Some bacteriological and immunological investigations on Coxiella burnetii (Q fever)

Abstract

Q fever is considered a neglected zoonotic disease and is caused by Coxiella burnetii. Because very little information is available on C. burnetii infections in cattle, sheep, and goat populations in Egypt, the aim of this study is to identify the seroprevalence of C. burnetii in humans and livestock and to test for the presence of C. burnetii DNA in sera from seropositive animals. Material and Methods: Blood samples were collected from 160 apparently healthy farm animals and 120 patients from three hospitals of the Assiut Governorate throughout 2017/2018. These populations were tested for antibodies against C. burnetii phase II antigen by immunofluorescence assay (IFA)) and enzyme-linked immunosorbent assay (ELISA). Seropositive samples were subjected to real-time quantitative PCR (RT-qPCR). Results: The results of the IFA revealed C. burnetii seroprevalence rates of 45.3%, 56.0%, 45.7%, and 53.3% in cattle, sheep, goats, and humans, respectively. In humans, the seroprevalence rates were 52.1%, 30.4%, 37.5%, 74.1%, and 62.5% in patients with fever of unknown origin, influenza, kidney dialysis, hepatitis C virus, and hepatitis B virus, respectively. Likewise, by ELISA, the seroprevalence in bovine was 50.7%; sheep, 60.0%; goats, 51.4%; and humans, 55.0% (54.3%, 30.4%, 37.5%, 77.8%, and 62.5% in patients with fever of unknown origin, influenza, kidney dialysis, hepatitis C virus, and hepatitis B virus, respectively). RT-qPCR targeting the repetitive element IS1111 confirmed the presence of C. burnetii DNA.