Overview of Q fever in Brazil: an underestimated zoonosis

ABSTRACT This review aims to provide current information about Q fever, elucidating the etiological, epidemiological, pathogenic, clinical, diagnostic, therapeutic, and prophylactic aspects of the disease for the medical community. We discuss the main forms of presentation of the agent, its ability to persist in the body, the infinite possibilities of susceptible hosts, the main known forms of transmission, its importance in populations at occupational risk, and the role of arthropods in the natural history of the disease. Focusing on Brazil, we present the cases already described and studies developed since its first report, and how there is still much to unravel. We are aware of the possibilities of the persistence of the agent and the development of severe clinical pictures and the specific treatments currently instituted. We also wish to raise awareness about the future, the new genotypes that are emerging, the need to study the effects of vaccines, and the impact of Q fever on the population. Q fever is a poorly understood disease in Latin America, and recent studies, especially in Brazil, have revealed the importance of developing new studies.

Febre maculosa na Região Metropolitana de Belo Horizonte, Minas Gerais - Brasil: Descrição dos casos e dos ambientes prováveis de infecção, 2017 / Spotted fever in the Metropolitan Region of Belo Horizonte, Minas Gerais - Brazil: Description of cases and probable environments of infection, 2017

Objetivo: investigar os casos de febre maculosa, verificar os aspectos relacionados à assistência à saúde e caracterizar o perfil epidemiológico desses e do ambiente de infecção. Métodos: estudo descritivo dos casos confirmados de FM entre janeiro e novembro de 2017. Foi elaborado um formulário semiestruturado para coleta dos dados. Para as análises epidemiológicas, foram utilizados os programas EpiInfoTM 7 e Qgis® 2.18.1. Foram calculadas frequências, medidas de tendência central, dispersão e indicadores de oportunidade de assistência. Nos ambientes prováveis de infecção, foram realizadas coletas de carrapatos que foram identificados e submetidos à pesquisa de Rickettsia do grupo da FM. Resultados: foram confirmados 15 casos de FM; desses, a maioria foi do sexo masculino (93%) com média de 42 anos de idade; 10 evoluíram para óbito. Todos apresentaram febre, 13(87%) cefaleia e 12(80%) mialgia. Apresentaram mediana e média de evolução para óbito pela doença de 6 dias (1 a 9), oportunidades de hospitalização, tratamento, diagnóstico e notificação de 4,5(0 a 8); 7(0 a 26); 9(DP±6) e 33(DP±45) dias, respectivamente. Para assistência à saúde, 14(93%) casos procuraram atendimento mais de duas vezes, com tempo de internação de 4,5 dias (0 a 8 dias). O hospital foi o serviço procurado, exclusivamente, no quarto atendimento. Dengue e FM foram as hipóteses diagnósticas mais frequentes. Foram coletados 250 espécimes de carrapatos em quatro municípios, sendo em um município identificado Amblyomma sculptum naturalmente infectados. Conclusões: foram assinaladas condições assistenciais pouco sensíveis à ocorrência da FM, o que, provavelmente, colaborou para ocorrência de óbitos, além da necessidade de sensibilização de equipes de saúde e vigilância quanto à ocorrência da FM na região.

Objective: investigate the cases of spotted fever, verify aspects related to health care and characterize the epidemiological profile of these and of the environment of infection. Methods: A descriptive study of confirmed cases of SF between January and November 2017. A semi-structured form for data collection was developed. EpiInfoTM 7 and Qgis® 2.18.1. Frequencies, measures of central tendency, dispersion and indicators of opportunity of assistance were calculated. In the probable environments of infection ticks were collected, identified and submitted to Rickettsia research of the SF group. Results: Fifteen SF cases were confirmed; of these, the majority was male (93%) and averaged 42 years old; 10 evolved to death. All presented fever, 13 (87%) headache and 12 (80%) myalgia. They presented an average of evolution to death by SF of 6 days (1 to 9), opportunities for hospitalization, treatment, diagnosis and notification of 4.5(0 to 8); 7(0 to 26); 9(DP± 6) and 33(DP± 45) days respectively. For health care, 14(93%) cases sought care more than twice and were hospitalized for 4.5-days (0 to 8 days). The hospital was the only service exclusively sought in the fourth service. Dengue and SF were the most frequent diagnostic hypotheses. A total of 250 specimens of ticks were collected in four counties, and in one municipality Amblyomma sculptum was identified as naturally infected. Conclusions: It was pointed out that assistance conditions were not very sensitive to the occurrence of SF which probably contributed to the instance of deaths as well as the need for sensitization of health and surveillance teams regarding the appearance of SF in the region.

Detection of a Rickettsia genotype related to the old world infecting Amblyomma sculptum tick in an endemic area of brazilian spotted fever

Brazilian Spotted Fever is an important tick-borne disease caused by Rickettsia rickettsii and transmitted mainly by the human-biting tick Amblyomma sculptum. During an epidemiological surveillance in Pedro Leopoldo, an endemic area of Minas Gerais State, southeastern Brazil, ectoparasites were collected from vertebrate hosts and from the environment. Rickettsial genes were obtained from a male A. sculptum and the resulting phylogenetic tree grouped this bacterium with Rickettsia sp. isolate Pampulha, a strain closely related to the pathogenic species Rickettsia tamurae and Rickettsia monacensis. This is the first report of sequences phylogenetically related to R. tamurae and R. monacensis infecting A. sculptum in Brazil.

Comparative growth of spotted fever group Rickettsia spp. strains in Vero cells

In Brazil, the spotted fever group (SFG) Rickettsia rickettsii and Rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. However, the SFG, Rickettsia rhipicephali, that infects humans, has never been reported. The study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. Here, the growth rates of the Brazilian isolates R. rickettsii str. Taiaçu, R. parkeri str. At#24, and R. rhipicephali HJ#5, were evaluated in Vero cells by quantitative polymerase chain reaction. R. rhipicephali showed different kinetic growth compared to R. rickettsii and R. parkeri.