Temperature exhibits U-shaped relationship with bacteremia, highest risk above 39.4 degree celsius

The study is published in the Journal of General Internal Medicine.

Recognising and managing bacteremia early is lifesaving. One of the well-known markers of bacteremia is fever. However, there needs to be more research on the predictive value of temperature.

To investigate this further, researchers described temperature as a predictor of bacteremia and other infections using a study design as a retrospective review of electronic health record data.

The study setting was a US healthcare system with 13 hospitals. The patients were adults without malignancy or immunosuppression.

The primary measure measured in the study was Maximum temperature, bacteremia, influenza and skin and soft tissue (SSTI) infections. Blood cultures and ICD-10 coding determined this.

The results of the study could be summarised as:

• Out of 97,174 patients, nearly 1,518 constituting 1.6%, had bacteremia.
• 1,392 patients constituting 1.4%, had influenza
• Three thousand two hundred eighty patients constituting 3.3%, had an SSTI.
• There was no identifiable temperature threshold providing sensitivity and specificity for bacteremia.
• 45% of patients with bacteremia had a maximum temperature ≥ 100.4˚F (38˚C).
• There was a U-shaped relationship between temperature and bacteremia.
• The highest risk was above 103˚F (39.4˚C).
• With increasing temperatures, there were positive likelihood ratios for influenza and SSTI. The threshold effect was at ≥ 101.0 ˚F (38.3˚C).
• For patients aged more than 65 years, the temperature effect was similar but blunted and frequently lacked fever despite bacteremia.

Concluding further, most patients with bacteremia had maximum temperatures below 100.4 ˚F. There is a more positive likelihood ratio of the fact that with high temperature, bacteremia increases.

They finally wrote efforts to predict bacteremia should incorporate temperature as a continuous variable.

Further reading:

Speaker SL, Pfoh ER, Pappas MA, Schulte R, Hu B, Gautier TN, Rothberg MB. Relationship Between Oral Temperature and Bacteremia in Hospitalized Patients. J Gen Intern Med. 2023 Mar 30. Doi: 10.1007/s11606-023-08168-6. Epub ahead of print. PMID: 36997793.