Can Tick-Borne Diseases Be Fatal? What You Should Know About Tick-Related Deaths

Tick-borne illnesses like Lyme disease, Tick-Borne Relapsing Fever (TBRF), and more make up a growing public health problem, especially considering the warming effects of climate change on deer and tick populations in the U.S. and abroad.

While awareness of the dangers of tick-borne diseases is spreading, there’s still a lot to be learned about which diseases ticks carry, their symptoms, whether they can be treated and how, and, of course, their potential long-term effects on one’s health. Along with that, many may wonder:

  • Can Lyme disease be fatal?
  • What about other tick-borne diseases?
  • How common are deaths from tick-borne illnesses?

This article will provide some background information to answer those questions.

Can Lyme disease be fatal?

Yes – though Lyme disease deaths are rare, they are possible. Reuters cites CDC research that found that between 1999 and 2003, there were 114 recorded deaths attributed to Lyme disease in the U.S. That includes one case in which long-term effects of Lyme on the patient’s central nervous system led to acute respiratory failure that caused their death.

It should be noted that most deaths related to Lyme disease are caused by complications from Lyme – especially untreated Lyme – rather than the disease itself. Some examples of such complications are described below.

Complications from Lyme disease that can be fatal

Lyme carditis

Lyme carditis is a rare but dangerous condition in which the bacteria that causes Lyme or TBRF enters the heart and causes inflammation. This can lead to irregular heartbeats or heart arrhythmia, as well as heart block that can be deadly. Just having Lyme disease or TBRF does not mean you will develop Lyme carditis, but there are several documented deaths linked to the condition.

Immune disorders

There is debate over the nature of chronic Lyme and Post-Treatment Lyme Disease Syndrome (PTLDS). One thing that is clear, however, is that those whose Lyme is untreated or treated too late can develop chronic health problems that can include new and debilitating illnesses.

One example is immune disorders, such as Mast Cell Activation Syndrome (MCAS). MCAS is one of several immune disorders related to the body’s ability to react to allergens. In MCAS, the body’s allergic responses become overactive, making even everyday foods or environmental triggers dangerous.

The condition can worsen over time and has been linked to at least one death.

Again, MCAS is just one example of several immune disorders that may arise with untreated or chronic Lyme. More research is underway to clarify the link between Lyme disease and chronic (and potentially deadly) health problems.

How common is death from Lyme disease?

Though experts maintain that Lyme disease deaths are rare, many Lyme-literate doctors (LLMDs) and other advocates point out that the data on Lyme disease deaths could be misleading.

This is partly because most of the current research relies on data from death records – i.e., the reason listed by physicians or those performing an autopsy. This does not necessarily guarantee that the cause of death is listed accurately, which could mean the actual number of deaths caused by Lyme or Lyme complications could be higher.

Another factor that could obscure the true number of Lyme-related deaths is the fact that Lyme disease can worsen other conditions, which can then lead to fatalities. In these cases, Lyme is often not seen as the cause or even mentioned at all.

What about deaths from other tick-borne diseases?

Lyme disease is not the only tick-borne disease that can cause deadly complications. Read on to learn about the most dangerous and possibly fatal tick-borne illnesses.

Rocky Mountain Spotted Fever (RMSF)

The CDC calls RMSF “the most deadly tick-borne disease in the world.” If not treated properly, death can occur within 8 days of the onset of symptoms – even in previously healthy people. This is partly because untreated RMSF can cause damage to blood vessels that leads to organ and tissue damage. Even for RMSF survivors, the CDC notes that a serious infection can lead to permanent damage that can include:

  • Amputation of limbs or extremities
  • Hearing loss
  • Paralysis
  • Mental disability

What you should know about RMSF:

  • It’s the deadliest tick-borne disease in the world and can lead to permanent damage even in survivors.
  • Symptoms may look like other tick-borne diseases, including fever, headache, rash, nausea and vomiting, stomach pain, muscle pain, and lack of appetite.
  • RMSF is treatable with antibiotics, but there is no vaccine.
  • A slight majority of RMSF cases occur in North Carolina, Tennessee, Oklahoma, Arkansas, and Missouri, but it can and does occur outside of those states.
  • Like other tick-borne diseases, RMSF is most common in spring and summer, but can and does occur all year-round.

To learn more about the symptoms, treatment, and testing for RMSF, read IGeneX’s article on the disease.

Powassan Virus

Unlike the other tick-borne diseases on this list (except Babesiosis), which are mostly bacterial infections, Powassan is a tick-borne virus. Though it is rare – one study found only 30 blacklegged ticks to be carrying Powassan virus out of 1,900 sampled in Connecticut – it is very dangerous.

Not only can the disease kill patients, but it can also lead to serious long-term health effects and complications which themselves can be deadly. Powassan caused the death of at least one New York man in 2019, and caused encephalitis that led to the death of former senator Kay Hagan later that year.

