ORIGINAL ARTICLE
Acute Bacterial Arthritis How Long Should You Wait for Culture Results? Percy Guanzon Balderia, MD,* Sherry Pomerantz, PhD,* and Robert Fischer, MD† Background: The optimal incubation period for synovial fluid cultures is unknown.
Objectives: Our study was designed to determine the positivity rate and time to positivity of synovial fluid cultures from adults with suspected acute bacterial arthritis. Methods: We reviewed the charts of 94 adults who had acute monoarthritis. Patients were classified as low risk or high risk for acute bacterial arthritis. The positivity rate and time to positivity of synovial fluid in combined agar plate and broth culture were calculated. Results: The overall positivity rate was 22.3% (21 of 94). None of the 21 low-risk patients had a positive culture. Twenty-one (28.7%) of 73 high-risk subjects showed growth, with a mean time to positivity of 36.7 ± 27.1 hours. While half of these turned positive within a day of incubation, growth was detected at up to 90 hours. Conclusions: In patients with acute monoarthritis, especially those at high risk for infection, it is reasonable to incubate cultures for 4 days before considering them to be negative.
Subjects The records of all patients 18 years or older who were admitted in Albert Einstein Medical Center from December 10, 2010, to September 18, 2013, for joint complaints and had a synovial fluid culture were screened for the study. Cases of patients with acute (onset within the previous 2 weeks) monoarthritis with a synovial fluid specimen sent for Gram stain and culture were classified as suspected acute bacterial arthritis. Patients with disseminated gonococcal disease were excluded. Subjects were then classified as high risk or low risk for acute bacterial arthritis. High-risk patients had any 1 of the following: age at least 80 years old, rheumatoid arthritis, osteoarthritis, diabetes mellitus, active malignancy, chemotherapy or immunosuppressant therapy, joint prosthesis in the affected joint, peripheral leukopenia ( 100,000/hpf
Fever, IDDM Peripheral leukopenia IDDM, gout
+ +
− −
+ +
− −
+ +
−
−
−
UA
−
Fever, IDDM, on interferon and ribavirin for hepatitis C NIDDM
−
+
−
−
−
−
−
−
−
−
Risk Factors
Neutrophils Blood >90% Crystals Culture
IDDM indicates insulin-dependent diabetes mellitus; NIDDM, non–insulin-dependent diabetes mellitus; SLE, systemic lupus erythematosus; UA, uric acid.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.jclinrheum.com
197
JCR: Journal of Clinical Rheumatology • Volume 21, Number 4, June 2015
Balderia et al
the results. Time to positivity could not be precisely determined because positive cultures were usually detected by inspection of the plates, typically performed once daily. Some patients may have been misclassified as low risk because of incomplete or inaccurate histories in the medical records. In conclusion, among patients with acute monoarthritis, especially those at high risk for infection, it is reasonable to incubate cultures for 4 days before considering them to be negative.
KEY POINT • In patients with acute monoarthritis, it is reasonable to incubate synovial fluid cultures for 4 days before considering them to be negative.
ACKNOWLEDGMENT The authors thank Drs Ha Nguyen, Lemuel Non, and Aaron Kosmin for commenting on the methodology; Mr Adam Zissman for furnishing a list of patients with arthritis who had synovial fluid cultures; Ms Marian Fitzpatrick for providing the synovial fluid culture results; and Ms Jessica Roque for checking the grammar of the manuscript.
198
www.jclinrheum.com
REFERENCES 1. Coakley G, Mathews C, Field M, et al. BSR & BHPR, BOA, RCGP and BSAC guidelines for management of the hot swollen joint in adults. Rheumatology. 2006;45:1039–1041. 2. Horowitz DL, Katzap E, Horowitz S, et al. Approach to septic arthritis. Am Fam Physician. 2011;84:653–660. 3. Mathews CJ, Coakley G. Septic arthritis: current diagnostic and therapeutic algorithm. Curr Opin Rheumatol. 2008;20:457–462. 4. Raad J, Peacock JE Jr. Septic arthritis in the adult caused by Streptococcus pneumoniae: a report of 4 cases and review of the literature. Semin Arthritis Rheum. 2004;34:559–569. 5. Swan A, Amer H, Dieppe P. The value of synovial fluid assays in the diagnosis of joint disease: a literature survey. Ann Rheum Dis. 2002;61: 493–498. 6. Margaretten ME, Kohlwes J, Moore D, et al. Does this adult patient have septic arthritis? JAMA. 2007;297:1478–1488. 7. Shirtliff ME, Mader JT. Acute septic arthritis. Clin Microbiol Rev. 2002;15:527–544. 8. Gallo J, Kolar M, Dendis M, et al. Culture and PCR analysis of joint fluid in the diagnosis of prosthetic joint infection. New Microbiol. 2008;31:97–104.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Acute Bacterial Arthritis How Long Should You Wait for Culture Results? Percy Guanzon Balderia, MD,* Sherry Pomerantz, PhD,* and Robert Fischer, MD† Background: The optimal incubation period for synovial fluid cultures is unknown.
