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A fatal case of Mediterranean spotted fever associated with septic shock was reported in a 61-year-old man living in a village in southeastern Iran. The patient had a history of tick bite a few days before symptom onset. Phylogenetic analysis confirmed infection by Rickettsia conorii subspecies israelensis.

A young healthy gardener became febrile with abdominal pain, nausea, vomiting and diarrhoea followed by palpable purpura, mostly on the legs and buttocks with associated arthralgia. Dehydration, azotemia and hyponatraemia resolved with fluid replacement. Tests demonstrated acute pancreatitis, hepatitis, thrombocytopenia, microscopic haematuria and proteinuria. He improved with doxycycline, but bipedal pitting oedema and punctate rash involving the soles/hands appeared. Microbiological tests revealed positive IgM and IgG serology for rickettsiae spotted fever. Skin biopsy of the purpura confirmed leucocytoclastic vasculitis, positive for Rickettsiae conorii by PCR amplification. Palpable purpura is a rare important manifestation of Mediterranean spotted fever (MSF), due to either secondary leucocytoclastic vasculitis or associated Henoch-Schonlein purpura (HSP), which best explains the distribution of the rash, arthralgia, gastrointestinal symptoms, and microhaematuria not usually seen in R. conorii infections. Likewise, the patient’s acute pancreatitis may be interpreted as a rare presentation of HSP or a seldom-encountered feature of MSF.

Mediterranean spotted fever-like illness (MSF-like illness) is a tick-borne disease caused by

Mediterranean Spotted Fever (MSF) is one of the most common spotted fever Rickettsioses. Most cases of MSF follow a benign course, with a minority of cases being fatal. The severity of the infection depends on bacterial virulence, dose and host factors such as effective immune response and genetic background. Herein, we reported data on typing by competitive allele-specific PCR of functionally relevant polymorphisms of genes coding for MyD88 adapter-like (

Background The most common Italian rickettsiosis is Mediterranean Spotted Fever (MSF). MSF is commonly associated with a symptom triad consisting of fever, cutaneous rash, and inoculation eschar. The rash is usually maculopapular but, especially in severe presentations, may be petechial. Other typical findings are arthromyalgia and headache. Herein, we describe for the first time an unusual case of Israeli spotted fever (ISF) associated with interstitial pneumonia and pleural effusion in which R. conorii subsp. israelensis was identified by molecular methods in the blood, as well as in the pleural fluid. Case presentation A 72-year-old male presented with a 10-day history of remittent fever. On admission, the patient’s general condition appeared poor with confusion and drowsiness; the first assessment revealed a temperature of 38.7°, blood pressure of 110/70 mmHg, a blood oxygen saturation level of 80% with rapid, frequent, and superficial breathing using accessory muscles (28 breaths per minute), and an arrhythmia with a heart rate of 90 beats per minute. qSOFA score was 3/3. Chest CT revealed ground-glass pneumonia with massive pleural effusion. Petechial exanthema was present diffusely, including on the palms and soles, and a very little eschar surrounded by a violaceous halo was noted on the dorsum of the right foot. Awaiting the results of blood cultures, broad-spectrum antibiotic therapy with meropenem 1 g q8h, ciprofloxacin 400 mg q12h, and doxycycline 100 mg q12h was initiated. Doxycycline was included in the therapy because of the presence of petechial rash and fever, making us consider a diagnosis of rickettsiosis. This suspicion was confirmed by the positivity of polymerase chain reaction on whole blood for R. conorii subsp. israelensis. Thoracentesis was performed to improve alveolar ventilation. R. conorii subsp. israelensis was again identified in the pleural fluid by PCR technique. On day 4 the clinical condition worsened. Blood exams showed values suggestive of secondary hemophagocytic lymphohistiocytosis; 4 out of 8 diagnostic criteria were present and empirical treatment with prednisone was started resulting in a gradual improvement in general condition. Conclusions Israeli spotted fever may be a severe disease. A high index of suspicion is required to promptly start life-saving therapy. Pleural effusion and interstitial pneumonia may be part of the clinical picture of severe rickettsial disease and should not lead the physician away from this diagnosis.

Objectives: Mediterranean spotted fever (MSF) is a tick-borne endemic disease caused by Rickettsia conorii conorii and transmitted to humans by the brown dog tick Rhipicephalus sanguineus. It is characterized by fever, maculopapular rash and a tick bite skin lesion "tache noire". The disease affects all age groups and usually has mild to moderate course. It has long been considered a benign infection. However, very severe "malignant" forms with fatal outcome strongly influenced by the patients' age were also observed. We aimed to reveal the features of MSF in children by comparing them with some of the disease patterns in adults. Methods: Our prospective study data are based on the monitoring of all inpatients of the Clinic of Infectious Diseases in Plovdiv City and environs, the largest MSF endemic region in Bulgaria. The total number of patients admitted and treated for MSF over a study period of 10 years is 549, the incidence reaching 9.44/100,000. MSF is confirmed by antibody response to a specific antigen measured by indirect immunofluorescence assay (IFA). IgG ≥ 128 and/or IgM > 64 were considered to be indicative of acute infection. Results: Eighty-five (15.48%) patients were children up to 14 years of age and 464 (84.52%) were aged 15-85 years. The skin lesion "tache noire" was present in 73.68% of children, and in 76.93% of the older age groups; symptoms as anorexia, nausea, vomiting, abdominal pain, and diarrhoea were more frequent in children, till general weakness and malaise was prevalent in adults. Children accounted approximately for 70% of the disease mild forms. No lethality was registered in this age group. Even though there were isolated cases of severe and malignant forms, children did not undergo the fatal complications seen in adults. Conclusion: Knowledge of the peculiarities of MSF in children will contribute to children's health protection, timely diagnose and disease prevention.

We describe 3 similar cases of rickettsial disease that occurred after tick bites in a mountainous rural area of Shandong Province, China. Next-generation sequencing indicated the etiologic agent of 1 patient was Rickettsia conorii subspecies indica. This agent may be more widely distributed across China than previously thought.

Background & objectives: Rickettsioses are zoonoses transmitted to humans by arthropods. They are due to strict intracellular bacteria belonging to the family Rickettsiaceae. Our purpose is to present the clinical and paraclinical characteristics of 14 new cases diagnosed in Al-Hoceima region, Morocco; indeed, the patients associated a diagnosis of Mediterranean Spotted Fever (MSF). Results: The average age of patients was 55 years. The patients were hospitalized for infectious syndrome, renal deficiency, pneumonia, and suspected meningitis. All cases had a general papular rash with palmo-plantar involvement, 12 out of 14 patients showed an escarotic spot, while neurological disorders were observed in 2 patients. Ophthalmic involvement was represented by retinal vasculitis in a single patient. Thrombocytopenia and cytolysis were constant in all patients. Renal deficiency was found in 3 cases and 2 cases had interstitial syndrome. The serology was positive in only one patient. All cases had been treated with doxycycline 200mg/day for 7 days with a good improvement of the clinical and biological symptoms. Interpretation & conclusion: The frequency of MSF in Morocco is not completely elucidated. A good knowledge of the clinical form allows an early diagnosis in order to institute an effective treatment.

