Long-term persistence of Coxiella burnetii in the host after primary Q fever

After a primary infection Coxiella burnetii may persist covertly in animals and recrudesce at parturition to be shed in the products of conception and the milk. Similar latent persistence and recrudescence occurs in man: name ly, infection of placenta, heart valve or mural endocardium, bone or liver. The numbers of organisms, their viability and cellular form, and the under lying organ sites of latent infection for the coxiella are obscure. During investigations of 29 patients with a chronic sequel to acute Q fever, the p ost-Q fever fatigue syndrome (QFS) [1-3], sensitive conventional and TaqMan -based PCR revealed low levels of C. burnettii DNA in blood mononuclear cel ls (5/29; 17 %), thin needle liver biopsies (2/14; 14%) and, notably, in bo ne marrow aspirates (13/20; 65 %). Irrespective of the ultimate significanc e of coxiella persistence for QFS, the detection of C. burnetii genomic DNA in bone marrow several years after a primary infection unveils a new patho logical dimension for Q fever.