No abstract

Three different spotted-fever group rickettsiae-Rickettsia conorii, R. massiliae, and R. rhipicephali-were detected and identified by PCR-restriction fragment length polymorphism analysis in Rhipicephalus ticks collected from domestic animals in the Fokida region of Greece, where a high seroprevalence of antibodies to R. conorii was previously demonstrated. The infection rate of ticks was 1.6%. Moreover, R. conorii was isolated from one Rhipicephalus sanguineus tick.Rickettsia conorii, the causative agent of Mediterranean spotted fever, is an obligate intracellular, gram-negative bacterium that infects humans. It is transmitted by the bite of infected arthropods (1, 9). The presence of the spotted-fever group (SFG) rickettsiae in ticks has been reported in several countries (2, 6-11, 13). Many rickettsiae remain poorly characterized due to the inability to be maintained in mammalian cell culture, embryonated chicken eggs, or small rodents, which have traditionally been the standard maintenance hosts used in rickettsiology. The advents of new culture techniques, such as the shell vial-centrifugation technique, and the detection of rickettsial DNA have increased the number of rickettsial species identified (6).A seroepidemiological survey, using an immunofluorescence assay and a Western blot method, was conducted in three villages (Leukaditi, Vounichora, and Makrini) of the Greek province of Fokida in 1991. This study reported a high seroprevalence of antibodies to R. conorii in humans (46%) (1). In a culture survey of ticks from the same area, strain GS (for "Greek strain") was isolated. This strain is genetically similar to Rickettsia massiliae; moreover, R. conorii was not found (2). As a follow-up to previous studies, we focused our efforts on determining the presence and infection rate of R. conorii in field-collected ticks from the three study villages of the Fokida (Fig. 1).In the summer of 1998 (May to August), a total of 439 ticks collected from goats, sheep, and dogs were examined for the presence of SFG rickettsiae. According to standard taxonomic keys, 207 ticks were identified as Rhipicephalus sanguineus, 94 were identified as Rhipicephalus turanicus, and 138 were identified as Rhipicephalus bursa (8). Each tick was triturated in 500 l of minimum essential medium supplemented with 4% fetal calf serum and 2 mM L-glutamine. Half of the above suspension was used for the detection of rickettsial DNA by PCR, and the rest was used for the isolation of rickettsiae by the shell vial technique (3, 4, 9, 11-13). The DNA extraction from the ticks was performed using the QIAamp tissue kit (Qiagen, Hilden, Germany), according to the instructions of the manufacturer. The primer set Rp.CS.877-Rp.CS.1258n was used to amplify a 381-bp sequence of the citrate synthase gene (9). As a negative control for each tick sample, pure PCR buffer treated in the same way as the tick samples was included. As a positive control, purified DNA from R. conorii (Moroccan strain) was used. The DNA from ticks that were positive for the c...

The seroprevalence and incidence of 10 zoonoses due to Rickettsia typhi, R. conorii, Coxiella burnetii, Burcella sp., Borrelia sp., Toxoplasma sp., Leishmania sp., Entamoeba histolytica, Echinococcus granulosus and Fasciola hepatica were studied in an animal husbandry and a farming village in Crete, Greece. The serum conversion incidence of each infectious agent was determined by testing 2 blood samples, collected in 1985 and in 1987. The surveillance was conducted using detailed transparent maps of the 2 villages studied, on which epidemiological data were interrelated to the results obtained from the serological tests. Thus the importance and spread of each infection were visualized. C. burnetii, Toxoplasma sp., R. conorii, and E. granulosus, were the most common infectious agents encountered during this study.

No abstract

Cases of murine typhus were described in Chalkis, capital town of the island Evia in Greece. In the present work a prospective study on murine typhus was carried out in Chalkis General Hospital in 1985, is presented. During this year 49 cases, serologically confirmed using indirect fluorescence assay, were diagnosed. Signs and symptoms of the patients as well as preliminary epidemiological data are reported in this paper.

No abstract

The aim of the present study was to determine the tolerance and efficacy of human brucellosis vaccine as well as the tolerance and sensitivity of the intradermal reaction test for brucellosis. A total of 1,121 subjects initially consented to participate in the study. Following clinical examination, 762 were tested with the intradermal reaction test (IDR Test, Pasteur Merieux, France), of whom 576 with no previous or current brucellosis infection were accepted for vaccination. Two hundred seventy-one were vaccinated with brucellosis vaccine and 305 with tetanus vaccine, the latter group serving as a comparative control group. The vaccinated persons were monitored monthly for at least nine months. Although brucellosis vaccine caused some unpleasant side effects in about one-fourth of the vaccinated persons, it appears safe for large-scale use in prevention programs. In addition, the results indicate that the intradermal reaction test is safe and sensitive for large-scale use in prevention programs. The test was positive in 28 of 30 individuals with previous infection, representing a sensitivity of 93.33%.