Objective: Mediterranean spotted fever (MSF) is a tick-borne rickettsial infection endemic to the Mediterranean coastline countries. As a result of growing tourism, imported cases have been registered in many nonendemic countries and regions. We present clinical laboratory parameters and histopathological data on renal impairment in patients with MSF. The study meets our goal of identifying kidney involvement and detecting renal damage in people with MSF. Subjects and Methods: Three hundred fifty patients with MSF with a diagnosis confirmed by immunofluorescence analysis were tested for serum urea, creatinine, and albumin. Fifty-five patients with malignant form of MSF were divided into 2 groups: 19 fatalities and 36 survivors. The percentage of patients with acute renal failure (ARF) was compared in both groups. Results: Subjects with elevated urea and creatinine levels increased from 5.21 to 3.47% in mild to 48.78 and 29.26% in severe MSF, respectively. Loss of serum albumin also increased from mild to severe MSF. Renal impairment comprised 60% of the cohort of 55 patients with malignant MSF: 89.4% in the group of deaths and almost twice less in the survivors. ARF developed in 84.2% of fatal cases and was >2 times less in survivors. Postmortem light microscopy of renal samples of 9 fatal cases revealed perivascular mononuclear inflammatory infiltrates, vasculitis with fibrinoid necrosis, acute tubular necrosis, interstitial edema, hemorrhage, and thrombosis. Conclusion: Renal pathology associated with MSF rickettsial infection consists of systemic small vessel vasculitis and vascular injury, leading to ARF in the most severe cases.

Background In Algeria, Mediterranean spotted fever (MSF), caused by Rickettsia conorii conorii and transmitted by Rhipicephalus sanguineus ticks, is endemic. However, the documentation of cases is rare due to a lack of laboratory facilities. Our aim was to screen for rickettsioses in patients with fever, rash and a possible inoculation eschar. Materials and methods Between 2013 and 2015, patients with a fever and a rash presenting at hospitals in the Tizi-Ouzou region were prospectively included in our study. Sera were screened using Indirect Immunofluorescence Assay (IFA) and qPCR was performed on swab samples from eschars. Results One hundred and sixty-six patients were included. For 57 patients, MSF due to R. conorii conorii was diagnosed by serology and qPCR on a swab eschar sample. Three patients were diagnosed with murine typhus, a flea borne rickettsiosis. In addition, two patients had a positive serology in IgM for R. felis. For nine patients, serology for rickettsiosis was positive, but the specific rickettsia involved could not be determined. Nine patients had a severe disease with neurological involvement or multi-organ failure. Conclusion Clinicians should routinely screen for rickettsioses in patients and travellers presenting with a rash upon return from Algeria. Doxycycline treatment must be given promptly because the prognosis can be severe.

Background Rickettsial diseases present as acute febrile illnesses, sometimes with inoculation eschars. Methods We performed a systematic review of studies published between 1997 and 2017 to assess the underestimation of non-eschar rickettsial disease (NERD) relative to eschar rickettsial disease (ERD), as a cause of acute fever in patients with rickettsial diseases that commonly present with eschar(s): scrub typhus (ST), Mediterranean spotted fever (MSF), and African tick-bite fever. We compared ERD/NERD ratios according to study design: ‘complete approach’ studies, with testing performed in all patients with ‘unspecified febrile illness’; versus ‘clinical judgement’ studies, with testing performed if patients presented with specific symptoms. Results In ‘complete approach’ studies, ERD/NERD ratios were significantly lower, suggesting a considerable under-diagnosis of NERD in ‘clinical judgement’ studies. Based on these results, we estimate that the diagnosis of rickettsial disease was missed in 66.5% of patients with ST, and in 57.9% of patients with MSF. Conclusions Study design influences the reported eschar rates in ST and MSF significantly. NERD is likely to be a vastly underdiagnosed entity, and clinicians should consider and test for the disease more often. PROSPERO registration number CRD 42016053348

Mediterranean spotted fever (MSF) is endemic in Italy, where Rickettsia conorii subsp. conorii was thought to be the only pathogenic rickettsia and Rhipicephalus sanguineus the vector and main reservoir. R. conorii subsp. israelensis, which belongs to the R. conorii complex, is the agent of Israeli spotted fever (ISF); apart from Israel, it has also been found in Italy (Sicily and Sardinia) and in different regions of Portugal. We describe here two severe cases of ISF which occurred in otherwise healthy Italian adults. Their characteristics are analyzed and discussed in the light of other 91 cases found through a systematic review of international literature.

International audience; As a result of migrations and globalization, people may face a possible increase in the incidence of central nervous system rickettsial infections (CNS R). These diseases, caused by Rickettsia species and transmitted to humans by arthropod bites, are putatively lethal. However , the diagnosis of CNS R is challenging and often delayed due to their nonspecific clinical presentation and the strict intracellular nature of rickettsiae. Furthermore, transfer of rickettsiae to the brain parenchyma is not yet understood. The aim of this review is to analyze and summarize the features and correlated findings of CNS R in order to focus attention on these intriguing but frequently neglected illnesses. We also incorporated data on CNS infections caused by Rickettsia-related microorganisms.

723 blood sera from 537 patients of Regional Infectious Clinical Hospital, Astrakhan were obtained during high activity period of Rhipicephalus ticks (May-September 2015) and retrospectively studied for IgG/IgM to antigen of spotted fever group (SFG) Rickettsia. IgG and/or IgM to Rickettsia conorii were detected in 145 sera from 130 patients, and antibodies to R. sibirica (group-specific) were detected in 143 sera from 145. Antibodies to R. conorii were detected for 71,4% patients with Astrakhan spotted fever (ASF), for 28,4% patients with acute respiratory viral infection, for 19,1% patients with infection of unspecified etiology and for 40% patients having symptoms of a adenovirus infection. Acute rickettsiosis, provably ASF, is serologically validated for 71 patients. Dynamic of IgM/IgG to R. conorii in sera of patients having different preliminary diagnoses is discussed. IgM to R. conorii in sera of patients having adenovirus infection symptoms were detected at a later time as compared with others. For regions of high risk of R. conorii subsp. caspia infection the differentiation of diagnostic and anamnestic specific antibodies is very important. The absence of serological and molecular biological markers in third of patients with ASF symptoms is necessary to study. Preparations and algorithms for diagnosis of SFG rickettsioses are needed to improve.

