Salmonella bacteremia occurs in a small percentage of patients with Salmonella intestinal infections. It can be serious if intravascular sites become seeded.
Lesions may include:
(1) arterial mycotic aneurysms
(2) infected thrombi, including mural thrombi within the heart
(3) endocarditis
(4) involvement of vascular grafts
Age of patient: Patients older than 50 years of age are a high risk group for vascular involvement, with up to 25% developing vascular infection
Historical findings:
(1) underlying valvular disease
(2) previous vascular surgery, especially with vascular grafts
Clinical findings - one or more of the following:
(1) peripheral stigmata of bacterial endocarditis
(2) new or changing cardiac murmur
(3) embolic phenomenon
Laboratory evaluation:
(1) isolation of Salmonella in blood cultures
(2) isolation of Salmonella from resected tissue
(3) histopathologic evidence of suppuration in resected tissue, with Gram-negative bacilli
Grade of bacteremia:
(1) high grade: more than 50% of 3 or more blood cultures are positive
(2) low grade: less than or equal to 50% of 3 or more blood cultures are positive
Imaging techniques useful to detect vascular or cardiac involvement:
(1) ultrasonography
(2) echocardiography
(3) arteriography
Therapy:
(1) If patient does not have high grade bacteremia and if no vascular structures are involved, then 7-14 days of intravenous antibiotic therapy is sufficient.
(2) Short term antibiotic therapy usually fails with high grade bacteremia or with involvement of vascular structures; intravenous therapy is recommended for at least 6 weeks.
(3) Resection of the infected area is recommended if feasible.
(4) If resection not feasible, then long-term antibiotic therapy may be required.
