Table 1.

Current hypothesis on pathogenesis of Q fever from clinical and experimental data

Pathogenesis factorData in humans and experimental animalsReference(s)
Acute Q fever (factors influencing clinical manifestations)
 Host factorsUnknown
C. burnetii strainUnknown
 Route of infectionAerosol versus intraperitoneal inoculation in BALB/c mouse and guinea pig models 183, 219
 Inoculum doseMyocarditis in guinea pigs 183
Chronic Q fever (factors influencing evolution to chronic Q fever)
 Host factors
  ImmunosuppressionPatients with acquired immunosuppression (cancers, lymphomas, or HIV infection) 138, 286, 294,295
Persistent infection in athymic mice 170
Reactivation of infection with steroids or whole-body irradiation in mice and guinea pigs 330, 331
Endocarditis in mice receiving cyclophosphamide 17
  ValvulopathyHuman endocarditis and previous valvulopathy 286, 290
Endocarditis in guinea pigs with damaged cardiac valves 181
  PregnancyEndocarditis in pregnant mice 351
Chronic Q fever in pregnant mammals and women 20, 350
C. burnetii strainGenetic heterogeneity among “acute” and “chronic” strains but lack of pathotype-specific gene in human strains 314, 348
Experimental endocarditis with Nine Mile “acute” strain 17, 181,239, 351