Diphtheria

What is Diphtheria?

Diphtheria is an illness caused by a bacterium known as Corynebacterium diphtheriae. This bacterium does not have any protective layer or ability to move, but it depends on air to survive. People can carry this bacterium without showing any symptoms, but it usually affects the breathing system and the skin. People are carriers and help in its spread, which mostly happens through air-droplets from the mouth or nose.

Individuals are most likely to contract diphtheria if they haven’t been vaccinated. The infection is more common during the spring and winter, and without antibiotics, it can spread for 2 to 6 weeks. Those with a weak immune system or who have not completed their vaccinations are more at risk upon exposure to an infected individual or a carrier.

A carrier is a person who has the bacterium but isn’t showing any symptoms. As the number of carriers decreases, so does the prevalence of the disease. The severity of the disease lies in the toxins produced by the bacterium, which can cause serious problems and mainly affect the heart and nervous system.

Diphtheria is diagnosed by isolating and growing the bacterium and checking for toxin production. Patients usually have a specific symptom, where a thick, grey membrane forms on their tonsils or throat. Effective treatment involves the patient being isolated and given antitoxins and antibiotics.

Diphtheria is more common in tropical regions but is a concern worldwide. To prevent this disease, vaccination is essential. A combination vaccine known as DTaP that protects against diphtheria, tetanus, and whooping cough has notably reduced diphtheria cases in the US. Since immunity can decrease over time, a booster shot is necessary to maintain protection. Vaccination doesn’t guarantee total prevention, but it can reduce the severity and number of fatal cases of the disease.

What Causes Diphtheria?

C. diphtheriae is a type of bacteria that does not form spores and is not able to move or encapsulate. It’s known for its unique club-shaped appearance and tends to form stick-like or V- or L-shaped groups. Other than C. diphtheria, Corynebacterium ulcerans can cause skin diphtheria and, rarely, may also contribute to breathing related diphtheria cases.

The health-related impacts of exotoxins, which are toxins released by bacteria, can affect both localised and whole-body aspects of the disease. Viruses known as bacteriophages carry the genetic code for these exotoxins, making it easier for them to spread among bacteria. Three different strains of C. diphtheriae have been found, and all are capable of producing toxins.

Many factors can contribute to the development of diphtheria, such as:

* Incomplete or lack of vaccinations
* Weakening immunity over time, which makes older people without booster shots more likely to get infected
* Low immunity in the community
* Traveling to areas where the disease is common
* Traveling to regions currently experiencing outbreaks
* Having a weakened immune system
* Low social economic status
* Massive movements of people
* Overcrowding, like in military barracks, prisons, and homeless shelters
* Domestic animals.

Risk Factors and Frequency for Diphtheria

Since the introduction of vaccines, the occurrence of diphtheria has fallen drastically. In the past, before 1920, the US saw about 200,000 cases each year. But, after vaccines became widespread, this number fell to just around 1,000 per year. Some people are at higher risk: those living in poverty, overcrowded situations, without vaccines, who travel to places where the disease is common, and those with other health conditions. Despite the decrease, cases are still higher in specific areas, like Southeast Asia and Africa. As for deaths related to diphtheria in the US, vaccination has brought this down to nearly zero.

However, the World Health Organization (WHO) notes that diphtheria still remains a challenge in developing countries. For example, India sees a lot of cases due to issues with making vaccines available to everyone. As a result, India is home to a big chunk of diphtheria cases worldwide.

• Diphtheria does not favor any race or gender.
• While it’s mostly known as a disease of children under 12, adults around the age of 40 and those with other health conditions can also get it.
• If a person doesn’t get regular shots and booster doses, their immunity to diphtheria naturally goes down, raising their risk of getting the disease.

Signs and Symptoms of Diphtheria

Diphtheria starts with symptoms similar to the flu like fever, a sore throat, and swollen glands in the neck. After around 2 to 5 days, you might start to notice a thick, gray layer forming on your throat and tonsils. This is a telltale sign of diphtheria, especially if you recently visited a place where the disease is common and you haven’t been vaccinated. The gray layer can cause problems with breathing and swallowing.

The gray layer, or ‘pseudomembrane’, is a mixture of red and white blood cells, dead cells, and bacteria. If you try to remove it, it usually causes bleeding. Other symptoms of diphtheria might include a low fever, feeling tired, a headache, difficulty swallowing, and sores in the mouth or throat. If the disease continues to spread in the body, it can cause damage to the tissues.

A common sign of diphtheria in people is a ‘bull neck’ appearance, where the neck becomes swollen. The main causes of death from diphtheria are either choking or inhaling the pseudomembrane into the lungs. Diphtheria can also infect the skin, causing sores covered by a gray layer but these sores do not spread and invade the surrounding tissues.

