Which is the Best Type of Swab to Use When Diagnosing the Flu?
To the average patient, a flu test may seem simple. Stick a long swab up someone's nose and test the swab for the virus. Easy, right?
We know differently.
Diagnosing the flu is a process, and like any other scientific process, it requires specific tools, the first of which is a specimen collection swab. But which type of swab is the best tool for the job?
The American Society for Microbiology (ASM) recommends flocked swabs as the preferred specimen collection device for flu testing. In fact, flocked swabs have been hailed by the microbiology and diagnostic communities for their ability to absorb and elute more specimen than traditional spun fiber or foam swabs.
How does the flocked swab work? At the microscopic level, the synthetic tip of a flocked swab is more abrasive than cotton and is therefore able to recover and elute more specimens. The brush-like tip of the flocked swab also provides for better sample collection and specimen release during testing.
Many physicians also find flocked swabs easier to use and report less patient discomfort than with other swab types.
Cotton Tipped Swabs:
The traditional spun cotton tipped swab is one of the most ubiquitous single-use devices in the medical industry. They're absorbent, soft, low cost, safe and incredibly useful in some applications, but they are not recommended for specimen collection.
Why is that, you ask? Cotton does not allow for the specimen to be released from the swab tip easily. The very nature of the spun fiber means the entrapment of the specimen. Cotton also has naturally occurring fatty acids that interfere with the processes used in microbiology.
Rayon and Polyester Tipped Swabs
Like the cotton swabs, rayon tipped swabs are made from spun fiber. They are low cost, soft and absorbent, but can be used for many applications where cotton would not be suitable, such as for specimen collection.
While not quite as efficient as the flocked swab, the manufacturing process for rayon tipped applicators eliminates any components that may damage the specimen or interfere with specimen transport or processing.
Polyester tipped swabs are the next step-up when it comes to specimen collection. They have excellent collection properties and, while somewhat more costly than cotton or rayon, are not as absorbent and boast superior release properties. Polyester fiber has been tested and validated for use in specimen collection in microbiology, rapid diagnostic tests and PCR analysis.
Foam Tipped Swabs
Medical grade polyurethane foam is also used as a tip material for diagnostics. The advantage of using a foam tipped swab is that they come in various tip shapes, sizes and porosities, so your intended use dictates which foam tipped swabs will work best.
All of these swab options are offered in sterile individually wrapped peel pouches or in dry transport tubes.