ABSTRACT
Aims: The aim of this review is to present Rickettsioses sensu lato, with emphasis on their current and future clinical diagnosis. The review presents the conditions, the agents that cause them, and the current gold standards on their diagnosis in national and international reference centres. Additionally, this review covers the various emerging technologies available in the diagnosis of Rickettsioses and discusses their potential for future use as gold standards in the diagnosis of these diseases. Introduction: The introduction presents Rickettsioses sensu lato and gives a broad overview of the conditions they cause, the issues associated with their current diagnosis and the need for their improved, earlier and more accurate diagnosis, in order to prevent current issues with false negatives, misdiagnosis or delay in the diagnosis associated with these conditions, which often renders them grave or lethal. Main Body: The main body of the review presents in independent sections Rickettsias, Ehrlichia, Anaplasma, Bartonella and Coxiella and the conditions associated with each of these bacteria. Spotted fever, endemic typhus, human granulocytic anaplasmosis, human monocytic ehrlichioses, bartonellosis and Q-fever are some of the conditions associated with this group of proteobacteria. The emphasis is on the clinical diagnosis of these conditions and an overview of the current practice, gold standards in reference laboratories and improvements in these methodologies is presented. The last part of the review focuses on novel technologies in bacterial detection and their application specifically on Rickettsioses sensu lato, demonstrating how these technologies are being applied in this field and how they could improve current standards and resolve issues associated with the clinical diagnosis of rickettsioses. Conclusion: Rickettsioses sensu lato are conditions associated with proteobacteria historically included in the Rickettsiaceae family, able to cause a number of conditions, often grave or lethal. One of the major issues associated with poor clinical outcome is the lack of early and accurate differential diagnostic methodologies. Current methods, including serological and molecular biology techniques have various advantages and disadvantages, which new technologies available or currently in development may be in a position to resolve and the issues associated with the institution of such technologies.
ABSTRACT
Bartonella is an important cause of blood culture-negative endocarditis in recent studies. Seroprevalence studies in the States of Minas Gerais and Rio de Janeiro have shown Bartonella IgG positivity around 14 percent in healthy adults and 40 percent in HIV seropositive adults, respectively. A case report of a 46-year-old white male with moderate aortic regurgitation (AR) due to rheumatic heart disease (RHD), admitted due to worsening heart failure, is presented. Clinical features were apyrexia, anemia, polyclonal hypergammaglobulinemia, hematuria and splenomegaly. He was submitted to surgery due to worsening AR. Histopathology of the excised valve showed active bacterial endocarditis and underlying RHD. Routine blood cultures were negative. Indirect immunofluorescence (IFI) assays for Coxiella burnetii were non-reactive. Bartonella henselae IgG titer was 1:4096 prior to antibiotics and 1:512 14 months after treatment. History of close contact with a young cat during the months preceding his admission was elicited.