Diagnosis Of Mediterranean Spotted Fever Research Articles

Mediterranean Spotted Fever: Current Knowledge and Recent Advances.

Mediterranean spotted fever (MSF) is an emerging tick-borne rickettsiosis of the spotted fever group (SFG), endemic in the Mediterranean basin. By virtue of technological innovations in molecular genetics, it has been determined that the causative agent of MSF is Rickettsia conorii subspecies conorii. The arthropod vector of this bacterium is the brown dog tick Rhipicephalus sanguineus. The true nature of the reservoir of R. conorii conorii has not been completely deciphered yet, although many authors theorize that the canine population, other mammals, and the ticks themselves could potentially contribute as reservoirs. Typical symptoms of MSF include fever, maculopapular rash, and a characteristic eschar (“tache noire”). Atypical clinical features and severe multi-organ complications may also be present. All of these manifestations arise from the disseminated infection of the endothelium by R. conorii conorii. Several methods exist for the diagnosis of MSF. Serological tests are widely used and molecular techniques have become increasingly available. Doxycycline remains the treatment of choice, while preventive measures are focused on modification of human behavior and vector control strategies. The purpose of this review is to summarize the current knowledge on the epidemiology, pathogenesis, clinical features, diagnosis, and treatment of MSF.

Assessment of the Percentages of T-lymphocyte Subsets in the Peripheral Blood of Mediterranean Spotted Fever Patients

Purpose: Mediterranean spotted fever (MSF) is a rickettsial disease. The aim was to evaluate the host immunе response to Rickettsia conorii. Material and methods: 62 patients were assigned into three groups: with mild, moderate or severe clinical forms of MSF. Controls were 32 healthy individuals. The diagnosis of MSF was confirmed by the indirect immunofluorescence assay. Immunophenotyping was performed using Epics XL-MCL Coulter. Results: The percentage of immune competent (CD3+) cells decreased, whereas that of helper/inducer (CD3+CD4+) and suppressor/cytotoxic (CD3+CD8+) did not change compared to controls. All three T-cell subset percentages did not parallel the disease severity. Naïve T-cells (CD4+CD45RA+) showed reduced levels, whereas activated memory (CD4+CD45RO+) T-cells did not change significantly. The percentage of activated (CD3+HLA-DR+) T-cells increased regardless of the disease severity, till the rise of stimulatory molecules (CD38+total) matched the disease severity forms. The percentage of costimulatory CD28-molecules corresponded to the disease severity as their levels increased significantly in mild forms and showed an evident downward trend towards the severe ones. Conclusion: Reduced T-lymphocyte subsets are likely related to trans-migration into perivascular inflammatory foci. The increased percentage of T-lymphocytes armed with stimulatory molecules probably reflects the mobilization of cell-mediated immune response in the healing process.

Mediterranean Spotted Fever with an Acute Pancreatitis

Mediterranean spotted fever (MSF) is a tick-borne acute febrile disease caused by Rickettsia conorii characterized by fever, maculo-papular rash and a black eschar at the site of the tick bite (tache noire). Acute pancreatitis is a rare complication of MSF. We report a 45 year old man admitted with fever, maculopapular rash, and eschar (tache noire). The working diagnosis at admission was MSF. Five day after admission, the patient developed signs of an acute abdomen, amylase and lipase elevation, and ultrasound hypoechoic pancreas. CT scan revealed a stage B pancreatitis. An immunofluorescence antibody test confirmed Rickettsia conorii infection. Diagnosis of MSF was made and treatment with oral doxycycline was started. After five days of therapy, there was completed remission of epigastric pain and fever. Gastrointestinal and hepatic complications are described in association with MSF. Much rarer is pancreatic involvement. Inflammation may play a role in the pathogenesis of pancreatitis. This suggests that pancreas should be explored in MSF patients even in the absence of underlying risk factors.

