Respiratory diphtheria
Diphtheria commonly infects the respiratory system and can cause:

• Weakness
• Sore throat
• Nasal discharge
• Mild fever
• Difficulty breathing or rapid breathing
• Swollen glands (enlarged lymph nodes) in the neck

Diphtheria makes a toxin that kills healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, gray coating that can build up in the throat or nose.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow.

If the toxin gets into the blood stream, it can cause heart, nerve, and kidney damage. Severe diphtheria can result in difficulty breathing, heart failure, paralysis, or death.

Skin diphtheria
Diptheria can also infect the skin and can cause:

• Redness and swelling
• Open sores or ulcers

Skin infections caused by diphtheria will rarely result in severe disease.

Diphtheria most often spreads from person to person through respiratory droplets, like from coughing or sneezing. People can also get sick from touching open sores or ulcers from an infected person.

Anyone infected with diphtheria can spread the disease, even if they have no symptoms or only mild symptoms.

Those at increased risk of getting sick include people who do not have diphtheria immunity and are:

• In the same household or who have frequent contact with an infected person
• Exposed to open sores or ulcers from the suspected infection site (e.g., mouth, skin) of an infected person

CDC recommends that persons who are exposed to someone with diphtheria receive antibiotics to prevent them from getting sick. In addition to getting antibiotics, exposed persons should be:

• Monitored for symptoms for 7 to 10 days from when they were last exposed to the infected person
• Tested for diphtheria with a sample collected from the nose and throat
• Given a diphtheria booster shot if they are not up to date with their vaccines

The best way to protect against diphtheria is to get vaccinated. The diphtheria vaccines protect nearly everyone (97 in 100) against diphtheria for approximately 10 years.

There are three kinds of vaccines used in the United States today to help protect against diphtheria, all of which also provide protection against other diseases:

• Diphtheria, tetanus, and pertussis (DTaP) vaccines
• Tetanus, diphtheria, and pertussis (Tdap) vaccines
• Tetanus and diphtheria (Td) vaccines

There are many places to get the diphtheria vaccine. If you have insurance, talk to your doctor or check with your local pharmacy to see what vaccines are offered. Most health insurances cover the cost of all recommended vaccines for children and adults.

If you are uninsured or underinsured, there are programs available to help cover the cost of vaccines. Children who are 18 years of age or younger are eligible to receive vaccines at no cost through the Vaccines for Children (VFC) Program if they are:

• Eligible for or are enrolled in Medi-Cal
• American Indian or Alaskan Native
• Uninsured (do not have health insurance)
• Underinsured (private health insurance does not cover the full cost of vaccines)

Click to see if your child is eligible to receive VFC vaccines: English | Spanish

Uninsured or underinsured adults can access free or low cost vaccines at select clinics enrolled in the Vaccines for Adults (VFA) program. For more information on who is eligible, read VFA Eligibility Based on Insurance Status. You can use the following resources for more information on locating clinics:

• A list of free and low-cost clinics in Los Angeles County.
• Interactive county map to locate free and low-cost vaccine clinics.
• LACDPH Vaccine Preventable Disease Control Program website for patients and their families to get more information on vaccines.

You can also dial 2-1-1 for a list of free or low cost vaccine clinics. This includes Vaccines for Children (VFC) provider locations that serve Medi-Cal eligible children and uninsured or underinsured adults. Learn more about specific vaccine information for different age groups:

• Vaccines for Infants and Children (LACDPH)
• Vaccines for Adolescents and Teens (LACDPH)
• Vaccines for Adults (LACDPH)

• Diphtheria (CDC)
• Diphtheria Vaccines (CDC):
• Tdap Vaccine for Preteens and Teens Fact Sheet (CDC):
• English | Spanish
• Diphtheria (Vaccinate Your Family)
• DTaP (Diphtheria, Tetanus, Pertussis) Vaccine (Voices for Vaccines)
• DTaP Vaccine Fact Sheet- Preparing for Your Child’s Well Baby Visit (Voices for Vaccines)
• Diphtheria Personal Stories (Shot by Shot)

Infection with C. diphtheriae can present with respiratory or cutaneous disease, but can disseminate to affect the heart, the nervous system, and the kidneys.

Respiratory diphtheria

• Respiratory diphtheria can present with a bluish – white membrane (pseudomembrane), a key diagnostic feature of diphtheria along with sore throat, low – grade fever, neck swelling due to cervical lymphadenopathy (bull neck), and difficulty swallowing.
• The membrane can involve all parts of the respiratory tract from the nasal passages to trachea.
• Most complications of respiratory diphtheria, including death, are attributable to effects of the diphtheria toxin. The most common complications of respiratory diphtheria include myocarditis and neuritis. Other complications include otitis media and respiratory insufficiency due to airway obstruction, especially in infants.
• The risk of developing myocarditis and other toxicities is proportional to the severity of local infection and can range from 10-25% of all patients.
• The overall case-fatality rate for diphtheria is 5%–10%, with higher death rates (up to 20%) among persons younger than 5 and older than 40 years of age.

