Everything You Need to Know About Specimen Collection Swabs

Close up to the rubber gloves on the asian medical staff is processing coronavirus or covid-19 test in the negative room pressure

I. Introduction

A specimen collection swab is a medical device used to collect and transfer samples from the human body for laboratory testing and diagnosis. It consists of a fibrous swab tip attached to a shaft or stick.

Proper specimen collection is critical for obtaining accurate and reliable diagnostic test results, avoiding rejected or contaminated specimens, preventing delays in treatment and additional costs for providers and patients, maintaining quality patient care and operational efficiency, ensuring staff and patient safety from exposure risks, and fostering patient trust and adherence to recommendations. Following recommended collection procedures enables timely diagnosis and intervention, optimizes healthcare outcomes, promotes productive office operations, reduces legal/financial liabilities, and strengthens the patient-provider relationship. Attention to proper specimen collection techniques is thus an essential component of delivering high-quality healthcare services.


II. Types of Specimen Collection Swabs


A. Nasopharyngeal swabs

Description and Purpose:

  • ✅A nasopharyngeal swab is a device used to collect a sample of nasal secretions from the back of the nose and throat (nasopharynx region).
  • ✅The collected sample is analyzed for the presence of organisms or markers of disease.
  • ✅It is commonly used to diagnose viral infections like influenza, coronaviruses (SARS, MERS, COVID-19), whooping cough, and diphtheria.

Common Materials Used:

  • ✅The swab consists of a narrow plastic rod with an adsorbing tip made of materials like cotton, polyester, or flocked nylon.
  • ✅Some older swab handles were made of nichrome or stainless steel wire.
  • ✅Flocked swabs (nylon fibers perpendicular to shaft) have been shown to collect a larger sample volume compared to fiber swabs.
  • ✅The material composition may vary based on the specific diagnostic test.


B. Oropharyngeal swabs

Description and purpose:

  • ✅Oropharyngeal swabs are used to collect cell samples from the oropharynx, which is the part of the throat behind the mouth, specifically the posterior pharyngeal wall and tonsillar areas.
  • ✅They are used to detect the presence of pathogens or viral particles, such as SARS-CoV-2 for COVID-19 testing.
  • ✅Oropharyngeal swabs are often used in combination with nasopharyngeal swabs for more comprehensive sampling of the upper respiratory tract.
  • ✅The collected cellular material containing potential viruses/pathogens can then be tested using methods like PCR.

Common materials used:

  • ✅The swab tips are made of synthetic fibers, usually polyester, rayon, or nylon.
  • ✅The fibers on the tip are soft and flocked (perpendicular fibers) to effectively collect cells.
  • ✅The swab shaft is designed to be flexible enough to reach the back of the throat/oropharyngeal area during sample collection.


C. Urogenital swabs

Description and purpose:

    - Urogenital swabs are used to collect samples from the urogenital area, which includes the vagina, cervix, urethra, and surrounding areas. The samples can test for sexually transmitted infections, vaginitis, urethritis, and other urogenital infections/conditions.

Common materials used:

    - Common materials for urogenital swab tips include rayon, nylon flocked fibers, and polyester. The shafts are usually plastic or wire for rigidity during sample collection.


D. Rectal/Anal swabs

Description and Purpose:

  • ✅Anal/rectal swabs are a type of medical swab made from absorbent materials primarily used for collecting samples from the rectum.
  • ✅They are utilized in the diagnosis of certain infections, diseases, or conditions such as sexually transmitted infections (STIs), gastrointestinal disorders, or rectal cancers.
  • ✅The collected samples from the anal/rectal area are then analyzed in a laboratory to determine the presence of pathogens, abnormalities, or other medical issues.

Common Materials Used:

  • ✅For the anal swabs described, the swab tip is made of absorbent cotton material.
  • ✅The shaft/handle of the swab is made of polypropylene (PP) plastic.
  • ✅Cotton is chosen as it is soft, non-irritating, and gentle for sensitive areas like the rectum.
  • ✅Cotton fibers also have a high capacity to absorb and retain liquids, making them suitable for sampling.


E. Wound/abscess swabs

Description and purpose:

  • ✅Swabbing a wound is a common method in primary care for sampling a wound to collect microbiological specimens.
  • ✅The purpose is to identify infectious organisms present in the wound to help guide antibiotic treatment.
  • ✅Swabbing is only recommended if there are clinical signs of infection and the wound is deteriorating, increasing in size, or failing to heal.
  • ✅Swabbing a wound without infection leads to identifying colonizing, non-pathogenic bacteria rather than the causative infectious organisms.