Incidence of Mediterranean Spotted Fever in Sicilian children: a clinical-epidemiological observational retrospective study from 1987 to 2010

Zoonoses are human infectious diseases caused by pathogens that primarily infect animals. Mediterranean Spotted Fever (MSF) represents one such example, affecting the Mediterranean region, in which household animals can be immune-carriers of infected ticks. We retrospectively analysed the incidence and the clinical and laboratory features of MSF caused by R.Conorii in children admitted to the Paediatric Operative Unit from 1987 to 2010, for persistent fever and generalised macular-popular erythematous lesions. Clinical, immunological and serological parameters of 55 cases of Rickettsia infections observed in children between 2 and 11 years of age were collected. We found an increasing incidence of MSF in childhood from 1987 to 2010. Diagnosis of MSF at the moment of hospital admission was done in 16 patients (29.09%). The presence of the typical Tache noire was observed in 16 cases out of 55 patients (29.09% of cases). We noticed a different representation of R. conorii antigens in serological testing over the time period of the study, corresponding to overall higher incidence rates for infection in the latter years. We also observed a higher incidence of infection in those years in which all four antigens were found positive at serum testing with respect to those years in which only two of the four antigens were observed (1987-1990: 0-16%; 2007-2010: 0.46%; P<0.005). These changes in R. conorii antigenicity may be the cause of higher pathogenicity in this parasite, perhaps linked to increased immigration along with consequent changes in the epidemiology of infectious diseases in host countries.

Mediterranean spotted fever in the Trakya region of Turkey

Mediterranean spotted fever (MSF) is caused by a tick-borne pathogen, Rickettsia conorii subsp. conorii, belonging to the spotted fever group (SFG) rickettsiae. The aim of the present study was to evaluate the cases with confirmed diagnosis of MSF from 2003 to 2009 in the Trakya region of Turkey. Patients with high fever, maculopapular rash (involving the palms or soles) and/or a black inoculation eschar at the site of the tick bite (tache noire) were included in the study. Before doxycycline treatment, skin biopsy specimens, preferably from the eschar or from the maculopapular rash, were obtained for DNA extraction. Immunofluorescence assay (IFA) was performed to detect IgM and IgG antibodies against R. conorii in acute and convalescent sera. Afterwards, a standard PCR reaction using primers suitable for hybridisation within the conserved region of genes coding for outer membrane protein A (ompA) and citrate synthase (gltA) and DNA sequencing were performed. There were 128 patients with confirmed MSF diagnosis. Using IFA, seroconversion or a fourfold or greater rise in titre was observed in 97 (77%) patients, whereas a single high titre was demonstrated in 16 (12.7%) patients. According to PCR analysis, 77 (72.6%) of 106 biopsy samples showed positive results. Of these, 58 (73%) of 79 biopsy specimens were from the eschar and 19 (70%) of 27 specimens were from the maculopapular rash. No significant difference was found between the rate of positive skin biopsies taken from the eschar and the maculopapular rash. DNA sequence analysis was performed to all PCR-positive cases, and R. conorii conorii (type strain: Malish, ATCC VR-613) was detected in each of them. MSF is prevalent, but has been underdiagnosed and underreported so far in Turkey. It is a potentially severe and even fatal disease resembling viral haemorrhagic fevers that has to be included in the differential diagnosis of febrile illness associated with thrombocytopenia, even in the absence of an eschar or a tick bite. While IFA allows for retrospective diagnosis in MSF, advanced molecular techniques provide the rapid detection of rickettsia in all skin samples, including eschar and maculopapular rash.

Diagnostic value of ocular examination in Mediterranean spotted fever

Mediterranean spotted fever (MSF), also named boutonneuse fever or tick-borne rickettsiosis, is endemic in Mediterranean countries [1] The aetiologic agent for this infection is Rickettsia conorii, a strictly intracellular alpha-proteobacterium. The pathophysiologic hallmark of R. conorii infection is the invasion of vascular endothelial cells by the organism, causing endothelial injury and tissue necrosis. Ocular involvement in rickettsioses has not been frequently reported and most published studies were single case reports. Data from recent prospective studies show that patients with acute MSF frequently exhibit ocular posterior segment changes that are commonly asymptomatic and self-limited [2,3]. These include retinitis, retinal vascular lesions, optic nerve changes, and numerous other findings. The aim of the present study was to better ascertain the frequency of retinitis and the role of fundus examination in the clinical diagnosis of MSF.

