Protection From Lyme Disease – At Last!

In Austria, hiking is serious business. It requires: top rate-hiking gear, a glossary of quaint foods at mountain huts in the applicable regional dialect, and the intricate knowledge of the lifestyle and eating habits of certain blood sucking parasites, like ticks.

Ticks might be small, but they have a big impact on public health: Current estimates suggest that one out of every five Austrian ticks is carrying Lyme disease.

Ticks are second only to mosquitoes as carriers of disease to humans. These parasites pick up pathogens from rodents and birds during a blood meal. If you are unlucky enough to be the tick’s next meal, the pathogens can be transferred to you.

 

Battling the bacteria

But a recent study published in the leading medical journal Lancet reports on a treatment that may make them less dangerous, with clinical trials showing for the first time an effective protection against the major forms of Lyme disease.

Lyme Borreliosis, or Lyme disease, is caused by the spirochete (cork-screw) bacteria Borrelia.  Within Europe, around 90,000 cases are reported each year and 16,000 of those are within Austria.

The disease often begins with flu-like symptoms and a characteristic bulls-eye rash. It is named after the towns of Lyme and Old Lyme, Connecticut, USA, where it was first discovered in 1975. At that time it was called "Lyme arthritis" because of the pain and swelling that it induced in the joints.

A few years later in 1981, the Swiss-born scientist Willy Burgdorfer identified the bacteria causing the disease and effective treatment with antibiotics began.

End of story? Not quite. Dr. Noel Barrett, leading the clinical study at Baxter BioScience at Orth an der Donau, told The Vienna Review that although the bacterial infection is usually treatable with antibiotics, around 10 per cent of those who get the infection are treatment resistant. Moreover, around 40 per cent do not get the bulls-eye rash. With symptoms of the disease appearing weeks or even months later, when the tick bite is long forgotten, patients are often unaware they are infected. Long-term, the infection can lead to cardiac and neurological problems if left untreated, and patients run the risk of re-infection. "This is why the development of a vaccine is so important," explained Dr. Barrett.

 

"The impact would be substantial" 

On an average Wanderung, chances of being bitten by an infected tick are higher than you might expect.

More than 30,000 Austrians are the blood meal of an infected tick each year, explained Prof. Herwig Kollaritsch of the Medical University of Vienna.

The risk of severe infection is compounded by the risk of misdiagnosis.

"Lyme disease is not easy to diagnose – many cases are detected very late and after a prolonged illness, which may be really annoying for the patients," he explained.

The Lancet study, conducted between 2011 and 2012, included 300 patients from Austria and Germany, treated with different doses of the vaccine to test for its safety and its ability to provide a protection against the infection in healthy adults.

The Lyme vaccine uses a conserved protein on the bacterial surface, called Outer Surface Protein A (OspA) as the "danger signal" for the immune system. When the vaccine is injected, the body produces antibodies – hallmark signs of protection – that recognise this protein as dangerous and trigger immune system responses to destroy it. Thus the Lyme vaccine works by preventing the transmission of the bacteria to the host.

Antibodies produced by the vaccinated host enter the tick and kill the bacteria in the tick mid-gut. This kind of vaccine technology might also have implications for the treatment of other diseases, such as malaria, with similarly complex lifecycles.

"All market research indicates that the impact of this vaccine would be substantial," Barrett said. This vaccine is expected to have an even greater impact within Europe than in the U.S., where awareness of tick-spread diseases is already high – such as the notorious tick-borne encephalitis (TBE).

Vaccination for TBE has already had a major impact on public health in endemic, vulnerable areas. The vaccine for this viral disease – one that attacks the nervous system, leading to severe swelling around the brain and even death – has been available for over 40 years and is transmitted by the same tick as Lyme Borreliosis. Within Austria, some 85 per cent of the population has received at least one dose of the TBE vaccine, which has prevented an estimated 4,000 cases  in the last decade alone.

"We think that the Lyme vaccine will follow a similar course as TBE," said Barrett. "People living within endemic areas will be advised to get the vaccine. There is a lot of enthusiasm from European health authorities already."

For now however, the Lyme vaccine is still in testing stages. So when you are packing up for your mountain hike this summer, along with maps, shoes and sunscreen, don’t forget the insect repellent and, always, long pants. No point in giving the ticks a free lunch.