Q fever – selected issues

Tomasz Mirski 1,  
Jerzy Gaweł 1,  
Biological Threats Identification and Countermeasure Center of the Military Institute of Hygiene and Epidemiology, Pulawy, Poland
Medical University, Department of Epidemiology, Warsaw, Poland
Ann Agric Environ Med 2013;20(2):222–232
Q fever is an infectious disease of humans and animals caused by Gram-negative coccobacillus [i]Coxiella burnetii[/i], belonging to the [i]Legionellales[/i] order, [i]Coxiellaceae[/i] family. The presented study compares selected features of the bacteria genome, including chromosome and plasmids QpH1, QpRS, QpDG and QpDV. The pathomechanism of infection – starting from internalization of the bacteria to its release from infected cell are thoroughly described. The drugs of choice for the treatment of acute Q fever are tetracyclines, macrolides and quinolones. Some other antimicrobials are also active against [i]C. burnetii[/i], namely, telitromycines and tigecyclines (glicylcycline). Q-VAX vaccine induces strong and long-term immunity in humans. Coxevac vaccine for goat and sheep can reduce the number of infections and abortions, as well as decrease the environmental transmission of the pathogen. Using the microarrays technique, about 50 proteins has been identified which could be used in the future for the production of vaccine against Q fever. The routine method of [i]C. burnetii[/i] culture is proliferation within cell lines; however, an artificial culture medium has recently been developed. The growth of bacteria in a reduced oxygen (2.5%) atmosphere was obtained after just 6 days. In serology, using the IF method as positive titers, the IgM antibody level >1:64 and IgG antibody level >1:256 (against II phase antigens) has been considered. In molecular diagnostics of [i]C. burnetii[/i] infection, the most frequently used method is PCR and its modifications; namely, nested PCR and real time PCR which detect target sequences, such as [i]htpAB[/i] and [i]IS1111[/i], chromosome genes (com1), genes specific for different types of plasmids and transposase genes. Although Q fever was diagnosed in Poland in 1956, the data about the occurrence of the disease are incomplete. Comprehensive studies on the current status of Q fever in Poland, with special focus on pathogen reservoirs and vectors, the sources of infection and molecular characteristics of bacteria should be conducted.