Mediterranean spotted fever is a reemerging acute tick-borne infection produced by the α-proteobacterium, Rickettsia conorii. Rickettsia conorii infects vascular endothelial cells producing disseminated plasma leakage, manifesting as nonspecific fever, headache, and maculopapular rash. Because there are no available tests of early infection, Mediterranean spotted fever is often undiagnosed and untreated, resulting in significant mortality. To address this critical need, we have applied a quantitative proteomics pipeline for analyzing the secretome of primary human umbilical vein endothelial cells. Of the 104 proteins whose abundance changed significantly in the R. conorii-infected human umbilical vein endothelial cells' secretome, 46 proteins were up-regulated: 45 were host secreted proteins (including cytokines), and 1 was a rickettsial protein, the putative N-acetylmuramoyl-l-alanine amidase RC0497. Proteins with sequence highly homologous to RC0497 were found to be shared by many species of the spotted fever group rickettsiae, but not typhus group rickettsiae. Quantitative targeted proteomics studies of plasma from a mouse model of sublethal and lethal R. conorii identified RC0497 in the blood, and its circulating levels were proportionally associated with infection outcome. Finally, the presence of RC0497 in the serum samples from a cohort of humans presenting with acute rickettsioses was confirmed. The detection of RC0497 has the potential to be a sensitive and specific marker for acute rickettsial spotted rickettsioses.

Background Mediterranean spotted fever (MSF) is a zoonotic disease caused by Rickettsia conorii and transmitted by Rhipicephalus sanguineus sensu lato. The aim of this study is to understand the epidemiology and trends regarding the disease in Spain, based on notifications to the Spanish National Epidemiology Surveillance Network (RENAVE) and the National Hospital Discharge Database (CMBD) between 2005 and 2015. Methods We carried out a retrospective cross-sectional study of the cases and the outbreaks reported to the RENAVE and of those found in the CMBD between January 1st, 2005 and December 31st, 2015. We studied the characteristics of the cases and analyzed their spatio-temporal distribution. Results 1603 cases notified to the RENAVE and 1789 cases registered in the CMBD were analyzed. The most affected group were men between 45 and 64. There were 8 MSF outbreaks during the study period. RENAVE registered lower rates until 2012, when it was decided that MSF in Spain would become a notifiable disease. Across the temporal series we saw that there was seasonality with an increase in cases in summer, and an overall upward trend according to the RENAVE data and descending according to the CMBD. The geographic distribution was heterogeneous throughout the territory, with maximum rates in La Rioja at 1.87 cases and 2.01 cases per 100,000 inhabitants according to the RENAVE and the CMBD, respectively. Conclusions It is of great importance to continue monitoring the disease since it appears to be endemic throughout Spain. There is a need for a common strategy on monitoring and reporting, which would facilitate a more accurate picture on the MSF epidemiological scenario. Entomological information will be of added value.

The objective of this study is to evaluate the characteristics and outcome of elderly patients with Mediterranean spotted fever (MSF). This study was a prospective observational cohort study of all adult cases with confirmed MSF treated in a teaching hospital (1984–2015) to compare the characteristics of elderly patients (> 65 years) with younger adults. We identified 263 adult patients with MSF, and 53 (20.2%) were elderly. Severe MSF was more frequent in the elderly (26.4% vs. 10.5%; p = 0.002). Gastrointestinal symptoms, impaired consciousness, lung infiltrate, oedema, acute hearing loss, raised alanine transaminase, hyponatremia, and thrombocytopenia occurred more frequently in elderly patients, and arthromyalgia occurred less frequently. Most patients were treated with a single-day doxycycline regimen (two oral doses of 200 mg for 1 day). All patients recovered uneventfully. Fever disappeared 2.55 ± 1.16 days after treatment initiation in elderly patients, and the remaining symptoms disappeared after 3.65 ± 1.42 days. These figures were similar to non-elderly patients. Severe MSF was more frequent in elderly patients. Some clinical manifestations occurred with different frequencies in the elderly compared with younger patients. Single-day doxycycline therapy is an effective and well-tolerated treatment for MSF in elderly patients.

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated acute inflammatory demyelinating disorder, which typically occurs after viral infections or immunisation. We present a case of a man with acute Rickettsia conorii infection whose diagnosis was delayed. He presented with fever, headache, an eschar and an acute paraplegia. The R. conorii IgM serum titre was 1:128. Magnetic resonance imaging showed multifocal lesions in the brain and spinal cord consistent with inflammatory demyelination. The patient responded well to doxycycline and a short course of high-dose corticosteroids. To our knowledge this is the first case of ADEM associated with Mediterranean spotted fever – we found a previous report of ADEM in a child with Rocky Mountain spotted fever, whose diagnosis of rickettsial infection was also delayed. We hypothesise that delayed diagnosis of spotted fever group rickettsial infections could rarely result in ADEM.

Since the Arab Spring, a resurgence of zoonotic diseases such as rickettsiosis, endemic in the Mediterranean basin, has been observed. It preferentially infects microvascular endothelial cells of mammalian hosts inducing vasculitis with endothelial injury. Rickettsioses are considered benign infectious diseases. Severe systemic manifestations have been reported and are often explained by a delay in diagnosis. We present a case of hemophagocytic syndrome occurring in a 4-year-old Libyan girl as a complication of Mediterranean spotted fever. Rickettsial infection was confirmed by serology and the patient was treated with clarithromycin, with a favorable outcome.

Rickettsia conorii and Rickettsia massiliae-Bar29 are related to Mediterranean spotted fever (MSF). They are intracellular microorganisms. The Shell-vial culture assay (SV) improved Rickettsia culture but it still has some limitations: blood usually contains low amount of microorganisms and the samples that contain the highest amount of them are non-sterile. The objectives of this study were to optimize SV culture conditions and monitoring methods and to establish antibiotic concentrations useful for non-sterile samples. 12 SVs were inoculated with each microorganism, incubated at different temperatures and monitored by classical methods and real-time PCR. R. conorii was detected by all methods at all temperatures since 7th day of incubation. R. massiliae-Bar29 was firstly observed at 28°C. Real-time PCR allowed to detected it 2-7 days earlier (depend on temperature) than classical methods. Antibiotics concentration needed for the isolation of these Rickettsia species from non-sterile samples was determined inoculating SV with R. conorii, R. massiliae-Bar29, biopsy or tick, incubating them with different dilutions of antibiotics and monitoring them weekly. To sum up, if a MSF diagnosis is suspected, SV should be incubated at both 28°C and 32°C for 1-3 weeks and monitored by a sensitive real-time PCR. If the sample is non-sterile the panel of antibiotics tested can be added.

The classic antibiotic treatment for Mediterranean spotted fever (MSF) is based on tetracyclines or chloramphenicol, but chloramphenicol's bone marrow toxicity makes tetracyclines the treatment of choice. However, it is convenient to have alternatives available for patients who are allergic to tetracyclines, pregnant women, and children P = not significant [NS]). Time to the disappearance of fever after treatment was 2.67 ± 1.55 days in the clarithromycin group versus 2.22 ± 1.35 days in the doxycycline/josamycin ( P = NS). The symptoms had disappeared at 4.70 ± 2.25 days in the clarithromycin group versus at 4.75 ± 3.08 days in the doxycycline/josamycin ( P = NS). There were no adverse reactions to treatment or relapses in either group. In conclusion, clarithromycin is a good alternative to doxycycline or josamycin in the treatment of MSF.

