Increase in Sepsis Cases

Norway

Sepsis is a serious condition. Just over 3,000 people die each year with a diagnosis of sepsis in Norwegian hospitals.

However, sepsis is not actually “poisoning.” The condition occurs when the immune system overreacts to an infection that can be caused by bacteria, viruses, fungi or parasites. The immune system attacks the body’s organs and the patient develops organ failure.

A new study of 300,000 admissions for sepsis has found that the condition is more prevalent than previously thought. However, many more patients survive than before and the increase in cases is largely due to more people repeatedly developing sepsis , rather than dying the first time they get it.

250 out of every 100,000

"Every year, 250 out of every 100,000 people in Norway develop sepsis for the first time," says Lise Tuset Gustad, a researcher at the Norwegian University of Science and Technology (NTNU), Nord University and Levanger Hospital.

“We see this in the average rates adjusted by age. The rates remained stable throughout the study period, but are higher than previous studies have shown,” she says.

The research group at the Norwegian Central Center for Sepsis Research at NTNU has analyzed the figures for the entire period from 2008 to 2021 inclusive. An article about the work has now been published in the British Medical Journal, BMJ Open .

The researchers conducted a national registry study, which means the quality of the data is very strong. To the researchers’ knowledge, this is the first time a nationwide sepsis study has been conducted over such a long period, and that includes all patients admitted to hospital and not just those requiring intensive care.

They found 317,705 hospital admissions due to sepsis during the period between 2008 and 2021 inclusive. No fewer than 222,832 of the patients were admitted to hospital with sepsis for the first time.

Tuset Gustad was Nina Vibeche Skei’s main academic supervisor during her doctoral work. Skei is a consultant anesthetist at Levanger Hospital. “This study helps to debunk the myth that an increase in the number of sepsis cases is due to increased awareness of the condition and therefore increased reporting. The proportion of people who developed sepsis for the first time per 100,000 inhabitants remained stable from 2008 to 2021 inclusive,” said Skei, first author of the article.

Sharp decline in mortality

The study also found that many more people survive than before.

"During this period, hospital mortality rates have been reduced by no less than 43 percent for those admitted with sepsis for the first time," Skei said. “In total, mortality rates in hospitals have decreased by 1/3, regardless of whether it was the patient’s first time suffering from sepsis or whether he had suffered from it before. The cause of the decrease in mortality could be greater awareness of the disease and updated guidelines for treatment,” says Skei.

Mortality from sepsis increases during the pandemic

During the first two years of Covid-19, the number of hospital admissions with sepsis for the first time decreased . Researchers believe this may be due to social distancing, which has resulted in fewer infections in the general population.

“We also found that fewer people over 70 were admitted to hospital with sepsis. This may be due to the great pressure on hospitals and the need to prioritize certain patient groups. These priorities caused many people over 70 years of age not to be hospitalized compared to a normal year,” says Tuset Gustad.

"Sepsis mortality rates in hospitals increased during the pandemic," says Skei, especially in 2021.

Covid-19 raises awareness about sepsis

Covid-19 made more people aware that infections can lead to organ failure . Many people were frightened by images of patients on ventilators in intensive care units, first in Wuhan, then in Italy and finally also in Norway. Infections, bacterial and viral, can cause multiple organ failure in some patients.

This is because the immune system can develop an exaggerated response to infections in certain patients. Patients can then develop sepsis, which is an infection with organ failure.

“Covid-19 put sepsis on the map. Before the pandemic, there was little awareness about sepsis caused by viral infections. The SARS-CoV-2 virus brought about increased awareness about sepsis caused by the virus in particular and about sepsis in general,” says Skei.

Higher mortality rates with Covid-19 as the cause

“During 2020 and 2021, 30,000 people were admitted with sepsis, of which 2,845 were admitted with sepsis due to Covid-19 . This equates to around 10 percent,” says Skei.

Nearly 90 percent of people with sepsis for the first time developed sepsis for reasons other than Covid-19, even during the pandemic. "However, a higher proportion of those who first developed sepsis due to Covid-19 died ," Skei said.

More people with recurrent sepsis

The figures also show that more people than before are developing repeated episodes of sepsis. “Hospital admissions with recurrent sepsis have increased during the period. The increase is mainly due to a doubling of recurrent episodes of sepsis among patients over 60 years of age,” says Skei.

In people over 80 years of age, recurrent sepsis increased fivefold in 2021 compared to 2008.

“The cause is probably that we have become better at treating other medical conditions such as cancer and that we are living longer. Patients with a weakened immune system and the elderly are more susceptible to both initial and recurrent sepsis,” Skei said.

Tracking required

Therefore, the results contradict what many professionals previously believed. They believed the increase in sepsis cases was due to changes in regulations for coding sepsis diagnoses. But that is not the case.

"We used the same codes for sepsis throughout the study period, so we know these are real changes," Tuset Gustad said.

The results are likely to be unique both globally and in Norway. The Norwegian studies above are old; the most recent used data from 2011 and 2012 and show survival trends for sepsis over a period of just two years. This study, on the other hand, looks at sepsis trends over a 14-year period .

"Being able to distinguish between first-time sepsis and recurrent sepsis is unique globally and this is due to Norway’s excellent medical records," said Tuset Gustad.

“Our results should have implications for clinicians and politicians, and for health policy planners. The burden of sepsis is greater than research communities previously thought. However, we must focus our attention in particular on the significant increase in patients developing recurrent sepsis and identify preventive measures for this group of patients,” Skei said.

“Health policy planners must take these results into account. We need to make the effort to prevent recurrent sepsis,” said Tuset Gustad.

The study was funded by doctoral funds from the collaborative body NTNU/Central Norwegian Health Region and the Health Authority Nord-Trøndelag HF.