Value of surveillance cultures in a bone marrow transplantation unit

Abstract

Because of the increased risk of infection with the associated diagnostic and therapeutic problems in bone marrow transplantation (BMT) patients, the usefulness of surveillance cultures (SC) at the BMT department of the National Institute of Haematology, Blood Transfusion, Transplantation and Immunology, Budapest, was reviewed. Between January 1992 and May 1995, 26 BMT operations were performed; 13 patients had 23 febrile espisodes. In 12 of these episodes infection was clinically documented; however, SC of these patients yielded bacteria identical with those in the blood culture in only two episodes (1 and 6 days before their blood cultures became positive, respectively). Out of a total of 1187 samples from these patients, potentially pathogenic bacteria were isolated from 145 SC and 43 blood cultures (drawn on 31 different days). Suppression of the gastrointestinal flora could be achieved by the department's decontamination regimen; however, overgrowth by gram-positive organisms (mainly coagulase-negative staphylococci) occurred in the intestine and at other body sites. On the basis of these results, SC are of limited value in predicting infection or identifying the causative organisms of fever. On the other hand, SC are useful in confirming the efficiency of suppression of the body flora by antimicrobial agents. Specific treatment was based on suitably sampled materials, and close contact between physicians, infectious disease specialists and microbiologists was essential.

Utility of surveillance blood cultures in patients undergoing hematopoietic stem cell transplantation

“…Rigby et al [16] reported that 3 of 43 positive blood cultures in neutropenic children which yielded organisms, when repeated prior to starting antibiotics were sterile, suggesting that these positive cultures represented colonization rather than infection. Czirok et al [17] found that in 14 episodes of fever in 23 HSCT patients , surveillance cultures yielded bacteria identical with those in clinical blood cultures in only one episode and in the remaining three documented BSIs the identified bacteria isolated by surveillance cultures was not the same as the bacteria identified by clinical blood cultures. They concluded that surveillance blood cultures were of limited value in predicting infection.…”

“…For these reasons, some experts have recommended surveillance blood cultures to detect occult bacteremia [12]. Previous studies regarding the utility of surveillance blood cultures in patients undergoing hematopoietic stem cell transplantation (HSCT) are scarce with small numbers of patients, and describe specific subgroups of patients in relation to the type of transplant or the patients’ age [13-17]. Moreover, these studies have come to differing conclusions [10-13].…”

Perfil microbiológico dos pacientes nos primeiros trinta dias pós transplante de medula óssea do Serviço de Transplantes da Santa Casa de São Paulo

“…Estes dados são semelhantes aos descritos por Czirók e cols. que estudaram culturas de vigilância em 26 pacientes submetidos ao TMO e observaram maior incidência de bactérias gram-positivas, sendo pele, orofaringe, glande e vagina os locais de maior colonização (5).…”

“…Riley et al estudaram 48 pacientes que realizaram TMO e questionaram o papel das culturas de vigilância ao observarem baixa sensibilidade (38%), especificidade (25%), valor preditivo positivo (20%) e valor preditivo negativo (20%) em relação ao desenvolvimento das infecções documentadas no grupo (3). Baixa correlação entre culturas de vigilância positivas e infecções clinicamente documentadas também foi observada por outros autores (5). Entretanto, as culturas de vigilância podem ser úteis na investigação dos efeitos dos tratamentos profiláticos na seleção de germes resistentes, e auxiliar o estudo da epidemiologia da colonização nos pacientes netropênicos.…”

Antibiotic-resistant bacteria in surveillance cultures from hematopoietic stem cell transplant patients

“…Patients who are colonized with multidrug-resistant bacteria may serve as a source of later infection in the same patient and also as infection risk for neighboring patients if not isolated. [5] Surveillance cultures may be helpful in identifying these multidrug-resistant bacteria, which may have a bearing on further patient management.…”