From Q Fever to Coxiella burnetii Infection: a Paradigm Change

Abstract

Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.

Acute Pericarditis due to Coxiellaburnetiiinfection, a case report

“…In Spain, 21% of episodes of fever lasting for more than 1 week and less than 3 weeks has been observed to be produced by C. burnetii. On the other hand, chronic Q fever is characterized by a spontaneous evolution lasting for > 6 months and a high level of IgG antibodies titre, generally determined by IFA [2,3].…”

“…In humans, acute C. burnetii is often asymptomatic or mistaken for an influenza-like illness or atypical pneumonia. On the other hand, chronic Q fever is characterized by a spontaneous evolution lasting for > 6 months and a high level of IgG antibodies titre, generally determined by the indirect fluorescence antibody (IFA) [3].…”

Q fever prosthetic joint infection

“…C. burnetii is found in a wide variety of mammals, reptiles, birds and ticks 7. Human infection occurs via inhalation of aerosolised bacteria from birth products, urine, faeces and other infected material.…”

Molecular characterization of Coxiella burnetii in the slaughtered animals of Southern Iran

“…The main causative agent of Q fever, C. burnetii, is an obligate intracellular Gram-negative bacterium which may infect a variety rang of vertebrate and invertebrate populations and is also assumed as a biological terrorist organism [2][3][4]. The reports have implied that farm animals including cattle, sheep, and goats, play a major role as reservoir of the infection, with high risk to the vulnerable populations including ranchers, veterinarian, butchers and personnel of slaughterhouses [5][6][7].…”

“…The reports have implied that farm animals including cattle, sheep, and goats, play a major role as reservoir of the infection, with high risk to the vulnerable populations including ranchers, veterinarian, butchers and personnel of slaughterhouses [5][6][7]. Transmission routes of the infection to human are including infected ticks, aerosols, direct contact with the infected animal fluids such as milk, urine, seminal fluid, contaminated tissues such as kidneys, mammary glands and lymph nodes [2,[8][9][10][11][12].…”