Genotyping Rickettsia conorii detected in patients with Mediterranean spotted fever in Algeria using multispacer typing (MST)

The aetiologic agent of Mediterranean spotted fever (MSF), Rickettsia conorii, is an obligate intracellular bacterium transmitted by the dog tick, Rhipicephalus sanguineus, to humans. Because of the fastidious nature of R. conorii, amplification and sequencing of partial gltA and ompA genes were frequently used for detection of this bacterium in ticks and molecular diagnosis of R. conorii infection in humans [1]. However, gltA and ompA sequences are too conserved to explore the intraspecies diversity of R. conorii. Multispacer typing (MST) incorporating three spacer sequences, dksA-xerC, mppA-purC and rpmE-tRNA, proved to be a reproducible and high-resolution genotyping method allowing not only clear identification of rickettsial strains at the species level but also strain-typing within some species including R. conorii [2,3]. In this study, we used MST to directly subtype R. conorii strains detected in skin biopsies from Algerian patients with MSF. Skin biopsies with tick bite were removed from Algerian patients with clinical diagnosis of MSF in Oran, Algeria, during January 2004 to December 2005. Total genomic DNAs were extracted from the skin biopsies using the QIAamp Tissue kit (QIAGEN, Hilden, Germany) as described by the manufacturer. Amplification of partial gltA and rompA genes was performed to detect R. conorii in the skin biopsies using the primer pairs 409 and 1258 and the primer pairs 190–70 and 190–701, respectively, as described [1]. Amplification and sequencing of the three spacers, dksA-xerC, mppA-purC and rpmE-tRNA, were performed as described [2]. To avoid contamination, no positive control was used. Sterile water was used as a negative control in each PCR assay. Amplicons were sequenced in both directions using the BigDye 1.1 chemistry (Applied Biosystems) on an ABI 3130XL automated sequencer (Applied Biosystems) as described by the manufacturer. Nucleotide sequences were edited using the Autoassembler package (PerkinElmer). For each intergenic spacer, a genotype was defined as a sequence exhibiting unique polymorphism that was defined by sequencing the corresponding spacers using forward and reverse primers, respectively. MST genotypes were defined as unique combinations of the three spacer genotypes. The sequences of three studied spacers were concatenated for phylogenetic analysis. We incorporated 27 MST genotypes previously identified among 39 R. conorii strains [2] and those identified in this study for phylogenetic analysis. Multiple alignment of sequences was carried out using the CLUSTALW software (Courtaboeuf, France). Phylogenetic relationships were obtained using the neighbour-joining and maximum parsimony methods within the MEGA 2.1 software (Courtaboeuf, France) [2]. R. conorii was detected in 22 skin biopsies from 22 patients with MSF using PCR assays targeting the partial gltA and ompA genes. For spacers mppA-purC and rpmE-tRNA, the 22 R. conorii human strains hold identical sequences and genotypes, types B and B, respectively, which have been previously identified [2]. Seven genotypes of spacer dksA-xerC were identified among 22 studied strains. Five of them, genotypes AS, AT, AU, AV and AW, were new and the sequences of them were submitted to GenBank with accession number: EU665226–EU665230. In total, seven MST genotypes based on the combination of genotypes of three spacers were identified among the 22 R. conorii human strains (Fig. 1). Of these, genotype 3 including 15 strains (68%) was previously identified. The Corresponding author and reprint requests: D. Raoult, CNRSIRD UMR 6236, Faculte de Medecine, Universite de la Mediterranee, 27 Boulevard Jean Moulin, 13385 Marseille cedex 05, France E-mail: didier.raoult@univmed.fr

