The Epidemiology of Q fever outbreak at an meat packaging business in South Korea

Introduction : Q fever is a zoonosis caused by Coxiella burnetii. A Q fever outbreak occurred among the workers in a meat packaging company on December 2017 at A city in South Korea. Epidemiologic investigations were performed to clarify the cause and the transmission route of the outbreak. Methods : We conducted a questionnaire survey among 25 persons who worked at the company between July 1 and December 11, 2017, and we examined the 25 blood specimens and 36 environmental specimens for the C. burnetii. In addition, we examined on a farmer and 268 goat of the farm that supplied the meat, for the C. burnetii. The confirmed case was defined as a workers who participated in the company with positive results for the PCR or antibody test and responsible symptoms of Q fever. Results: The attack rate of the Q fever among the workers was 32%. The workers of meat packaging were found to be at the highest risk(relative risk 7.6; 95% confidence interval 1.187-52.951). Most of the meat packaging workers(75%) were not wearing masks during work, and there were no suitable ventilation and air conditioning facilities in the place where the meat packaging was done. In 10 of the 36 environmental specimens were positive PCR test for the C. burnetii (27.7%). 21 of 268 goats in the farm was infected by C. burnetii (7.8%), and the farmer was identified as asymptomatic case of Q fever. Conclusion: We concluded that the route of transmission of the outbreak was inhalation of aerosol generated during the cutting of goat meat infected by C. burnetii. Meat packaging workers need to wear masks and follow personal hygiene compliance, and the work area needs ventilation to ensure adequate air circulation. Infected patients must be required to follow-up to confirm chronic progression.