Serological and molecular evidence of Coxiella burnetii in samples from humans and animals in China

Abstract

Introduction. Coxiella burnetii is the agent of Q fever, a worldwide zoonosis. To add to the available knowledge of the disease in China, C. burnetti infections were investigated in convenience samples from five animal species and humans from Yangzhou, Jiangsu province, eastern China. Materials and methods. Commercial ELISA kits were used to detect antibodies to phase I and II C. burnetii. A FRET-qPCR targeting the outer membrane protein com1 gene was also developed to detect C. burnetii DNA in blood samples from animals and humans, and bovine milk samples. Results. Seropositive cattle (44/150; 29%), goats (33/150; 22%), humans (45/180; 25%) and pigs (4/130; 3%) were found, while dogs (0/136; 0%) and cats (0/140; 0%) were seronegative. Seropositivity in humans was associated with increasing age, but there was no gender difference. DNA was amplified from two milk samples (2/150, 1.3%), while none of the blood samples were positive. The sequences of the obtained amplicons were identical to those of the com1 gene of the universal C. burnetii RSA 493 strain and other stains from China. Conclusions. The findings indicaten that C. burnetii is endemic in Yangzhou, China, and therefore human and animal health workers should be aware of the possibility of infections and the occurrence of outbreaks of Q fever.