Monday, March 19, 2007

Diphtheria


I happened to be watching a biographical show about Eleanor Roosevelt on public television and it mentioned that her mother, Anna Hall Roosevelt, died at the tender age of 29, of diphtheria, when Eleanor was a child.

This made me think about diphtheria, one of the dread diseases of the past that in the United States has been rendered rare because of widespread vaccination. However, there are still cases of it from time to time here, and in other parts of the world it is still common, particularly in parts of the former Soviet Union, where there was a serious epidemic between 1990 and 1998 (over 150,000 cases).

My father had diphtheria when he was about six years old and, obviously, recovered. However, I wondered whether his lifelong tendency to a nervous cough may have been a leftover effect of the traumatic feeling of his throat closing off from the swelling and membranous material that diphtheria causes in the throat.

I also recall reading about diphtheria in my favorite Cherry Ames nurse books when I was young; this series was written originally in the 1940's so diphtheria was not as uncommon then as it is now (19,000 cases in 1945) so Nurse Cherry did run into it in some of her cases. The description of the symptoms left a lasting impression on me. (For those not familiar with Cherry Ames, you can read more about her here).

Diphtheria is a nasty disease, and if you aren't sure when you had your last booster shot for it, I'd recommend having one, especially if you travel to other parts of the world. It is given in conjunction with the tetanus vaccine, and it is recommended you get a booster every 10 years.

What is it?

Diphtheria is a highly contagious infectious disease that is caused by a bacterium. Unfortunately, unlike your ordinary run-of-the-mill bacterium, this one creates a toxin (similar to what happens with botulism or tetanus).

Diphtheria is quite contagious and easy to spread. People get diphtheria by breathing in diphtheria bacteria after an infected person has coughed or sneezed. People can also catch it from coming in contact with discharges from an infected person's mouth, nose, throat, or skin.

There are several kinds of diphtheria; the milder type is called Anterior Nasal Diphtheria and it mainly affects the back of the nose and doesn't tend to expose the person to a lot of the toxin.

Another common type is pharyngeal and tonsillar diphtheria. If a patient gets this type of diphtheria, a good amount of toxin is usually absorbed, which can cause serious consequences.

Laryngeal Diphtheria affects the larynx (voicebox); it is sometimes an extension of the pharyngeal type or can occur on its own.

Diptheria can also occur in the skin, called Cutaneous Diphtheria; this usually shows up as some type of ulceration or rash.

What are the symptoms?

Anterior Nasal: The symptoms mimic a common cold, but with a nasty nasal discharage and a whitish membrane that forms in between the nostrils on the "septum" that separates the insides of your nose. This sounds pretty nasty but it's not as bad as what happens with the other kinds. This type of diphtheria is pretty easily cured by administration of antibiotics and anti-toxin.

Pharyngeal/Tonsillar: This starts with a feeling of general crumminess (malaise), sore throat, lack of appetite and low grade fever. After a couple of days, a bluish grey membrane starts to form in the back of the throat. Eventually it can appear blackish if bleeding occurs. It sticks to the tissues of the throat and can't be removed without causing bleeding. It can result in obstruction of the throat and interfere with breathing. This is the criical point; at this time a patient may recover, or else develop further complications. If a large amount of toxin is absorbed,the patient can become weak, with a rapid pulse and pale skin; and can even fall into a coma. The neck can become markedly swollen due to swollen lymph nodes. Death can occur within 6-10 days if treatment is ineffective.

Laryngeal: Symptoms of this type of diphtheria can include hoarseness, a "barking" cough, and a fever. The membrane can also obstruct the airway. This type can also lead to death due to these complications.

Cutaneous: More common in the tropics or among the homeless population in the United States. This type causes a rash or clearly outlined ulcers with a membrane. But the skin type of diphtheria is less dangerous since most infections do not cause the toxin to be released which results in fewer symptoms and complications. Even if the bacterium involved does produce the toxin, the cutaneous type is less severe.

Symptoms usually appear 2-5 days after exposure but the range can be from 1 to 10 days in different cases.

Complications:

Most of the most serious complications of diphtheria, beyond the airway obstruction from the membrane, are the results of the toxin. They include:

Inflammation of the heart (myocarditis): Can include heart arrhythmia; if it happens early in the course of the disease it is often fatal.

Inflammation of the nerves (neuritis): Between the third and fifth week of the disease, paralysis of the soft palate (back of the throat), eye muscles, limbs and diaphram can occur. If the diaphram is affected it can cause pneumonia, breathing problems or even death.

Inflammation of the kidneys (nephritis): Can result in kidney damage.