SUMMARYThe incidence of Mediterranean spotted fever (MSF) in Catalonia (Spain) has decreased in the last two decades. The prevalence of antibodies to Rickettsia conorii in human beings and dogs in the region of Vallès Occidental (Catalonia) was assessed by indirect immunofluorescence, and the results compared with those obtained in a similar study from 1987. Nineteen (5·0%) out of 383 human serum samples had antibodies to R. conorii. This seroprevalence was significantly lower (11·5%) (P = 0·003) than that recorded in the 1987 survey. Forty-two out (42·0%) of 100 canine serum samples had antibodies to R. conorii. A high proportion of the studied dogs (91·0%) were receiving anti-tick treatment, mainly with permethrin-imidacloprid spot-on (Advantix, Bayer, Germany). The current canine seroprevalence was not significantly different from that recorded in the 1987 survey (36.9%). In conclusion, this study shows a significant decrease in the prevalence of antibodies to R. conorii in the human population of Catalonia in the last 20 years, which corresponds with a decrease in the number of cases of MSF. We suggest that the widespread use of anti-tick treatment in dogs could limit the introduction of ticks to humans due to a reduction of infestation duration in dogs, thus contributing to the decrease in MSF incidence.

Background Spotted fever group of rickettsial infections are emerging in Sri Lanka. We describe a patient with rapidly progressing ARDS and myocarditis secondary to spotted fever caused by Rickettsia conorii. ARDS and myocarditis are rare complications of Rickettsia conorii infections and only a few cases are reported to date. Case presentation A 53 years old manual worker presented with fever for 5 days and a skin rash. He was in circulatory failure on admission and developed severe hypoxaemia with gross changes in chest radiograph by next day requiring assisted ventilation. He had myocarditis causing left ventricular failure and acute respiratory distress syndrome. He was confirmed to have spotted fever rickettsial infection with rising titre of indirect immunofluorescence antibodies to Ricketssia conorii and made a complete recovery with appropriate antibiotic therapy and supportive care. Conclusion Rickettsial infections can present with diverse manifestations. Even the patients with severe organ involvements such as myocarditis and ARDS can be completely cured if timely identified and treated.

Purpose: Among the major groups of rickettsiosis, the commonly reported diseases in India are: (a) Typhus group induced—scrub typhus, murine flea-borne typhus; (b) Spotted fever group induced—Indian tick typhus; and (c) Q fever. Though many scrub typhus outbreaks have been reported from India, only one outbreak of spotted fever—serologically proven Indian tick typhus (Rickettsia conorii)—has been reported. We report for the first time ocular manifestations of serologically proven R. conorii infection in a cluster of patients. Methods: In this retrospective study, case records patients with serologically proven Indian tick typhus (Rickettsia conorii) were reviewed for clinical manifestations and treatment outcomes. Results: In the months of February to April 2016, a cluster of 12 patients (23 eyes) visited us with defective vision. Examination showed multifocal retinitis; mostly bilateral; patients had a history of fever approximately 4 weeks prior to onset of symptoms. After excluding other causes of multifocal retinitis, a diagnosis of rickettsial retinitis was made after Weil–Felix test (WFT) was significantly positive, and enzyme-linked immunosorbent assay was positive for R. conorii. Course of the disease, visual outcome, and investigations are discussed. Doxycycline along with oral corticosteroids was effective in treating the condition. Conclusion: Systematic fundus examination should be part of the routine evaluation of any patient who presents with fever and/or skin rash living in or returning from a specific endemic area. Clinical clues to diagnosing ocular rickettsiosis could be multifocal retinitis predominantly involving the posterior pole and macular involvement in the form of serous macular detachment or macular hard exudates. A positive WFT still serves as a useful and cheap diagnostic tool for laboratory diagnosis of rickettsial disease. Doxycycline along with oral corticosteroids was effective in treating the condition.

The objective of this study is to evaluate the results of single-day doxycycline therapy for Mediterranean spotted fever (MSF). This is a prospective cohort study of cases with confirmed MSF treated with the single-day doxycycline regimen in a teaching hospital from 1990 to 2015. Patients received two oral doses of 200 mg of doxycycline for 1 day. The outcomes evaluated were the time interval between the start of treatment and apyrexia, the time interval between the start of treatment and disappearance of other symptoms, and the adverse reactions to treatment and death. The study included 158 subjects, 18 of whom (11.4%) had a severe form of MSF and 31 (19.6%) were >65 years. The interval between onset of symptoms and start of treatment was 4.31 ± 1.54 days. All patients recovered uneventfully. Fever disappeared 2.55 ± 1.14 days after the start of treatment. The remaining symptoms (headache, arthromyalgia) disappeared 3.63 ± 1.35 days after the start of treatment. Only one patient had a delay in reaching apyrexia (8 days). The fever disappeared somewhat later in severe cases (median, 3 days; interquartile range [IQR], 2 to 4 days) than in nonsevere cases (median, 2 days; IQR, 2 to 3 days). Likewise, the remaining symptoms disappeared later in severe cases (median, 5 days; IQR, 4 to 6 days) than in nonsevere cases (median, 3 days; IQR, 3 to 4 days). The outcome was similar in both elderly and nonelderly patients. Eight patients had mild adverse effects possibly related to treatment. The results of the study confirm that single-day doxycycline therapy is an effective and well-tolerated treatment for MSF, including elderly patients and severe cases.

A healthy 41 year old man was bitten by a tick while on safari in the Kruger National Park in South Africa. He developed severe fever and malaise 5 days later. A characteristic red skin sore with a dark centre and surrounding erythema (eschar, tache noir) developed at the site of the tick bite. The travel history and clinical picture were strongly suggestive of a tick borne fever.The diagnosis of tick bite fever caused by rickettsia (spotted fever group) was proven serologically. The clinical course of the disease was complicated by myocarditis, indicated by an elevated troponin I and later confirmed by cardio-MRI. The complicated clinical course and the singular eschar suggested Rickettsia conorii as the etiological agent.The rickettsial infection was treated with doxycycline, which led to a rapid improvement of the patient's clinical status. However, recovery from this imported infection was delayed due to myocarditis.Rickettsioses should be included in the differential diagnosis in travellers returning from Africa. The clinical course is usually mild but can be complicated by involvement of major organs even in formerly healthy young people.Ein 41-jähriger, bis dato gesunder Mann zog sich während einer Safaritour im Krüger Nationalpark einen Zeckenstich zu. 5 Tage später bekam er hohes Fieber mit schwerem Krankheitsgefühl. An der Zeckenstichstelle entwickelte sich ein charakteristisches Ulkus mit schwärzlichem Grund, Schorfbildung und rotem Hof (Eschar, Tache noir). Reise -und Zeckenstichanamnese legten den Verdacht einer Rickettsiose nahe.Die Diagnose einer Rickettsiose aus der Zeckenstichfiebergruppe (spotted-fever-group) wurde serologisch bestätigt. Der klinische Verlauf der Rickettsiose wurde durch eine Myokarditis kompliziert, die zunächst nur durch ein erhöhtes Troponin-I auffiel und später mittels Kardio-MRT bestätigt wurde. Der komplizierte Verlauf und der singuläre Eschar sprechen für eine Infektion mit Rickettsia conorii.Es kam es zu einer raschen Rückbildung der Symptome der febrilen Infektionserkrankung unter der Therapie mit Doxycyclin. Die Rekonvaleszenz der importierten Reisekrankheit war durch die Myokarditis verzögert.Rickettsiosen sollten bei Afrikareisenden differenzialdiagnostisch in Erwägung gezogen werden. Sie verlaufen in der Regel mild; komplizierte Verläufe können auch bei gesunden jungen Menschen auftreten.