During a physical exam, patients usually have a low-grade fever but may appear sickly, and often have a swollen neck. General symptoms include an increased heart rate, bad breath, and feelings of anxiety. A thick, gray, tough membrane normally covers the tonsils and throat. Trying to scrape this off causes bleeding. The patient may also hold their head in an extended position due to the ‘bull neck’. They may speak differently and also have breathing difficulties, with sounds like stridor, wheezing, or retractions.

After 1 to 2 weeks of illness, the heart can become involved after the throat symptoms improve. This may manifest in several ways, such as heart failure, changes in heart rhythms, or possibly, heart inflammation particularly if you have an artificial heart valve.

Neurological complications can occur based on how severe the throat infection is. Common problems are cranial nerve deficits, peripheral sensory neuropathy which feels like you’re wearing a stocking and glove, and peripheral neuritis.

The following are the main symptoms and signs of Diphtheria:

• Flu-like symptoms (fever, sore throat, swollen glands in the neck)
• A thick, gray layer on the throat and tonsils
• Low fever
• Feeling tired
• Headache
• Difficulty swallowing
• Sores in the mouth or throat
• ‘Bull neck’ appearance (swollen neck)
• Increased heart rate
• Bad breath
• Feelings of anxiety
• Difficulty breathing

Testing for Diphtheria

Diagnosing diphtheria involves checking your symptoms, taking some lab tests, and even having scans done in some cases. Here’s a closer look at what’s involved:

In most cases, the doctor will start by examining your throat and checking whether you have any signs of infection. They may also be interested in your immunization history and whether you’ve traveled to any locations where diphtheria is more common.

In addition, there are a few specific tests that are used to identify the diphtheria bacteria:

* Throat culture: The doctor swabs any visible throat sores you may have and the sample is put onto a culture to see if the bacteria is present. How the sample reacts to different types of media will let them know if you have diphtheria.

* Gram stain: This gives the bacteria a color so it can be seen under a microscope. Even though this test can’t confirm diphtheria, it acts as an initial check in suspected cases.

Alongside these, a few other lab tests might be carried out:

* Toxin detection: These tests are used to confirm whether the bacteria is producing toxins.

* Serology: These blood tests help the doctor to understand how your body is responding to the infection.

If you’re having breathing problems or the doctor is worried that you might have complications like pneumonia, they might take a chest x-ray. This can help them to see if your lungs are involved.

Also, there is a chance you might be advised to undergo an echocardiogram if they suspect that the infection has affected your heart. While it’s not very common, it’s best to check and be sure that there’s no damage to your heart valves.

Finally, the doctor might want to check your total white blood cell count, which can indicate if your body is fighting off an infection. Assessing the heart-damaging enzyme, troponin, in your blood can also give a clue about how severe the infection is.

Treatment Options for Diphtheria

The main ways to treat diphtheria include giving antitoxins and antibiotics as quickly as possible. If someone is suspected of having diphtheria, the antitoxin should be given immediately, even before lab tests confirm the diagnosis. These patients must also be kept away from others and precautions must be taken to stop the disease from spreading. It’s also crucial to check for any trouble with breathing and to make sure the patient’s heart is working properly.

Diphtheria Antitoxin

Diphtheria antitoxin is a crucial part of treatment and is obtained from a horse’s immune response. This antitoxin works by neutralizing any unbound diphtheria toxin circulating in the person’s blood. Once the toxin has stuck to a cell, the antitoxin can’t neutralize it. The amount of antitoxin given depends on how bad the person’s diphtheria symptoms are. The antitoxin can be given as a shot or through an IV. Before giving the antitoxin, the doctor should check if the person is likely to have a severe allergic reaction. Emergency medication for a serious allergic reaction should be kept nearby when the antitoxin is given.

Antibiotic Treatment

The preferred antibiotics to treat diphtheria are erythromycin or penicillin G. Erythromycin is typically given as a 500 mg dose four times a day for two weeks. Penicillin G is given as a shot: 300,000 units are given every 12 hours to patients who weigh 10 kg or less, and 600,000 units every 12 hours to those who weigh more. Once the person can swallow pills, the doctor will usually switch to penicillin V, given as a 250 mg dose four times a day for two weeks. Antibiotics should be started as soon as possible to eliminate the diphtheria bacteria from the body, limit the toxin release, speed up recovery, and stop the infection from spreading to others. If someone is resistant to these antibiotics, other drugs like linezolid or vancomycin may be an option.

Close contacts of the person with diphtheria, like people who live in the same house or have been in direct contact with them, should also get antibiotics to stop the infection from spreading. This includes members of the medical staff who have been exposed to the patient’s respiratory secretions. They will receive a single dose of penicillin G as a shot, with the quantity depending on their age. Alternatively, they could take oral erythromycin four times daily for 7 to 10 days. It’s critical that antibiotics are given as soon as possible to both treat the person with diphtheria and to prevent possible outbreaks or spreading at a community level.

What else can Diphtheria be?

