Presence of bacteria in the blood. Short-term bacteremia follows dental or surgical procedures, especially if local infection or very high-risk surgery releases bacteria from isolated sites. In some cases, prior antibiotic therapy can prevent this. It causes little problem to a healthy immune system but can be serious for those with prostheses (where infection can center) or high susceptibility to bacterial invasion. Extensive bacteremia can release toxins into the blood (septicemia), leading to shock and vascular collapse. Antibiotic-resistant bacteria have increased the rate of severe bacteremia.