Background Purpura fulminans is an acute life-threatening disorder characterized by intravascular thrombosis and hemorrhagic infarction of the skin complicated with disseminated intravascular coagulation. It is commonly seen in acute infections following meningococcal and streptococcal infections. Few cases of purpura fulminans following rickettsial infections have been described in the literature. Case presentation We report a case of a 55-year-old Sri Lankan woman who presented to Teaching Hospital Peradeniya with a febrile illness, headache, and myalgia that progressed to an erythematous rash starting over the bilateral lover limbs and hands and that became black and necrotic with a few hemorrhagic blebs. She had normocytic anemia, platelet clumps, and monocytosis as well as a deranged clotting profile. The result of immunofluorescence antibody testing for rickettsial immunoglobulin G was strongly positive for Rickettsia conorii with a rise in titer convalescent sera, and a diagnosis of purpura fulminans following rickettsial infection was made. The patient made an excellent recovery with chloramphenicol treatment. Conclusions The treating physician should consider the rare but very treatable condition of rickettsial infection as a differential diagnosis in the etiological diagnostic workup of patients presenting with severe purpuric and hemorrhagic rash with fever.

The Mediterranean spotted fever (MSF) rickettsiosis is the predominant rickettsial disease among the spotted fever group (SFG) rickettsiae in the Mediterranean countries and North Africa. Its causative agent is Rickettsia conorii, although, SFG rickettsiosis - cases due to Rickettsia monacensis, Rickettsia massiliae and Rickettsia aeschlimannii were also described. A retrospective study based on hospital discharge records with a diagnosis of SFG rickettsiosis was carried out to describe the spatial pattern, the trend of the disease, and the epidemiological characteristics of persons hospitalized in the period 2001-2015. Standardized hospitalization ratios were calculated at municipal level using the European population. Smoothed maps were produced using a localised smoothing Poisson model. The mean annual standardized hospitalization rate was 1.36/100,000 person years (95%CI: 1.34; 1.39). Rates showed strong summer seasonality and tended to decrease over time. During the study period, 28.89% of municipalities had smoothed standardized hospitalization ratios greater than 1 and 14.01% above 20. Higher standardized hospitalization ratios were found in areas along the Tyrrhenian coast, especially in the south of Calabria and in the islands of Sardinia and Sicily, where the disease is of public health relevance.

BACKGROUND: Ticks are vectors and important reservoirs for microbial agents that cause disease in humans and animals. Among these pathogens, the members of Rickettsia species play an important role in public health. AIM AND METHODS: One hundred twenty-nine ticks belonging to four tick species (Ixodes ricinus,Rhipicephalus turanicus,Dermacentor marginatus, and Haemaphysalis punctata) were collected at different sites of the Insugherata Natural Reserve, localized in the urban area of Rome, Italy. Questing ticks were tested by PCR for Rickettsia spp., amplifying partial gene of ompA. RESULTS: Forty-six ticks were found to be infected with Rickettsia species. Five SFG rickettsiae were identified: three human pathogens Rickettsia conorii, Rickettsia massiliae and Rickettsia aeschlimannii, and two putative new strains Rickettsia sp. strain RM1 and Rickettsia sp. strain RM2. The phylogenetic analysis of partial gene sequences of ompA, gltA, and 17-kd antigen showed that they clustered with several rickettsiae with unidentified pathogenicity. However, Rickettsia sp. strain RM1 and Rickettsia sp. strain RM2 clustered in a statistically supported clade with R. massiliae, and R. monacensis, respectively. CONCLUSION: Our findings suggest that Rickettsia species other than R. conorii are implicated in human disease in Italy.

Endemic zoonoses, such as Q fever and spotted fever group (SFG) rickettsiosis, are prevalent in South Africa, yet often undiagnosed. In this study, we reviewed the demographics and animal exposure history of patients presenting with acute febrile illness to community health clinics in Mpumalanga Province to identify trends and risk factors associated with exposure to Coxiella burnetii, the causative agent of Q fever, and infection by SFG Rickettsia spp. Clinical and serological data and questionnaires elucidating exposure to animals and their products were obtained from 141 acutely febrile patients between 2012 and 2016. Exposure or infection status to C. burnetii and SFG Rickettsia spp. was determined by presence of IgG or IgM antibodies. Logistic regression models were built for risk factor analysis. Clinical presentation of patients infected by SFG rickettsiosis was described. There were 37/139 (27%) patients with a positive C. burnetii serology, indicative of Q fever exposure. Patients who had reported attending cattle inspection facilities ("dip tanks") were 9.39 times more likely to be exposed to Q fever (95% CI: 2.9-30.4). Exposure risk also increased with age (OR: 1.03, 95% CI: 1.002-1.06). Twenty-one per cent of febrile patients (24/118) had evidence of acute infection by SFG Rickettsia spp. Similarly, attending cattle inspection facilities was the most significant risk factor (OR: 8.48, 95% CI: 1.58-45.60). Seropositivity of females showed a significant OR of 8.0 when compared to males (95% CI: 1.49-43.0), and consumption of livestock was associated with a decreased risk (OR: 0.02, 95% CI: 0.001-0.54). A trend between domestic cat contact and SFG rickettsiosis was also noted, albeit borderline non-significant. In this endemic region of South Africa, an understanding of risk factors for zoonotic pathogens, including exposure to domestic animals, can help clinic staff with diagnosis and appropriate therapeutic management of acutely febrile patients as well as identify target areas for education and prevention strategies.

Objective: To describe a rare case of acute Q fever with tache noire. Clinical Presentation and Intervention: A 51-year-old man experienced acute Q fever showing tache noire, generally considered a pathognomonic sign of Mediterranean spotted fever (MSF) and MSF-like illness, but not a clinical feature of Q fever. The patient was treated with doxycycline 100 mg every 12 h. Conclusion: In the Mediterranean area, tache noire should be considered pathognomonic of MSF but it should not rule out Q fever. Clinical diagnosis should be supported by accurate laboratory diagnostic tests to guide proper management.

