BACKGROUND - Patients with AIDS incur higher rates of infection than the general population. However, little evidence exists to guide family physicians in selecting antibiotics for initial empiric therapy for suspected septicemia.
METHODS - We recorded the causative organisms of septicemia (defined here as bacteremia, fungemia, or both) in 83 patients with AIDS admitted to the teaching hospitals of the University of Louisville from 1996 to 2006. All patients fulfilled the requirements for a diagnosis of AIDS on the basis of the 1993 Centers for Disease Control criteria. In addition to the causative organism, demographic information, immunologic data, portal of entry, and mortality were collected.
RESULTS - Only 53% of the patients presented with fever and the median leukocyte count was 4400 cells/mm(3). The most common organisms causing septicemia were, in decreasing order, methicillin-sensitive Staphylococcus aureus (MRSA; n = 21; 21.4%), Mycobacterium avium complex (n = 10; 10.2%), coagulase-negative staphylococci (n = 9; 9.2%) and Streptococcus pneumoniae (n = 9; 9.2%). Other pathogens included Escherichia coli, Pseudomonas aeruginosa, and MRSA. Polymicrobial septicemia was identified in 12 cases (14.5% of the episodes). The portals of entry of the organism were (in decreasing order) primary, lung, intravascular line, and skin. The types of organisms found in patients with primary septicemia patterned those found overall. The mortality rate was 12.1%.
CONCLUSIONS - AIDS patients with septicemia may not present with the signs that would a non-AIDS patient with septicemia. On the basis of the range of organisms identified in this study, antibiotic coverage of AIDS patients with suspected septicemia, both in primary septicemia and septicemia overall, should take into consideration bacteremia with a wide range of organisms: Gram-positive organisms including MRSA and M. avium complex and Gram-negative organisms including Pseudomonas species. In addition, physicians should be aware that polymicrobial septicemia may be present.