Atrial fibrillation in Mediterranean spotted fever

Mediterranean spotted fever (MSF) is a tick-borne acute febrile disease caused by Rickettsia conorii and characterized by fever, maculo-papular rash and a black eschar at the site of the tick bite ('tache noir'). We describe the case of a 58-year-old man affected by MSF who developed atrial fibrillation. The patient presented himself to the hospital after 7 days of fever, malaise and severe headache. Cardiac auscultation revealed a chaotic heart rhythm and an electrocardiogram confirmed atrial fibrillation with a fast ventricular response. Diagnosis of MSF was made after the appearance of a maculo-papular skin rash, and treatment with oral doxycycline was started. An immunofluorescence antibody test confirmed R. conorii infection. The patient recovered after 7 days of treatment. Cardiac arrhythmia is a rare complication of MSF. Inflammation may play a role in the pathogenesis of atrial fibrillation. R. conorii is an intracellular bacterium which could trigger atrial fibrillation. Our patient was previously healthy and had no reported history of cardiac disease. This suggests that heart function should be monitored in MSF patients even in the absence of underlying risk factors.

Early diagnosis of severe Mediterranean spotted fever cases by nested-PCR detecting spotted fever Rickettsiae 17-kD common antigen gene

We describe 3 cases of Mediterranean spotted fever (MSF) who presented with severe sepsis, in 2 of which the clinical diagnosis was unclear at presentation. In each case the diagnosis of MSF was made using a nested-PCR assay for Rickettsia conorii 17-kD protein gene. The nested-PCR based diagnosis preceded the serological results of MSF that were all negative at admission. The early diagnosis of MSF by specific PCR will facilitate an early institution of appropriate therapy, saving unnecessary tests and medications.

Clusters of Mediterranean Spotted Fever in Israel

Mediterranean spotted fever (MSF) usually occurs as sporadic cases. We report five clusters of MSF in Israel. Each cluster consisted of two to three patients. In two clusters, one patient died while the other recovered. In the other three clusters the patients presented with a benign course of the disease. The diagnosis of MSF in the fatal cases was confirmed by nested-polymerase chain reaction (PCR) tests performed on samples obtained from internal organs. Rickettsial DNA was also found in a tick obtained from a dog owned by one of the patients. MSF was diagnosed in the recovered patients by serology. The diagnosis of MSF fever in one family member should raise the awareness to the possibility of other cases in the vicinity.

Mediterranean spotted fever: A review of fifteen cases

We aimed to determine the following things: the frequency of patients with Mediterranean spotted fever (MSF) during the last 10 years among those patients admitted with fever and rash, their clinical features, and the factors predicting the diagnosis of MSF among patients admitted with fever and rash. Between 1993-2002, the files of all patients admitted to our hospital with fever and rash were collected. The clinical features and serologic results of the patients diagnosed with MSF were further investigated. The diagnosis of MSF was established by epidemiological and clinical features and also by the clinical response within 2 days after doxycycline treatment. During the previous 10 years, 140 patients were admitted with fever and rash, and 15 (10%; four females, 11 males; mean age: 41 years; range: 17-70) of them were diagnosed with MSF. Clinical features were as follows: fever (100%), rash (100%), myalgia and/or arthralgia (93%), headache (87%), petechiae (27%), tache noire (13%), leucocytosis (74%), thrombocytopenia (33%), and accelerated erythrocyte sedimentation rate (100%). In nine of these patients, the diagnosis of MSF was established by epidemiological and clinical features and was confirmed by serologic studies. As a complication, one patient developed facial paralysis. Six (40%) were given several antibiotics. In conclusion, MSF should be considered in the differential diagnosis when a patient is admitted with fever, maculopapular rash, headache, myalgia and/or arthralgia, especially in spring, summer, or autumn.