Mediterranean spotted fever is an infectious disease included in the human rickettsiosis group, with its main distribution in the Mediterranean and South European countries. It is an endemic disease in Portugal, with dogs acting as the main domestic reservoir. Children are a particularly vulnerable group due to their close contact with household animals and by frequently playing outdoors. In this study, we aim to describe the local epidemiology and characterize the clinical features and treatment options in a Portuguese endemic region.We performed a prospective descriptive study of the Mediterranean spotted fever cases admitted to the paediatrics emergency department of a of a group II hospital, between January 1st 2013 and December 31st 2015. All patients were examined by a physician, who was later asked to fill out a detailed questionnaire regarding clinical presentation, diagnostic attitudes and treatment of their patients. Parents were later interviewed and questioned about post-discharge disease evolution.We registered 32 cases (93.9% reported between July and October). After fever, the most frequent reported symptoms were myalgia (37.5%), abdominal pain (25%) and headache (25%). Exanthema was present in 84.4% of cases by the third day of fever:maculonodular (53.1%), papular (37.5%) and macular (9.4%). Eschars were found in 59% of patients, with regional lymphadenopathypresent in 46.9% of cases. Azithromycin (84.4%) and doxycycline (15.5%) were the selected treatments in our population, with no cases of therapeutic failure or side-effects reported.The incidence of Mediterranean spotted fever is higher in our population in comparison with the rest of the country. Fever, myalgia, abdominal pain and headache were the most common presenting symptoms, while exanthema was the predominant cutaneous finding. Azithromycin was the preferred treatment and it proved to be successful and safe in all cases.Introdução: A febre escaro-nodular é uma doença infeciosa aguda incluída no grupo das rickettsioses humanas, que atinge sobretudo os países da bacia do Mediterrâneo e sul da Europa. É uma doença endémica em Portugal com o cão como principal reservatório doméstico. As crianças são um grupo particularmente vulnerável devido ao contato próximo com animais domésticos e a brincarem em campos e jardins. O principal objetivo deste estudo foi perceber e estudar a epidemiologia local, bem como caracterizar a clinica e a resposta terapêutica da nossa população. Material e Métodos: Foi realizado um estudo prospetivo descritivo de todas as crianças com febre escaro-nodular admitidas no serviço de urgência de um hospital grupo II, entre janeiro de 2013 e dezembro de 2015. Todos os doentes foram avaliados por médico, que respondeu a um questionário referente as manifestações clínicas apresentadas e atitudes de diagnóstico e terapêuticas instituídas. Os pais foram posteriormente contatados, por telefone, e questionados sobre a evolução da doença. Resultados: Foram registados 32 casos (93,9% de julho a outubro). Além da febre, as queixas mais frequentes foram mialgias (37,5%), dor abdominal e cefaleias (25%). O exantema estava presente no terceiro dia de febre em 84,4%: maculopapulonodular (53,1%); papular (37,5%) e macular (9,4%). Foi identificada escara em 59% e adenopatia satélite em 46,9%. Azitromicina (84,4%) ou doxiciclina (15,5%) foram os antibióticos de escolha, com sucesso em qualquer dos casos. Não foram relatadas complicações. Conclusão: A incidência de febre escaro-nodular na nossa população é alta, quando comparada com a incidência no restante país. Febre, mialgias e cefaleias foram os principais sintomas e sinais registados enquanto a presença de exantema foi o achado dermatológico predominante. Azitromicina, antibiótico de escolha na maioria dos casos, mostrou ser eficaz.

Background Mediterranean Spotted Fever (MSF) is a tick-borne zoonosis caused by Rickettsia conorii which is endemic in Malta, an island in the South Mediterranean that is a popular tourist destination. Diagnosis is frequently based on clinical manifestations as laboratory results are often limited to a retrospective diagnosis. We describe the clinical presentation, diagnosis and treatment of children Method The demographics, clinical findings, laboratory results, management and outcome of all children hospitalised with suspected MSF based on the presence of fever and an eschar, were retrieved from their case notes. Results Over the five-year study period six children, aged between 17 months and 15 years, were diagnosed with MSF. All children had contact with ticks and the majority presented in summer. Laboratory results were non-specific and included elevated inflammatory markers, lymphocytosis/lymphopenia and hyponatraemia. Serological and molecular techniques were used for diagnosis. Response to clarithromycin or doxycycline was immediate. Conclusion MSF should be included in the differential diagnosis of fever, rash and an eschar in children who travel to Malta. Despite advances in molecular diagnostics, clinical diagnosis remains important in the management of children with suspected MSF.

Ticks are important vectors for Rickettsia spp. of the spotted fever group all around the world. Rickettsia conorii is the etiological agent of boutonneuse fever in the Mediterranean region and Africa. Tick identification was based on morphological features and further characterized using the 16S rRNA gene. The ticks were individually tested using pan-Rickettsia real-time-PCR for screening, and 23S-5S intergenic spacer region, 16S rDNA, gltA, sca4, ompB, and ompA genes were used to analyze the Rickettsia positive samples. Rickettsia conorii ssp. caspia was detected in tick collected in Zambia for the first time, thus demonstrating the possibility of the occurrence of human disease, namely Astrakhan fever, due to this Rickettsia ssp. in this region of Africa. The prevalence of R. conorii ssp. caspia was 0.06% (one positive tick out of 1465 tested ticks) and 0.07% (one positive tick out of 1254 tested Rh. sanguineus).

Rickettsial infections continue to cause serious morbidity and mortality in severe human cases around the world. Host cell adhesion and invasion is an essential requisite for intracellular growth, replication, and subsequent dissemination of pathogenic rickettsiae. Heparan sulfate proteoglycans [HSPGs] facilitate the interactions between fibroblast growth factor(s) and their tyrosine kinase receptors resulting in receptor dimerization/activation and have been implicated in bacterial adhesion to target host cells. In the present study, we have investigated the contributions of fibroblast growth factor receptors [FGFRs] in rickettsial entry into the host cells. Inhibition of HSPGs by heparinase and FGFRs by AZD4547 (a selective small-molecule inhibitor) results in significant reduction in rickettsial internalization into cultured human microvascular endothelial cells (ECs), which represent the primary targets of pathogenic rickettsiae during human infections. Administration of AZD4547 during R. conorii infection in a murine model of endothelial-target spotted fever rickettsiosis also diminishes pulmonary rickettsial burden in comparison to mock-treated controls. Silencing of FGFR1 expression using a small interfering RNA also leads to similar inhibition of R. rickettsii invasion into ECs. Consistent with these findings, R. rickettsii infection of ECs also results in phosphorylation of tyrosine 653/654, suggesting activation of FGFR1. Using isobaric tag for relative and absolute quantitation [iTRAQ]-based proteomics approach, we further demonstrate association of β-peptide of rickettsial outer membrane protein OmpA with FGFR1. Mechanistically, FGFR1 binds to caveolin-1 and mediates bacterial entry via caveolin-1 dependent endocytosis. Together, these results identify host cell FGFR1 and rickettsial OmpA as another novel receptor-ligand pair contributing to the internalization of pathogenic rickettsiae into host endothelial cells and the potential application of FGFR-inhibitor drugs as adjunct therapeutics against spotted fever rickettsioses.