Cutaneous diphtheria

• Cutaneous diphtheria causes a scaling rash or non-healing skin ulcers that have clearly demarcated edges and an overlying membrane. Cutaneous diphtheria infections rarely cause system disease.

Presumptive diagnosis of respiratory diphtheria is usually made on the basis of clinical presentation and epidemiological risk factors (e.g. travel to endemic areas with low immunization coverage) since it is imperative to begin presumptive therapy quickly. However, definitive diagnosis for diphtheria infection is made by isolating C. diphtheriae and testing the isolate for toxin production by the Elek test.

• Culture – Nasal, oropharynx, and throat specimens can be collected on separate swabs (cotton or synthetic swab) and place into separate Bacterial Culturettes or if available, a Diphtheria Culture Kit.
  • Collect a specimen from beneath the “adherent membrane”, on the pharyngeal tonsillar area of the oral cavity for patients who are symptomatic. Store specimen in sterile saline.
  • Specimens from an open sore or ulcer can also be obtained for culture to determine if the bacteria that causes diphtheria grows from the sample.
• Virulence testing - If diphtheriae is found on cultures of nose or throat, isolate should be sent to Public Health Lab for additional testing.
• Collect specimens before the patient starts antibiotic treatment.

Specimen Storage

• Store swabs and pseudomembrane culture specimens in the refrigerator at (2-8°C) *.
• Isolates should be stored at room temperature (15-25°C).
• Transport refrigerated on cold packs to the laboratory overnight.

*If specimen cannot be transported to Public Health Laboratory within 8 hours, keep cool in refrigerator (2-8°C) (do not freeze) until lab pick-up the next day. Ship with a cold pack. Specimens should be transported and received in the PHL within 24 hours of collection.

Contact the Vaccine Preventable Disease Control (VPDC) Program for additional guidance on specimen collection and transport to PHL. See Reporting section for contact information.

Proper vaccine storage and handling practices play an important role. For general recommendations and guidance access the Vaccine Storage and Handling Toolkit.

Please contact the LAC DPH Vaccine-Preventable Disease Control Program to report a case, obtain any other technical assistance with specimen collection or completion of forms for diphtheria.  

Confirmed or suspected diphtheria cases are to be reported immediately from identification, by telephone to Los Angeles County Public Health Department. (Title 17, Section 2500, California Code of Regulations).

• Weekdays Telephone: 8:30 am to 5:00 pm: Call 213-351-7800 
• After Hours: Call 213-974-1234 
• Email: vpdc@ph.lacounty.gov  
• Fax number: 213-351-2782 

Click here for more information on reporting a Vaccine Adverse Event.

Patients who have suspect or confirmed respiratory diphtheria, according to the Council of State and Territorial Epidemiologists case definition, are eligible to receive Diphtheria Antitoxin (DAT) early in the course of disease. DAT may also be used in cases of respiratory diphtheria-like illness caused by laboratory-confirmed toxigenic C. ulcerans. A patient’s eligibility for treatment will be determined through discussion between the CDC diphtheria duty officer and the treating clinician.

Physicians requesting DAT should contact the LA County Vaccine Preventable Disease Control Program (VPDCP) at 213-351-7800 during normal working hours to arrange for its release from the CDC Quarantine Station at Los Angeles International Airport. After working hours, contact the Administrative Officer of the Day through the County Operator at 213- 974-1234.

Treatment of cutaneous diphtheria with antibiotics is usually sufficient, and antitoxin is typically not needed.  Appropriate antibiotic therapy should be administered for at least 14 days to kill the organism and prevent further toxin production. Antibiotics recommended for the treatment of diphtheria include:

• Erythromycin – 10 mg/kg/dose up to a maximum of 500 mg IV/po 4 times a day for 14 days.
• Procaine Penicillin G – 300,000 units IM every 12 hours for patients <10kg, and 600,000 units IM every 12 hours.
  • Switch to oral penicillin V (250 mgs 4 times a day for 14 days) once the patient is able to tolerate oral intake.

• Diphtheria (CDC)
• Diphtheria Checklist for Providers (LAC DPH)
• Diphtheria, Tetanus, and Pertussis Vaccination: Information for Healthcare Professionals (CDC)
• Pink Book – Diphtheria Chapter (CDC)
• Ask the Experts: Diphtheria Vaccine Products (immunize.org)
• DTaP/IPV/Hib/HepB ACIP Vaccine Recommendations (CDC)
• DTaP/Tdap/Td ACIP Vaccine Recommendations (CDC)
• Catch-Up Guidance for Children
  •  4 months – 6 years | 7 – 18 years (CDC)
• DTap (Diphtheria, Tetanus, Pertussis (VIS)
• Tdap (Tetanus, Diphtheria, Pertussis) (VIS)
• Multiple Vaccines (DTaP, Hib, Hepatitis B, PCV, and Polio)
• Vaccine Safety (CDC)
• Paying for Vaccines (LAC DPH)
• Child and Adolescent Vaccine Assessment Tool (CDC)
• The Adult Vaccine Assessment Tool (CDC)