Tickborne diseases are likely to increase, say NIAID officials

July 26, 2018, NIH/National Institute of Allergy and Infectious Diseases
Engorged deer tick, or Ixodes scapularis, a species of tick that can transmit Lyme disease. Credit: NIAID

The incidence of tickborne infections in the United States has risen significantly within the past decade. It is imperative, therefore, that public health officials and scientists build a robust understanding of pathogenesis, design improved diagnostics, and develop preventive vaccines, according to a new commentary in the New England Journal of Medicine from leading scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

Bacteria cause most tickborne diseases in the United States, with Lyme representing the majority (82 percent) of reported cases. The spirochete Borrelia burgdorferi is the primary cause of Lyme disease in North America; it is carried by hard-bodied ticks that then feed on smaller mammals, such as white-footed mice, and larger animals, such as white-tailed deer. Although there are likely many factors contributing to increased Lyme disease incidence in the U.S., greater tick densities and their expanding geographical range have played a key role, the authors write. For example, the Ixodes scapularis tick, which is the primary source of Lyme disease in the northeastern U.S., had been detected in nearly 50 percent more counties by 2015 than was previously reported in 1996. Although most cases of Lyme disease are successfully treated with antibiotics, 10 to 20 percent of patients report lingering symptoms after effective antimicrobial therapy. Scientists need to better understand this lingering morbidity, note the authors.

Tickborne virus infections are also increasing and could cause serious illness and death. For example, Powassan virus (POWV), recognized in 1958, causes a febrile illness that can be followed by progressive and severe neurologic conditions, resulting in death in 10 to 15 percent of cases and long-term symptoms in as many as 70 percent of survivors. Only 20 U.S. cases of POWV infection were reported before 2006; 99 cases were reported between 2006 and 2016.

The public health burden of tickborne disease is considerably underreported, according to the authors. For example, the U.S. Centers for Disease Control and Prevention (CDC) reports approximately 30,000 cases of Lyme disease annually in the U.S. but estimates that the true incidence is 10 times that number. According to the authors, this is due in part to the limitations of current tickborne disease surveillance, as well as current diagnostics, which may be imprecise in some cases and are unable to recognize new tickborne pathogens as they emerge. These limitations have led researchers to explore new, innovative diagnostics with different platforms that may provide clinical benefit in the future.

It is also critical that scientists develop vaccines to prevent disease, the authors write. A vaccine to protect against Lyme disease was previously developed, but was pulled from the market and is no longer available. Future protective measures could include vaccines specifically designed to create an immune response to a pathogen, or to target pathogens inside the ticks that carry them.

By focusing research on the epidemiology of tickborne diseases, improving diagnostics, finding new treatments and developing preventive vaccines, and researchers may be able to stem the growing threat these diseases pose. In the meantime, the authors suggest, healthcare providers should advise their patients to use basic prevention techniques: wear insect repellant, wear long pants when walking in the woods or working outdoors, and check for ticks.

Explore further: Diseases from ticks, fleas, mosquitoes soar in US

More information: Catharine I. Paules et al, Tickborne Diseases—Confronting a Growing Threat, New England Journal of Medicine (2018). DOI: 10.1056/NEJMp1807870

Related Stories

Diseases from ticks, fleas, mosquitoes soar in US

May 1, 2018
Diseases from mosquitoes, ticks and flea bites tripled in the United States from 2004 to 2016, and officials said Tuesday rising temperatures and an increasingly connected global society are to blame.

Lyme disease cases among children are on the rise in western Pennsylvania

June 20, 2018
Lyme disease cases among children are on the rise in western Pennsylvania, according to researchers from Children's Hospital of Pittsburgh of UPMC. The findings are published online today in Clinical Infectious Diseases.

Ticks that vector Lyme disease move west into North Dakota

September 11, 2014
According to the U.S. Centers for Disease Control, there are more than 300,000 cases of Lyme disease in the U.S. each year. Last year, most Lyme disease cases reported to the CDC were concentrated heavily in the Northeast ...

Lyme disease is on the rise – an expert explains why

May 17, 2018
May marks the beginning of the summer season when black-legged ticks that spread Lyme disease are more prevalent – even in California.

Scientists develop infection model for tickborne flaviviruses

August 22, 2017
National Institutes of Health (NIH) scientists have filled a research gap by developing a laboratory model to study ticks that transmit flaviviruses, such as Powassan virus. Powassan virus was implicated in the death of a ...

Study sheds light on new Lyme disease-causing bacteria

July 5, 2017
A new species of bacteria that causes Lyme disease needs the same amount of time for transmission after a tick bite compared to previously implicated bacteria, according to new research by the Centers for Disease Control ...

Recommended for you

PET scans to optimize tuberculosis meningitis treatments and personalize care, study finds

December 6, 2018
Although relatively rare in the United States, and accounting for fewer than 5 percent of tuberculosis cases worldwide, TB of the brain—or tuberculosis meningitis (TBM)—is often deadly, always hard to treat, and a particular ...

Silicosis is on the rise, but is there a therapeutic target?

December 6, 2018
Researchers from the CNRS, the University of Orléans, and the company Artimmune, in collaboration with Turkish clinicians from Atatürk University, have identified a key mechanism of lung inflammation induced by silica exposure, ...

Infectivity of different HIV-1 strains may depend on which cell receptors they target

December 6, 2018
Distinct HIV-1 strains may differ in the nature of the CCR5 molecules to which they bind, affecting which cells they can infect and their ability to enter cells, according to a study published December 6 in the open-access ...

Protecting cell powerhouse paves way to better treatment of acute kidney injury

December 6, 2018
For the first time, scientists have described the body's natural mechanism for temporarily protecting the powerhouses of kidney cells when injury or disease means they aren't getting enough blood or oxygen.

New study uncovers why Rift Valley fever is catastrophic to developing fetuses

December 5, 2018
Like Zika, infection with Rift Valley fever virus can go unnoticed during pregnancy, all the while doing irreparable—often lethal—harm to the fetus. The results of a new study, led by researchers at the University of ...

Study highlights potential role of bioaerosol sampling to address airborne biological threats

December 5, 2018
As a leading global city with a high population density, Singapore is vulnerable to the introduction of biological threats. Initiating an early emergency response to such threats calls for the rapid identification of the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.