Symmetric peripheral gangrene (SPG) is a symmetrical distal ischemic lesion on at least 2 or more extremities in the absence of proximal arterial obstruction and vasculitis. It is a rare and severe clinical entity. The aim of this study was to describe clinical symptoms, etiological agents and the management of SPG through a series of 4 cases.We included all cases of SPG hospitalized between 2000 and 2014. The inclusion criterion was the presence of distal ischemic damage at two or more sites in the absence of large vessel obstruction.Four patients (2 men and 2 women) were included. The mean age was 43.2±12 years. Two patients had a history of splenectomy. All patients had blackening of the tips of the fingers and toes. Three patients presented with septic shock. The etiology was bacteremia involving Streptococcus pneumoniae in two cases and a malignant form of Mediterranean spotted fever (MSF). In addition to specific antibiotics, we used a potent vasodilator (iloprost) in two cases and curative heparin therapy in two cases. The outcome was favorable in 3 cases, with regression of necrotic lesions. One case required the amputation of non-perfused necrotic fingers and toes.SPG can complicate MSF in some rare cases. Thorough and repeated skin examinations are essential to ensure timely diagnosis and treatment of GPS in order to improve the prognosis.

Haemophagocytic syndrome (HS) is a rare disease with a severe prognosis that is defined by clinical, laboratory and histopathological criteria. Infections represent the classical cause of HS. HS secondary to Mediterranean spotted fever (MSF) is rare with only a few cases being reported in the literature.We report two cases of HS secondary to MSF in 2 men aged 77 and 63 years presenting a febrile maculo-purpuric eruption with inoculation ulcer associated with laboratory abnormalities (cytopenia, elevated ferritin, hypertriglyceridaemia). Haemophagocytosis was present in 2 cases. Serology and PCR for Rickettsia conorii were positive and militated in favour of recent infection responsible for the diagnosis of MSF.The first case of HS was described in 1979. Sixteen cases of HS secondary to MSF are described in the literature. Cytopenia associated with hyperferritinaemia and hypertriglyceridaemia strongly suggests MSF complicated by HS. The prognosis depends on the time elapsed since diagnosis and host-specific factors. Immunosuppressants and antibiotics may be necessary to ensure healing.Rickettsioses can induce HS, and this potential complication with a severe prognosis must be known.

La fièvre boutonneuse méditerranéenne (FBM) est une rickettsiose du groupe boutonneux due à rickettsia conorii. Cette zoonose est réputée d'évolution bénigne mais peut se compliquer dans les formes sévères d'une atteinte neurologique qui en font parfois toute la gravité. Nous rapportons l'observation d'une patiente âgée de 49 ans ayant présenté au cours de son hospitalisation en dermatologie pour une rickettsiose, une hémiplégie droite massive d'installation brutale. L'angio-IRM cérébrale a objectivé un accident vasculaire cérébral ischémique sylvien profond gauche. Le diagnostic de rickettsiose de type conorii a été retenu sur l'aspect des lésions dermatologiques et la positivité des sérologies par immuno-fluorescence indirecte. L'évolution était favorable sous anti-biothérapie (doxycycline et fluoroquinolone). Exceptionnellement rapporté dans le cadre des manifestations neurologiques des rickettioses, l'infarctus cérébral reste une complication à ne pas méconnaitre surtout en regard d'un bilan étiologique en particulier cardiovasculaire demeuré négatif.

INTRODUCTION: Mediterranean spotted fever (MSF) is a zoonotic disease caused by Rickettsia conorii. In Spain, deficiencies in the official reporting result in misreporting of this disease. This study aims to describe the clinical and temporal-spatial characteristics of MSF hospitalizations between 1997 and 2014. MATERIALS AND METHODS: We performed a retrospective descriptive study using the Hospitalization Minimum Data Set (CMBD). All CMBD's hospital discharges with ICD-9 CM code 082.1 were analyzed. Hospitalization rates were calculated and clinical characteristics were described. Spatial distribution of cases and their temporal behavior were also assessed. RESULTS: A total of 4,735 hospitalizations with MSF diagnosis were recorded during the study period, out of which 62.2% were male, mean age of 48. Diabetes mellitus, alcohol dependence syndrome, and chronic liver disease occurred in 10.8%, 2.4% and 2.8% hospitalizations, respectively. The median annual hospitalization rate showed a decreasing trend from a maximum of 12.9 in 1997 to a minimum rate of 3.1 in 2014. Most admissions occurred during the summer, showing a significant annual seasonal behavior. Important regional differences were found. DISCUSSION: Although MSF hospitalization rates have decreased considerably, it remains a public health problem due to its severity and economic impact. Therefore, it would be desirable to improve its oversight and surveillance. This study was supported by Project “PI15/01398”, funded by Instituto de Salud Carlos III and co-funded by European Union (ERDF/ESF, “Investing in your future”) and the Network Biomedical Research on Tropical Diseases (RICET in Spanish) RD12/0018/0001, supported by the European Regional Development Fund (FEDER) from the European Comission. Sí

The main clinical signs and symptoms caused by a rickettsial infection typically begin 6-10 days after the bite and are accompanied by nonspecific findings such as fever, headache and muscle pain. The diagnosis is mainly based on serological tests, however antibody presentation may be delayed, at least at the early stages of the disease, while seroconversion is usually detected 10-15 days after disease onset. Culture is difficult, requires optimized facilities and often proves negative. Under this scope, the presence of a characteristic inoculation eschar at the bite site may prove a useful clinical tool towards the early suspicion and diagnosis/differential diagnosis of tick-borne rickettsioses, even before the onset of rash and fever or serological confirmation. We describe herein the presence of skin lesions and/or an inoculation eschar at the tick bite site in 17 patients diagnosed, by molecular means, as suffering from spotted fever group rickettsioses. The detection of the pathogen's DNA in biopsy samples proved to be a useful means for early rickettsiae detection and identification. Moreover, the presence of an infiltrated erythema always seemed to precede the appearance of an eschar by 2-5 days and the initiation of fever by 1-10 days; these two signs might also prove useful in the context of the final diagnosis.

