Diphtheria Culture (from Nasopharyngeal Swab)

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like sore throat, fever, or difficulty breathing, especially if you’ve been exposed to someone with diphtheria. It’s also used to confirm a diagnosis in suspected cases or to monitor immunity in people who’ve received the diphtheria vaccine.

What to Expect Before the Test

You’ll likely have a quick swab of your throat or nose taken by a healthcare professional. No special preparation is needed, but avoid eating or drinking for about 30 minutes before the procedure if instructed.

What Happens During the Test?

The swab is placed in a sterile container and sent to a lab, where it’s cultured over several days to see if the bacteria grows. Results may take up to 7 days or longer, depending on the lab’s process.

What Are the Results Mean?

A positive result means the bacteria responsible for diphtheria was found. This requires immediate medical attention, as treatment with antibiotics and potentially antitoxin may be needed. A negative result means no diphtheria bacteria were detected in this sample.