What is Conjunctival Swab Culture?
The conjunctiva is a piece of tissue which is located in such a manner that it covers the outer eye and thus acts as a connection between the internal structure of the eye and the external environment. It comes into contact with different microorganisms, allergens and other irritants that can lead to infections or inflammatory reactions.
A conjunctival swab culture is a diagnostic test which is used in the identification of bacterial, viral and fungal pathogens in the conjunctiva which is the mucous membrane that covers the area around the eye and inside the eyelids. This test is very important in identification of pathogens in conjunctivitis also known as pink eye and other ocular infections to enable appropriate treatment to be given. A conjunctival swab culture helps to distinguish between different infectious agents and determines whether the infection is bacterial, viral or fungal.
How is the Test Performed?
The test is minimally invasive and simple procedure involving the collection of the sample from the conjunctival surface.
Preparation
- The doctor advises to stop using eye drops and medications before the test.
Collection
- The sample is collected by the healthcare professional, by gently swabbing with Dacron swab or sterile cotton on the lower conjunctival sac or the affected area.
Laboratory Analysis
- The sample is then analyzed in the laboratory by culturing it on various mediums
What are the symptoms that prompt this test?
The healthcare provider warrants this test when the person is showing the following symptoms;
General Symptoms
- Discharge from the eyes
- Redness in the sclera
- Vision blurriness
- Swelling of the eyelids
- Burning and Itching in the eyes
What are Normal Ranges for This Test?
This test is a qualitative test and the result is reported as the presence or absence of the pathogen. The result is interpreted according to the type of the bacteria.
- Normal flora – Presence of non-pathogenic bacteria in low quantity
- Pathogenic bacteria – Detection of pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, or Pseudomonas aeruginosa.
- Fungal Pathogens – Detection of Candida or Aspergillus
- Presence of Virus – Adenovirus or herpes simplex virus presence
**Additional testing such as antibiotic susceptibility testing is required to start an effective treatment if abnormal microbial growth is detected. **
What Happens if Test Results Show Abnormal Levels?
Abnormal microbial growth indicates the presence of an active infection that requires immediate medical intervention. The treatment depends on the type of the pathogen diagnosed;
Bacterial Infection
- Antibiotics or eye drops are suggested such as tobramycin and ciprofloxacin
Fungal Infection
- Antifungal medications are given including natamycin or amphotericin B
Viral Infection
- Antiviral medications are prescribed for herpes-related disorders including acyclovir
Severe Cases
- Steroid therapy and even hospitalization in extreme cases.
On-time diagnosis and treatment is crucial for the prevention of complexity such as ulcers in the cornea, loss of vision, and systemic infections.
