0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
ARTICLE |

False-Positive Direct Fluorescent Antibody Testing for Legionella

David A. Johnson, MC; Kenneth F. Wagner, MC; James Blanks, MSC; JACQUELYN SLATER, MS
JAMA. 1985;253(1):40-41. doi:10.1001/jama.1985.03350250048013.
Text Size: A A A
Published online

To the Editor.—  Direct fluorescent antibody (DFA) testing of lung tissue or respiratory tract secretions has proved to be an expedient, reliable means for establishing the diagnosis of legionnaires' disease. The specificity of the DFA test on sputum is about 95% using the polyvalent reagent supplied by the Centers for Disease Control (CDC) in Atlanta.1 False-positives with DFA have been described in cases wherein filter water and/or reagents for rinsing contain Legionella.2 False-positive cross-reactions have been reported with isolates of Pseudomonas, Flavobacterium- xanthomonas group, and Bacteroides fragilis.3 We have observed two separate instances when Hemophilus influenzae in the sputum cross-reacted with pool C of the polyvalent assay (Legionella bozemanii, Legionella micadadei, Legionella gormanii, and Legionella longbeachae), resulting in 4+ fluorescence (≥5 bacilli per high-power field, magnification × 1,000) consistent with the CDC criteria for a positive test result. Sputum for culture and monovalent DFA test results were

Topics

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Figures

Tables

References

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
brightcove.createExperiences();