Diphtheria

Dr. Parang Mehta, MD.

This is a disease caused by a bacterium, Corynebacterium diphtheriae.  The bacteria localise mainly in the throat, but produce a toxin that causes problems in other organs like the kidneys, heart, and nervous system.  It was a major cause of childhood death at one time, but public health measures, including vaccination, have made it relatively rare.

Diphtheria infects the throat and tonsils, and is easy to treat. The danger is with its complications

The infection most commonly affects the throat or tonsils, and sometimes the nose or larynx. Sometimes, a skin wound, the eyes, or the ears, may be infected.  The typical feature is a grey colored membrane that forms at the site.  The fever associated with diphtheria is usually moderate, and there is a nasal discharge which may be blood tinged.  Enlargement of the lymph nodes of the neck give a "bull neck" appearance.  Local extension of the disease, with blockage of the airway, can cause death.

Most of the deaths in this disease are due to Toxic Myocardiopathy, the effect of the diphtheria toxin on the heart.  This occurs in 10-25% of cases of diphtheria, and appears 2-3 weeks after the acute attack.  The other major organs affected are the nerves (Toxic Neuropathy), and the kidneys.

Treating the infection is not difficult, because C.  diphtheriae is susceptible to a number of antibiotics, including the penicillins and Erythromycin, which can be taken orally.  The difficulties arise because of the complications, and antitoxin therapy is essential in all cases.  Because diphtheria is rare these days, the antitoxin is not always readily available.  Children with diphtheria must be isolated to prevent spread of this dangerous disease.  All family members and other close contacts need careful watching and should receive protective antibiotics.

Prevention of Diphtheria

Diphtheria is a very dangerous disease, often fatal, and vaccination is recommended for all children.  The vaccine is a toxoid -- a weakened form of the diphtheria toxin.  This vaccine does not provide immunity against infection by diphtheria bacteria.  However, it prevents local tissue spread, toxic complications, and transmission of the disease.  Thus, though infection may occur, the dangers of diphtheria are avoided.

The diphtheria vaccine is not available alone -- it is always combined with the tetanus and pertussis (whooping cough) vaccines.  This DTP vaccine is started at the age of 6-8 weeks, and three doses are given in the first year, at intervals of 6-8 weeks.  A booster dose is given at 15-18 months, usually.  Another booster dose should be given at age 4-6 years.

For those children who have received this full series, an additional dose of tetanus and diphtheria toxoids and acellular pertussis vaccine (Tdap, the adolescent preparation) is recommended at age 11-12 years.

 

Last Revision: May 22, 2020