Summary Objectives To study the epidemiology, clinical features, and changing pattern of rickettsial infections on the western slopes of the hilly Central Province of Sri Lanka over 6 years. Methods All patients with rickettsial infections who presented to the Teaching Hospital, Peradeniya were studied prospectively from January 2002 to December 2007. An immunofluorescent antibody assay (IFA) was used to confirm the diagnosis. Results Of the 371 clinical cases of rickettsial infection, 122 underwent IFA to confirm the diagnosis. Species-specific IgG antibodies were positive in 105/122 (86.1%) cases: 43/105 (40.9%) to Rickettsia conorii and 6/105 (5.7%) to Orientia tsutsugamushi , with mixed antibody reactivity to more than one antigen in 56/105 (53.3%) cases, including Rickettsia typhi in 27/105 (25.7%). Among those with mixed IgG reactivity, IgM assays were used to detect pathogens responsible for acute infections. Finally, a total of 55 spotted fever group (SFG) infections, seven scrub typhus infections, and one case of murine typhus were identified. Of the 105 positive cases, 53 (50.5%) were male and 52 (49.5%) were female, and the mean age was 40 years (range 11–83 years). In the SFG patients, 13/55 (24%) had severe vasculitis with fern leaf type skin necrosis and 17/55 (31%) had arthritis. Three patients (5%) had an altered level of consciousness. A patient with scrub typhus had transient deafness. None of the 105 patients had an eschar. Conclusions It appears that SFG rickettsioses are on the rise in the hilly Central Province of Sri Lanka, whilst murine typhus and scrub typhus are present at a lower rate.

INTRODUCTION: Mediterranean spotted fever (MSF) is a tick-borne disease caused by Rickettsia conorii subspp. conorii. It is transmitted by the bite of the tick Rhipicephalus sanguineus. Modified by the rickettsial invasion, the micro-vascular endothelium acquires an activated inflammatory phenotype and initiates secretion of cytokines and expression of cell adhesion molecules (CAMs) and chemoattractans. AIM: This study aims at investigating the alterations in the soluble cellular adhesion molecules (sCAMs) and chemokine MCP-1 levels in patients with MSF of varying severity in the acute and convalescence stage in order to assess their diagnostic and prognostic value. MATERIALS AND METHODS: The soluble forms of cellular adhesion molecules (sCAMs) - sЕ- selectin and sР-selectin, the intercellular (sICAM-1) and vascular (sVCAM-1) adhesion molecules as well as the monocyte chemoattractant protein-1 (MCP-1) were studied in the sera of 80 patients with MSF. The presence of MSF was confirmed serologically by indirect fluorescence assay (IFA). In order to study disease dynamics, serum samples from 80 patients were drawn on day 1 following the onset of rash; in 60 patients (part of the surveyed 80) a second sample was taken in the convalescence period - 14 days post hospital discharge. The investigation was focused on mild, moderate and severe forms of MSF. Enzyme linked immune-sorbent assay was used for sCAMs determination (Quantikine IVD colorimetric ELISA). RESULTS: Overall, in the acute stage, patients presented with increased levels of sЕ-selectin, sICAM-1, sVCAM-1 and MCP-1, whereas sР-selectin level was decreased. The levels of sЕ-selectin, sICAM-1 and sVCAМ-1 were significantly elevated in mild, moderate and severe forms of the disease with sE-selectin level exhibiting a plateau tendency and sICAM and sVCAM levels demonstrating an upward trend from mild towards severe MSF forms. MCP-1 level was elevated only in severe MSF. In all forms of MSF, in the convalescence period, sICAM-1, sVCAM-1 and МСР-1 concentration returned to reference levels whereas sE-selectin level persisted elevated. In the convalescence stage, sP- selectin concentration also showed an upward tendency, which in severe forms of MSF slightly exceeded the level in controls. sP-selectin levels correlated directly with platelet count, whereas sICAM-1 and sVCAM-1 levels showed a reverse correlation. sE-selectin, sICAM-1 and MCP-1 levels directly correlated with aminotransferase activity (ALT and/or AST). CONCLUSION: The soluble forms of CAMs reflect the endothelial inflammatory potential. There is evidence that endothelium activation is more potent in severe forms of MSF. Assessment of the endothelial response in the course of the disease is an important predictor of the outcome, the choice of therapeutic approach and disease prognosis.

Mediterranean spotted fever (MSF) is widely prevalent in many endemic regions in Bulgaria. The disease is still not quite thoroughly studied as to some aspects of its pathogenesis and especially to issues that concern the crucial signals for apoptosis in the target microvascular endothelial cells. To study the expression of Bcl-2 family proteins and Caspase-3 in the dermal capillary endothelial cells from skin papules and in the eschar (tache noire) epidermal layers of patients with MSF so that we can establish apoptotic processes and the time of their occurrence and deployment. Immunohistochemical reactions for Bcl-2, Bax and Caspase-3 were obtained in slices of punch-biopsies taken from papules of the skin rash and from the eschars of eight patients with MSF. The average intensity of the reactions was compared with that in control punch-biopsy slices from four healthy subjects. MSF was etiologically confirmed in all patients by positive antibody response to a specific antigen, Rickettsia conorii, with indirect immunofluorescent assay performed by the Rickettsial Reference Laboratory. The immune reaction for Bcl-2 was found to be poorly expressed in the capillary endothelial cells of skin papules of patients without any differences from controls. The expression of Bax and Caspase-3 was strongly upregulated in comparison with the controls. The Bcl-2/Bax ratio was significantly decreased. Microvascular endothelial cells of the eschar showed similar changes. While the Bcl-2/Bax ratio decreased in the epidermal layers of the eschar "tache noire", there were no changes in the intensity of the immunoreactivity of Caspase-3 as compared with controls. The upregulation of Bax and Caspase-3 is an indication of ongoing apoptotic processes in the dermal microvascular endothelial cells of MSF patients. The epidermal layers of the eschar showed increased sensitivity to apoptosis, however, executive phase of apoptosis did not occur.

Small regulatory RNAs comprise critically important modulators of gene expression in bacteria, yet very little is known about their prevalence and functions in Rickettsia species. R. conorii, the causative agent of Mediterranean spotted fever, is a tick-borne pathogen that primarily infects microvascular endothelium in humans. We have determined the transcriptional landscape of R. conorii during infection of Human Microvascular Endothelial Cells (HMECs) by strand-specific RNA sequencing to identify 4 riboswitches, 13 trans-acting (intergenic), and 22 cis-acting (antisense) small RNAs (termed ‘Rc_sR’s). Independent expression of four novel trans-acting sRNAs (Rc_sR31, Rc_sR33, Rc_sR35, and Rc_sR42) and known bacterial sRNAs (6S, RNaseP_bact_a, ffs, and α-tmRNA) was next confirmed by Northern hybridization. Comparative analysis during infection of HMECs vis-à-vis tick AAE2 cells revealed significantly higher expression of Rc_sR35 and Rc_sR42 in HMECs, whereas Rc_sR31 and Rc_sR33 were expressed at similar levels in both cell types. We further predicted a total of 502 genes involved in all important biological processes as potential targets of Rc_sRs and validated the interaction of Rc_sR42 with cydA (cytochrome d ubiquinol oxidase subunit I). Our findings constitute the first evidence of the existence of post-transcriptional riboregulatory mechanisms in R. conorii and interactions between a novel Rc_sR and its target mRNA.