Diphtheria needs to be set apart from other similar illnesses that affect the upper respiratory tract. Here are the conditions to keep in mind while determining a diagnosis:

• Epiglottitis: This condition causes a sudden inflammation or swelling in the epiglottis area, a flap on your windpipe that stops food from entering your lungs.
• Retropharyngeal abscess: This condition features high fever and causes abscess or buildup of pus behind the throat, needing immediate medical attention to drain the abscess.
• Angioedema: This condition causes widespread swelling in the lower layers of skin and tissue under the skin, including tissues in the mouth and throat.
• Infectious mononucleosis: This illness, often called “mono,” causes symptoms like tiredness, discomfort, sore throat, fever, loss of appetite, and cough. Kids with mono often have a fever, sore throat, and swollen lymph nodes.
• Pharyngitis: This inflammation of the throat (pharynx) causes symptoms like a sudden onset of a sore throat, difficulty swallowing, fever and cough.
• Oral candidiasis: Also known as oral thrush, this fungal infection in the mouth usually has a distinct white appearance that needs to be differentiated from the grayish color of the membrane in diphtheria.
• Vincent angina: This gum infection causes symptoms like painful, bleeding gums and gum tissue death.

Each of these conditions should be properly reviewed and assessed during the diagnostic process.

What to expect with Diphtheria

The outcome of diphtheria, a bacterial infection, can depend on several factors. These include:

* Age: People under 5 years old and those over 40 tend to have a higher risk of dying from diphtheria.

* Length of illness: Cases where symptoms have been present for more than 4 days before treatment often result in increased death rates.

* Heart involvement: If the infection impacts the heart, particularly causing certain types of heart block, the outcome is generally worse.

* System-wide impact: If the infection has spread throughout the body, this can also significantly increase the chance of a negative result, such as death.

Possible Complications When Diagnosed with Diphtheria

Diphtheria is a major health concern because it can have severe complications such as myocarditis, which is an inflammation of the heart muscle, and neuritis, an inflammation in the nerves. Unfortunately, the disease can be fatal in about 5% to 10% of cases. Furthermore, it can create a pseudomembrane, which is like a thin layer, in the upper parts of the respiratory system. This can obstruct breathing and may require immediate attention with the initiation of mechanical ventilation or tube insertion for open airflow.

The above complications are categorized as cardiac and neurologic complications.

Cardiac complications from diphtheria can result in myocarditis, which may cause irregular heart rhythms and various heart blocks. These conditions might result in inadequate blood flow through the body. Changes in an electrocardiogram (ECG), a test that checks heart performance, in affected patients might include an extended P-R interval and ST and T wave transformations.

Neurologic complications connected to diphtheria may cause weakness or paralysis in the nerves, notably involving the cranial nerves and those in the extremities, leading to muscle weakness. Involvement of the pharyngeal muscles and the soft palate can cause food and fluids to be ejected into the nose during ingestion. Uncommonly, diphtheria can trigger encephalitis, a brain inflammation, especially in affected children.

Preventing Diphtheria

Diphtheria vaccines are created from denatured proteins or toxoids. These are harmless versions of the harmful bacterial toxins that cause diseases. The vaccines are designed to prompt your body to produce antibodies, which fight off diphtheria. Usually, the diphtheria vaccine is given in combination with vaccines for tetanus and pertussis, or whooping cough. Here are the various forms of combined vaccines and what they protect against:

• DTaP: Protects against diphtheria, tetanus, and pertussis.
• Tdap: Protects against tetanus, diphtheria, and pertussis.
• DT: Protects against diphtheria and tetanus.
• td: Protects against tetanus and diphtheria.

In the US, babies usually get the DTaP vaccine, beginning at 2 months old. They get additional doses at 4 and 6 months, between 15 and 18 months, and between 4 and 6 years old. At 11 or 12 years old, they get a booster shot with the Tdap vaccine. After that, booster shots of either Tdap or td are recommended every 10 years, for life. If a pregnant person has been fully vaccinated before, they should get a Tdap vaccine between 27 and 36 weeks of their pregnancy.

Vaccination is the key in preventing diphtheria. Doctors and nurses need to inform parents about the importance of regular vaccination in preventing the disease. If it’s not certain whether or not a vaccination was missed or the records are lost, it’s important to talk to the doctor right away. With immunity from the vaccine decreasing over time, it becomes crucial to get booster shots on time. Community awareness about the benefits of vaccination is important. Those who have been in close contact with a suspected case of diphtheria should reach out to medical professionals right away. Anyone diagnosed with diphtheria should limit their contact with others until a healthcare professional says it’s safe to resume normal activities.

For those who have recently come into close contact with someone with diphtheria, it’s necessary to monitor any symptoms of the disease. They should be isolated immediately, and a sample should be taken for further testing. It’s recommended to take erythromycin, an antibiotic, for 7-10 days. If it’s not clear whether or not the person was vaccinated or needs a booster shot, it may be advisable to give them a booster dose of the diphtheria vaccine.