Tularemia is a disease occurring towards the end of the summer

18.8.2009

<p>Tularemia is an infectious disease caused by a bacterium ( <em>Francisella tularensis</em>). This bacterium is highly pathogenic and can infect various animal species in several ways. Bloodsucking insects also spread these bacteria, which is why tularemia most frequently occurs during the warm season, typically towards the end of the summer.</p>

Infects people as well as animals

Tularemia is a zoonosis, i.e., a disease spreading between people and animals. Several different animal species can get the infection, but its seriousness varies with the species. In people, high fever and swollen lymph nodes can be symptoms of tularemia . Among animals, mountain hares and brown hares easily catch tularemia and often die soon after having been infected.

Rodents (voles, mice, lemmings, muskrats, beavers) are major hosts of tularemia bacteria. Many birds also can catch tularemia. Among pets, dogs most often do not get the disease and, surprisingly, rabbits are much more resistant than hares to the bacterium. Cats have been reported to catch the infection, which may be due to their habit of catching small rodents.

Many ways to catch the disease

Only a few tularemia bacteria suffice to generate the disease in people. It is spread by bloodsucking insects and infections among Finnish people most often have been transmitted by insects. Normal contacts between people directly do not transmit the disease between persons. One can get infected through wounds on hands or mucous membranes when handling animals that have died of tularemia. If the bacteria reach the eyes, they will cause conjunctivitis. Other routes of infection are through inhaled air, and intake of water or food contaminated by the bacteria.

Incidences vary

Tularemia occurs in various places in Finland. In material at Evira, an average of 8 % of hares investigated have died from tularemia. Annual variations can be significant: in 2007 nearly every fourth hare had tularemia, while in 2001 the proportion was less than 1 %. Apparently, 2009 will turn an average year as of tularemia among wild animals. This year, hares having died from tularemia have been sent to Evira from Northern Savonia, the western parts of the province of Oulu, Ostrobotnia and Kymenlaakso.

Evira analyzes animal samples

Evira’s Fish and Wildlife Health Research Unit in Oulu does research on diseases among wild animals. Whole carcases of animals having recently died can be sent to be analyzed for tularemia or other diseases.

Avoid touching dead animals with bare hands; wash your hands immediately after handling.

Instructions on the packaging and sending of animals to investigation for animal diseases, and addresses
A covering letter shall always follow animals dispatched to Evira  (in Finnish)

Read more on tularemia on Evira’s web pages (in Finnish) and the web pages of The National Institute for Health and Welfare (THL)  (in Finnish).

Additional information:
Researcher Marja Isomursu, Fish and Wildlife Health Research Unit, marja.isomursu at-merkki-kapea.gifevira.fi,
tel. 020 77 24910 or 020 77 24924

 

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