This quick, local, precautionary post-bite therapy promises to get around the difficulty of early diagnosis – a special risk for those who won’t develop the rash.
Lyme disease is a dangerous disease which is transmitted by ticks. Blood-sucking ticks ingest the agents that cause the disease – bacteria of the species Borrelia burgdorferi and its relatives – during a blood meal, and subsequently transmit them to the next victim they feast on, often a person.
It is estimated that, in Western Europe, up to half of all ticks carry the bacteria. Although the early symptoms of the illness are quite mild, if left untreated, it can result in serious damage to the skin, the joints, the heart and the nervous system, and effective therapy becomes very difficult.
A team of researchers led by the veterinary bacteriologist Professor Reinhard Straubinger at Ludwig-Maximilians University Munich has now shown, in an animal model, that application of a gel containing the antibiotic azithromycin to the site of the bite rapidly terminates the infection.
The efficacy of this local antibiotic therapy for the treatment of borreliosis in humans is now being tested in a Phase III clinical trial. (Phase III studies are randomized controlled multicenter trials on large patient groups.)
Currently, the most recommended early treatment is oral antibiotic therapy for several weeks; and, in many cases, the drug must be administered intravenously – which is distressing not only for children.
Furthermore, treatment measures are often initiated on suspicion, because the bacteria are not detectable in the blood soon after one has been bitten by an infected tick. And to make matters worse, 20% to 30% of those who become infected don’t develop the early-stage Lyme rash.
“Our approach simply involves applying a transparent, self-adhesive plaster to the site of the wound,” says Prof. Straubinger. “Because the plaster contains very little antibiotic, the effects are localized and side-effects are negligible.”
To read their findings, published online Sep 15 in the Journal of Antimicrobial Chemotherapy, see “Evaluation of the preventive capacities of a topically applied azithromycin formulation against Lyme borreliosis in a murine model.”
Source: Ludwig Macimilians University, Munich news release, Sep 15, 2011