scholarly journals Severe clinical forms of Mediterranean spotted fever: A case series from an endemic area in Bulgaria

2018 ◽  
Vol 75 (7) ◽  
pp. 704-709 ◽  
Author(s):  
Magdalena Baymakova ◽  
Liliya Pekova ◽  
Pavlina Parousheva ◽  
Radina Andonova ◽  
Kamen Plochev

Background/Aim. Mediterranean spotted fever (MSF) belongs to Rickettsioses, the Spotted fever group (SFG). The causal agent is Rickettsia conorii conorii and the transmission to humans occurs through dog tick Rhipicephalus sanguineus bites. The aim of this study was to describe clinical and laboratory characteristics in patients with severe form of Mediterranean spotted fever admitted to Bulgarian university hospital in endemic region. Methods. A retrospective study was conducted at Stara Zagora University Hospital (Southeastern Bulgaria) between April 2015 and August 2016. During the analyzed period, 58 cases had clinical and laboratory data for MSF. Serological tests were applied for the etiological diagnosis. MSF-specific immunoglobulin (IgM) and IgG antibodies were detected in serum by indirect immunoenzyme assay (ELISA IgG/IgM, Vircell, Spain) ? R. conorii ELISA IgG sensitivity 85%, specificity 100% and R. conorii ELISA IgM sensitivity 94%, specificity 95%. Statistical analysis was made by MS Excel 2007 and SPSS Statistics, version 19.0. Results. Eighteen patients presented as severe forms. The predominant gender of them were males (78%) and 22% were females. The median age of the analyzed group was 55 years (range: 14? 78 years). Ten patients developed hepatic disorder while 4 had neurological signs. Laboratory data showed thrombocytopenia in 15 patients, mean value of platelet (PLT) count for the whole group was 108.6 ? 53.8 ? 109/L. Liver enzymes were elevated with mean value of aspartate aminotransferase (AST) 161.4 ? 90.1 IU/L and alanine aminotransferase (ALT) 163.9 ? 81.5 IU/L. Acute phase reactant as C-reactive protein (CRP) had mean value of 140.3 mg/L (range: 9?230 mg/L). Kidney function was impaired in some cases; the mean value of creatinine for the studied group was 134.7 ?mol/L (range: 78?313 ?mol/L) and mean value of urea was 9.6 mmol/L (range: 4.2?27.4 mmol/L). Conclusion. Bulgaria is an endemic area for tick-borne diseases. Cases of MSF are reported annually. Severe forms of MSF are not rare. Typical clinical and laboratory markers for severity should be actively searched for. Early diagnosis and proper treatment is the key to avoid complications and enable patient recovery.

Author(s):  
Emmanuel A. Burdmann ◽  
Vivekanad Jha

Rickettsiae are obligate intracellular bacteria transmitted by arthropods to a vertebrate host. Clinically relevant rickettsioses have a similar clinical pattern, manifesting as an acute febrile disease accompanied by headache, articular and muscle pain, and malaise.Epidemic typhus is a worldwide distributed disease caused by the Rickettsia prowazekii, with a human louse as a vector. Data on epidemic typhus-related renal injury is extremely scarce.Murine typhus is caused by the Rickettsia typhi and has a rodent flea as the vector. It is one of the most frequent rickettsioses, and is usually a self-limited febrile illness. Proteinuria, haematuria, elevations in serum creatinine (SCr) and/or blood urea nitrogen (BUN) and AKI have been reported. The real frequency of renal involvement in murine typhus is unknown. Renal abnormalities recover after the infectious disease resolution.Scrub typhus, caused by the Orientia tsutsugamushi, has the Leptotrombidium mite larva as vector. It is endemic in the Tsutsugamushi triangle delimited by Japan, Australia, India, and Siberia. It can manifest either as a self-limiting disease or as a severe, life-threatening multiorgan illness. Early administration of adequate antibiotics is essential to prevent adverse outcomes. Proteinuria, haematuria, and acute kidney injury (AKI) are frequent.Tick-borne rickettsioses are caused by bacteria from the spotted fever group and have ticks as vectors. Rocky Mountain spotted fever (RMSF) is caused by Rickettsia rickettsii. It is the most severe of the spotted fever rickettsial diseases, causing significant morbidity and lethality. RMSF occurs in North, Central, and South America. Renal impairment is frequent in severe forms of RMSF. Mediterranean spotted fever is caused by Rickettsia conorii, and is endemic in the Mediterranean area. It is usually a benign disease, but may have a severe course, clinically similar to RMSF. Haematuria, proteinuria, increased serum creatinine, and AKI may occur. Japanese spotted fever is caused by Rickettsia japonica. Lethal cases are reported yearly and AKI has occurred in the context of multiple organ failure.


2021 ◽  
Vol 6 (4) ◽  
pp. 172
Author(s):  
Nikolaos Spernovasilis ◽  
Ioulia Markaki ◽  
Michail Papadakis ◽  
Nikolaos Mazonakis ◽  
Despo Ierodiakonou

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.