Common materials used:

  • ✅Sterile swabs with cotton, alginate or rayon tips are commonly used.
  • ✅Sterile saline solution is used to moisten the swab tip before sampling to aid in picking up bacteria.
  • ✅The swab is passed over the wound surface in a zig-zag pattern while rotating to ensure the entire swab tip contacts the wound area.
  • ✅A separate swab may be used to sample any pockets or sinus tracts in the wound.
  • ✅The swab sample is then labeled with patient details and sent to a microbiology lab for bacterial culture and antibiotic susceptibility testing.


III. Proper Specimen Collection Techniques

Strict adherence to proper specimen collection and handling protocols is critical for obtaining accurate and clinically relevant microbiology laboratory results. Careful execution is required at every step, from pre-collection preparation to the actual collection, labeling, transportation, and delivery to the lab, in order to avoid contamination, changes to the microflora, compromised specimen quality, and other errors that could completely negate the value of the laboratory testing. Close collaboration and mutual respect between clinical staff and laboratory personnel is essential to develop and rigorously follow standard operating procedures that ensure diagnostic results are accurate and relevant to guide clinical treatment and ultimately provide high-quality patient care. Errors introduced by deviating from established protocols can lead to misleading results, inaccurate diagnoses, inappropriate therapies, and compromised patient outcomes.


A. Nasopharyngeal

To collect a nasopharyngeal swab specimen, use a flexible, flocked minitip swab. Measure the distance from the patient's nostril to the nasopharynx, which is approximately halfway to the base of the ear. Hold the swab at this measured length and gently insert along the floor of one nostril, straight back - not upwards. Advance the swab no further than this measured nasopharyngeal distance. Once the swab has reached the nasopharynx, rotate it 2-3 times while holding in place for 5 seconds. Carefully remove the swab and place it into a tube containing viral transport medium. Finally, break off the excess length of the swab shaft at the scored line to allow the tube to be capped securely. Proper technique is essential to collect an adequate sample from the nasopharyngeal area while avoiding injury.


B. Pharyngeal/Oropharyngeal

Before beginning, wash hands and gather the Xpert Swab Specimen Collection Kit containing a pink-capped transport tube with reagent and an individually wrapped swab.

  1. 1. Open the swab wrapper carefully, avoiding contact with the soft tip. Discard the larger extra swab.
  2. 2. While holding the collection swab, unscrew the cap from the transport tube, being careful not to spill the contents.
  3. 3. Immediately place the swab into the open transport tube.
  4. 4. Locate the scoreline on the swab shaft. Hold the shaft with your thumb and forefinger at the scoreline.
  5. 5. Instruct the patient to open their mouth wide and position their tongue down.
  6. 6. Swab the pharyngeal areas thoroughly, including the tonsils, posterior pharyngeal wall, uvula, and surrounding areas.
  7. 7. Withdraw the swab and carefully snap the shaft against the side of the tube at the scoreline to break off the top portion. Avoid splashing.
  8. 8. Re-cap the transport tube tightly with the swab portion inside the reagent.
  9. 9. Invert or gently shake the capped tube 3-4 times to elute the sample into the reagent. Avoid foaming.
  10. 10. Label the tube with patient identification and date of collection.
  11. 11. Transport the specimen at 2-30°C. It can be stored that way for up to 60 days prior to testing.


C. Oral

Begin by using a swab to remove any oral secretions or debris from the surface of the lesion. Then, take a second fresh swab and vigorously sample the lesion itself, being careful to avoid collecting normal surrounding tissue. Superficial swab samples from just lightly brushing the surface are not adequate - the swab should be vigorously sampled across the lesion. Whenever possible, submit an actual tissue sample or needle aspirate from the lesion rather than just a swab, as those specimen types are preferred over swabs for optimal diagnostic testing. Proper sampling technique that obtains cells/material from within the lesion is crucial for an accurate laboratory diagnosis.