Infection of the middle ear can also be a complication.

If you are interested in looking at some of the symptoms in living color, this website, http://www.vaccineinformation.org/diphther/photos.asp, has a number of graphic images of the membrane in the throat and other manifestations of diphtheria. Not for the weak of stomach, but as true hypochondriacs I'm sure you may want to take a look and make sure you don't have any of these symptoms.

Of course, the most severe "complication" is death. Even today, the overall death rate for this disease is 5-10%, and up to 20% among young children under 5 or people over 40.

How is it diagnosed?


Initial presentation of symptoms indicative of diphtheria are enough to motivate a physician to start treatment even before the definitive diagnosis, given the time-sensitive nature of catching the disease before too much toxin is produced.

A throat culture is also taken to identify the presence of Corynebacterium diphtheriae , the diphtheria bacterium. Sometimes more complex tests are needed to definitively diagnose the disease, including staining of the material in the membrane of the throat or testing of antibodies in the blood.

How is treated?

If initial examination indicates diphtheria, treatment should be started immediately, even before test results are available.

Diphtheria anti-toxin is given as a shot into a muscle or through an IV (intravenous line). The anti-toxin is strictly controlled by the Centers for Disease Control. It is produced in horses and dates back to its development in the late 1800's. People can be allergic to it, so a patient should be tested for sensitivity before using the anti-toxin. Anti-toxin does not neutralize the toxin if it is already in the body's tissues, but it will bind with circulating toxin and will prevent further progression of the disease.

The infection is then treated with antibiotics, such as penicillin or erythromycin. They may be administrated orally or by injection. After 48 hours the disease will no longer be contagious.

People with diphtheria may need to stay in the hospital while the anti-toxin is being received, and should be isolated until no longer contagious.

Depending on symptoms, other treatment may include:

-Fluids by IV
-Oxygen
-Bed rest
-Heart monitoring
-Insertion of a breathing tube
-Correction of airway blockages

Anyone who has come into contact with the infected person should be receive immunization or booster shots against diphtheria. Protective immunity lasts only 10 years from the time of vaccination, so it is important for adults to get a booster of tetanus-diphtheria (Td) vaccine every 10 years.

Those without symptoms but who carry diphtheria should be treated with antibiotics.

Of course, the best thing to do is not to get diphtheria in the first place. In the developed world, most people are vaccinated as children. The diphtheria vaccine is usually given in a combination shot with tetanus and pertussis vaccines, known as DTP vaccine. A child should have received four DTP shots by 18 months of age, with a booster shot at age 4 years to 6 years. After that, diphtheria and tetanus boosters should be given every 10 years to provide continued protection. The diphtheria toxoid (inactivated toxin that causes the body to produce protective antibodies) vaccine was developed in the 1920's but was not widely used until the 1930's and 40's when it was combined with the pertussis (whooping cough) and tetanus vaccines and began to be used routinely.

Will you get it?

If you live in the United States or western Europe, it isn't likely at all. From 1980 to 2004, only 57 cases of diphtheria have been reported in the United States; only 5 since 2000. Most occurred in adults, with over 40% of them in adults over 40, in people who were unimmunized or had let their immunity lapse.

This chart shows the dramatic decrease in diphtheria deaths after the vaccine became widely used.


However, other parts of the world still have a problem with diphtheria due to undervaccination and poor living conditions. As mentioned previously, the newly independent countries that were formerly part of the Soviet Union had a severe outbreak in the 1990's. If you are traveling to other parts of the world, make sure your vaccinations are up to date.

Information on this topic was taken from the following sources:

http://www.cdc.gov/nip/publications/pink/dip.pdf

http://www.nlm.nih.gov/medlineplus/diphtheria.html

http://www.astdhpphe.org/infect/dip.html

http://www.healthsentinel.com/pictures/graphs/Picture/US-UK-Diphtheria-1901-1965.gif

1 comment:

Erica said...

Mauigirl, you exhibit true clinical symptoms of the gloriously informed hypochondriac, and if I ever feel a pseudomembrane growing across the back of my throat, I'll know who to thank for my panic! Diptheria is a terrifying disease, and waves of it used to cripple America every winter and spring. All that hacking and caughing, and the propensity to take baths every year (whether needed or not) surely must have helped spread it. This disease takes advantaged of the undernourished, too, and kids were indeed so not too long ago. Within living memory, American mothers were advised to feed their sprogs bread and milk every day, as fruits, veggies, proteins etc. were considered too rich for a child. Hoo boy! Thanks for the straight dope and the reminder to get booster vaccines every ten years. Good job!