Diphtheria

Diphtheria is an infection of the respiratory tract or skin caused by a bacterium known as Corynebacterium diphtheriae. The organism is transmitted from person to person through exposure to respiratory secretions or fluid from infected skin. The incubation period ranges from one to six days. In respiratory tract infections, the main symptoms are sore throat and fever, sometimes accompanied by nausea, vomiting, headache, and swelling of the neck. A distinctive grayish membrane, which is particularly characteristic of diphtheria, may develop in the throat or other areas of the oral cavity and may obstruct breathing. Other complications may include nerve weakness (neuropathy), inflammation of the heart (myocarditis), or pneumonia. Prompt administration of diphtheria antitoxin (serum containing diphtheria antibodies) is essential. At the present time, there is no preparation of diphtheria antitoxin licensed in the United States. However, diphtheria antitoxin produced by Pasteur Merieux, Lyon, France is licensed in Europe and is available in the United States through an Investigational New Drug (IND) protocol through the CDC. Physicians treating a case of suspected diphtheria can telephone the diphtheria duty officer at (404) 639-8255 from 8 a.m. to 4:30 p.m. Eastern time or (404) 639-2889 at all other times. Penicillin or erythromycin should also be given, though not as a substitute for antitoxin. Cases of respiratory tract diphtheria must be strictly isolated. Contacts should be given a booster dose of diphtheria vaccine. Contacts who may not have immunity to diphtheria should also be given a course of prophylactic antibiotics.

Diphtheria of the skin is typically an indolent, chronic infection, seen most often in the tropics, but observed elsewhere in settings of poverty and poor hygiene. All skin infections should be treated with antibiotics, but some longstanding cases may not require antitoxin.

Combined tetanus-diphtheria vaccine is recommended for all adults who have not been immunized within the past 10 years. Diphtheria vaccine consists of diphtheria toxin that has been inactivated by formaldehyde and adsorbed onto aluminum salts to increase its effectiveness. The vaccine is routinely given, in combination with tetanus and pertussis vaccines, to all children at ages 2 months, 4 months, 6 months, 15-18 months, and 4-6 years, followed by a tetanus-diphtheria booster every 10 years thereafter. An accelerated immunization schedule is recommended for children who have not completed their immunizations and who will be traveling to developing countries, especially the newly independent states of the former Soviet Union, where a massive diphtheria epidemic is in progress. Unvaccinated persons more than seven years of age should receive three doses of adult tetanus-diphtheria vaccine. The first two doses should be separated by 4-8 weeks, and the third dose should be given 6-12 months after the second. Reactions to tetanus-diphtheria vaccine may include fever or discomfort and swelling at the injection site. Severe allergic reactions, which occur rarely, are a contraindication to further doses of the vaccine.

High-risk countries for diphtheria include Algeria, Egypt, most countries in sub-Saharan Africa, Brazil, Dominican Republic, Ecuador, Haiti, Afghanistan, Bangladesh, Myanmar, Cambodia, China, India, Indonesia, Iran, Iraq, Laos, Mongolia, Nepal, Pakistan, Philippines, Syria, Thailand, Turkey, Vietnam, Yemen, Albania, and all countries of the former Soviet Union.

From the World Health Organization (WHO)

Diphtheria toxoid vaccine