DIAGNOSIS OF MEDITERRANEAN SPOTTED-FEVER BY CULTIVATION OF RICKETTSIA-CONORII FROM BLOOD AND SKIN SAMPLES USING THE CENTRIFUGATION-SHELL VIAL TECHNIQUE AND BY DETECTION OF R-CONORII IN CIRCULATING ENDOTHELIAL-CELLS - A 6-YEAR FOLLOW-UP

Rickettsia conorii, an obligate intracellular bacterium that infects v ascular endothelial cells, is the etiologic agent of Mediterranean spo tted fever. We correlated the results of 205 R. conorii blood and skin cultures for 157 patients and the results of 48 detections of R. cono rii in circulating endothelial cells (CEC) for 41 patients with releva nt serological, clinical, and therapeutic data, R. conorii was culture d from 40% of patients and 29.8% of samples, R. conorii was detected i n CEC in 50% of samples, representing 46.2% of patients, When these ca lculations were limited to the samples from untreated patients prior t o their seroconversion to R. conorii, the sensitivity of culture was 5 9%, whereas it remained at 50% for detection in CEC, We also performed PCRs for the detection of R. conorii on eight shell vial supernatants from positive cultures and on 43 blood samples, Only nonfrozen supern atants from fresh cultures were positive, The methods described in thi s report are suitable for use in all laboratories, Our findings sugges t that for samples to be suitable for culture they must be collected p rior to the initiation of an antibiotic regimen, as early as possible in the course of the disease, and be inoculated onto shell vials with minimal delay, if R. conorii is to be successfully isolated, For patie nts who have been treated or who have a delayed diagnosis, detection o f R. conorii in CEC remains helpful.