Objectives: Our study was designed to determine the positivity rate and time to positivity of synovial fluid cultures from adults with suspected acute bacterial arthritis. Methods: We reviewed the charts of 94 adults who had acute monoarthritis. Patients were classified as low risk or high risk for acute bacterial arthritis. The positivity rate and time to positivity of synovial fluid in combined agar plate and broth culture were calculated. Results: The overall positivity rate was 22.3% (21 of 94). None of the 21 low-risk patients had a positive culture. Twenty-one (28.7%) of 73 high-risk subjects showed growth, with a mean time to positivity of 36.7 ± 27.1 hours. While half of these turned positive within a day of incubation, growth was detected at up to 90 hours. Conclusions: In patients with acute monoarthritis, especially those at high risk for infection, it is reasonable to incubate cultures for 4 days before considering them to be negative.
Subjects The records of all patients 18 years or older who were admitted in Albert Einstein Medical Center from December 10, 2010, to September 18, 2013, for joint complaints and had a synovial fluid culture were screened for the study. Cases of patients with acute (onset within the previous 2 weeks) monoarthritis with a synovial fluid specimen sent for Gram stain and culture were classified as suspected acute bacterial arthritis. Patients with disseminated gonococcal disease were excluded. Subjects were then classified as high risk or low risk for acute bacterial arthritis. High-risk patients had any 1 of the following: age at least 80 years old, rheumatoid arthritis, osteoarthritis, diabetes mellitus, active malignancy, chemotherapy or immunosuppressant therapy, joint prosthesis in the affected joint, peripheral leukopenia ( 100,000/hpf
Fever, IDDM Peripheral leukopenia IDDM, gout
+ +
− −
+ +
− −
+ +
−
−
−
UA
−
Fever, IDDM, on interferon and ribavirin for hepatitis C NIDDM
−
+
−
−
−
−
−
−
−
−
Risk Factors
Neutrophils Blood >90% Crystals Culture
IDDM indicates insulin-dependent diabetes mellitus; NIDDM, non–insulin-dependent diabetes mellitus; SLE, systemic lupus erythematosus; UA, uric acid.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.jclinrheum.com
197
JCR: Journal of Clinical Rheumatology • Volume 21, Number 4, June 2015
Balderia et al
the results. Time to positivity could not be precisely determined because positive cultures were usually detected by inspection of the plates, typically performed once daily. Some patients may have been misclassified as low risk because of incomplete or inaccurate histories in the medical records. In conclusion, among patients with acute monoarthritis, especially those at high risk for infection, it is reasonable to incubate cultures for 4 days before considering them to be negative.
KEY POINT • In patients with acute monoarthritis, it is reasonable to incubate synovial fluid cultures for 4 days before considering them to be negative.
ACKNOWLEDGMENT The authors thank Drs Ha Nguyen, Lemuel Non, and Aaron Kosmin for commenting on the methodology; Mr Adam Zissman for furnishing a list of patients with arthritis who had synovial fluid cultures; Ms Marian Fitzpatrick for providing the synovial fluid culture results; and Ms Jessica Roque for checking the grammar of the manuscript.
198
www.jclinrheum.com
REFERENCES 1. Coakley G, Mathews C, Field M, et al. BSR & BHPR, BOA, RCGP and BSAC guidelines for management of the hot swollen joint in adults. Rheumatology. 2006;45:1039–1041. 2. Horowitz DL, Katzap E, Horowitz S, et al. Approach to septic arthritis. Am Fam Physician. 2011;84:653–660. 3. Mathews CJ, Coakley G. Septic arthritis: current diagnostic and therapeutic algorithm. Curr Opin Rheumatol. 2008;20:457–462. 4. Raad J, Peacock JE Jr. Septic arthritis in the adult caused by Streptococcus pneumoniae: a report of 4 cases and review of the literature. Semin Arthritis Rheum. 2004;34:559–569. 5. Swan A, Amer H, Dieppe P. The value of synovial fluid assays in the diagnosis of joint disease: a literature survey. Ann Rheum Dis. 2002;61: 493–498. 6. Margaretten ME, Kohlwes J, Moore D, et al. Does this adult patient have septic arthritis? JAMA. 2007;297:1478–1488. 7. Shirtliff ME, Mader JT. Acute septic arthritis. Clin Microbiol Rev. 2002;15:527–544. 8. Gallo J, Kolar M, Dendis M, et al. Culture and PCR analysis of joint fluid in the diagnosis of prosthetic joint infection. New Microbiol. 2008;31:97–104.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
