Borrelia infection from a tick bite just as possible in a city centre park

The chances of getting a Borrelia infection from a tick bite are no different in a city centre park than they are out in the archipelago. This is one of the recent discoveries of Professor Matti Viljanen and his research team who are looking into how the Borrelia bacteria deceives and manipulates the human immune defence system. The research project under the supervision of Professor Viljanen is part of the Academy of Finland’s Microbes and Man Research Programme.

One in three ticks in the parks in Helsinki, Finland, carry the Borrelia bacteria. Professor Viljanen and his team have also shown that ticks and Borrelia can be transmitted across continents in migratory birds. In birds, the Borrelia bacteria may cause an asymptomatic latent infection. During migration, variations in the bird’s hormone levels will activate the bacteria and cause it to grow in the bird’s blood. This will ensure that the bacteria is transmitted into the ticks living off the bird and improve its prospects of conquering new territory.

The Borrelia bacteria can deceive and manipulate the immune defence system in various different ways. It can mask itself using human proteins and in this way avoid the attacks of the white blood cells that are responsible for first-phase defence. It is also capable of altering the balance of the immune response to its own advantage.

The project is interested to know how the Borrelia bacteria deceives and manipulates the immune defence system at different stages. A further concern is with the question of how the bacteria advances in tissue and how it penetrates the walls of blood vessels. One area of special interest is the activation of a latent infection. The researchers will also be trying to find drugs that can help to restore the balance of the immune system and to cure chronic, rheumatic symptoms. The new information generated will help to produce more effective means for the prevention and treatment of Borrelia infections.

Professor Viljanen from Turku University, Finland, shares responsibility for running the programme with Professor Sven Bergström from Umeå University, Sweden: the Microbes and Man Research Programme is a joint Finnish-Swedish venture