How is diphtheria spread?

When an infected person coughs, sneezes, or talks at close range, bacteria may travel in respiratory secretions. Touching saliva, nasal discharge, or fluid from a skin lesion can also spread the bacteria, particularly when hands then touch the nose or mouth. Shared personal items may carry secretions. Transmission is more likely with prolonged close contact, but the exact risk cannot be judged from distance alone.

A person may carry bacteria without dramatic symptoms. Immunisation reduces the chance that exposure will lead to toxin-related disease, but it does not make a possible exposure irrelevant.

If exposure is possible, contact a healthcare service promptly and explain when and how it happened. Avoid close contact and do not share cups, utensils, towels, or toothbrushes until advised. Wash hands after coughing, sneezing, or touching a sore, and cover coughs with a tissue or elbow. Follow instructions about testing, antibiotics, and contact precautions. See [Sore Throat](/symptoms/sore-throat/), [Antibiotic Treatment](/treatments/medical-management/antibiotic-treatment/), and [Childhood Immunisation](/treatments/preventive-care-and-vaccination/childhood-immunisation/).

Call emergency services for breathing difficulty, noisy breathing, inability to swallow saliva, blue lips, collapse, or rapidly worsening neck swelling. Seek same-day advice after a known exposure, or for a sore throat with a thick coating, marked weakness, or a skin ulcer that is not healing. Keep the person with possible infection away from close contacts until assessed.

Ask whether household members need assessment, whether preventive medicine is appropriate, and whether your immunisation record is complete. Confirm which symptoms require urgent review and how long precautions should continue.