The Presence of Eschars, but Not Greater Severity, in Portuguese Patients Infected with Israeli Spotted Fever

In Portugal, Mediterranean spotted fever (MSF) is caused by R. conorii Malish and Israeli spotted fever (ISF) strains. It has been suggested that the ISF strain isolated from patients with MSF causes different clinical manifestations compared to those caused by Malish strain, namely the absence of eschar and greater severity. The aim of this study was to analyze the presence or absence of eschar and of fatality in Portuguese patients infected with either Malish or ISF strain. Of 94 patients with a clinical diagnosis of MSF between 1994 to 2004, 47 were infected with Malish strain and 47 with ISF strain. Eschars were reported in 20 patients (49%) infected with Malish strain, and in 17 (39%) with ISF strain. The presence of eschar is not statistically associated to a greater extent with either R. conorii strain (P=0.346). A total of 22 patients died, 9 infected with Malish strain and 13 infected with ISF strain, and no statistically significant difference was found (P=0.330). This study showed that the concepts of absence of the eschar and greater severity in Israeli spotted fever infection should be revised.

LABORATORY-CONFIRMED MEDITERRANEAN SPOTTED FEVER IN A JAPANESE TRAVELER TO KENYA

A Japanese traveler returning from Kenya became ill, presenting with fever and a prominent, generalized rash without an eschar. Results of the immunofluorescence antibody assay of the patient's sera performed in Japan were compatible with illness due to a spotted fever group (SFG) rickettsia, and a presumptive diagnosis of African SFG rickettsiosis, probably either Mediterranean spotted fever (MSF) or African tick-bite fever (ATBF), was rendered. To further define the disease diagnosis, sera were examined in France by Western immunoblotting combined with cross-adsorption, which confirmed the diagnosis of MSF but not of ATBF. Because of the need to further characterize the epidemiologic and clinical features of the two African SFG rickettsioses, clinicians are encouraged to contact a specialized laboratory when encountering such cases.

Plasma interleukin-6 levels in Mediterranean spotted fever.

Mediterranean spotted fever (MSF) is a rickettsiosis endemic to Mediterranean countries caused by Rickettsia conorii, an obligate intracellular bacterium with endothelial cell tropism [1]. In a previous study we found an association between high plasma levels of tumor necrosis factor alpha (TNF-α) and severe MSF, raising the question of whether TNF-α is a causal contributor to disease pathogenesis or whether it is a nonspecific epiphenomenon [2]. In order to better characterize the role of proinflammatory cytokines in the pathogenesis of MSF we conducted the present study in which the plasma levels of interleukin-6 (IL-6) were analyzed and the variables significantly associated with disease severity were examined. The prospective study included 19 patients consecutively diagnosed with MSF at our hospital and 20 healthy controls. In all cases the diagnosis of MSF was confirmed by indirect immunofluorescence to R. conorii. Patients were considered to have severe MSF if they developed significant dysfunction of a major organ, as evidenced by neurological symptoms, or if they experienced a recent rise in serum creatinine levels, respiratory failure, or shock [3, 4]. Plasma IL-6 and TNF-α levels were determined using an enzyme-linked immunosorbent assay. The nonparametric Mann Whitney and Spearman’s correlation coefficient tests were used for the univariate analysis of clinical associations and analytical correlations, respectively. Multivariate analyses were performed to identify the variables significantly associated with disease severity in MSF patients. Plasma IL-6 levels were significantly higher in MSF patients on admission than in healthy controls (mean, 49.6 pg/ml [SD, 57.8], vs <4.0 pg/ml in all controls; P<0.001). Only two patients with active MSF had normal (undetectable) levels of IL-6. All patients had fever and rash, with the rash being purpuric in eight cases. Five patients developed severe MSF. Patients with severe MSF had higher plasma IL-6 levels than milder cases (mean, 97.1 pg/ml vs 32.7 pg/ml, respectively), but the difference was not statistically significant (P=0.10). Plasma IL-6 levels correlated significantly with plasma TNF-α (r=0.65, P=0.003) and serum C-reactive protein (r=0.49, P=0.03) levels, and inversely with the blood lymphocyte count (r= −0.76, P<0.001). In view of the association between severe MSF and increased levels of both IL-6 and TNF-α, we performed a stepwise logistic regression analysis to identify whether both cytokines contributed independently to the development of severe MSF. In this analysis, the only variable that approached statistical significance was plasma TNF-α (odds ratio of presenting severe MSF for each 10 pg/ml increase in TNF-α levels, 1.98; 95% confidence interval, 0.97–4.05; P=0.06), leaving plasma IL-6 outside the regression model. Several experimental studies give support to the hypothesis that proinflammatory cytokines might play a role in the pathogenesis of MSF. In vitro, activated macrophages and endothelial cells infected by R. conorii synthesize proinflammatory cytokines like TNF-α and IL6 [5, 6]. In addition, we reported high plasma levels of TNF-α and soluble TNF-α receptors in patients diagnosed with MSF, and the higher levels were associated with severe disease [2, 7]. In the present study, we also found high levels of IL-6 in plasma during the acute phase of MSF. As in many other inflammatory conditions, plasma IL-6 levels correlated J. Oristrell Internal Medicine Service, Corporacio Parc Tauli, C/ Parc Tauli s/n, 08208 Sabadell, Barcelona, Spain

