Test Code AFSD AFB Studies, TB
Additional Codes
Acid-Fast Bacilli (AFB)
AFB (Acid-Fast Bacilli)
Bacillus, Acid-Fast
Culture, TB (Tuberculosis)
MTB (Mycobacterium tuberculosis)
Mycobacteria Culture
Mycobacterium tuberculosis (MTB)
TB (Tuberculosis)
TB (Tuberculosis) Culture
Tuberculosis (TB)
Performing Laboratory
YRMC Laboratory, Microbiology Department
Blood Cultures for Myocbacteria are performed by Mayo Medical Laboratories
Day(s) Test Set Up
Monday through Friday
Specimen Requirements
All specimens must be submitted in a leak-proof container and sealed in a biohazard bag. Specimens that are received leaking or spilled will be rejected for testing.
Submit only 1 of the following specimens - specimen source is required:
Abscess
Container/Tube: Sterile, screw capped container or syringe with needle removed. Needle may be replaced with sterile syringe cap or sterile capped blunt cannula. Specimens submitted on swabs are sub-opitmal for Mycobacterial culture and do not typically yield productive growth of Mycobacteria.
Specimen Volume: 1-2 ml. aspirate material or abscess drainage.
Collection Instructions:
1. For most open lesions and abscesses, remove the superficial flora by decontaminating the skin before collecting a specimen from the advancing margin or base.
2. A closed abscess is the specimen site of choice. Aspirate the abscess contents with a syringe and submit the specimen in a the syringe or expell the contents into a sterile, screw capped container.
3. Please indicate on the request or order if Mycobacterium marinum infection is suspected. This organism requires specialized processing and incubation requirements for optimal recovery.
Note: 1. Label container with patient’s
name (first, last, and middle initial), medical record number (if
appropriate), date of birth, date and time of collection and
collector’s initials and or ID number.
2. Specimen source is required.
Blood
Container/Tube: Two, 7-mL green-top (sodium or lithium
heparin) tubes-Plasma gel tube is not acceptable.
Specimen Volume: 10 mL of whole blood
Collection Instructions: Do not centrifuge
or refrigerate. Collect specimen as follows:
1. Apply tourniquet to patient’s arm.
2. Palpate area to locate vein.
3. Thoroughly cleanse venipuncture site with 70% alcohol moving in
concentric circles to periphery. Do not palpate
vein after sterilizing area. If site must be touched during
venipuncture, disinfect gloved finger. Allow to dry.
Note: 1. Label tubes with patient’s name
(first, last, and middle initial), medical record number (if
appropriate), date of birth, date and time of of collection and
collector’s initials and or ID number.
2. Specimen source is required.
Bronchial Wash/Bronchial Lavage
Container/Tube: Aspirate trap. Attach the tubing firmly to the top of the aspirate trap to ensure the specimen does not leak during transport. Do not add cytology preservative(CytoLyt®) to specimens submitted for culture.
Specimen Volume: Minimum volume: 7.5 ml
Collection Instructions: Collect per established bronchoscopy protocol.
Note: 1. Label container with patient’s name (first, last, and middle initial), medical record number (if appropriate), date of birth, date and time of collection and collector’s initials and or ID number.
2. Specimen source is required.
Body Fluid
Container/Tube: Screw-capped, sterile container, evacuated
collection contaimer. Specimens submitted on swabs are not
acceptable.
Specimen Volume: 5 mL of body fluid
Collection Instructions: Collect aseptically.
Disinfect site with alcohol if collecting by needle and
syringe.
Note: 1. Label container with patient’s name
(first, last, and middle initial), medical record number (if
appropriate), date of birth, date and time of collection and
collector’s initials and or ID number.
2. Specimen source is required.
Gastric Aspirate
Container/Tube: Sterile, screw capped container or aspirate trap. Attach the tubing firmly to the top of the aspirate trap to ensure the specimen does not leak during transport.
Specimen Volume: 5 – 10 ml gastric aspirate.
Collection Instructions: Collect per established gastric aspiration protocol.
Note:
1. Gastric aspirates are often the preferred specimen for diagnosing Myocbacterium tuberculosis in pediatric patients.
2. Aspirate specimens for AFB culture should be collected after the patient has had at least 6 hours of un-interrupted sleep and has been fasting for at least 6 hours.
