Complete Blood Count (CBC): A Routine Blood Test That Measures the Cells in Your Blood to Help Evaluate Your Overall Health and Detect a Wide Range of Conditions
This laboratory test identifies anaerobic bacteria (bacteria that grow without oxygen) found in a fistula, helping doctors determine the cause of infection and select appropriate treatment.
{"The test detects anaerobic bacteria that cause infections in abnormal passages (fistulas) between body structures","Sample is collected from the fistula tract using a sterile swab or aspirate","Results help guide antibiotic therapy by identifying specific bacteria and their sensitivity to antibiotics","Anaerobic infections often produce foul-smelling discharge due to gas-producing bacteria","Treatment typically involves long-term antibiotics and sometimes surgical intervention"}
Key facts at a glance
- LOINC
- 106037-5
- Short code
- ANAFIST
- Synonyms
- Bacteria Fistula Anaerobe Cult
- Category
- chemistry
- Sample
- serum
- Container
- Sterile anaerobic transport system (e.g., Port-a-Cul vial, anaerobic swab in Amies or Stuart transport medium), or sterile screw-cap container for aspirated material
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- anaerobic-culture
- CPT
- 87075
- SNOMED
- 442126008
- Specimen volume
- 1-2 mL of purulent material or fistula exudate; swab specimens collected in duplicate when possible
- Stability
- Maintain at room temperature (20-25°C) in anaerobic transport medium. Process within 2 hours of collection for optimal anaerobic organism recovery. If delayed, refrigerate at 2-8°C for no more than 24 hours, though viability of strict anaerobes may decrease.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 72–240 hours
- Order
- routine
A complete blood count, or CBC, is a common blood test that measures the different cells circulating in your blood, including red blood cells, white blood cells, and platelets. Your doctor may order it as part of a routine checkup or to help diagnose conditions such as anemia, infections, and other disorders.
The Anaerobic Fistula Culture test is a laboratory procedure that collects and analyzes discharge or fluid from a fistula to identify anaerobic bacteria. A fistula is an abnormal tunnel-like passage that forms between two organs or between an organ and the skin. This test specifically looks for bacteria that thrive in low-oxygen environments, which are common causes of deep tissue and fistula infections.
The sample is collected by drawing a small amount of blood from a vein, usually on the inside of your elbow or the back of your hand. A healthcare professional will clean the site, wrap a band around your upper arm, and insert a thin needle to fill one or more collection tubes. The procedure typically takes only a few minutes.
Your healthcare provider will collect fluid or discharge from the fistula using a sterile swab, needle aspiration, or surgical collection. The sample must be placed in a special anaerobic transport container immediately to prevent oxygen exposure, as anaerobic bacteria are sensitive to air. Proper collection technique is crucial for accurate results.
In the laboratory, your blood sample is analyzed by specialized equipment that counts and measures each type of blood cell. The results report the number, size, and other characteristics of your red blood cells, white blood cells, and platelets, which your doctor interprets together with your symptoms and medical history.
The collected sample is sent to a microbiology lab where it is cultured (grown) in controlled conditions without oxygen. Laboratory technicians observe the bacterial growth over several days and identify the specific types of anaerobic bacteria present. Additional testing may determine which antibiotics will be most effective against the identified bacteria (sensitivity testing).
No special preparation is usually required for this test, and you can normally eat and drink before your appointment unless your doctor gives you different instructions. Let the person drawing your blood know about any medications or supplements you take, since some of them can influence the results.
No special fasting or preparation is typically required. However, you should inform your doctor about any current antibiotics you are taking, as these may affect test results. Follow your healthcare provider's specific instructions regarding wound care or cleaning of the fistula area before sample collection.
Reference range
No growth of pathogenic anaerobic bacteria. Reporting includes organism identification and antimicrobial susceptibility when clinically indicated.N/A
Discontinue topical antibiotics, antiseptics, and antimicrobial wound dressings at least 48 hours prior to specimen collection whenever possible. The fistula site should not be cleaned with alcohol or iodine immediately before sampling, as these agents may kill anaerobic organisms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is clinically significant because anaerobic bacteria are a common cause of persistent fistula infections that do not respond to standard antibiotics. Identifying the specific organism allows physicians to prescribe targeted antibiotic therapy. Common anaerobic bacteria include Bacteroides, Clostridium, and Peptostreptococcus species. Positive results help differentiate between infection and other causes of fistula drainage, guide treatment duration, and may indicate need for surgical intervention if conservative treatment fails.
Frequently asked questions
Is the sample collection painful?
How long does it take to get results?
What if the culture is negative?
Can I have a fistula without infection?
Sources
- 1Mayo Clinic - FistulaSource
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy