How was Diphtheria found?
Humans have known about diphtheria for thousands of years. Nowadays, diphtheria is remarkably limited due to widespread vaccination against infectious disease.
In the 5th century BCE, Hippocrates is first to describe the condition. He perceives that it can cause the formation of a new membrane on mucous membranes. In the later 19th century, the bacteria liable for diphtheria are recognised by the German scientists Edwin Klebs and Friedrich Löffler.
Then the antitoxin treatment was derived from horses in 1892 and first practised in the U.S. Following this, the development of the toxoid is used in vaccines in 1920.
What is Diphtheria?
Diphtheria is an extremely contagious bacterial infection of the nose and throat. Diphtheria is a disease of the past in most parts of the world. The illness has a severe onset and the main features are painful throat, moderate fever and inflamed glands in the neck, and the toxin may, in severe cases, cause myocarditis or peripheral neuropathy.
The diphtheria toxin causes a membrane of dead tissue to build up over the throat and tonsils, making breathing and swallowing difficult. The disease is developed through direct physical communication or from breathing in the aerosolized discharges from coughs or sneezes of infected people.
In countries where there is a weaker uptake of booster vaccines, however, such as in India, there live thousands of cases each year. In 2014, there were 7,321 cases of diphtheria notified to the World Health Organization (WHO), globally.
In people who are not immunised against the bacteria that cause diphtheria, the disease can cause serious complications, such as heart failure, nerve problems, and even death.
Overall, 5 to 10 per cent of people who get affected with diphtheria will die. Some people are more exposed than others, with a death rate of up to 20 per cent of infected people under 5 years or older than 40 years of age.
What causes Diphtheria?
Diphtheria is a communicable disease caused by the bacterium Corynebacterium diphtheria, which originally infects the throat and upper airways, and delivers a toxin hitting other organs. Other Corynebacterium species can be responsible, but this is unusual.
Some efforts of this bacterium create a toxin, and it is this toxin that causes the most severe complications of diphtheria. The bacteria produce a toxin because they are contaminated by a certain type of virus called a phage.
How does Diphtheria Spread?
Diphtheria is a contagion spread only among humans. It is spreading by direct physical contact with:
- droplets exhaled into the air
- secretions from the nose and throat, such as saliva and mucus
- infected skin wounds
- objects, such as bedcovers or clothes an infected person has used, in rare cases
- The infection can grow from an infected patient to any mucous membrane in a new person, but the toxic disease most frequently attacks the lining of the nose and throat.
What are the symptoms of Diphtheria?
Specific symptoms and signs of diphtheria depend on the selective strain of bacteria involved, and the site of the body affected.
One type of diphtheria, more common in the tropics, causes skin ulcers rather than respiratory infection. These crises are usually less dangerous than the typical cases that can lead to critical illness and seldom death.
The typical case of diphtheria is an upper respiratory infection caused by bacteria. It creates a grey pseudomembrane or a covering that resembles like a membrane, over the covering of the nose and throat, around the area of the tonsils. This pseudomembrane may also be greenish or blueish, and even black if there has been bleeding.
Early features of the infection, before the pseudomembrane appears, include:
- Swollen glands on the neck
- Low fever, malaise, and weakness
- Swelling of soft tissue in the neck, giving a ‘bull neck’ appearance
- Fast heart rate
- Nasal discharge
Children with a Diphtheria infection in a cavity behind the nose and mouth are more likely to have the following early features:
- Nausea and vomiting
- Chills, headache, and fever
After a person is first infected with the bacteria, there is a normal incubation period of 5 days before early symptoms and signs appear. After the initial symptoms have emerged, within 12 to 24 hours, a pseudomembrane will start to form if the bacteria are deadly, leading to:
- A painful throat.
- Difficulty swallowing
- A possible obstacle that causes breathing difficulties
If the membrane spreads to the larynx, hoarseness and a barking cough are more likely, as is the risk of complete blocking of the airway. The membrane may also reach further down the respiratory system toward the lungs.
