SAN FRANCISCO—Bacteremia occurs in 13% of solid organ donors and the causative pathogens infect about 3% of recipients, according to Spanish investigators.
Their study of 934 donors suggests that clinicians may need to establish an appropriate antibiotic regimen for recipients prior to transplantation, when bacteremia is confirmed in the donor. This approach may be especially important in cases where the donor organs are infected with Staphylococcus aureus and Enterococcus faecalis because they can be resistant to many commonly used antibiotics.
Researchers at the University of Barcelona looked at all recipients of solid organs from donors at their institution from January 1997 through April 2004. During this period and at the time of organ extraction, investigators obtained two blood cultures from all donors; infectious episodes were documented during the first 30 days post-transplant.
Of 934 donors, 126 (13%) had bloodstream infections, the study found. The most frequently isolated microbes were coagulase negative Staphylococcus in 70 donors (56% of the 126 donors) and S. aureus in 23 donors (18%). Enterobacteria species were present in 16 donors (13%), E. faecalis in nine (7%) and P. aeruginosa in seven (6%). Multiple bacterial species were isolated from 15 (12%).
A total of 217 recipients received an organ from a bacteremic donor (102 kidneys, 75 livers, 19 kidney-pancreas combinations, 17 heart, and three kidney-liver combinations). All recipients received surgical antibiotic prophylaxis within the first 30 days of receiving their organs. Eighty-five patients (39%) had a documented infection, 12 with bacteremia (5%). Three died in the first 30 days post-transplant, but none of the deaths was related to donor bacteremia.
Six infections in the recipients matched those found in the donors’ bacteremia (two S. aureus, two E. faecalis, one Serratia marcescens, and one coagulase negative Staphylococcus). Two of the six recipients had bacteremia, two had deep surgical wound infections, one had a lung infection, one had a UTI. The overall transmission rate was about 3% (six of 217 recipients).
“In cases of bacteremic donors with Staphylococcus aureus and Enterococcus faecalis, the recipient must be treated intensively to control the infection,” said investigator Carlos Cervera, MD, professor of infectious diseases. “This is very difficult be-cause it is oftentimes not recognized at the time of the transplant and it can take three to five days to get the [culture] results. So, we need to introduce this type of antibiotic therapy when a high suspicion of infection with these microorganisms exists, even if the recipient does not have any evidence of this infection.” He reported findings here at the 46th annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
Even though the study was at one institution in Spain, Dr. Cervera said he believes this is a significant problem at many transplant centers around the world. These infections carry a high morbidity, so it is important that patients are carefully monitored and treated aggressively.
“The frequency of bacteremic donors at our institution was higher than frequencies reported in previous studies, which are around 5%,” he said. “This could be explained by a higher proportion of marginal donors in recent years and, in our opinion, these kinds of donors will be increasing with time. So, we need to take this into account for the management of kidney transplant recipients.”