Recognising blood poisoning more easily

HZI scientists determine new diagnostic benchmark for intensive care units


Blood cultures are used to search for pathogenic bacteria. For this purpose, a certain amount of blood is taken from the patient and immediately placed in the "blood culture flasks".


Every year, more than 150,000 people in Germany become afflicted by Sepsis, also called blood poisoning in the vernacular. The disease is fatal for almost one in three patients. Scientists of the Helmholtz Centre for Infection Research (HZI) in Braunschweig recently investigated how the diagnostic processes done upon the manifestation of Sepsis can be improved. They published the results in the "Journal of Clinical Microbiology".

Each year, pathogens including methicillin-resistant Staphylococcus aureus, or MRSA, cause a large number of - often fatal - infections in German hospitals. Most often the cause of death is bacterial Sepsis: An inflammatory reaction of the body to an Infection that spreads throughout the entire body.

In order to diagnose the disease in due time and thus prevent fatalities, doctors use the so-called blood culture diagnostics. "This is a very good method," says Prof Rafael Mikolajczyk, who is the director of the "Epidemiological and Statistical Methods" research group at the HZI. "However there is some evidence that the method is not applied frequently enough in Germany."

For this reason, HZI scientists collaborated with their colleagues from the "National Reference Center for Surveillance of Nosocomial Infections" and the "Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen - Center for Sepsis Control and Care" to establish a benchmark for clinics to determine how often they should do blood culture diagnostics. Only if the clinics reach this benchmark most cases of sepsis are recognised in due time and reliably and the afflicted patients can be treated adequately.

 "Initially, we are limiting this to intensive care units since this is where most of the sepsis cases occurs," says Dr André Karch, who is a scientist at the HZI and the lead author of the study. "We were able to show in this context that only a third of the intensive care units investigated in our study actually does a sufficient number of blood cultures. This may happen even less often at intensive care units that did not participate in the study."

The scientists from the HZI now aim to determine benchmarks for other hospital wards through further studies. "We are hoping, in the long term, to help the hospitals to improve their sepsis diagnostics," says Karch. "This is an important step to reduce the number of fatalities."

Original publication:

André Karch, Stefanie Castell, Frank Schwab, Christine Geffers, Hannah Bongartz, Frank M. Brunkhorst, Petra Gastmeier, Rafael T. Mikolajczyk (2015). Proposing an empirically justified reference threshold for blood culture sampling rates in intensive care Units. Journal of Clinical Microbiology, DOI:10.1128/JCM.02944-14.