Isolation of Coxiella burnetii in patients with nonspecific febrile illness in South Korea.

BACKGROUND: The number of human Q fever cases in South Korea has been rapidly increasing since 2015. We report the first isolation of Coxiella burnetii in Korea in two patients who initially presented with non-specific febrile illness and were finally diagnosed with acute Q fever in South Korea. CASE PRESENTATION: Two adult patients with fever had serologic tests against C. burnetii initially negative, and polymerase chain reaction against 16S rRNA using whole blood was also negative. After bacterial amplification of C. burnetii in immune-depressed mice, we isolated C. burnetii from patients with acute Q fever. The isolates KZQ2 and KZQ3 were confirmed by polymerase chain reaction, nucleotide sequence analysis, and morphologic observation using a transmission electron microscope. CONCLUSIONS: These results can help us understand the clinical and epidemiologic features of Q fever in South Korea.

Protection of ferrets from infection by swine-origin 2009 A (H1N1) influenza virus by the inactivated vaccine.

Swine-origin pandemic 2009 A (H1N1) influenza viruses are still infecting humans, and humans are currently being vaccinated with the inactivated vaccine of 2009 A (H1N1) influenza virus. We wanted to determine the efficacy of 2009 A (H1N1) inactivated vaccine in ferrets. Ferrets immunized with one dose (7.5 microg) of 2009 A (H1N1) inactivated vaccine were not protected from infections of either pandemic H1N1 or seasonal H1N1 influenza viruses, while ferrets immunized with two doses of 2009 A (H1N1) inactivated vaccine were protected from infections of pandemic H1N1, but not seasonal H1N1 influenza viruses. IgG subtype of antibody was dominantly detected in tissues of immunized ferrets. Our study suggests that pandemic H1N1 vaccine may not elicit the antibody cross-reactive to the seasonal H1N1 influenza virus.