Tackling Lyme disease: How researchers plan to disarm ticks

The treatment options for chronic Lyme disease, a tickborne illness, are still limited. But now, researchers are pursuing a new approach: Eliminating the cause directly at the source.

Lyme disease may eventually be a thing of the past, says Kim Lewis, professor of biology and director of the Antimicrobial Discovery Center at Northeastern University in the US city of Boston.

The reason for this optimism is the rediscovery of a chemical that is deadly to the bacterium causing the tick-borne illness but harmless to animals. But more on that in a moment.

Lyme disease is caused by a bacterium called Borrelia burgdorferi, which lurks in small rodents such as rats or mice, as well as in deer. They do not show symptoms of the disease. Ticks serve as vectors, meaning they become infected when they feed on blood from these animals and transfer the bacteria to new hosts —such as humans.

Signs of infection

If a person becomes infected with Lyme disease after a tick bite, it can present in a variety of different symptoms. One of the most common signs is the typical circular skin inflammation that forms around the tick bite and spreads in a ring shape. In people with darker complexions, the rash can look like a bruise. This so-called migratory redness (erythema migrans) occurs in 80 to 90 out of 100 infected persons.

However, Lyme disease can also manifest itself in other ways. For example, within the first few weeks after the tick bite, flu-like symptoms such as fatigue, joint pain, muscle pain, a raised temperature or night sweats may indicate an illness. Irregular heartbeat, lower back pain or nerve pain may also occur.

Don't let ticks get to you

It is not yet possible to prevent Lyme disease. Tick bites should be avoided from the outset — also in view of the fact that the insects can transmit other diseases as well, such as tick-borne encephalitis (TBE), for example.

This means that anyone who is out and about in meadows or forests should wear clothing that is as long as possible, especially on the legs. Putting on long socks also makes life a little more difficult for the little parasitic arachnids, especially if they are pulled up over the bottom of the pant legs. Ticks are more visible on lightcolored clothing. Anti-tick sprays keep ticks away, at least for a limited time, but not all products are equally reliable.

After returning home from an outing in the wild, you should thoroughly check for ticks. If you find one, you should remove it immediately (here is a detailed description of how to do so correctly). The sooner, the better!

How is Lyme disease treated?

In the early stages, Lyme disease is treatable with antibiotics such as doxycycline. However, such medications can disrupt the gut microbiome, leading to symptoms such as diarrhea. At worst, the antibiotic could promote the development of antibiotic resistance. However, if Lyme disease is not treated, it becomes chronic and keeps coming back.

In the US and Canada, there used to be a vaccination against Lyme disease, called LYMErix. In 1998, it was approved by the US national public health agency CDC for high-risk patients, but in 2002, GlaxoSmithKline discontinued the vaccine, saying it was selling poorly.

So, at present, people can be vaccinated only against the viral tick-borne disease TBE. In veterinary medicine, however, Lyme disease vaccinations are still available today — for dogs, for example. They need to be refreshed every year.

Very recently, in September 2021, there was news about another possible vaccine against Lyme disease for humans: The two pharmaceutical companies Valneva and Pfizer published positive Phase 2 results, including a booster response, for the vaccine candidate VLA15.

"Lyme disease represents a high unmet medical need which impacts the lives of millions of people in the Northern Hemis

Borrelia burgdorferi bacteria can trigger chronic diseases — but a remedy may be in sight