Mediterranean Spotted Fever in Travelers from the United States

Background: We wish to increase awareness by U.S. physicians of the clinical manifestations and diagnosis of Mediterranean spotted fever (MSF), and to determine the incidence of MSF among travelers returning to the United States from endemic areas. Methods: We report a case of a 56-year-old female physician from New Orleans who returned from a 3-week safari trip to Zimbabwe and Zambia with clinical findings of MSF. The diagnosis was confirmed with a greater than fourfold rise in titer of IgM and IgG antibody to Rickettsia conorii on acute and convalescent sera (16 days apart) using indirect immunofluorescence technique. In addition, we conducted a MEDLINE computer search of published MSF cases in U.S. travelers returning to the United States and obtained the United States data over the past 20 years from the Centers for Disease Control and Prevention (CDC). Results: Less than 50 imported cases of MSF have been reported and confirmed by the CDC. Only seven cases have been published in the literature and none in the last 7 years. Conclusions: Despite the increasing incidence of MSF in Europe, Asia and Africa, and the high number of U.S. citizens traveling to these endemic areas, only a few imported cases of MSF in travelers have been reported in the United States. Physicians in the United States are not familiar with the clinical findings and diagnosis of MSF; therefore this disease is underrecognized in the majority of cases.

Mediterranean Spotted Fever in Central Tunisia.

Mediterranean spotted fever (MSF) is a tick-borne rickettsiosis caused by Rickettsia conorii. The disease was first described in Tunisia by Conor and Brush in 1910.’ However, only a few studies suggested the persistence of this disease in Tunisia.2 Edlinger et a13 emphasized the fact that MSF is one of the travel diseases that can be contracted in many Mediterranean countries, including Tunisia. Harris et a1 also reported boutonneuse fever in American traveler^.^ The investigators retrospectively reviewed the charts of 80 patients with MSF observed from January 1984 to December 1991 in the Internal Medicine and Infectious Diseases Units of Sousse and Monastir University Hospitals in Tunisia. In all cases, diagnosis was based on clinical features and epidemiologic data. Serologic confirmation using indirect immunofluorescence reaction was obtained in 54 cases (68%). A fourfold rise in titer was noted in 43 patients, a seroconversion in five and a titer (> 1/256) was noted in a single sample in the six remaining patients. The investigators included 26 cases, despite the absence of serological confirmation. This was because these cases met the criteria gathered in the diagnostic score chart established by Raoult et al’ for the diagnosis of MSF. Indeed, these cases had a score > 25 because all epidemiologic and clinical criteria selected by Raoult diagnostic score were satisfied. Fifty-nine men and 21 women (sex ratio, 2.8:l) were seen in the above-mentioned units from 1984 to 1991 (the mean was 10 cases per year). The mean age was 36 (range was 6 to 70 years). Forty-seven percent of patients were between 20 and 40 years. Sixty-one percent of patients were rural inhabitants. Seventynine cases (99%) were noted in the hot season (from April to October); 68 of them (87%) occurred from July to October. Forty-nine (61%) patients had dogs in their proximity, and 41 of them reported contact with dogs’ ticks, Rhipicephalus sanguineus. As Table 1 demonstrates, fever, headache, weakness, and myalgia were the most frequently reported clinical symptoms. Clinical presentation was typical of MSF in that presence of the characteristic symptomatic triad (i.e., fever, rash, and “tache noire”) was noted in 70 patients (88%). Fever was present in 78 patients (98%) and was higher than 385°C in 80% of cases. Rash was observed in all patients. The rash was macular in 30% of cases, maculopapular in 55%, papular in 10% of cases, and purpuric in one case. The nature of rash was unknown in 4% of cases. Rash appeared on the third day of disease in 63% of cases and between the fourth and seventh days in 25% of patients. The date of appearance of the rash was unknown in 13% of patients. “Tache noire” was noted in 70 patients (88%). It was the sole manifestation in 61 of 70 patients (87%), and multiple (two or three) in the remaining cases. “Tache noire” was located in various sites of the body, especially limbs (36%), trunk (27%), and wrinkles (22%). White blood cell count was normal in 61% of patients as is shown in Table 2 . Various nonspecific abnormalities were noted. Cutaneous biopsy was performed in eight patients. In seven cases, the biopsy showed inflammatory damage of endothelial cells with perivascular reactional lymphohistiocytic crown, which can be considered highly suggestive of the lesions of MSF. Direct immunofluorescence staining was not performed. Forty-four patients ( ~ S ’ % O ) received antibiotics for more than 48 hours before consultation. Antibiotics were appropriate in only two cases (chloramphenicol). Thus, the investigators had the opportunity to note that previously prescribed p-lactam antibiotics (20 cases), trimethoprim-sulfamethoxazole (1 case), erythromycin (8 cases), lincosamine (11 cases), and aminoglycoside (2 cases) were ineffective in the treatment of MSF. Seventy-eight patients were treated in hospital with tetracyclines (500 mg q.i.d. during 10 days). Two received ofloxacin (200 mg b.i.d. during 5 days). Recovery was noted in all patients. In all cases, fever disappeared within the first 48 hours after appropriate therapy. Several complications occurred, including mild gastrointestinal hemorrhage (2 cases), granulomatous hepatitis (1 case), acute reversible renal failure (3 cases), uveitis (1 case), and meningo-encephalitis (1 case). All patients had a favorable outcome. As emphasized by our series, MSF is still present in central Tunisia. Although serologic confirmation is not available in 26 patients, the investigators firmly believe that these patients should not be excluded from this series because all meet the epidemiologic and clinical criteria of the MSF diagnostic score chart established by Raoult et al. Furthermore, the favorable outcome after tretracycline therapy argues strongly for the diagnosis of MSF. Thus, in this series, 80 cases

Diagnosis of Mediterranean spotted fever by indirect immunofluorescence of Rickettsia conorii in circulating endothelial cells isolated with monoclonal antibody-coated immunomagnetic beads.

Rickettsia conorii, an obligate intracellular bacterium that infects vascular endothelial cells, is the etiologic agent of Mediterranean spotted fever (MSF). A new procedure using indirect immunofluorescence was used to directly detect R. conorii in circulating endothelial cells (CEC). CEC were separated from other blood components by using anti-endothelial cell monoclonal antibody-coated magnetic beads. An anti-R. conorii polyclonal rabbit antiserum was used to stain rickettsiae. The entire procedure took 3 h. R. conorii was detected in CEC from 9 of 12 patients ultimately confirmed as having MSF. Among the patients, 5 with R. conorii isolated by centrifugation-shell vial assay were also positive by the new technique. None of 3 patients whose diagnosis was other than MSF had R. conorii detected in CEC. The procedure may be helpful for rapid diagnosis of MSF and may lead to new technical approaches for the diagnosis of infectious diseases caused by intracellular pathogenic microorganisms.