Coxiella burnetii
| Coxiella burnetii | ||||||||||||
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Coxiella burnetii |
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| Scientific name | ||||||||||||
| Coxiella burnetii | ||||||||||||
| ( Derrick 1939) Philip 1948 |
Coxiella burnetii is a gram-negative and aerobically living, only approx. 0.4 µm long and therefore almost cocoid rod-shaped bacterium from the family of the Coxiellaceae . Coxiella burnetii , the only species of the genus Coxiella, is the causative agent of Q fever and was first described in Australia in 1937. The species was named after Frank Macfarlane Burnet . The pathogen Coxiella burnetii is in Germany and Switzerland notifiable .
features
Coxiella burnetii is an obligate intracellular bacterium, ie it can only multiply within the host cell, where it is enclosed by a vacuole. In the free environment outside the host, Coxiella burnetii forms a cell form with a thickened cell wall that is highly resistant to external influences. As with the rickettsiae, free cultivation on nutrient medium is difficult; yolk sacs from chicken embryos are often used for cultivation.
transmission
The pathogen is distributed worldwide and can be transmitted to humans primarily from sheep, but also from domestic animals such as dogs and cats as well as from cattle and goats.
Ticks act as the actual vector for transmission between animals . It can also be transmitted through the ingestion of infected excreta such as faeces or milk. The infection of humans occurs airborne, e.g. B. inhalation of infected dust. Coxiella burnetii is extremely viable; in dry materials the bacterium remains infectious for several months. Person-to-person transmission is rare. Q fever is widespread worldwide and there are also cases of illness in Germany (Germany 2017: 107 reported cases). The immunity induced by Coxiella burnetii lasts for a long time.
Systematics
Coxiella burnetii was formerly part of the Rickettsiaceae family . Here you can find other pathogens that, like Coxiella, are intracellular parasites. Coxiella is morphologically very similar to Rickettsia , but genetically they are far apart. So Coxiella was placed in a different class, the Gammaproteobacteria , whereas the Rickettsiaceae are assigned to the Alphaproteobacteria .
Reporting requirement
In Germany, the direct or indirect detection of the bacterium must be reported by name in accordance with Section 7 of the Infection Protection Act , if the evidence indicates an acute infection.
In Switzerland, the positive and negative laboratory analytical finding is the pathogen notifiable namely by following the Epidemics Act (EpG) in connection with the epidemic Regulation and Annex 3 of the Regulation of EDI on the reporting of observations of communicable diseases of man .
literature
- Gerd Herold: Internal Medicine 2016
- Köhler, Werner (Ed.) Medical Microbiology , 8th edition, Urban and Fischer, Munich / Jena 2001 ISBN 978-3-437-41640-8 .
- Michael Rolle, Anton Mayr (ed.): Medical microbiology, infection and epidemic theory. 6th edition. Enke Verlag, Stuttgart 1993, ISBN 3-432-84686-X .
Individual evidence
- ^ Robert Koch Institute: Infection Epidemiological Yearbook of Notifiable Diseases for 2017 . Berlin 2018, p. 187 (www.rki.de/jahrbuch).