D. Nasal

Using a sterile swab, gently insert it into one nostril until you meet resistance at the level of the turbinates, which is approximately 1-2 cm into the nose. Once inserted to that depth, rotate the swab firmly against the nasal mucosal surface for 3 seconds. Apply slight external pressure on the outside of the nose with your finger to ensure good contact between the swab and the inside of the nasal cavity. Then, using the same swab, repeat this sampling technique in the other nostril. Proper technique with insertion depth, rotation, and compression is important to collect an adequate sample of nasal secretions from both nasal turbinate areas. Avoid inserting the swab too deeply into the nasopharyngeal area.


E. Genital

For genital cultures to detect Neisseria gonorrhoeae, an Amies liquid transport swab should be used. Transport the swab to the microbiology laboratory immediately after collection.

Endocervical specimen:

Before beginning, gather the Mantacc Vaginal/Endocervical Specimen Collection Kit which contains: A) Pink-capped transport tube with reagent and individually wrapped collection swab B) Large individually wrapped cleaning swab

  1. 1. Open package A containing the transport tube and collection swab. Set the tube aside.
  2. 2. Open the collection swab wrapper carefully, avoiding contact with the soft tip.
  3. 3. Use the large cleaning swab (B) to remove excess mucus from the cervical os and surrounding area. Discard this cleaning swab.
  4. 4. Insert the collection swab into the endocervical canal. Gently rotate the swab clockwise for 10-30 seconds while in the canal.
  5. 5. Withdraw the swab carefully.
  6. 6. While holding the collection swab, unscrew the cap from the transport tube, being careful not to spill the contents.
  7. 7. Immediately place the collection swab into the open transport tube.
  8. 8. Locate the scoreline on the swab shaft. Hold at the scoreline and carefully snap the shaft against the tube to break off the top portion. Avoid splashing.
  9. 9. Re-cap the tube tightly with the swab portion inside the reagent.
  10. 10. Invert or gently shake the capped tube 3-4 times to elute the sample into the reagent. Avoid foaming.
  11. 11. Label the tube with patient identification and date of collection.

Vaginal specimen:

Before beginning, the patient should wash their hands and undress from the waist down.

  1. 1. Open package A containing the pink-capped transport tube with reagent and individually wrapped collection swab. Discard the larger swab B.
  2. 2. Open the collection swab wrapper carefully, avoiding contact with the soft tip.
  3. 3. With the patient in a comfortable position, they should carefully insert the swab about 5 cm (2 inches) into the vaginal opening.
  4. 4. Once inserted, gently rotate the swab for 10-30 seconds, ensuring the swab touches the vaginal walls to absorb moisture.
  5. 5. Withdraw the swab carefully while still holding it.
  6. 6. Unscrew the cap from the transport tube, being careful not to spill the contents.
  7. 7. Immediately place the collection swab into the open transport tube.
  8. 8. Locate the scoreline on the swab shaft. Hold at the scoreline and carefully break the swab shaft against the side of the tube to snap off the top portion. Avoid splashing.
  9. 9. Re-cap the tube tightly with the swab portion inside the reagent.
  10. 10. The patient should return the capped and labeled tube as instructed.
  11. 11. A healthcare provider should then invert or gently shake the tube 3-4 times to elute the sample into the reagent, avoiding foaming.
  12. 12. Label the tube with patient identification and collection date.

Urethral specimen:

  1. 1. Instruct the patient not to urinate for at least 1 hour prior to collection.
  2. 2. Insert a small, narrow swab 2-4 cm into the urethral lumen.
  3. 3. Once inserted, rotate the swab gently to collect the sample.
  4. 4. Leave the swab in place for 2 seconds to facilitate absorption before withdrawing.


F. Rectal

Before beginning, wash hands and gather the materials - the Mantacc Rectal Swab Specimen Collection Kit containing a pink-capped transport tube with reagent and an individually wrapped swab.

  1. 1. Open the swab wrapper carefully, avoiding contact with the soft tip. Discard the larger extra swab.
  2. 2. While holding the collection swab, unscrew the cap from the transport tube, being careful not to spill the contents.
  3. 3. Immediately place the swab into the open transport tube.
  4. 4. Locate the scoreline on the swab shaft. Hold the shaft with your thumb and forefinger at the scoreline.
  5. 5. Carefully insert the swab about 1 cm past the anal sphincter and rotate gently to collect the sample.
  6. 6. Withdraw the swab and carefully snap the shaft against the side of the tube at the scoreline to break off the top portion. Avoid splashing.
  7. 7. Re-cap the transport tube tightly with the swab portion inside the reagent.
  8. 8. Invert or gently shake the capped tube 3-4 times to elute the sample into the reagent. Avoid foaming.
  9. 9. Label the tube with the patient identification and date of collection.
  10. 10. Transport the specimen at 2-30°C. It can be stored that way for up to 60 days prior to testing.


