune system. Sepsis caused 47 – 50 million cases and 11 million deaths worldwide in 2017. Unfortunately, 40% of cases are in children under 5 years of age.   It is a major worldwide cause of morbidity and mortality wherein 1 in 5 deaths is associated with sepsis. Eighty five percent of sepsis cases and 84.8% of sepsis related deaths occur in countries with low, low-middle, or middle sociodemographic indices, particularly in sub-Saharan Africa and South-East Asia.

Sepsis and septic shock (severe sepsis causing organ failure and dangerously low blood pressure) can result from an infection anywhere in the body as in pneumonia, diarrheal disease, urinary tract infection, post-surgical infections etc. The infection could be acquired in the community setting or in health care facilities. Health care-associated infections are among the most frequent type and are often resistant to antibiotics which can worsen the clinical conditions.

Bacterial infections are the primary cause of sepsis; however, viruses and fungi also cause it specially in immunocompromised patients and those with other comorbidities.   Prevention of sepsis in both community and health care facilities requires the appropriate antibiotic treatment of infection, prompt seeking of medical care, and early detection of bug or microbe causing it. The culture test (regarded as gold-standard currently) is widely used to grow bacteria and fungi, however, it takes a long time to produce actionable results. The inability of the culture technique to accurately differentiate between the causative organisms is another shortfall.

To increase the speed of diagnosis, molecular detection techniques for bacterial, viral and fungal DNA have been developed but still they are not in widespread clinical use. Techniques like PCR (Polymerase Chain Reaction), Microarray and Next Generation Sequencing (NGS) based methods use the knowledge of the genome of the microbe. These techniques apart from helping in detection, also give information if the bacteria are resistant to an antibiotic or not. Multiplex and RT- PCR tests have a promise to overcome the shortfalls of  conventional tests like culture and provide rapidity, higher accuracy to detect and differentiate between multiple microbes in a single test.  They are also highly sensitive wherein they can detect microbe in the patient’s sample even if it is present in lower quantity or loads. Speed is of pivotal importance for the diagnosis of sepsis, hence molecular techniques will be extremely useful for reducing hospitalization and ICU stay, as well as decreasing the mortality.

The 2020 World Sepsis Day is at a time when we are amidst the thick of COVID-19 pandemic. SARS-CoV2 virus can also cause sepsis and therefore raising awareness about sepsis are critical to save lives.  With COVID-19, there has come a general awareness about infectious diseases and molecular test like RT-PCR, which is the gold standard for diagnosis of COVID-19.  With widespread development of infrastructure for molecular methods it will be pivotal to extend the available technology and laboratory infrastructure to other critical infections, such as sepsis which is both reversible and preventable.

  • The author of this article is Dr Gunisha Pasricha, Principal Scientist- Infectious Diseases at MedGenome Labs Ltd

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