Comparative evaluation of paired blood culture (aerobic/aerobic) and single blood culture, along with clinical importance in catheter versus peripheral line at a tertiary care hospital.
OBJECTIVE
Paired blood culture (PBC) is uncommon practice in hospitals in India, leading to delayed and inadequate diagnosis. Also contamination remains a critical determinant in hampering the definitive diagnosis.


OBJECTIVE
To establish the need of PBC over single blood culture (SBC) along with the degree of contamination, this comparative retrospective study was initiated.


METHODS
We processed 2553 PBC and 4350 SBC in BacT/ALERT 3D (bioMerieux) between October 2010 and June 2011. The positive cultures were identified in VITEK 2 Compact (bioMerieux). True positivity and contaminants were also analyzed in 486 samples received from catheter and peripheral line.


RESULTS
Out of 2553 PBC samples, positivity was seen in 350 (13.70%). In 4350 SBC samples, positivity was seen in 200 samples (4.59%). In PBC true pathogens were 267 (10.45%) and contaminants were 83 (3.25%), whereas in SBC 153 (3.51%) were true positives and contaminants were 47 (1.08%). Most of the blood cultures (99.27 %) grew within 72 h and 95.8% were isolated within 48 h. In 486 PBCs received from catheter/periphery (one each), catheter positivity was found in 85 (true positives were 48, false positives 37). In peripheral samples true positives were 50 and false positives were 8.


CONCLUSIONS
Significantly higher positive rates were seen in PBCs compared with SBCs. Automated blood culture and identification methods significantly reduced the time required for processing of samples and also facilitated yield of diverse/rare organisms. Blood culture from catheter line had higher false positives than peripheral blood culture. Thus every positive result from a catheter must be correlated with clinical findings and requires further confirmation.
Max Super Speciality Hospital,(West Block), 1, Press Enclave Road, Saket, New Delhi - 110 017, India.
B
B
Tarai
P
P
Das
D
D
Kumar
S
S
Budhiraja
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation / Q000379:methods; D016470:Bacteremia / Q000175:diagnosis*; D001431:Bacteriological Techniques / Q000379:methods*; D001769:Blood / Q000382:microbiology*; D057785:Catheters / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D005260:Female; D006761:Hospitals; D006801:Humans; D007194:India; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors; D055815:Young Adult