Recently, we reported (Jansen et al., 2017) that C. burnetii induces the sheddases MMP-1 and MMP-9 production in PBMCs of healthy persons exposed in vitro to the bacterium; that the single nucleotide polymorphisms (SNPs) in MMP-7 and MMP-9 were more frequent in patients with persistent Q fever; and, that the circulating MMP-7 serum levels were higher in patients with persistent Q fever. This evidence concerns the gene MMP9 and Q fever.