Diphtheria: Causes, Signs, Treatment & How to Prevent It

Diphtheria is a serious bacterial infection that mainly affects the throat and breathing passages. Though it is now rare in many countries because of widespread vaccination, diphtheria can still occur if people are not properly immunized. In this article, we will explain what diphtheria is, what causes diphtheria and how it spreads, how to recognize early signs and symptoms of diphtheria, the best diphtheria treatment options, and most importantly, how to prevent diphtheria in kids and adults. 

What Is Diphtheria and How It Spreads 

Diphtheria is caused by the bacterium Corynebacterium diphtheriae. When someone with diphtheria coughs or sneezes, they release droplets that carry the bacteria into the air. Another person can breathe in these droplets and become infected. Touching contaminated objects—like utensils or toys—and then touching the mouth or nose can also spread diphtheria. 

• Mode of transmission: Respiratory droplets, close contact, contaminated surfaces 
• Incubation period: Typically 2–5 days after exposure 
• Risk factors: Unvaccinated status, crowded living conditions, poor hygiene 

Causes of Diphtheria 

Bacterial Toxin Production 

Once C. diphtheriae enters the throat, it produces a toxin that damages tissues. The toxin kills cells in the throat lining, creating a thick gray membrane that can block the airway and make breathing difficult. 

“Diphtheria is caused by a toxin-producing strain of Corynebacterium diphtheriae.” (CDC) 

Why Some People Are More Vulnerable

• Children under 5 years and adults over 60 are at higher risk. 
• People with weak immune systems or malnutrition may experience more severe disease. 
• Unvaccinated individuals or those whose last dose was more than 10 years ago can become susceptible. 

Signs & Symptoms of Diphtheria 

Recognizing diphtheria symptoms early can save lives. Symptoms usually start with mild throat irritation but can progress rapidly. 

Common Symptoms 

• Sore throat and hoarseness 
• Low-grade fever and chills 
• Swollen glands (lymph nodes) in the neck 
• Thick gray or white patch (pseudomembrane) on the tonsils, throat, or nasal tissues 

More Severe Signs 

• Difficulty breathing or rapid breathing 
• Bluish skin due to lack of oxygen 
• Nasal discharge (may be bloody) 
• Weakness and general fatigue 

Recognizing in Children vs. Adults 

• In children, look for irritability, poor feeding, drooling, and trouble swallowing. 
• In adults, hoarseness and fatigue may be more prominent before respiratory distress sets in. 

Diagnosing Diphtheria in a Lab 

When diphtheria is suspected, a healthcare provider will: 

• Swab the throat or membrane region. 
• Culture the sample in the lab to grow the bacteria. 
• Confirm toxin production using specific tests. 

Lab confirmation helps distinguish diphtheria from other throat infections and guides the correct diphtheria treatment. 

Treatment of Diphtheria 

Quick and proper diphtheria treatment can prevent severe complications. 

Antitoxin Administration 

• Diphtheria antitoxin neutralizes the toxin. 
• Dosage depends on severity; given by injection. 
• Early administration is crucial—antitoxin does not reverse damage already done but stops further harm. 

Antibiotics Used to Treat Diphtheria 

• Erythromycin or penicillin are the most common choices. 
• Antibiotics kill the bacteria and prevent spread to others. 
• Typical course lasts 14 days. 

Hospital Care for Severe Cases 

• Airway support: In critical cases, a breathing tube (intubation) or tracheostomy may be required. 
• Isolation: Keep patients in respiratory isolation to reduce transmission risk. 
• Monitoring: Watch for complications like heart or nerve damage. 

Side Effects of Treatment 

• Some people may experience allergic reactions to antitoxin or antibiotics. 
• Common antibiotic side effects: nausea, diarrhea, rash. 
• Notify the doctor immediately if severe reactions occur. 

Complications of Untreated Diphtheria 

If untreated, diphtheria can cause: 

• Heart damage (myocarditis) leading to heart failure 
• Nerve injury causing paralysis, especially of the diaphragm 
• Death, particularly in young children 

How to Prevent Diphtheria 

Importance of DTP Vaccine for Diphtheria 

The DTP (Diphtheria–Tetanus–Pertussis) vaccine is the cornerstone of prevention. In India, the recommended diphtheria vaccination schedule in India is: 

• Primary series: At 6, 10, and 14 weeks of age 
• Boosters: 16–24 months, 5 years, and 10 years 

Booster Doses and Adult Vaccination 

• Td vaccine (Tetanus–Diphtheria) is given to older children and adults. 
• Boosters every 10 years ensure lasting immunity. 
• Who should get diphtheria vaccination: All children and adults without a recent booster. 

Herd Immunity and Community Protection 

When over 80% of a community is immunized, diphtheria spread drops significantly. Protecting infants too young for vaccination relies on high community coverage. 

Hygiene Measures 

• Cover mouth and nose when coughing or sneezing. 
• Wash hands regularly with soap and water. 
• Disinfect shared items and surfaces.