Current and Future Trends in the Clinical Diagnosis of Rickettsioses Sensu Lato.

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.

Human bartonellosis: seroepidemiological and clinical features with an emphasis on data from Brazil - A review

Bartonellae are fastidious Gram-negative bacteria that are widespread in nature with several animal reservoirs (mainly cats, dogs, and rodents) and insect vectors (mainly fleas, sandflies, and human lice). Thirteen species or subspecies of Bartonella have been recognized as agents causing human disease, including B. bacilliformis, B. quintana, B. vinsonii berkhoffii, B. henselae, B. elizabethae, B. grahamii, B. washoensis, B. koehlerae, B. rocha-limaea, and B. tamiae. The clinical spectrum of infection includes lymphadenopathy, fever of unknown origin, endocarditis, neurological and ophthalmological syndromes, Carrion's disease, and others. This review provides updated information on clinical manifestations and seroepidemiological studies with an emphasis on data available from Brazil.

Bartonella native valve endocarditis: the first brazilian case alive and well

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.

Study of hantavirus infection in captive breed colonies of wild rodents

Wild sigmondontine rodents are known to be the reservoir of several serotypes of New World hantaviruses. The mechanism of viral transmission is by aerosol inhalation of the excreta from infected rodents. Considering that the captive breed colonies of various wild mammals may present a potencial risk for hantaviral transmission, we examined 85 speciemens of Thrichomys spp. (Echimyidae) and 17 speciemens of Nectomys squamipes (Sigmodontinae) from our colony for the presence of hantavirus infections. Blood samples were assayed for the presence of antibodies to Andes nucleocapsid antigen using enzyme-linked immunosorbent assay (ELISA). Additionally, serum samples from workers previously exposed to wild rodents, in the laboratories where the study was conducted, were also tested by ELISA to investigate prevalence of anti-hantavirus IgG antibodies. All blood samples were negative for hantavirus antibodies. Although these results suggest that those rodent's colonies are hantavirus free, the work emphasizes the need for hantavirus serological monitoring in wild colonized rodents and secure handling potentially infected rodents as important biosafety measures.