ESwab™ for Ophthalmology! Diagnosing Bacterial Keratitis
Posted: November 13, 2015
We all lead busy, fast-paced lives. The reality is that with so much on our plates, our health tends to take a back seat. All too often we wait until major symptoms arrive, or progress, before we receive the message our body is giving us and take action. Benjamin Franklin wrote, “An ounce of prevention is worth a pound of the cure.” But, once passed the point of prevention, collection and diagnosis for treatment are your next best applications to get you back to an optimal state of health. In this week’s blog, we examined the use of ESwab™ for collection and diagnosis of bacterial keratitis in patients based on the study, The Corneal Ulcer One-Touch Study: A Simplified Microbiological Specimen Collection Method, published on September 11, 2014 by the American Journal of Ophthalmology.
Bacterial keratisis or ‘infectious corneal ulcer’, is due to the spread of microorganisms (including bacteria, fungi, viruses and parasites) which can inflame or destroy the eye. Such an incident occurs either due to injury or poor hygiene with contact lens use. Bacterial keratitis is fast moving and if left untreated, can potentially lead to blindness. The prescribed treatment is antibiotic drops, however sometimes the patient may require surgery. Keratitis is an opportunistic infection, meaning that by protecting the integrity of the normal corneal flora in the eye, which naturally helps fight off infection, one can help the prevention of an ulcer.
When injury or symptoms are present, the traditional methods of collection and diagnosis for keratitis involve scraping the cornea with either a sharp blade or sterile spatula, followed by antimicrobial susceptibility testing. In order to identify the pathogen, the sample (which has a very low microbial count) is plated onto several agar plates, including: blood, chocolate, Lowenstein-Jensen medium, Thayer-Martin, Sabouraud and Thyoglicollate broth. This requires multiple corneal scrapings (between 5-7), which is an uncomfortable experience for any patient and also increases the risk for contamination. The current method is also expensive to ophthalmologists, especially those who are non-corneal specialists, who prefer empiric therapy. For most, having to stock, preserve and properly transport unexpired media is a heavy deterrent and can be costly. Thus, efficient alternatives are sought out.
Testing a new ‘one-touch’ method using ESwab™, the study found that they were able to reduce collection down to only one sample taken from the cornea! ESwab™ consists of one FLOQSwab™ (flocked swab) and a tube containing 1mL of Liquid Amies transport medium. Collection using FLOQSwabs™ improves results with a higher rate of both specimen collection and release, than that of traditional swabs. The short fiber strands, which create a thin absorbent layer ensure that the entire sample stays close to the surface for complete elution. After collection, the swab is broken into the transport tube filled with 1mL of liquid Amies, and can be plated at the point of care. Alternatively, the sample can be easily transported to the lab, using the ESwab™ collection and transport system.
To test the ESwab™ system, eighty-one eyes from 80 patients were sampled. The culture positivity rate for the multi-sample method and ESwab™ were 70% and 69% respectively, with a 75% agreement rate. The sensitivity rate for ESwab™ was 84%.
With its impressive statistics for culture growth backed by countless studies, ESwab™ not only proves to be a comparable option, but also preferred for its accessibility and ease of use now in corneal culturing. ESwab™ is easy to store and manufactured for convenient transport! The outcomes of this study are great news for ophthalmologists and patients alike! Ophthalmologists are happy because ESwab™ is easy to use for collection, yields an excellent return of sample, is less invasive to the patient, can be preserved for up to 48 hours, and provides up to 10 aliquots of sample for testing. Patients are happy because ESwab™ is much less invasive, and reduces the amount of samples to be collected. The study was another great example of the versatility that the innovation of ESwab™ offers both physicians and patients alike.