G. Wound/abscess

For optimal recovery of organisms from an abscess, tissue samples or needle aspirates are vastly superior to swab samples. First, wipe away any surface exudate by cleaning with sterile saline or 70% alcohol. Then, using a needle and syringe, aspirate material directly from the abscess cavity.

For the aspirated sample, cleanse the rubber stopper of an anaerobic transport vial (cat# 59546) with alcohol and allow it to fully dry for 1 minute before inoculating. Push the needle through the stopper's septum and inject the entire volume of aspirated abscess material onto the vial's agar surface.

If a swab specimen must be collected instead, pass the swab deeply into the base of the abscess lesion and firmly sample the fresh, leading edge of the abscess. Avoid just swabbing the surface.

Tissue or aspirate samples should be transported to the laboratory promptly, within 2 hours of collection if possible, to preserve organism viability. Proper specimen collection from the active interior of the abscess is critical, rather than just swabbing surface areas, in order to recover the causative pathogens accurately.


IV. Quality Control and Safety Measures

Strict protocols were followed including establishing a negative pressure room with air disinfection systems for specimen collection, thorough training of dedicated nurses on proper PPE use and swabbing techniques, requiring full PPE with N95 masks that was changed every 4 hours, rotating nurses in 2-hour shifts, obtaining patient consent and preparing them appropriately, using viral transport media tubes and carefully swabbing the nasopharyngeal/oropharyngeal areas without contamination, promptly placing swabs in biohazard bags, storing at 4°C, and transporting to the lab within 2 hours. Psychological support was provided to nurses as well. These comprehensive environmental controls, training, PPE requirements, standardized collection procedures, and safe specimen handling measures together aimed to ensure high-quality diagnostic samples while protecting staff from infection risks.


V. Troubleshooting Common Issues

  1. 1. Expired Collection Products:
    •     - Do not use expired swab kits or transport media as components degrade over time, leading to false results.
    •     - Check expiration dates and replace any expired products by contacting supply chain or lab.
  2. 2. Anaerobic Cultures:
    •     - Swabs are inappropriate for anaerobic cultures as the cotton fibers inhibit growth.
    •     - Use needle aspirates or tissue samples placed in anaerobic transport medium instead of swabs.
  3. 3. Leaky Lukens Traps:
    •     - Do not transport respiratory samples like endotracheal aspirates in Lukens traps closed only with tubing as they often leak.
    •     - Use the provided screw-top transport caps to prevent leaks that risk contamination.
  4. 4. Surveillance Cultures (MRSA, C. diff):
    •     - Use the correct swab kit for each - Copan eSwab for MRSA nares, BD CultureSwab for C. diff rectal.
    •     - Wrong swabs lead to mix-ups giving potential false negatives. Recollect if needed.
  5. 5. Specialized Cultures:
    •     - Some cultures like AFB, fungal blood, and viral require special transport media.
    •     - Check test menu or call lab for media needs. Generic swabs may not suffice.


VI. What We Need to Do

Proper specimen collection using swabs is a critical first step for obtaining accurate and meaningful microbiology culture results. From selecting the right swab type and transport medium, to mastering specific collection techniques for different specimen sources, to handling swabs carefully to preserve organism viability and avoid contamination - attention to detail in swab-based specimen procurement is vital.

While molecular diagnostic methods are increasingly used, culture remains an essential tool for comprehensive pathogen identification and antimicrobial susceptibility testing. Ensuring high-quality specimens make it to the laboratory is a team effort, requiring close collaboration between clinicians, nurses, laboratory staff, and all other personnel involved in the specimen management process.

Healthcare facilities should provide ongoing education and training reinforcing best practices, have systems in place to remove expired supplies, and encourage open communication channels so any swab collection issues can be promptly addressed. Investing time and resources into implementing rigorous swab specimen protocols ultimately pays dividends through improved diagnostic fidelity, better patient outcomes, and prevention of healthcare-associated infections.

With emerging threats from antibiotic resistance and novel pathogenic agents, maintaining excellence in this fundamental aspect of the microbiology workflow is more critical than ever before. Swab-based sampling may seem simple, but it deserves the utmost care and attention to detail at all times.

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