What are the risk factors for Diphtheria?
Possibly life-threatening difficulties can occur if the toxin invades the bloodstream and harms other vital tissues.
- Myocarditis, or heart damage
- Neuritis, or nerve damage
Less severe disease from infection at other locations:
If the bacterial infection induces tissues other than the throat and respiratory system, such as the skin, the illness is usually milder. This is because the body digests lower amounts of the toxin, particularly if the infection only harms the skin.
The infection can coincide with other infections and skin conditions and may look no distinct from psoriasis, eczema, or impetigo. However, diphtheria in the skin can create ulcers where there is no skin in the middle with clear edges and sometimes greyish layers.
Other mucous membranes can mature infected by diphtheria including the conjunctiva of the eyes, women’s genital tissue, and the visible ear canal.
How is Diphtheria diagnosed?
A diagnosis of diphtheria may be done by analyzing tissue samples under a microscope.
There are definitive tests for diagnosing a cause of diphtheria, so if symptoms and history create suspicion of the infection, it is almost straightforward to confirm the diagnosis.
Doctors should be suspicious when they detect the characteristic membrane, or patients have unexplained swollen lymph nodes in the neck, pharyngitis, and low-grade fever. Hoarseness, paralysis of the palate, or stridor (high-pitched breathing sound) are also signed.
Tissue samples taken from a sufferer with suspected diphtheria can be used to separate the bacteria, which are then cultured for identification and experimented for toxicity:
- Clinical samples are taken from the nose and throat.
- All assumed cases and their close connections are tested.
- If feasible, swabs are also used from under the pseudomembrane or detached from the membrane itself.
The tests may not be immediately available, and so doctors may need to rely on a professional laboratory.
What are the treatments should be taken to prevent Diphtheria?
Treatment is most powerful when given early, so an immediate diagnosis is important. The antitoxin that is applied cannot fight the diphtheria toxin once it has connected with the tissues and caused the damage.
Treatment aimed at countering the bacterial effects has two components:
- Antitoxin is also known as an anti-diphtheritic serum to offset the toxin delivered by the bacteria.
- Antibiotics erythromycin or penicillin to destroy the bacteria and prevent it from spreading.
Patients with respiratory diphtheria and symptoms would be treated in an intensive care unit in the clinic, and closely monitored. The healthcare team may separate the patient to limit the spread of the infection.
This will be maintained until tests for bacteria frequently return negative results in the days following the fulfilment of the course of antibiotics.
What are the preventive measures taken to avoid Diphtheria?
Vaccines are routinely used to prevent diphtheria infection in almost all countries. The vaccines are obtained from a purified toxin that has been extracted from a strain of the bacterium.
Two strengths of diphtheria toxoid are used in routine diphtheria vaccines:
- D: a higher-dose initial vaccine for children under 10. This is normally given in three doses – at 2, 3, and 4 months of age.
- d: a lower-dose version for use as a primary vaccine in children over 10, and as a booster for strengthening the usual immunization in babies, about 3 years after the initial vaccine, normally between 3.5 and 5 years of age.
Modern vaccination schedules carry diphtheria toxoid in the childhood immunization, known as diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP).
This vaccine is the prospect of choice suggested by the U.S. Centers for Disease Control and Prevention (CDC), and more knowledge is provided, including why some children should not get the DTaP vaccine or should wait.
The doses are given the following ages:
- 2 months
- 4 months and after 4 weeks
- 6 months and after 4 weeks
- 15 to 18 months and after 6 months
If the fourth dose is given before the age of 4, this fifth, booster dose is suggested at 4 through 6 years of age. However, this is not obliged if the fourth primary dose was provided on or after the fourth birthday.
Booster doses of the adult form of the vaccine, tetanus-diphtheria toxoids vaccine (Td), may be needed every 10 years to maintain immunity.