Abstract

Q fever is an acute and chronic zoonotic disease of highly public health importance worldwide. The disease is caused by an obligate gram-negative bacterium; Coxiella burnetii (C. burnetii). Coxiella burnetii belongs to the genus Coxiella of the gamma sub-division of Proteobaccteria along with the genera Legionella, Francisella, and Rickettsiella. Unlike the other members of Proteobaccteria, C. burnetii is highly resistant to adverse physical conditions and chemical agents, so it can survive for months and even years in the environment. Domestic animals such as cattle, sheep and goats act as the major reservoirs of C. burnetii which can infect a large variety of animals, humans, birds, and arthropods. Human infection results from inhalation of contaminated aerosols, consumption of contaminated unpasteurized dairy products, direct contact with contaminated milk, urine, feces, or semen of infected animals, and tick bites. Clinical presentation is non-specific and highly variable ranging from asymptomatic infection or self-limiting febrile illness to a typical rapidly progressive pneumonia and/or hepatitis. In animals, Q fever is frequently asymptomatic. Sheep and goats may exhibit abortion, stillbirth, pre-mature delivery, and delivery of weak offspring while cattle and camel may develop infertility, metritis, and mastitis. Diagnosis and isolation of C. burnetii are mainly focused on molecular tests (PCR), and serological tests such as Complement Fixation Test (CFT), Enzyme-Linked Immunosorbent Assay (ELISA) and Indirect Fluorescence Assay (IFA). Doxycycline and Oxytetracycline are the drug of choice for the treatment of Q fever infection. Due to its wide range of reservoir hosts and severity of infection both in animals and humans, emphasis should be given in the control and prevention of this zoonotic disease.

Keywords:Q fever; Coxiella burnetii; Zoonosis; Animals; Humans