Incidences of community onset severe sepsis, Sepsis-3 sepsis, and bacteremia in Sweden - A prospective population-based study.

Background: Sepsis is a major healthcare challenge globally. However, epidemiologic data based on population studies are scarce.

Methods: During a 9-month prospective, population-based study, the Swedish Sepsis-2 criteria were used to investigate the incidence of community onset severe sepsis in adults aged ≥18 years (N = 2,196; mean age, 69; range, 18-102 years). All the patients who were admitted to the hospital and started on intravenous antibiotic treatment within 48 hours were evaluated. Retrospectively the incidence of sepsis according to Sepsis-3 criteria was calculated on this cohort.

Results: The annual incidence of community onset severe sepsis in adults at first admission was 276/100,000 (95% CI, 254-300). The incidence increased more than 40-fold between the youngest and the oldest age group, and was higher for men than for women. The respiratory tract was the most common site of infection (41% of cases). Using the Sepsis-3 criteria, the annual incidence of sepsis was 838/100,000 (95% CI, 798-877), which is 3-fold higher than that of severe sepsis. The main reason for the discrepancy in incidences is the more generous criteria for respiratory dysfunction used in Sepsis-3. Bacteremia was seen in 13% of all the admitted patients, giving an incidence of 203/100,000/year (95%, CI 184-223), which is among the highest incidences reported.

Conclusions: We found a high incidence of community onset severe sepsis, albeit lower than that seen in previous Scandinavian studies. The incidence increased markedly with age of the patient. The incidence of community onset sepsis according to the Sepsis-3 definition is the highest reported to date. It is 3-fold higher than that for severe sepsis, due to more generous criteria for respiratory dysfunction. A very high incidence of bacteremia was noted, partly explained by the high frequency of blood cultures.