Let's talk infectious diseases, the reason for vaccines: ᴰⁱᵖʰᵗʰᵉʳⁱᵃ

Diphtheria can be caused by one of several strains of bacteria called Corynebacterium diphtheria (C. diphtheria). The bacteria that causes diphtheria is spread when someone inhales droplets from an infected person's cough or sneeze. It affects the mucous membranes of the throat and nose.

Once you’re infected, the bacteria release dangerous substances called toxins. The toxins spread through your bloodstream and often cause a thick, gray coating to form in these areas of the body: nose, throat, tongue, and airway. In some cases, these toxins can also damage other organs, including the heart, brain, and kidneys. This can lead to potentially life-threatening complications, such as: myocarditis (inflammation of the heart muscle), paralysis, and/or kidney failure.

After someone is exposed to diphtheria bacteria and becomes infected, the respiratory symptoms usually appear within two to five days, though the incubation period may be up to 10 days. Diphtheria infection can start out similarly to a normal respiratory infection. At first, symptoms may be mild. However, if the infection is not diagnosed and treated, severe complications can develop. The general symptoms of diphtheria include:

▪️Fever and chills

▪️Sore throat

▪️Runny nose

▪️Swollen glands in the neck ("bull's neck" appearance)

▪️Fatigue and feeling weak

▪️Wheezing and difficulty breathing

▪️Hoarseness and difficulty talking

▪️Racing heart (tachycardia)

▪️Nausea and vomiting (more common in children)

One of the hallmark features of diphtheria is the formation of a thick, hard, gray-colored coating (pseudomembrane) lining the throat. It may coat the tonsils, the nose, and other membranes in the respiratory tract. As the membrane builds up and thickens, it can make it difficult to breathe. When trying to remove or scrape off the membrane, bleeding of the tissue will occur. The membrane is highly infectious and filled with diphtheria toxin. Not only does this mean it can spread the infection, but it can also make the person with diphtheria very ill if the toxin spreads through the body.

Cutaneous diphtheria is another type of diphtheria infection, which is less common, that affects the skin. Cutaneous diphtheria is usually less severe than respiratory diphtheria. At first, the skin infections may appear very similar to other chronic conditions like eczema or psoriasis. Symptoms of cutaneous diphtheria include:

▪️Scaly rash

▪️Ulcers

▪️Secondary wound infections

Timely and accurate diagnosis is critical, as skin lesions caused by diphtheria bacterium are highly contagious, and the ease with which they shed makes the spread of the disease more likely.

Approximately 20% to 40% of people with diphtheria infection of the skin may develop the respiratory infection as well. Diphtheria infection is far more serious when it infects the mucous membranes of the respiratory tract, such as the nose, throat, and lungs.

Diphtheria is a serious condition, so your doctor will want to treat you quickly and aggressively.

The first step of treatment is an antitoxin injection. This is used to counteract the toxin produced by the bacteria. Your doctor will also prescribe antibiotics, such as erythromycin or penicillin, to help clear up the infection.

During treatment, your doctor may have you stay in the hospital so you can avoid passing your infection on to others. They may also prescribe antibiotics for those close to you.

Someone who has been severely ill from diphtheria may have a very long recovery and need to limit their activities to prevent complications. Once a person has recovered from diphtheria, they are required to get the vaccine, as getting sick with diphtheria does not make a person immune to the infection for the rest of her or his life.

1613 in Spain was known as “El Año de los Garotillos” (“strangulations”) for its epidemic of diphtheria. Since this disease wasn't named yet it was called by several names. In 1659 a Boston minister referred to it as Malady of Bladders in the Windpipe.

A terrifying diphtheria epidemic swept through New England in 1735. In some cases, entire families died of the disease. In one New Hampshire town, 32% of children under 10 died of diphtheria. The case-fatality ratio was almost 40%. There was no treatment proving successful in curing diphtheria.

The disease finally earned the name we now know it as in 1826 when French physician Pierre Bretonneau called it diphtérite. The origin was the Greek word for “leather” or “hide,” which describes the coating that appears in the throat. Bretonneau also distinguished diphtheria from scarlet fever, which until then there had been a lot of confusion about.

To relieve troubles breathing Dr. Bretonneau experimented with tracheotomy as a way to open the airway. This became another treatment method tried and at one point another physician, Armand Trousseau, reported about a 25% survival rate in the tracheotomies he performed on diphtheria sufferers.

Diphtheria was proving hard to understand and treat.

A small breakthrough happened in 1888 when scientists Émile Roux and Alexandre Yersin showed that a substance produced by C. diphtheriae caused symptoms of diphtheria in animals. Building on that find Shibasaburo Kitasato and Emil von Behring created a heat-treated diphtheria toxin in 1890 and studies showed it to be successful. They called the substance antitoxin and their treatment serum therapy.

Finally, there was some momentum building toward curing this awful disease.

In October 1894, two young Cincinnati physicians treated a two-year-old girl successfully with diphtheria antitoxin. This is one of the earliest documented uses of diphtheria antitoxin in the United States.

Until 1895 diphtheria antitoxin could only be procured outside of the United States. So in 1895, after some successful treatments were documented, Mulford Company of Philadelphia (later Merck Sharp & Dohme) began to produce and test diphtheria antitoxin in the United States.

The New York City Health Department began producing diphtheria antitoxin this year as well. Deaths from the disease began to drop as the treatment was increasingly used.

A first step in producing diphtheria antitoxin involved incubating the bacteria and then determining which samples were of adequate strength to produce antitoxin.

In 1907, Emil von Behring published a paper showing that a mixture of diphtheria toxin and antitoxin produced safe and lasting immunity to diphtheria in humans. The combination of toxin and antitoxin needed to be carefully balanced to provide enough toxin to elicit active immunity and the right amount of antitoxin to prevent the toxin from causing disease.

In 1914, William Park took Behring's work further by adjusting the amounts of the substances until he achieved a balance between lasting immunity and reactions to the mixture. This method was used for immunizing humans until toxoid immunization replaced it.

Working independently from one another, scientists Gaston Ramon and Alexander Thomas Glenny both developed diphtheria toxoid in 1923. It was able to induce antibodies that blocked natural toxin from attaching to cells. This breakthrough provided the simplest and most effective means to prevent diphtheria.

In 1926, Glenny increased the effectiveness of diphtheria toxoid by treating it with aluminum salts. Efforts to improve diphtheria toxoid were necessary because toxoid alone produced a lower level of antibody response than desired. Moreover, the immunity it produced was shorter than desired. Glenny began to add substances to the toxoid to trigger such a response. Today those substances are called adjuvants, and they are used in several types of vaccines.

Respiratory diphtheria has almost disappeared in the United States. Since 2004, the CDC has recorded no cases of respiratory diphtheria in the United States.

Diphtheria is now vaccinated against in a combination vaccine that addresses tetanus, pertussis, and diphtheria.

{You can find all the sources I used by clicking here.}