Epidemiological investigation of Coxiella burnetii in rural properties at Northwestern State of São Paulo after an outbreak of q fever in a slaughterhouse workers

Abstract

Q fever is a worldwide zoonosis caused by the obligate intracellular bacterium Coxiella burnetii. The main sources of infection for humans are cattle, sheep and goats, which shed the agent in profusion in birth or abortion products and to a lesser extent in milk, feces and urine. The bacterium is shed in the environment in a highly resistant form, which remains infectious for long time. The main mode of transmission is inhalation of aerosols or dust containing the agent. In humans, the acute phase of the disease has the self-limiting influenza-like syndrome as the most common clinical manifestation, while the chronic form triggers more often endocarditis. In domestic ruminants, the bacterium causes abortion and other reproductive problems. Although the disease is likely to be underreported, eventually outbreaks in humans are reported, characterized by high morbidity and low mortality, but with the possibility of persistent infections and chronic forms of the disease. In 2015, a Q fever outbreak was detected in workers in a slaughterhouse at Barbosa municipality, located in the northwestern state of São Paulo. In this work, it is intended to search in rural properties that sent cattle to Barbosa's slaughterhouse 7-30 days before the start of the outbreak, the presence of IgG antibodies against C. burnetii in animals and humans, the possible risk factors associated with seropositivity, and the presence of bacterial DNA in blood samples, milk, vaginal swab and ticks of animals, as well as trying the isolation of C. burnetii from ticks collected in animals. (AU)