Cats are assumed to be one of the most important reservoirs of causative agent of human Q fever especially in urban areas. There is no evidence of Coxiella burnetii infection in cats in Japan prior to this. Sera from 100 cats, collected in various parts of Japan, were examined for antibody against C. burnetii. Sixteen out of the 100 samples contained antibodies against C. burnetii. The prevalence of the antibody decreased from the northeastern to the southwestern part of Japan. A high prevalence of the antibodies was observed in sera from cats of more than four years of age. It is difficult to deny that cats would be one of the important sources of human Q fever in Japan.

No abstract

Abstract. The causative agents of rickettsial diseases (Rickettsia conorii, R. typhi, and Coxiella burnetii) have been reported throughout the African continent. However, there have been no reports on epidemiologic surveys of these infections in Zambia. This study was designed to clarify the prevalence of three rickettsioses in 377 humans in Zambia. The seroprevalence of antibodies against R. conorii, R. typhi, and C. burnetii was 16.7%, 5.0%, and 8.2%, respectively. The rates of antibody positivity against R. conorii and C. burnetii were higher in the eastern (23.1% and 11.8%) and western (16.8% and 7.4%) areas of Zambia than in the northern (3.0% and 3.0%) area of this country. There was little difference among the three areas in the distribution of antibodies against R. typhi. Since cattle breeding is more extensive in the western and eastern areas than in the northern area, it is thought that cattle-breeding areas are foci of R. conorii and C. burnetii infections in Zambia.Recently, serologic surveys of antibodies against spotted fever group (SFG) rickettsia, Rickettsia typhi, and Coxiella burnetii in humans living in African countries (Angola, Burkina Faso, Central African Republic, Comoros, Congo, Ivory Coast, Mali, and Tanzania) using an indirect immunofluorescent antibody (IFA) test have demonstrated a high prevalence of antibodies to rickettsiae. 1,2 However, there has been no seroepidemiologic survey of antibodies against rickettsiae in humans living in Zambia. In this study, the extent of infection with three rickettsioses (SFG rickettsia, murine typhus, and Q fever) in humans living in Zambia was investigated.Serum samples were collected from inhabitants of Kasama (northern area), Chipata (eastern area), and Limulunga and Senanga (western area) Zambia by one of the authors (FH) in 1989 for an epidemiologic survey of Rift Valley fever. 3 These sera were collected after informed consent was obtained for surveys of infectious diseases. The study was approved by the School of Veterinary Medicine of the University of Zambia and the Graduate School of Veterinary Medicine of Rakuno-Gakuen University. Information on sex, age, occupation, contact with livestock (cattle), participation in meat processing, and handling of aborted fetuses of cattle was obtained by questionnaires at the time of the collection of blood samples. Sera were absorbed in blood sampling papers and dried according to the manufacturer's instructions for blood sampling filter paper (Toyo-Roshi, Tokyo, Japan). The papers were kept at 4ЊC until 1996 and eluted into 600 l of phosphate-buffered saline (PBS), pH 7.5 (Nissui Pharmaceutical Co., Tokyo, Japan). The eluted serum was considered a 16-fold dilution.The R. conorii Moroccan strain, the R. typhi Wilmington strain, and the C. burnetii Nine Mile phase II strain (VR-616; American Type Culture Collection, Rockville, MD) were grown and maintained in Vero E6 cells, BSC-40 cells, and BGM cells, respectively, and used as antigens of SFG rickettsia, murine typhus, and Q fever, respectively. Ricke...

We attempted to detect Coxiella burnetii in dust samples collected from a barn housing dairy cattle by the polymerase chain reaction (PCR) method. Ten dust samples (five from ventilation fans and five from crossbeams) were collected from two areas in a barn on a farm near Sapporo, Hokkaido. C. burnetii was detected in 5 of the 10 dust samples. It was believed that aerial contamination by C. burnetii occurred in the barn.

The prevalence and seasonal variations of infection by Coxiella burnetii in cattle were investigated seroepidemiologically on a farm in Hokkaido, Japan, by an immunofluorescent antibody test. A total of 364 serum samples from 28 cows were collected from August 1993 to October 1995 in two barns on the farm.It was found that the number of antibody-positive cows and their antibody titers were significantly elevated in winter and decreased in summer. In addition, antibodies were detectable in seroconverted cows for about five months.