"The Strangler" (Diphtheria) By Louis J. Tesoro, M.D. The Pediatric Group, P.A., Princeton

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All one has to do is search in local papers to realize that despite the marvels of modern medicine, we have not escaped the scourge of epidemics. "Nine more die of SARS in China." "Authorities gear up to fight West Nile." "Doctors encourage tick checks to prevent Lyme Disease." "1,000 cattle slaughtered in Canada to prevent spread of mad cow disease." But none of these compare to the terror and damage caused by The Strangler, diphtheria. In the 1920's in America, more than 200,000 individuals annually were infected with diphtheria and nearly 40,000 perished. While frightening, the current threats of Severe Acute Respiratory Syndrome, West Nile Virus infection, Lyme Disease, and mad cow disease pale in comparison to the havoc reaped by diphtheria.

To understand why diphtheria is so fearsome, you first have to understand its causative agent and how it is spread. The principle bacterial agent responsible for diphtheria is a small rod-shaped organism known as Corynebacterium diphtheriae. Human beings are the only reservoir for this organism, unlike the causative agent for Lyme Disease, which resides in ticks and deer as well as humans and other animals. By itself, Corynebacteria would cause only mild disease (upper respiratory infection or skin rash), but organisms whose virulence has been altered by bacteria-phage viruses produce harmful toxins, which make diphtheria deadly.

The infection is transmitted from one person to another by close contact, through droplets of oral and nasopharyngeal secretions, dust, and contaminated clothing. Crowded living conditions, poor hygiene, and decreased host immunity are risk factors for infection. Infected individuals may remain contagious for up to four weeks following the onset of infection. Symptoms of diphtheria usually develop within two to five days after contact.

As with many illnesses, the initial symptoms of diphtheria are non-specific and flu-like in nature. 50-85% develop fever and chills; 85-90% sore throat, and many complain of malaise. Hoarseness and dysphagia, or trouble swallowing, are also fairly common (26-40%). Marked edema (swelling) of the neck and anterior lymph nodes occurs in half, and is responsible for the term "bullneck" that describes the appearance of one infected by diphtheria. There is also marked edema of the tonsils, uvula, and pharynx with the formation of the classic pseudomembrane, a thick tenacious parchment-like secretion that covers the back of the throat and gives diphtheria its name (from the Greek, diphthera, leather). Respiratory symptoms (runny nose, cough, stridor [difficulty inhaling], and wheezing) are frequently present and may progress rapidly to respiratory arrest from airway obstruction due to the membrane (thus, The Strangler).

Symptoms from the diphtheria toxin develop in as many as 75%, and are responsible for much of the morbidity associated with diphtheria. Approximately two-thirds of patients develop myocarditis-inflammation and weakness of the cardiac muscle-one to two weeks after the illness begins. A third to one half of these patients are so severely affected that they develop cardiac dysfunction, arrhythmias, and heart failure. About three-quarters of patients develop toxin-mediated paralysis or weakness. These symptoms occur two to eight weeks following onset and, fortunately, resolve completely in most instances. Treatment of diphtheria is carried out in a hospital. The most important ingredient in the treatment of diphtheria is antitoxin. Diphtheria antitoxin is derived from horse serum and neutralizes toxin before entry into cells. It is, therefore, most effective when administered early in the course of the infection. Some individuals are unable to receive antitoxin because of allergy to horse serum. Antibiotics, particularly erythromycin and penicillin, are effective in eradicating the organism, limiting toxin production, and preventing spread. Close contacts are also treated with antibiotics after a culture is obtained to identify the organism. Supportive treatment includes intravenous fluids and heart monitoring. Placing a tube in the airway to maintain its patency may be necessary. A cardiac pacemaker may be required for heart block and arrhythmia.

But the most certain form of treatment is prevention. A clean environment, a healthy population, and vaccination are the surest means of preventing diphtheria, as can be seen in recent outbreaks. During the 1990's in the new independent republics of the former Soviet Union, there was a resurgence of diphtheria. Between 1990 and 1996, there were more than 110,000 cases and 2,900 fatalities. The resurgence was blamed on overcrowding, low hygiene levels, and falling vaccination rates created by the changing political climate. Immunization with inactive diphtheria toxoid, which stimulates antibody production against the toxin confers immunity. (A primary series of DaPT is completed between four and six years followed by booster of Td every ten years. The "d" in each series represents diphtheria toxoid.) Vaccination needs to be repeated every ten years to ensure the higher antibody levels needed to protect against toxin.

The Strangler, diphtheria, was a fearsome infection in its day, but improvements in sanitation, personal hygiene, antibiotics and immunization tamed this epidemic. But we must remain vigilant and continue to vaccinate our children, or else, as the lessons from the former soviet republics demonstrate, diphtheria will return. And potentially, it could be deadlier than anything that we currently face in the United States.

Dr. Louis J. Tesoro

Dr. Tesoro has been a member of the staff at The Pediatric Group since 1988. Dr. Tesoro is Attending Pediatrician, Medical Center at Princeton, 1988 to present. He has served on several Departmental and hospital committees and was Chairman, Department of Pediatrics, Medical Center at Princeton from 1996 - 2000. He has lectured at the Universiy of Pennsylvania and has published original articles both while at The Children's Hospital of Philadelphia and at The Pediatric Group.

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