What you should know about Powassan Virus:

  • Powassan Virus can be transmitted in less than 1 hour.
  • 10% of those who contract Powassan Virus die from it.
  • Half of the survivors experience long-term health effects.
  • There has been an increase in cases of Powassan Virus in recent years, but researchers are not sure if it’s because the disease is actually becoming more common or if it’s because our awareness and testing technology has improved.
  • Because it is a virus, not a bacterial infection, Powassan cannot be treated with antibiotics.

Since Powassan Virus is so dangerous and cannot be treated with antibiotics, it’s as important as ever to practice good tick prevention methods. That includes checking for ticks daily and removing them immediately. To learn more about what to do after a tick bite, read IGeneX’s guide.

Tick-Borne Relapsing Fever (TBRF)

TBRF is caused by a different group of species of Borrelia than those that cause Lyme disease. That means it often looks and behaves like Lyme disease, but won’t show up on traditional Lyme disease tests. If left untreated, TBRF can be deadly and/or cause similar, potentially fatal complications to those associated with Lyme disease.

What you should know about TBRF:

  • Symptoms can mimic those of Lyme, but TBRF will not show up on standard diagnostic tests for Lyme. Tests must be designed to detect the specific bacteria that causes TBRF.
  • The characteristic recurring fever associated with TBRF does not show up in all patients. You can still have TBRF even if you don’t have relapsing fevers.
  • TBRF has been found in 49 of the 50 states.


Bartonellosis, caused by species of the bacteria Bartonella, is a group of diseases that cause serious illness in humans, including but not limited to:

  • Cat Scratch Disease – Usually spread to cats from the bite or droppings of fleas, then spread to humans from the bite or scratch of an infected cat
  • Trench fever – Transmitted to humans from cats or from other humans through the body louse
  • Carrion’s disease – Transmitted to humans through the bite of the female sand fly

Primarily associated with fleas and lice, Bartonellosis is now understood to also be spread by the same ticks that carry Lyme disease. Several types of Bartonellosis can cause fatal complications for immunocompromised patients, such as those with HIV.

What you should know about Bartonellosis:

  • Bartonellosis is found worldwide.
  • Bartonellosis has been found in both Eastern and Western blacklegged ticks (the same ticks that spread Lyme disease).
  • Common symptoms of Bartonellosis include fever, headaches, fatigue, poor appetite, brain fog, muscle pain, and swollen glands around the head, neck and arms. Others include photophobia, tachycardia, bowel problems, OCD behavior, anxiety, rapid relapse off of antibiotics, psychiatric problems, pain behind the eyes, and no response to previous antibiotic treatments.


Babesiosis is a malaria-like disease spread to humans by the same hard-bodied ticks that spread Lyme disease.

What makes Babesiosis similar to malaria is the way the causative agent Babesia affects the body. Like malaria, Babesiosis is caused by microscopic parasites that infect red blood cells. This usually causes initial flu-like symptoms, though some patients are asymptomatic.

What you should know about Babesiosis:

  • For those patients with symptoms, Babesiosis can cause high fevers, chills, and other flu-like symptoms 1-9 weeks after infection. As the infection progresses, symptoms can include one or more of the following: fatigue, malaise, muscle pain, headaches, myalgia, nausea, shortness of breath, vomiting, reduced appetite, and depression.
  • A small minority of patients are asymptomatic. Though it is uncertain what complications are possible with untreated, asymptomatic Babesiosis, there is concern that the disease can be spread through blood transfusions.
  • CDC notes that Babesiosis can be life-threatening for immunocompromised patients (such as those with HIV, cancer, lymphoma, or other serious health conditions) and those who have no spleen.

Tick prevention is key

Because some of the most dangerous tick-borne diseases can be transmitted quickly and/or are not treatable by antibiotics, tick prevention is crucial. Always check for ticks, know how to properly remove attached ticks, and save any ticks you find for testing by local authorities.

It’s also imperative that you have access to the latest diagnostic testing at a reputable center, ideally under the guidance of a physician who has experience with tick-borne diseases.



Great article – but a few points:

  1. Ticks laugh at the weather.  Seriously.  They hide under leaf litter or snow cover and survive:  This is a very important point because research dollars for Lyme/MSIDS is scant and highly sought after. Research money for climate data has not and will not ever help patients.  This is like the mask issue for COVID.  “Let it go, let it go”…..(theme from Frozen) An independent researcher has even called out a faulty paradigm being used for this supposed climate connection:
  2. Please read this excellent article on the type of research needed which would also help answer the question about Lyme/MSIDS fatalities:
  3. Historically our public ‘authorities’ have downplayed tick-borne illness by continuing to state things are ‘rare.’  They’ve continually had to eat crow as well by having to admit later it’s much more prevalent than they thought.  Trust me on this when I say the same will happen regarding the prevalence of Lyme/MSIDS caused fatalities.
  4. Please note how these same people will twist, bend, and lie about COVID numbers to keep them high:
  5. Not only are they counting those with ZERO symptoms but they completely stopped counting the regular flu.  Everything is COVID now:,

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