[Time course of the levels of antibodies to Coxiella burnetii and detection of C. burnetii-DNA in three imported cases of acute Q fever].

Three patients developed acute Q fever after returning from an inspection tour of farms and abattoirs to Australia. Serum levels of antibodies to Coxiella burnetii and the presence of C. burnetii-DNA in blood samples were examined for more than 100 days. Four-fold raises of IgM and IgG antibodies against C. burnetii phase 2 were observed within the first three weeks in all the three cases. Maximum titers of IgM and IgG antibodies were 1,024-2,048 and 512-4,096, respectively. According to the temporal diagnostic criteria of acute Q fever in the convalescent serum: the IgM titer of > or = 64 and IgG titer of > or = 512 against phase 2, patient A, B and C were determined to be antibody positive for 45, 199 and 122 days, respectively. The result suggests that this standard is practical and reasonable for diagnosis of acute Q fever. C. burnetti-DNA was detected in the sera and buffy coat samples of patient A who developed high fever, severe thrombocytopenia and liver disfunction, but not in those of patient B and C. This study provides useful information for optimization and standardization of Q fever diagnosis in Japan.

[Three imported cases of acute Q fever after an inspection tour to Australia and New Zealand].

After an inspection tour to farms and abattoirs in Australia and New Zealand, three Japanese persons simultaneously developed febrile illnesses in Japan. They generally had slight fever and general fatigue, followed by thrombocytopenia and hepatic dysfunction. However, no respiratory symptoms were observed. In one of the cases, severe thrombocytopenia (1.3 x 10(4)/microliter) and high fever up to 40 degrees C were observed. These clinical symptoms were compatible with Q fever. All of the cases showed four hold-elevations of IgM and IgG against Coxiella burnetii phase II between acute and convalescent sera by a serological test. C. burentii-DNA was also detected in the serum of one patient. Minocycline was highly effective in all cases. This report illustrates the typical clinical courses of acute Q fever.