초록
Background
This study analysed patterns of requests for repeated blood cultures and the microorganisms isolated in follow-up cultures.
Methods
The frequencies and intervals of repeated blood cultures performed during January and Feb-ruary of 2010 at seven university-affiliated hospitals in Korea were evaluated. Results of microbiological cultures at follow-up were analysed with respect to pathogen replication, immune clearance, appearance of new pathogens, and skin contaminants.
Results
Among 3,072 patients who received repeated blood cultures, the average number of requests was 3.2. Of the 5,241 follow-up blood culture events recorded, durations of 1, 2, and 3 days between cultures were identified for 23.1%, 21.4%, and 15.0% of events, respectively. Relative to each initial culture, persistent pathogen growth in subsequent culture(s) accounted for 2.3% of events, whereas immune clearance was confirmed in 8.5% of events. Previously undetected pathogens were isolated in 5.2% of the follow-up cultures, the majority of which grew after an interval of six days. Skin contaminants were detected in 7.6% of the repeated cultures, and 76.1% of the follow-ups displayed no growth of microorganisms.
Conclusion
The most common numbers of repeat culture requests were two and three, and these were typically performed within three days of the initial culture. Among the follow-up cultures, new pathogens were identified in 5.2%, and the majority of this group likely presented for follow-up during a new disease episode.
REFERENCES
1.Clinical and Laboratory Standards Institute. Principles and Procedures for Blood Cultures; Approved Guideline. Document M47-A. Wayne PA. Clinical and Laboratory Standards Institute. 2007.
2.Fowler VG Jr., Olsen MK., Corey GR., Woods CW., Cabell CH., Reller LB, et al. Clinical identifiers of complicated Staphylococcus aureus bacteremia. Arch Intern Med. 2003. 163:2066–72.
3.Mylotte JM., Tayara A. Blood cultures: clinical aspects and controversies. Eur J Clin Microbiol Infect Dis. 2000. 19:157–63.
4.Grace CJ., Lieberman J., Pierce K., Littenberg B. Usefulness of blood culture for hospitalized patients who are receiving antibiotic therapy. Clin Infect Dis. 2001. 32:1651–5.
Table 1.
Initial/follow-up culture | Hospitals | |||||||
---|---|---|---|---|---|---|---|---|
A (82)∗ | B (279) | C (334) | D (424) | E (447) | F (533) | G (973) | Total (3,072) | |
Growth†/growth | 7.3 | 2.2 | 1.2 | 2.6 | 1.3 | 3.0 | 3.1 | 2.3 (70) |
No growth/growth | 14.6 | 5.0 | 4.5 | 2.1 | 4.5 | 4.7 | 6.8 | 5.2 (161) |
Growth/no growth | 12.2 | 7.2 | 4.8 | 5.7 | 11.0 | 6.0 | 11.3 | 8.5 (261) |
Contaminants‡ | 13.4 | 11.8 | 2.1 | 5.0 | 7.4 | 8.6 | 8.3 | 7.6 (232) |
No growth/no growth | 52.5 | 73.8 | 87.4 | 84.6 | 75.8 | 77.7 | 70.5 | 76.4 (2,348) |