What causes diphtheria?

Diphtheria is caused by Corynebacterium diphtheriae, a bacteria that infects the mucous membranes of the throat and nose. Once the bacteria colonize these areas, they produce a powerful toxin that damages tissue and can spread through the bloodstream to the heart, kidneys, and nervous system. The infection spreads from person to person through respiratory droplets from coughing or sneezing, or through direct contact with contaminated objects or skin lesions.

What is the best test for diphtheria immunity?

The Diphtheria and Tetanus Antitoxoid test is the most important test for assessing diphtheria immunity because it measures the levels of protective antibodies in your blood. Low antitoxoid levels indicate insufficient immunity to Corynebacterium diphtheriae, meaning you have higher susceptibility to infection and need vaccination or booster shots. This blood test is essential for determining whether your current immunity is adequate or if additional vaccination is recommended to maintain protection against this potentially life-threatening bacterial infection.

When should I get tested for diphtheria immunity?

You should get tested if you are unsure about your vaccination status or have not received a diphtheria booster in over 10 years. Healthcare workers, travelers to countries where diphtheria is still common, and anyone who may have been exposed to the infection should also consider testing. Additionally, pregnant women and people with weakened immune systems should verify their immunity levels to ensure adequate protection for themselves and those around them.

What are the symptoms of diphtheria?

Diphtheria symptoms typically begin with a sore throat, mild fever, and swollen glands in the neck. The hallmark sign is a thick gray or white coating that forms on the throat and tonsils, which can make breathing and swallowing difficult. Other symptoms include weakness, difficulty breathing, rapid heartbeat, nasal discharge, and in severe cases, the toxin can damage the heart and nervous system causing paralysis or heart failure.

Who is at risk for diphtheria?

People at highest risk include unvaccinated or incompletely vaccinated individuals, particularly children under 5 years old. Adults who have not received booster shots within the past 10 years have declining immunity and increased risk. Travelers to countries with endemic diphtheria, healthcare workers, and people living in crowded or unsanitary conditions are also at elevated risk. Additionally, individuals with weakened immune systems may be more susceptible to severe infections.

What happens if diphtheria is left untreated?

Untreated diphtheria can lead to life-threatening complications as the bacterial toxin spreads throughout the body. The thick membrane in the throat can block airways causing suffocation, while the toxin can damage the heart muscle leading to heart failure or abnormal heart rhythms. Nerve damage can cause paralysis of the throat, arms, or legs, and kidney failure may occur. Even with treatment, diphtheria has a mortality rate of 5-10%, which increases significantly without proper medical care.

Can diphtheria immunity be diagnosed with a blood test?

Yes, diphtheria immunity can be assessed with a blood test that measures antitoxoid antibody levels. While blood tests cannot diagnose an active diphtheria infection (which requires throat culture), they are fundamental for determining your protection level against the disease. The Diphtheria and Tetanus Antitoxoid test measures protective antibodies and helps healthcare providers determine if you need vaccination or booster shots to maintain adequate immunity.

How is diphtheria treated?

Diphtheria is treated as a medical emergency with diphtheria antitoxin to neutralize the bacterial toxin in the body, and antibiotics such as penicillin or erythromycin to kill the bacteria. Patients typically require hospitalization for monitoring and supportive care, including airway management if breathing is compromised. Isolation is necessary to prevent transmission to others, and close contacts should receive prophylactic antibiotics and vaccination if needed. Early treatment is critical to prevent serious complications.

How can I prevent diphtheria?

Vaccination is the most effective way to prevent diphtheria and is typically given as part of the DTaP vaccine for children and Tdap or Td boosters for adolescents and adults. Adults should receive booster shots every 10 years to maintain immunity. Avoiding close contact with infected individuals, practicing good hand hygiene, and maintaining up-to-date vaccination records are essential prevention strategies. Travelers to areas where diphtheria is common should ensure their vaccinations are current before departure.

What can I do at home if I suspect diphtheria?

If you suspect diphtheria, seek immediate medical attention rather than attempting home treatment, as this is a medical emergency requiring professional care. While waiting for medical help, isolate yourself from others to prevent transmission, stay hydrated, and rest. Do not attempt to remove the membrane from your throat as this can cause bleeding and worsen airway obstruction. Keep your vaccination records accessible to share with healthcare providers, and inform close contacts so they can seek preventive treatment if necessary.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

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Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

Diphtheria Immunity Blood Test

What is Diphtheria?

Diphtheria is a serious bacterial infection that primarily affects the mucous membranes of the throat and nose, potentially causing life-threatening complications. It is caused by Corynebacterium diphtheriae bacteria that produce a powerful toxin damaging tissues and organs. The Diphtheria and Tetanus Antitoxoid test is the most important test for assessing immunity and determining if vaccination or booster shots are needed for protection.

Written by Private MD Labs Medical Team

Last updated: December 29, 2025

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

support@privatemdlabs.com