Timely intervention in recurrent episodes of sepsis poses a major problem in intensive care, because the diagnosis is often made after the onset of sepsis, delaying the initiation of treatment. There are only a few animal models that cover this situation. We have developed a baboon model of recurrent bacteremia (3 x 2 h intravenous infusion of 1 x 10(8) CFU Escherichia coli/kg), which leads to late organ failure. In this model (tested on 16 animals) we began anti-tumor necrosis factor antibody treatment (BAYX 1351; Bayer AG, 7.5 mg/kg or saline placebo) after the first bacteremic episode (+4 h), which significantly (p < .05) protected animals from death, none out of eight (100% survival), in the treatment group in contrast to four animals out of eight died (50% survival) in the placebo group. This effect was also reflected in improved organ function and in attenuated cytokine and plasminogen activator inhibitor release. From these studies we conclude that the delayed application of anti-tumor necrosis factor antibodies in recurrent bacteremia is a powerful tool for preventing septic death.