2012 ◽  
Vol 80 (8) ◽  
pp. 2735-2743 ◽  
Author(s):  
Sean P. Riley ◽  
Jennifer L. Patterson ◽  
Juan J. Martinez

ABSTRACTPathogenic species of the spotted fever groupRickettsiaare subjected to repeated exposures to the host complement system through cyclic infections of mammalian and tick hosts. The serum complement machinery is a formidable obstacle for bacteria to overcome if they endeavor to endure this endozoonotic cycle. We have previously demonstrated that that the etiologic agent of Mediterranean spotted fever,Rickettsia conorii, is susceptible to complement-mediated killing only in the presence of specific monoclonal antibodies. We have also shown that in the absence of particular neutralizing antibody,R. conoriiis resistant to the effects of serum complement. We therefore hypothesized that the interactions between fluid-phase complement regulators and conserved rickettsial outer membrane-associated proteins are critical to mediate serum resistance. We demonstrate here thatR. conoriispecifically interacts with the soluble host complement inhibitor, factor H. Depletion of factor H from normal human serum rendersR. conoriimore susceptible to C3 and membrane attack complex deposition and to complement-mediated killing. We identified the autotransporter protein rickettsial OmpB (rOmpB) as a factor H ligand and further demonstrate that the rOmpB β-peptide is sufficient to mediate resistance to the bactericidal properties of human serum. Taken together, these data reveal an additional function for the highly conserved rickettsial surface cell antigen, rOmpB, and suggest that the ability to evade complement-mediated clearance from the hematogenous circulation is a novel virulence attribute for this class of pathogens.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 228
Author(s):  
M. Nathan Kristof ◽  
Paige E. Allen ◽  
Lane D. Yutzy ◽  
Brandon Thibodaux ◽  
Christopher D. Paddock ◽  
...  

Rickettsia are significant sources of tick-borne diseases in humans worldwide. In North America, two species in the spotted fever group of Rickettsia have been conclusively associated with disease of humans: Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, and Rickettsia parkeri, the cause of R. parkeri rickettsiosis. Previous work in our lab demonstrated non-endothelial parasitism by another pathogenic SFG Rickettsia species, Rickettsia conorii, within THP-1-derived macrophages, and we have hypothesized that this growth characteristic may be an underappreciated aspect of rickettsial pathogenesis in mammalian hosts. In this work, we demonstrated that multiple other recognized human pathogenic species of Rickettsia, including R. rickettsii, R. parkeri, Rickettsia africae, and Rickettsiaakari can grow within target endothelial cells as well as within PMA-differentiated THP-1 cells. In contrast, Rickettsia bellii, a Rickettsia species not associated with disease of humans, and R. rickettsii strain Iowa, an avirulent derivative of pathogenic R. rickettsii, could invade both cell types but proliferate only within endothelial cells. Further analysis revealed that similar to previous studies on R. conorii, other recognized pathogenic Rickettsia species could grow within the cytosol of THP-1-derived macrophages and avoided localization with two different markers of lysosomal compartments; LAMP-2 and cathepsin D. R. bellii, on the other hand, demonstrated significant co-localization with lysosomal compartments. Collectively, these findings suggest that the ability of pathogenic rickettsial species to establish a niche within macrophage-like cells could be an important factor in their ability to cause disease in mammals. These findings also suggest that analysis of growth within mammalian phagocytic cells may be useful to predict the pathogenic potential of newly isolated and identified Rickettsia species.


1996 ◽  
Vol 38 (6) ◽  
pp. 427-430 ◽  
Author(s):  
Elba R.S. de Lemos ◽  
Raimundo D. Machado ◽  
José R. Coura ◽  
Maria A.A.M. Guimarães ◽  
Nelson Chagas

In order to obtain information on Brazilian spotted fever, a study in domestic animals was performed in the County of Pedreira, State of São Paulo, Brazil, where 17 human cases had been notified. Serum samples obtained from animals were tested by indirect immunofluorescence for detectable antibodies to spotted fever-group rickettsiae. Seropositivity was revealed in 12 (36.4%) of 33 dogs and seven (77.8%) of nine horses from the endemic area. For comparison, blood samples from dogs and horses from non endemic area were tested and four (12.9%) of 31 dogs and three (27.3%) of 11 horses were positive. The highest titers of antibodies by IFA (IgG > 1:1024) were found only in three dogs and six horses from endemic area. The results suggest that dogs as horses may serve as environmental sentinels for estabilishing the prevalence of foci of spotted fever in Brazil.


2020 ◽  
Vol 18 (2) ◽  
pp. 111-119
Author(s):  
Iv. Baltadzhiev ◽  
P. Pavlov

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.


2006 ◽  
Vol 1078 (1) ◽  
pp. 170-172 ◽  
Author(s):  
R. N ANGERAMI ◽  
M. R RESENDE ◽  
A. F.C FELTRIN ◽  
G. KATZ ◽  
E. M NASCIMENTO ◽  
...  

1999 ◽  
Vol 43 (10) ◽  
pp. 2400-2403 ◽  
Author(s):  
Michel Drancourt ◽  
Didier Raoult

ABSTRACT Rickettsiae are gram-negative, obligately intracellular bacteria responsible for arthropod-borne spotted fevers and typhus. Experimental studies have delineated a cluster of naturally rifampin-resistant spotted fever group species. We sequenced the 4,122- to 4,125-bp RNA polymerase β-subunit-encoding gene (rpoB) from typhus and spotted fever group representatives and obtained partial sequences for all naturally rifampin-resistant species. A single point mutation resulting in a phenylalanine-to-leucine change at position 973 of theRickettsia conorii rpoB sequence and present in all the rifampin-resistant species was absent in all the rifampin-susceptible species. rpoB-based phylogenetic relationships among these rickettsial species yielded topologies which were in accordance with previously published phylogenies.


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