Q-Fieber

Human Q-fever caused by the bacterium Coxiello burnetii is a re-emerging zoonosis in Germany causing recently outbreaks involving large numbers of patients. In humans most infections induce no symptoms but an influenca-like presentation can be seen in diseased persons. Endocarditis is the life threatening complication in chronic disease. Ruminants (sheep, goats, cattle) are considered to be the main reservoir for human infection. These animals excrete the agent in significant numbers during birth. In animals symptoms are rare but abortion, birth of weak offspring and respiratory symptoms may be present. C burnetii forms stress resistant spore-like particles being stable for a long time in the environment. Cultivation of the agent is troublesome thus diagnosis mainly relies on serologic techniques which are well evaluated for human use only. PCR and genomic typing methods (MLST, VNTR) facilitate rapid identification of C burnetii and may elucidate chains of infections. Serological and PCR results are often difficult to interpret in the light of an outbreak and thus the source of infection remains usually unknown. Thus, single observation made during regional outbreaks may not be generalised. It can be noticed that still many facts considering epidemiology (existence of natural reservoir?), pathopysiology, improvement of culture techniques and management of an outbreak are still unknown and research in these fields has to be focused