3. Do not use any NG tube lubricant. All lubricants are bacteriostatic.
4. Label container with patient’s name (first, last, and middle initial), medical record number (if appropriate), date of birth, date and time of collection and collector’s initials and or ID number.
5. Transport the specimen to the Microbiology department without delay.
6. Specimen source is required.
Sputum, Expectorated
Container/Tube: Screw-capped, sterile
container.
Specimen Volume: Expectorated sputum (minimum
volume: 5 mL). Regulating bodies (CDC, WHO, APHL) recommend a
series of at least 3 sputum specimens collected 8 to 24 hours apart
with at least one early morning sputum specimens for tuberculosis
rule out.
Collection Instructions: Collect specimen as
follows:
1. Have patient remove dentures, if applicable.
2. Instruct patient to brush his/her teeth and/or rinse mouth well
with water to minimize contaminating specimen with food particles,
mouthwash, or oral drugs which may inhibit growth of
mycobacteria.
3. Instruct patient to take a deep breath, hold it momentarily,
then cough deeply and vigorously into container.
Nasal secretions or saliva are not acceptable
specimens.
Note: 1. Label container with patient’s name (first,
last, and middle initial), medical record number (if appropriate),
date of birth, date and time of collection and collector’s
initials and or ID number.
2. Specimen source is required.
Sputum, Induced
Container/Tube: Screw-capped, sterile container(s)
or aspirate trap. If an aspirate trap specimen is submitted, attach
the tubing firmly to the top of the aspirate trap to ensure
specimen does not leak during transport.
Specimen Volume: Early-morning induced sputum
(minimum volume: 5 mL) Regulating bodies (CDC, WHO, APHL) recommend
a series of at least 3 sputum specimens collected 8 to 24 hours
apart with at least one early morning sputum specimens for
tuberculosis rule out.
Collection Instructions: Induce cough by
inhalation of sterile, hypertonic saline, and collect expectorated
material. Avoid sputum contamination with nebulizer reservoir
water.
Note: 1. Label container with patient’s name
(first, last, and middle initial), medical record number (if
appropriate), date of birth, date and time of collection, and
collector’s initials and or ID number.
3. Specimen source is required.
Tissue
Container/Tube: Screw-capped, sterile container(s) without
fixative or preservative-Specimen in formalin is not
acceptable.
Specimen Volume: 1 g of tissue, if possible
Collection Instructions: Collect aseptically
avoiding indigenous microbiota. Select caseous portion if
available. Do not immerse in saline or other fluid or wrap in
gauze.
Note: 1. Label container with patient’s name
(first, last, and middle initial), medical record number, date of
birth, date and time of collection and collector’s initials
and or ID number.
2. Specimen source is required.
Urine
Container/Tube: Screw-capped, sterile container(s)
Specimen Volume: 30 mL to 50 mL from a random
urine collection
Collection Instructions:
Note: 1. Label container with patient’s name
(first, last, and middle initial), medical record number (if
appropriate), date of birth, date and time of collection and
collector’s initials and or ID number.
2. Specimen source is required.
Specimen Transport Temperature
Ambient
Refer to Microbiology Special Instructions for specimen stability.
Reference Values
Negative for AFB at 6 weeks
Test Classification and CPT Coding
87116 - AFB Culture
87206 - AFB Smear
87015 - Concentrate, AFB (specimen dependent)
Testing Algorithm
1. Testing includes a culture and an AFB smear for all specimens submitted except Blood Cultures for AFB.
2. Specimens submitted for AFB culture and smear are processed Monday through Friday.
3. AFB Smears are available Sunday through Saturday upon STAT request. For specimens that require digestion/decontamination (ie: respiratory specimens and those specimens typically contaminated with indiginous flora), direct AFB smears will be prepared and reported for STAT requests. All specimens that received a STAT direct AFB smear will receive a follow-up concentrated AFB smear.
Methodology
Conventional Acid Fast Bacillus culture methods including liquid (volume dependent) and solid culture media.
Includes Acid Fast Bacillus smear.
Loinc Code
543-9